**M/ADD Drill Project Progress Report**

####### October 2004

**Table of Contents**

1\. Progress Report October 2004 [2](#progress-report-october-2004)

Project Team [2](#project-team)

1.1 Programmatic Context [2](#programmatic-context)

1.2 JSC-Baker Hughes Drill [3](#jsc-baker-hughes-drill)

1.2.1 Drill Components [5](#drill-components)

1.2.2 LabView for Drill Control and Data Acquisition
[8](#labview-for-drill-control-and-data-acquisition)

2\. UC Berkeley Laboratory Research
[9](#uc-berkeley-laboratory-research)

3\. Plans for Drill automation [16](#plans-for-drill-automation)

4\. Contamination of Cores retrieved in Summer 2003
[19](#dept.-of-natural-resource-sciences-mcgill-university-quebec-canada-h9x-3v9.-2.-biotechnology-research-institute-national-research-council-of-canada-montreal-canada-h4p-2r2)

5\. Results from the Eureka Field Tests, September 2004
[29](#results-from-the-eureka-field-tests-september-2004)

5.1 Functional testing of the JSC-BHI drill in permafrost
[31](#functional-testing-of-the-jsc-bhi-drill-in-permafrost)

5.2 UC Berkeley Experiments at Eureka
[37](#uc-berkeley-experiments-at-eureka.)

5.3 Contamination Assessment [45](#contamination-assessment)

6\. Mars Drilling Team eArchive [47](#mars-drilling-team-earchive)

7\. Plans for FY 2005 [51](#plans-for-fy-2005)

#  

# 

# 

##### 1. Progress Report October 2004

# Project Team

Geoffrey Briggs/NASA ARC Principal Investigator

George Cooper/U.C. Berkeley

Tim Cooper/Aerotek

Brian Derkowski/NASA JSC

Michael Drever/Lockheed-Martin

Samantha Domville/U. Santa Clara

Roger Fincher/Baker Hughes

Jeffrey George /NASA JSC Drill Manager

Pascal Lee/SETI Inst

Chris McKay/NASA ARC

Chris Omelon/U. Toronto

Wayne Pollard/McGill U.

Lyle Whyte/McGill U.

Kris Zacny/U.C. Berkeley

# 1.1 Programmatic Context

The M/ADD Project is an element of the Astrobiology Technology and
Instrument Development Program begun toward the end of the first quarter
of FY 2003. The project has the goal of demonstrating a substantially
automated, lightweight, low-power drill that will be capable of
acquiring aseptic core samples from tens of meters below the surface of
Mars. The demonstration of capability is to be carried out over three
years in permafrost regions of the Canadian Arctic. The drill is also
intended to provide a portable semi-automated capability for terrestrial
researchers to acquire aseptic samples from depth in extreme
environments.

The M/ADD Project is led from NASA Ames with the Exploration Office at
NASA JSC providing the hardware through a collaboration with
Baker-Hughes Inc. Concurrent laboratory research is being carried out at
U.C. Berkeley into the physics of drilling under martian conditions of
pressure, temperature and atmospheric composition. The Lunar and
Planetary Institute and the University of Texas, Austin are
collaborating in various aspects of the project. A collaboration between
UCB and NASA ARC is developing approaches to 1) the autonomous
collection of engineering data and 2) the autonomous control of the
drilling process. NASA-ARC and our collaborating Canadian colleagues are
leading the effort to identify an optimum approach to control/minimize
the contamination of core samples and to be able to accurately assay any
contamination that may, in fact, occur.

As an ASTID project (rather than an ASTEP project), our focus is on
technology development for future astrobiology research rather than on a
combination of technology development and astrobiology field science.
Nevertheless, because cores retrieved from the Arctic permafrost do have
significant science value, the project has greatly benefited from the
participation of scientists from McGill University and the University of
Toronto. These scientists have analyzed cores acquired in summer 2003
both in terms of contamination and microbial content. Similar
participation has been provided in 2004 and is anticipated in 2005.

The M/ADD Project is no longer linked to the complementary MARTE Project
(an ASTEP Project) that is focused on further developing and
demonstrating automated core acquisition from a site on the banks of the
Rio Tinto in Spain. This change came about because the new Space
Exploration Initiative has created significant added burdens to the JSC
Exploration Team and led them to conclude that they could no longer
support two development efforts (MARTE is now proceeding via a
collaboration with Honeybee Robotics).

In the second year of the M/ADD Project there have been three main
thrusts:

1.  Design, fabrication and test of the Mk II version of the drill
    including the Control and Data Acquisition system

2.  Continued laboratory research

    a.  Low power, dry drilling into different kinds of materials under
        terrestrial and martian conditions of pressure and temperature

    b.  Acquisition of performance data to support design improvements
        and the ability to automate the process

3.  First field test of the Mk II drill in the Arctic permafrost on
    Ellesmere Island

    a.  Basic functionality of drill in extreme environment

    b.  Operational data while drilling in rock and ice

    c.  Evaluation of bit performance

    d.  Acquisition and curation of cores for biological analysis and
        contamination potential

# 1.2 JSC-Baker Hughes Drill

-   System Design

The drill system adopts a wireline approach in which a bottom hole
assembly (BHA) anchors itself to the sides of the hole and, by means of
a drive mechanism, exerts force on bit (FOB) from that location rather
than from the top of the hole.

The system is designed to acquire a sequential core in \~15 cm segments
from the top to the bottom of the hole. This has obvious science
benefits but also minimizes the amount of rock that must be comminuted,
saving energy and minimizing the thermal alteration of the samples
collected.

In the absence of any drilling fluid (because of mass and other
considerations) the comminuted material is moved upwards from the bit by
means of an auger and collected in a container on top of the core
barrel. When the core barrel is full, the core is broken off and the
core and cuttings are winched to the surface where the cuttings are
dumped and the core retrieved for analysis.

The wireline approach simplifies the process of lowering and raising the
BHA multiple times since it is not necessary to assemble and disassemble
a conventional drill string each time. Alternatively, for a drill string
that remains in place while the cores are retrieved by a wireline, the
M/ADD approach does not require auger transport of the cuttings all the
way from the bottom of the hole to the surface. The M/ADD cable is much
lighter than a drill string and increasing hole depth does not pay a
large mass penalty (unlike drill strings where increasing the drill
string length is mass intensive).

The wireline approach is well-suited to automation of the penetration
process because communication connectivity between the BHA and the
surface is greatly simplified. The number of control variables are few
-- motor RPM and force on bit (FOB). The rate of penetration is readily
measured and is a key parameter for control of the bit. The required
torque to maintain penetration is another key parameter for the drill
controller. In the absence of a drilling fluid to remove cuttings and
cool the bit, successful dry drilling under martian conditions will
require measurement of the temperature at the bit -- important to track
the state of wear of the bit as well as for its implications for thermal
alteration of samples.

# 1.2.1 Drill Components

# 

-   **Bit**

-   

-   The baseline bit used in the laboratory testing (mainly drilling in
    sandstone) consists of diamonds impregnated in a matrix of cobalt.
    Under nominal conditions this performs well, leading to a rate of
    penetration of up to 10 cm per hour in sandstone.

> In basalt, which is harder, more fine-grained and not encountered in
> terrestrial oil and gas drilling, this bit is much less successful
> because, as our UCB laboratory work has shown, the diamonds wear (or
> fracture) while the matrix does not wear rapidly enough to expose
> fresh diamonds. Thus the bits become dull and ineffective. We have
> specified bit matrix properties that will allow for improved
> performance in basalts. The bit matrix should be made of the softer
> material such as bronze.
>
> On Mars we expect to drill into materials that contain quantities of
> ground ice and, perhaps, dirty ice lenses. Conventional drill bits are
> not well suited for this situation where a chisel type cutting surface
> is most effective. We have carried out laboratory experiments with
> such a bit and have acquired a special-purpose bit for use in the
> Arctic using a simple hand drill arrangement i.e., not in the JSC-BH
> system. Results are discussed in Sections 2 and 5.2.

-   **Auger**

> The auger carries the cuttings from the bit to the container above the
> core barrel, a distance of about 20 cm, from where they are winched to
> the surface along with the core and bottom hole assembly. Laboratory
> tests and analysis have led us to identify the optimum pitch of the
> auger. Low friction surface coatings and increased RPM contribute to
> the successful removal of cuttings by the auger.
>
> The auger turns within a sheath that serves as a low friction
> containment for the cuttings; this design works well under most
> circumstances. Laboratory tests at UCB have demonstrated circumstances
> in which the system works better in the absence of this sheath. Thus,
> the system needs to be designed to work in both modes. This is
> discussed in more detail later.
>
> For drilling in ice a special bit with Teflon-coated auger flights has
> been acquired.

-   

-   **Hole Stabilization**

> In the Arctic, where ground ice serves to stabilize the hole, we do
> not expect to encounter problems. Similarly, hole stability is not
> expected to be a concern for holes drilling over most of the martian
> surface. In particular, holes drilled at latitudes of key
> astrobiologic interest (\~ 60 degrees, into ground ice where ancient
> organisms may most readily be preserved) are expected to be very
> stable.

-   **Core Retrieval**

-   

> The Mk I drill developed and tested in the first year of this project
> did not include a device to snap off the core when the barrel became
> full. The Mk II drill developed during the second year will include
> this feature but for current field work core break-off is handled
> manually. In laboratory tests in a 2 m block of sandstone, 23
> sequential cores were retrieved, typically of length 12 cm and 110 gm
> mass. Most of the cores were retrieved in one piece, three were in two
> pieces. Our project does not include automation for the subsequent
> retrieval of the cores from the barrel.

Tests conducted at UCB laboratory in water saturated, frozen Ohio
Sandstone have shown that cores would break off every time the drill
string was pulled out. This is because rock cuttings would lodge
themselves between the rock core and the inner wall of the drill tube
and they would get wedged when the bit was lifted. This has not been
observed when coring under terrestrial conditions.

-   **Engineering Data Record**

> In the laboratory at UC Berkeley the control of the drill and the
> recording of data (including measurements of sample temperatures
> inside the core and near the bit) are accomplished using Labview
> software provided by the National Instruments (see below). The Mk II
> drill has been similarly equipped.

-   

-   **Automation**

> The Mk II drill is presently controlled manually from the virtual
> control panel by adjusting the current/RPM of motors and the WOB based
> upon the observed rate of penetration. Automation of the penetration
> process will benefit greatly by the availability of additional
> information from the BHA, specifically, bit temperature and auger
> torque via thermistors and strain gauges. With these sources of
> information (RPM, WOB, ROP, bit temperature and auger torque)
> automated control can be implemented -- a goal for our third year. The
> necessary software will comprise an executive, diagnostics, and
> Labview control. The diagnostics element will be based on the UCB
> *Payzone* drill simulation program.

The top level requirements for the Mk II drill tested in Eureka to
establish TRL-5 (system in field environment) at the end of our second
year were established at the end of the first year's development:

• System level mass \< 20 kg

• Power \<50 W but with more capability for terrestrial testing

• Broad applicability to terrestrial geologic sites

• Capable of penetrating hard sandstones, basalts, frozen
sand/gravel/ice mixtures, pure ice and unconsolidated sand mixtures

• Capable of mechanized core break-off

The Mk II drill has been designed and fabricated with the Arctic
environment in mind:

• Multiple formations with differing compressive strengths

• Very low temperatures

• Gloved operation

• Mud/filth/water tolerance

The Mk II bottom hole assembly structural components are constructed of
stainless steel where the Mk I drill used aluminum. This leads to a mass
increase but also greatly increased strength.

**Mk II Anchor**:

The Mk I drill was designed with a motor to expand and contract the
frictional anchoring pads at the top of the BHA. While these proved
generally effective in laboratory experiments, the design is not
considered robust enough to function reliably on a Mars mission.
Therefore a new Mk II design has been developed (Figure).

![](media/image1.jpeg){width="3.436111111111111in"
height="1.0451388888888888in"}

Since schedule pressures and available resources made it infeasible to
test the anchor before the September field test, we have chosen to adopt
an interim measure whereby the BHA is anchored by pins in the spud tube.

**Mk II Active Force on Bit**:

The compressed spring that served to provide FOB (in a diminishing
amount as the spring expands) in the Mk I drill has been replaced by an
electromagnetic linear actuator and a lead screw to provide active
control. The design of joints, seals and field-serviceable connections
were made with the severe Arctic environment in mind.

**Mk II Sensor/Control Architecture:**

The BHA is controlled from a rugged portable computer based on a number
of essential sensor measurements --

• Anchor current • Anchor extension • FOB current • FOB extension

• Down-force exerted on bit

• Auger/Bit Motor Current • Auger/Bit Motor Speed • Auger/Bit Motor
Temperature

• Winch Motor Current • Total Depth

# 1.2.2 LabView for Drill Control and Data Acquisition

![](media/image2.png){width="3.0in" height="2.5in"}

![](media/image3.png){width="3.0in" height="2.8in"}

LabView Control Panel

The COTS hardware and software available from LabView have proven very
effective for controlling the UCB laboratory equipment as well as the
MkII drill. LabView software is customized to each application with the
above figure showing the virtual control panel developed for our drill.
The interface between this virtual control panel and the drill is
provided by a 'General Purpose Interface Bus', allowing for control of
RPM and WOB based on monitoring of various parameters (motor currents,
rate of penetration, temperature ...).

The same equipment allows the various sensor measurements to be
displayed on the control panel and stored to a binary file. The data can
be filtered and saved to another convenient format such as an Excel
spreadsheet or displayed as a graph.

##### 2. UC Berkeley Laboratory Research

The laboratory-based research at UC Berkeley continues to produce
important results regarding drilling under martian conditions of low
temperature and pressure. In the first year of research results provided
the first available measurement data on

• wear characteristics of diamond impregnated bits under low P/T for dry
and ice saturated Ohio sandstone

• the role of water vapor released from rocks by the comminution process
and its significance for clearing cuttings away from the bit

• the effectiveness of releasing small flows of gas to assist in
clearing the cuttings from the hole

• the dust-like dimensions of cuttings created by diamond bits operating
at very low RPM and modest WOB

• the 'freeze-dried' nature of low P/T cuttings from materials
containing water ice and the increased efficiency of drilling under
martian conditions

• friction on the sheath within which the auger operates as a function
of auger fullness and cuttings compaction

![](media/image4.jpeg){width="4.01875in" height="4.616666666666666in"}

Figure 1. Laboratory arrangement at UCB. Shown are rock sample with
embedded thermocouples and a drill with a sheath.

Drilling under martian conditions in a water-saturated rock was found to
be very different in many respects from drilling under terrestrial
conditions. This is mainly because the martian atmospheric pressure is
in the vicinity of the pressure at the triple point of water. Thus ice,
heated by contact with the rotating bit, sublimed and released water
vapor. The volumetric expansions of ice turning into a vapor was over
150 000 times. This continuously generated volume of gas effectively
cleared the freeze-dried rock cuttings from the bottom of the hole as
shown the figure. In addition, the subliming ice provided a powerful
cooling effect that kept the bit cold and preserved the core in its
original state. Under virtually the same drilling conditions, coring
under martian low temperature and pressure conditions consumed only half
the power while doubling the rate of penetration as compared to drilling
under terrestrial conditions. However, the rate of bit wear was found
also to be much higher under martian conditions.

![](media/image5.jpeg){width="3.567361111111111in"
height="3.8819444444444446in"}

Figure 2. Drilling under martian conditions in water saturated frozen
sandstone.

![](media/image6.jpeg){width="3.1805555555555554in"
height="2.861111111111111in"}

Figure 3. Drilling in water saturated rock under martian conditions.

![](media/image7.jpeg){width="3.1944444444444446in"
height="2.8472222222222223in"}

Figure 4. Drilling under atmospheric conditions.

In the second year of this project laboratory research has focused on
understanding the implications of drilling into clay minerals, products
of the chemical weathering of rocks in the presence of water. Such
minerals are a quite probable component of the martian regolith and
their penetration is expected to present quite different problems than
drilling into basalts and sedimentary rocks such as sandstone. Drilling
into sands and silts that contain even a few percent of clay can be very
different from drilling in a pure sand, gravel or rock. Therefore, a
series of experiments was conducted to determine the behavior of the
drill in water-saturated, frozen clayey materials under Mars-like
conditions. The bit used contained diamond impregnated segments, the
most likely choice for a Mars drill. The soil samples were obtained from
Eureka by the team at the time of the previous year's reconnaissance
visit (when a Webster drill from New Zealand was used to learn about
conditions there).

![](media/image8.jpeg){width="2.513888888888889in"
height="3.361111111111111in"}

Figure 5. Drilling in Eureka mud under martian conditions. Mud is
freeze-dried.

![](media/image9.jpeg){width="2.611111111111111in"
height="3.361111111111111in"}

Figure 6. Drilling in Eureka mud under atmospheric conditions. Mud is
sticky.

A second series of tests was conducted under Earth atmospheric
conditions for comparison purposes and, importantly, to ensure that we
did not meet with surprises in the first tests of the Mk II drill at
Eureka.

It was found that the drilling power required for a similar rate of
penetration was lowest under atmospheric conditions and doubled under
martian conditions. This is attributed to the fact that, under
atmospheric pressure, the heat generated during drilling was used to
warm up and soften the underlying soil. Once the soil became softer the
cutting segment could effectively sink into it. Under martian pressures,
a large fraction of the heat was used up as latent heat of fusion and
vaporization of the water ice. Thus, the underlying soil remained hard
frozen and the drilling continued in the form of slow abrasion rather
than effective cutting.

During drilling, excessive heat generated caused the newly formed core
to lose its integrity and break up into small chunks. Intermittent stops
in drilling helped to preserve the core integrity.

Successful drilling in clay-containing materials is very temperature
dependent. If the temperature is 10˚C or more below freezing the clay is
solidly frozen. The diamond impregnated bit cannot penetrate this clay
because the diamonds leave uncut 'ribs'. If the clay is only a few
degrees below freezing the clay becomes ductile and the sharp edges of
the cutting elements can penetrate the clay. The limit on the rate of
penetration is set by the relief angle which is very low for diamond
bits. Intermittent stops of the drilling help keep the clay below
freezing. Above freezing the clay assumes the consistency of peanut
butter; penetration can continue but refreezing of the clay prevents the
unit from being pulled up out of the hole.

The friction between the rotating metal bushing and the metal ring
holding the auger's sheath serve to heat up the upper part of the
drilling assembly. This resulted in further freeze drying of the clay
cuttings in the upper part of the auger while drilling in near vacuum.
In addition the excess heat caused the upper part of the core to warm
up. We conclude that if an auger sheath is used then consideration must
be given to reducing the frictional heat build-up. Tests in sandstone
confirmed the frictional effects of the auger sheath and indicate that
we may well need the option of drilling without an auger sheath.

The laboratory research has confirmed the expectation that cuttings
removal is the weak link in the process of successful drilling without a
drilling fluid. To improve the efficiency of cuttings removal the auger
has to be optimized with respect to its pitch angle and surface friction
properties. The latter is critical because the RPM of the auger is very
low (\~100) and the cuttings tend to be pushed up from below rather than
dragged by the friction against the sheath. The auger surface must be
extremely smooth and we are looking at coatings developed by the
Magnaplate Co., coatings that have high abrasion resistance and very low
friction. The auger pitch can also be optimized for our application; a
theoretical analysis indicates that optimum value is a pitch angle of
\~20˚.

On Earth, rock cuttings are removed via circulating water, mud or
compressed air. On Mars, no fluids can be used due to weight constraints
and due to extreme temperature and pressure conditions. Compressing the
thin martian atmosphere to useful pressure levels for continuous air
circulation may be prohibitive. However, periodical blasts of gas could
be effective in clearing the cuttings. The tests conducted under martian
conditions proved that one liter of gas at differential pressures of up
to ten times the martian pressure could clear at least 30 grams of
cuttings from depths of 25 cm or more. This could be adequate for a
wireline drilling arrangement. During a gas blasts particles were lifted
out of the hole at a maximum speed of 6 m/s or more at a differential
pressure of 25 torr and ambient pressure of 5 torr. A single gas blast
lasted on average for 2 seconds. The experiments also showed the
existence of a threshold pressure below which no cuttings were cleared
and above which the majority of cuttings were removed. This threshold
pressure depended on the initial quantity and on the size distribution
of the cuttings. Other variables such as a type of gas used (carbon
dioxide or atmospheric air), the BHA clearances, the particle size
distribution of the rock powder and the effect of ambient pressure were
investigated and proved to effect the efficiency.

![](media/image10.jpeg){width="2.582638888888889in"
height="3.109027777777778in"}

Figure 7. Intermittent gas blasts can effectively clear the rock
cuttings from the holes on Mars.

All the results described above have been published in the open
literature (JGR) for the benefit of all the teams that are developing
drill for martian applications:

Zacny, K. A., M. C. Quayle, and G. A. Cooper (2004), Laboratory drilling

under Martian conditions yields unexpected results, J. Geophys. Res.,
109,

E07S16, doi:10.1029/2003JE002203. Also appeared in the special section
of J.

Geophys. Res., \'Space Simulations in Laboratory: Experiments,

Instrumentation, and Modeling\'.

Zacny, K. A., and G. A. Cooper (2004), Investigation of
diamond-impregnated

drill bit wear while drilling under Earth and Mars conditions, J.
Geophys.

Res., 109, E07S10, doi:10.1029/2003JE002204. Also appeared in the
special

section of J. Geophys. Res., \'Space Simulations in Laboratory:
Experiments,

Instrumentation, and Modeling\'.

In Press

K. Zacny, M. Quayle and G. Cooper, \"Enhancing Cuttings Removal with Gas

Blasts While Drilling on Mars\". J. Geophys. Res., doi:2004JE002340.

Grace W. Su, Joseph S.Y. Wang, and Kris Zacny, \"In situ
freeze-capturing of

fracture water using cryogenic coring\"; Vadose Zone Journal, in press

The UCB laboratory research was also directed to provide support for
Carol Stoker's Rio Tinto team using samples of materials that had been
obtained by a previous reconnaissance effort there using a conventional
drill. Details of these results are not provided here since they are not
germane to the M/ADD project.

##### 3. Plans for Drill automation

# 

> The autonomous drill control software will eventually reside in the
> rugged laptop that is presently used to record operating data; the
> software will receive input from various motor current meters, RPM,
> temperature sensors &, perhaps, vibration sensors and will serve to
> operate the drill based on experience gained in the laboratory and the
> field. Once the meter/sensor values are input, diagnosis algorithms
> will identify appropriate actions/commands that are responsive to the
> environmental conditions and the health/state of the drill. The
> control goal will be to assess and anticipate the drill's operating
> state to: 1. maintain it within safe limits at all times (to avoid
> getting stuck in the hole such that recovery may be impossible), 2. to
> *safe* the drill if ever necessary (to await human analysis of
> potential problems), 3. to maintain an optimum rate of penetration and
> 4. to determine when the core barrel is full and the core ready for
> capture.
>
> A basic function of the software, therefore, is to diagnose the
> operational state of the drill and the nature of its environment \--
> including the status of the auger and its sleeve as cuttings begin to
> fill the cuttings basket and the flights of the auger. For normal
> terrestrial drilling operations that use a fluid to remove the
> cuttings and cool the bit such auger considerations do not arise. Our
> circumstances, therefore, represent new automation challenges.
>
> We anticipate that an in-depth analysis of the data collected both in
> the laboratory and the field \-- where a variety of rock types have
> been drilled using several types of bit and auger \-- will provide the
> basis for understanding the physical processes involved with
> sufficient clarity that a heuristic set of algorithms (combinations of
> *if* statements leading to *then* commands) can be developed for the
> diagnostic/control software. We will benefit significantly from the
> experience of team member George Cooper who developed *Payzone,* a
> drilling physics simulation program used to educate petroleum and gas
> drilling engineers. In any case, conservative boundaries will be
> identified to ensure that the drill always avoids becoming jammed
> within the hole and avoids burning out motor current fuses.
>
> Linear feedback loops from the meter/sensor measurements will operate
> within *Labview*, using a "PID" function that serves to correct errors
> and the effects of noise. The PID functionality can help optimize gain
> settings for the pre-determined drill operational profile.
>
> We will first automate the drill used in the UC Berkeley laboratory
> and test it against a variety of rock types under a range of
> terrestrial and martian operating conditions. When sufficiently proven
> we will automate the JSC-BHI drill for laboratory demonstration and,
> finally, demonstrate the automation in the field.
>
> **Accomplishments**:
>
> Development of software that interacts with the drill's sensors via a
> RS-485/USB connection:

-   Meter and sensor data displayed in real time (Figure xx)

-   Display includes calculation of the rate of penetration

-   Meter and sensor data are archived into an Excel spreadsheet file

-   Meter/sensor's data are continuously compared against limits and the
    display provides visual and audible warning as limits are approached

> **Plans:**

-   Add information gained from the Arctic 2004 field test. Also include
    actions taken in the field test which corrected problems that
    occurred while drilling

-   Learn communication protocols of the microcontrollers that support
    the FOB, anchor, and drill motors

-   Add the software sensor limits once the max/safe ranges are
    determined

-   Integrate into the software tasks that command and control the speed
    of the bit, weight on bit, and anchor functions

-   Build heuristic control algorithms

-   Monitor the fullness of the core barrel

-   Integrate and test the control software with the UCB and JSC-BHI
    drills

# • **4. Contamination of Cores retrieved in Summer 2003**

**Analysis of Fluorescent Micropheres during fluidless drilling of High
Arctic permafrost and massive ground ice in Eureka, Nunavut**

**Whissell, G^1,2^, Juck, D.F. ^2^, Greer, C.W. ^2^, and Whyte,
L.G^1^.**

# 1. Dept. of Natural Resource Sciences, McGill University, Quebec, Canada H9X 3V9. 2. Biotechnology Research Institute, National Research Council of Canada, Montreal, Canada H4P 2R2

Sept. 3, 2003

There exist several methods for monitoring the presence of biological
contaminants in a given environmental sample obtained by drilling, all
of which rely on the use of a tracer compound. The nature of the
sediment, ice or rock dictates the choice of tracer used to monitor
contamination of the extruded core. Application of tracer compounds for
both soil and rock are well documented. In contrast, very little if any
work on the application of tracer compounds to frozen soil and/or ice
samples appears in the literature. For this reason we have developed a
new method for applying tracer compounds to these types of samples when
performing fluidless drilling.

The tracer compound chosen for this project was fluorescent micropheres
(Fluoresbrite Carboxylated Microspheres YG, Polyscience Inc.,
Warrington, PA) with diameters of 0.05µm and 0.5µm. These sizes are
representative of bacteria which might be introduced as contamination.
These beads have been successfully used in fluidless drilling
operations - a method in which the drill remains cool enough to prevent
melting of the frozen samples, without relying on cooling fluids which
contaminate samples and the environment. However, this tracer compound
has only been successfully applied in environments above freezing. Thus,
to optimize their use in the frozen environment of Eureka, Nunavut,
several methods for applying these tracers were examined. The results
were analyzed visually on site using a hand held UV light and by means
of epifluorescence microscopy at the Biotechnology Research Institute
(BRI).

Three methods for applying these beads were used: 1) the *[snow ball
method]{.underline}*, 2) the *[pour down hole method]{.underline}*, and
3) the *[painted bit method]{.underline}*. The *snow ball method*
constituted mixing a dilute solution of beads with snow to make small
snow balls which were frozen over night at --20°C. This snow was dropped
in the drill hole, packed with a weight and allowed to set for 10-15
minutes. In the field it was apparent that the snow ball method did not
allow for the transfer of the beads to the sample being drilled. The
weight of the drill bit crushed the snowballs resulting in the packing
of the vast majority of beads into the catch tube. Therefore little if
any of the beads were found to be transferred to the exterior of the
extruded samples.

The three areas chosen for drilling possessed three distinct vertical
profiles. Eureka1 (Eu1), located at 79°59.900'N, 85°53.755'W, was the
first site and consisted of clayey-soil permafrost throughout the entire
drilled depth of 12.61m. There were occasional thin ice layers
encountered, but not the desired massive ground ice. The Eureka2 (Eu2)
site, located at 79°59.893'N, 85°52.614'W, was chosen so as to drill
through an ice wedge in order to experiment with different drill bits.
Two holes were drilled at this site (Eu2 and Eu2a), approximately 2m
apart. The top of the ice wedge at Eu2 was encountered at a depth of
2.06m with a clearly defined ice/soil permafrost interface at 6.03m. At
Eu2a, clear ice was first encountered at 0.75m and continued until to
2.00m. Between 2.00m and 2.30m, a mixed ice and soil horizon was
encountered and drilling was stopped. Eureka3 (Eu3), located at
80°0.029'N, 85°50.367'W, hit massive ground ice before 1.82m. At a depth
of 16.05m, when the drilling was stopped, massive ground ice was still
present.

The *pour down hole method* used a dilute mixture of beads (200ml) that
was placed into a thin plastic bag containing a 30cm nail. Both the bag
and the nail were tied to separate strings and carefully lowered down
the hole. Once the bag had reached the bottom of the hole the bag was
briskly pulled toward the nail, puncturing the bag and causing the bead
solution to pool at the base of the hole. The pooled bead solution was
allowed to set over night. When the drill passed through this frozen
layer, it transferred beads into the environmental sample, mimicking
potential contamination. Although this method did at times successfully
transfer beads throughout the exterior of some samples, it did not prove
to be reliable. An undesirable consequence was that the first run of the
day often scraped a large amount of cuttings from the side of the hole
onto the surface of the frozen bead layer. The resulting mixture of
mainly cuttings and beads reduced the amount of sample collected
limiting further analysis.

The *painted bit method* consisted of mixing a concentrated solution of
beads with 100% ethanol (50:50) and painting this solution onto the
edges and inside of the bit, core catcher and first inch of the core
tube. The bead solution quickly dried and was ready for drilling within
minutes. Of the three methods used, the *painted bit method* was the
simplest and fastest. The fluorescent microspheres were readily and
reliably transferred from the painted surfaces to the extruded cores,
and were easily visualized in the field under normal light (Figure 1a).
Visualization of the microspheres using a portable U.V. light source was
also easily accomplished in the field (Figure 1b).

The analysis of the bead covered cores was accomplished using a newly
developed strategy for sectioning ice and soil cores that avoids
transferring beads toward the center of the sample (Figure 2). To
accomplish this, a chisel was used to section the core several times in
order to obtain clean faces which permitted drilling and proper
sectioning of the sample for microscopic analysis. The first lateral
break in the core produced a hockey puck shaped sample. The sample was
then placed clean side up and cut laterally once again from the clean
side outward producing a second clean face. The center of the second
clean face served as the starting point from which the drilling was
initiated. The adjacent sides of the clean face opposite the bead
covered exterior were firmly placed in a vice in preparation for
drilling. The sample was drilled to a distance approximately 10mm from
the bead covered exterior. A final lateral cut accomplished the
splitting of the sample and the exposure of the third clean face. The
third clean face of the sample was horizontally placed in a vice to
allow millimeter sections to be carved from the base of the drill hole
outward. This method of sectioning the cores allowed us to analyze
millimeter sections of the cores from the center outward, thus avoiding
the dragging of superficial beads into the deeper layers of the core.
Other methods for sectioning the cores which did not utilize a chisel
were attempted, but resulted in the transfer of beads to nearly every
sample examined. The ice samples were prepared for microscopic analysis
by melting, pooling, and then drying the slurry onto prepared microscope
slides. The frozen soil samples were liquefied by the addition of water,
homogenized and dried onto prepared microscope slides. Before microscopy
was performed the samples were hydrated with 20µl of water for ice
samples and 40-60µl for soil samples. The samples were examined
qualitatively, for the presence or absence of beads. Quantitative
analysis was not performed because of the uneven distribution of the
beads on the exterior surfaces of the cores (Figure 1a) making
quantification of beads seen in the interior highly variable.

Several aspects of bead application were examined. The cores were
examined with regard to bit type, method used to administer the beads
and sample type (Table 1). The samples collected using the tungsten
carbide bit and the sipre auger were analyzed microscopically (Figure 3)
for bead penetration and showed very similar results between the two bit
types (Table 2). Comparison of the *pour down hole* and *painted bit
methods* was problematic due to the poor quality of several samples,
which consisted mainly of cuttings (Figure 4). However, based on the
samples examined, these two methods demonstrated similar maximum
microsphere penetration distances of 4-6mm (Table 2). Sample type played
a minor role in the extent of bead penetration. In the 3 intact soil
permafrost samples, beads were found between 2-5mm (average
3[+]{.underline}1.7mm) and in the 4 ice samples between 2-6mm (average
4.3[+]{.underline}1.7mm).

While in the field DNA was extracted from two soil cores located well
within the permafrost zone. The drilling sites from which samples were
taken were sites Eu1 and Eu2 at depths of 8.87m and 6.82m, respectively.
The Eu1 sample was a wet clay while Eu2 was a dry clay. Two bead beater
methods were used to test their efficacy in extracting DNA from these
samples. One of the methods used was a previously published protocol
with several modifications, while the second method was a commercially
available kit from MO BIO (MO BIO Laboratories, Inc., Solana Beach, CA).
These methods were performed using 0.5g soil samples. Due to the
frequent lack of adequate refrigeration in the field, several methods
were examined for the storage and transportation of DNA at temperatures
above 0°C. The extracted DNA from the bead beater protocol was either
resuspended in 70% ethanol or 100mM Tris-HCl (pH 8.0) or air dried and
transported as a pellet. The precipitation solution for the MO BIO was
lost during transportation so only Tris-HCl suspension of the DNA was
performed. When the DNA samples arrived in the laboratory they were
stored at 4°C for a period of 20 days to simulate field conditions. The
ethanol suspended DNA was precipitated, and then resuspended in sterile
deionized H~2~O. The dried DNA pellet was also resuspended in sterile
deionized H~2~O and both samples purified using PVPP spin columns. All
samples, i.e. dried and ethanol transported bead beater samples and MO
BIO Tris-HCl samples, were then visualized on an agarose gel (data not
shown). These samples were then PCR amplified using universal
Eubacterial 16S primer pair u341-u758, to test the quality of the DNA.
Although 16S bands from both methods were observed for the majority of
the samples, it was obvious that the MoBIO kit produced the most intense
bands and thus produced the cleanest DNA PCR amplification (Figure 5);
further molecular analyses of the 16S fragments are now in progress.

This study has resulted in the development of a new method for tracking
the extent of possible microbial contamination in frozen permafrost and
ground ice samples and will undoubtedly be of use to researchers
interested in analyzing the microflora that exists in Polar
environments.

*Table 1. Cores used to determine the penetration of fluorescent
microspheres.*

  ------------ -------------------- -------------------- ----------------------
  **Method**   **Carbide Cutters**                       **Sipre Auger**

               **Permafrost**       **Ground Ice**       **Ground Ice**

  Painted      A (*Eu1*-11.58m)     C (*Eu2*-2.06m)      E (*Eu3*-6.48m)

               G (*Eu1*-11.58m)                          D (*Eu3*-6.61m)

               H (*Eu1*-11.58m)                          

                                                         

  Poured       B (*Eu2*-6.82m)                           F (*Eu3*-7.15m)
  ------------ -------------------- -------------------- ----------------------

##### 

##### Table 2 Summary of fluorescent microsphere penetration

  ------------------ ---------------- ------------ ----------------------------
  **Sample**         **Permafrost**   **Ground     **Depth of Beads (mm)^a^**
                                      Ice**        

  A (*Eu1*-11.58m)   \*                            5

  B (*Eu2*-6.82m)^b^ \*                            10+

  C (*Eu2*-2.06m)                     \*           5

  D (*Eu3*-6.61m)                     \*           2

  E (*Eu3*-6.48m)                     \*           6

  F (*Eu3*-7.15m)                     \*           4

  G (*Eu1*-11.58m)   \*                            2

  H (*Eu1*-11.58m)   \*                            2
  ------------------ ---------------- ------------ ----------------------------

**^a^** Depth of beads (mm) penetrating from the exterior of the core
sample

^b^ Sample B consisted mainly of cuttings.

*Figure 1.* Visualization of fluorescent microspheres on subsurface
cores. a) Observation of fluorescent microsphere transfer to the core
surface in the field using ambient light. b) Observation of fluorescent
microspheres under U.V. light in the field.

![](media/image11.jpeg){width="2.797222222222222in"
height="2.1173611111111112in"}
![](media/image12.jpeg){width="2.797222222222222in"
height="2.1173611111111112in"}

##### *Figure 2.* Schematic of core processing steps for the estimation of fluorescent microsphere penetration.

![](media/image13.jpeg){width="5.8125in" height="7.75in"}

*Figure 3.* Fluorescent microsphere penetration into subsurface cores.
Core A (Eu1, 11.58m) was used and is representative of the other
samples. a) Section at 1mm from core surface. b) Section at 2mm from
core surface. c) Section at 4 mm from core surface. d) Section at 6mm
from core surface. No beads were observed in sections greater than 6mm
from core surface.

![](media/image14.jpeg){width="2.8319444444444444in"
height="2.1173611111111112in"}
![](media/image15.jpeg){width="2.8319444444444444in"
height="2.1173611111111112in"}

![](media/image16.jpeg){width="2.8319444444444444in"
height="2.1173611111111112in"}
![](media/image17.jpeg){width="2.8319444444444444in"
height="2.1173611111111112in"}

*Figure 4.* Demonstration of retrieved core containing primarily
cuttings from the sides of the hole. The top unconsolidated layer
represents the cuttings sitting upon the solid core piece.

![](media/image18.jpeg){width="2.0854166666666667in"
height="2.754166666666667in"}

*Figure 5.* Agarose gel and ethidium bromide visualization of 16S rDNA
PCR amplification products.

![](media/image19.jpeg){width="4.7in" height="3.525in"}

Reports:

Steven, B., Pollard, W.H., McKay, C.P., Greer, C.W. and Whyte, L.G.
2004. Diversity of culturable bacteria isolated from permafrost and
ground ice from the Canadian high Arctic.10th International Symposium on
Microbial Ecology (ISME-10). Cancun, Mexico, Aug. 22-27, 2004.

Whissell, G.T., Juck, D.F., Steven, B. Pollard, W.H., McKay, C.P.,
Greer, C.W. and Whyte, L.G. 2004. Assessing microbial integrity of
permafrost and ground ice core samples from the Canadian high Arctic.
10th International Symposium on Microbial Ecology (ISME-10). Cancun,
Mexico, Aug. 22-27, 2004.

# Juck, D.F., Whissell, G., Steven, B., Pollard, W., McKay, C.P., Greer, C.W., and Whyte, L.G. 2004. Utilization of fluorescent microspheres and a GFP-marked strain for assessing microbiological contamination of permafrost and ground ice core samples from the Canadian High Arctic. **accepted in Appl. Environ. Microbiol. Sept. 10. 2004**. 

##### 5. Results from the Eureka Field Tests, September 2004

![](media/image20.png){width="2.717361111111111in"
height="2.439583333333333in"}

Figure 1.1 The Arctic

![](media/image21.png){width="2.717361111111111in"
height="1.8118055555555554in"}

Figure 1.2 Ellesmere Island

![](media/image22.png){width="2.717361111111111in"
height="2.1979166666666665in"}

Figure 1.3 Eureka Geology (legend below)

![](media/image23.png){width="2.7083333333333335in"
height="1.2520833333333334in"}

Figure 1.4 Eureka Geology (legend below)

Legend:

Blue: Upper Jurassic Awingak Formation

Sandstone, siltstone, minor shale

Light Blue: Lower, Middle and Upper Jurassic Savik Formation

Green sandstone, shale

Pink: Lower Jurassic Borden Island Formation

Sandstone

Light Green: Upper Triassic Heiberg Formation

Sandstone, siltstone, minor shale

Green: Middle and Upper Triassic Blaa Mountain Formation

Dark colored shale, siltstone, minor sandstone

The first permafrost field test of the Mark II drill took place on the
Fosheim Peninsula of Ellesmere Island near the Eureka Weather Station
between 25 and 30 September 2004. The goals of this first test were both
technological and scientific:

• Demonstration of the basic functionality of the drill

• Acquisition of operating data, including thermal, in two types of
strata -- sandstone and ice

• Evaluation of different types of bits and augers for drilling into
rock, frozen mud and in ice

• Understanding the practicalities of deploying the drill in an extreme
cold environment

• Acquisition and curation of targeted cores for microbiological
analysis by the Canadian members of the team

• Evaluation of the contamination of the cores using fluorescent
microsphere tracers

Field team members (below, left to right) were:

Chris Omelon (Field Team Leader)

Geoffrey Briggs (Principal Investigator)

Samantha Domville

Kris Zacny

Tim Cooper

Mike Dreever

Jeffrey George (NASA JSC Project Manager)

Brian Derkowski

Lyle Whyte

![](media/image24.png){width="2.717361111111111in"
height="2.0284722222222222in"}

Figure 2. Team Photograph on final day of field operations at iceberg on
Slidre Fjord

##### 5.1 Functional testing of the JSC-BHI drill in permafrost

The sites selected for drilling into sandstone (Figures 1.3, 1.4, 3.1,
3.2) were identified by the field team leader (Chris Omelon) on the
basis of his ongoing research into the distribution and characteristics
of endolithic organisms in the marine sediments on the Fosheim
Peninsula. Specifically the sites were outcroppings of sandstone in the
Heiberg Formation (Upper Triassic) within two kilometers of the Eureka
Weather Station.

![](media/image25.png){width="2.717361111111111in"
height="4.075694444444444in"}

Figure 3.1 Sandstone ridge viewed from Site 1

![](media/image26.png){width="2.717361111111111in"
height="2.0409722222222224in"}

Figure 3.2 Sandstone ridge viewed from fjord

The drill's surface support equipment (Figure 4) takes the place of a
landed spacecraft and consists of a sturdy aluminum assembly that is
provided with sufficient inertia by means of bolts or ballast. The
target rocks were chosen to be conveniently flat consistent with the
limited geometric flexibility of the support system.

![](media/image27.png){width="2.7090277777777776in"
height="1.8006944444444444in"}

Figure 4. Surface Support System

For simplicity and because of inadequate time to lab test the newly
developed anchor (Figure 5), the bottom hole unit was pinned (Figure 6)
rather than anchored in the spud tube.

![](media/image28.png){width="2.43125in" height="0.75in"}

Figure 5. Anchor (not used in the field)

![](media/image29.png){width="1.9229166666666666in"
height="4.077083333333333in"}

Figure 6. Pin serves to anchor BHA in spud tube

![](media/image30.png){width="2.717361111111111in"
height="1.8118055555555554in"}

![](media/image31.png){width="2.717361111111111in"
height="2.372916666666667in"}

Figure 7. Drill control and data acquisition system

![](media/image32.png){width="2.717361111111111in"
height="2.536111111111111in"}

Figure 8. Data acquisition computer

Once target rocks along the sandstone outcrop had been identified, daily
operations consisted of setting up the surface support system (unless it
was still in place from the previous day's effort), powering up the
drill and control/data acquisition equipment, and proceeding to
penetrate the rock.

![](media/image33.png){width="2.717361111111111in"
height="1.8173611111111112in"}

Figure 9. Operations at Site 1

![](media/image34.png){width="2.3069444444444445in"
height="1.8194444444444444in"}

Figure 10. Drill operations at Site 2 where there is a meteorological
station 100 m upslope from Site 1

![](media/image35.png){width="2.0069444444444446in"
height="3.0006944444444446in"}

Figure 11. Operations at Site 3 \~20 meters up the slope from Site 2

The core barrel filled at depth intervals of \~ 15 cm at which time the
drilling was halted and the core retrieved by the team (Figure 12).

Cores were extracted manually by inserting a clear lexan tube over the
core, snapping the base of the core, capturing it in the tube and
pulling it out of the hole (Figures 13.1 and 13.2).

![](media/image36.jpeg){width="1.8194444444444444in" height="2.38125in"}

Figure 12. Disassembly to retrieve sandstone core at Site 2

![](media/image37.jpeg){width="2.577777777777778in" height="1.5375in"}

![](media/image38.png){width="1.8055555555555556in"
height="1.3444444444444446in"}

Figures 13.1 and 13.2. Core extraction

The individual cores (each up to 15 cm in length) were then stored in
sterilized, transparent tubes with end caps. Each was labeled for
subsequent analysis at McGill U. and the U. of Toronto.

Cuttings from the drilling process were removed from the bit by means of
an auger turning within a sleeve. The cuttings deposited in the chamber
above the core barrel were removed after each core had been extracted.
Cuttings remaining in the auger (Figure 14) were cleaned before resuming
the drilling process.

![](media/image39.png){width="2.717361111111111in"
height="3.079861111111111in"}

Figure 14. Fine sandstone cuttings fill auger at Site 1.

The changing state of fill of the auger and changes in the hardness of
the rock being penetrated made drill control an active process (manually
undertaken by Brian Derkowski and Michael Drever). The drill was not
stuck at any time. Analysis of the data acquired while drilling and
correlation with the characteristics of the cores will provide essential
information for drill automation.

In addition to the measured rate of penetration, motor currents &
temperatures, and RPM, the drill controllers also relied on the changing
sound of the drilling process to exercise control of Force on Bit and
RPM.

Therefore, consideration will be given to the addition of a microphone
and/or accelerometers to the sensing that will be used to autonomously
control the drill.

Conditions during drilling operations were cold (air temperature \~
-10˚C) but generally favorable -- meaning dry and generally calm.
Temperatures reached --20˚C on the final day and any wind above 10 knots
would have been very challenging. The drill operators (Derkowski,
Drever, Cooper and George) were, in fact, functioning for more than six
hours each day in conditions that were sufficiently extreme.

Length of day and quality of illumination (considering that the sun
never reached more than 10˚ above the horizon) were surprisingly good.
The ground was thoroughly frozen at the surface thus avoiding the
shallow mud that can be encountered in summer.

A total of fifteen cores were retrieved from the sandstone having a
cumulative length of \> one meter. The greatest depth penetrated in a
single hole was about 50 cm.

**Testing in Ice**

The 2004 testing took place shortly after the Fall Equinox when snow had
already covered the ground at Eureka thus presenting a challenge in
finding the site where, in 2003, the Webster drill had cored in ground
ice underlying several feet of soil. Therefore, given this problem and
the limited time available, ice testing was carried out more
conveniently on a small iceberg that had become trapped in the frozen
Slidre Fjord (ice cover 30 cm thick) near the Weather Station, Figure
15.

![](media/image40.png){width="2.717361111111111in"
height="1.8118055555555554in"}

Figure 15. Garage-sized Iceberg 200 m from edge of Slidre Fjord

On the morning of the final day of field operations (9/30/04) the
drilling equipment was moved to the iceberg where a small horizontal
ledge was chipped out of the iceberg on the side opposite to that seen
in Figure 15 above. The surface support system was bolted to this ledge
and drilling undertaken during the afternoon (Figure 16).

![](media/image41.png){width="2.717361111111111in"
height="4.075694444444444in"}

Figure 16. The JSC-BH drill in operation on the small iceberg

A special ice-coring bit and auger had been procured (from a Canadian
specialist company), Figure 17, and as expected, penetration rates were
much more rapid than for the sandstone sites.

![](media/image42.png){width="2.717361111111111in"
height="1.9076388888888889in"}

Figure 17. Ice coring drill and auger with teflon flights

Two meters of penetration, Figure 18, was achieved without difficulty.
However, the ice proved to be less consolidated than anticipated so that
the cores retrieved were a combination of solid disks and
shattered/crumbly ice.

![](media/image43.png){width="2.717361111111111in"
height="2.0409722222222224in"}

Figure 18. JSC team note the depth of penetration achieved.

Temperatures were very cold and there was light snow on this final day
in the field. Nevertheless the control and data recording equipment
worked without problems, Figure 19.

![](media/image44.png){width="2.717361111111111in"
height="2.0409722222222224in"}

Figure 19. Operations at Iceberg Site

## 5.2 UC Berkeley Experiments at Eureka.

# In addition to the main experimentation using the JSC-BHI drill, ancillary experiments were carried out by Kris Zacny using a hand held battery-driven electric drill (Ridgid R84015, 18V). The drill was used to turn the bit and the human effort was used to apply the weight on bit. The torque setting on the drill was 485 in.lb.,while the speed was manually controlled. The maximum rotational speed was 1200 revolutions per minute and the maximum available power was 350 Watt. Two types of bits were tested, namely a hybrid bit and a Polycrystalline Diamond Compact (PDC) bit. A hybrid bit contained a combination of diamond impregnated segments and PDC cutters brazed in certain order.

# 

# The drill string included a 25 cm long auger and 25 cm long extension rod. Thus the total length of the drill string was 50 cm, which resulted in bit wobble or bit walk on the surface of the rock or frozen mud. To stabilize the drill for the initial bite, the bit was placed between the boots. Once the drill penetrated approximately 1 cm or so, no additional guidance of the bit was needed.

### 5.2.1 Test Results

#### 5.2.1.1 Hybrid bit

The first test was conducted in permafrost approximately two meters from
the bank of the Slidre Fjord. The ground could be described as sandy
gravel. The bit penetrated approximately 5 cm in 3 minutes before the
battery was completely discharged. The drill experienced a lot of
vibrations. At one stage, the penetration almost ceased completely. Upon
inspection of the bit, it was found that the core inside the auger had
formed a plug. Later it was found that the plug was actually a few
pebbles wedged inside the auger.

The temperature of the formation was approximately - 10 deg C. After the
bit was pulled out, the temperature of the top surface of the core that
remained inside the hole was + 10 deg C and the temperature of the
bottom of the hole was + 5 deg C. The bit inspection revealed that one
of the PDC cutters broke off completely. The fracture most probably
happened when the cutter hit a pebble.

The second drilling attempt was made in the old creek bed (see Figure
20). The underlying frozen mud (mainly clayey silt) was easily
penetrated down to about 8 cm. Below this depth pebbles were
encountered. The impact of the hybrid bit on the pebbles chipped the
remaining three PDC cutters and removed two inner diamond impregnated
cutters (see arrows in Figure 21). Unfortunately the hybrid bit could
not be repaired easily in Eureka.

![](media/image45.jpeg){width="2.2527777777777778in"
height="1.7743055555555556in"}

Figure 20. The slipring assembly attached to the drill rod, lying on the
surface of the river bed

![](media/image46.jpeg){width="2.5368055555555555in"
height="2.4291666666666667in"}

Figure 21. A close up of a hybrid bit. Note that all inner cutters and
two outer PDC cutters are missing.

An attempt was made to measure the temperature of the bit while
drilling. For this purpose, the slipring assembly was attached to the
drill shaft as shown in Figure 20. During the drilling, the slipring set
screw loosened and the thermocouple wires broke off. This method of
measuring temperature in the field was not robust enough. In addition,
reconnecting thermocouples wearing gloves was not easy. Although the set
up can be improved by using much stronger wires and better ways of
holding the slipring assembly in place, a person solely dedicated to
keeping temperature data is also required.

The air temperature was - 15 deg C and the ground temperature was - 10
deg C. After drilling with the hybrid bit the core temperature was
measured to be + 35 deg C, while the auger temperature was + 20 deg C.

#### 5.2.1.2 PDC bit

The first drilling attempt using a PDC bit was made in 5 cm thick blocks
of type A sandstone, which can be described as a fine-grained sandstone.
The PDC drill penetrated at a rate of 3 cm per minute. The drilling
effort as felt by the driller could be described as low. The driller
could easily feel that with a higher weight on bit, the rate of
penetration increased. The same bit was also used on a much harder rock.
During that test one PDC cutter broke off and one was chipped.
Subsequently two new cutters were brazed on in the local shop. The braze
was strong but one of the cutters broke off during the test trial. Even
with three out of four cutters present, the bit penetrated type A rock
easily. After trial tests were completed a new PDC cutter was brazed on.
Therefore, the final PDC bit prior to full scale field drilling had two
new outside cutters and two old and chipped inner cutters.

The field test was conducted nearby the weather station constructed for
Chris Omelon of University of Toronto (see Figure 22 and 23).

![](media/image47.png){width="2.717361111111111in"
height="3.6256944444444446in"}

Figure 22. Drilling in the Arctic in B-type rock.

![](media/image48.jpeg){width="2.713888888888889in" height="1.3625in"}

Figure 23. Drilling in type B-type rock - close-up.

Overall, the PDC bit with two chipped cutters on the inside and two new
cutters on the outside, drilled three 20 cm deep holes in A-type rock
and another three 20 cm deep holes in B-type rock (see Figure 24).
B-type rock could be described as fine-grained sandstone/siltstone. It
is much stronger than A-type rock and a higher weight on bit had to be
used to achieve penetration.

![](media/image49.jpeg){width="2.716666666666667in"
height="1.8881944444444445in"}

Figure 24. Six cores were cored out, three from each rock type.

Using a bathroom scale to quantify the weight on bit, it was found that
for A-type rock the weight on bit was approximately 20 kg, while for
B-type rock it was up to 50 kg.

The only factors that limited the final depth of the hole were the
length of the core barrel and the extension rod as well as the life of
the batteries. It was found that approximately 1.5-battery life was
required to drill 20 cm deep hole.

Core retrieval was found to be difficult especially because the core
would break into 2 cm or larger sections (see Figure 25). A new core
barrel/auger design would require a core catcher. Most cores would break
off at the end of the drilling. In order to preserve core integrity,
coring was done in 10 cm intervals. After drilling first 10 cm, the core
would remain in the hole and had to be broken off manually (see Figure
26). The second 10 cm bite would result again in the core being broken
off and remaining in the hole. Mechanical grippers had to be used to
retrieve the core from the hole. This procedure resulted in longer
cores.

![](media/image50.jpeg){width="2.8409722222222222in"
height="1.0222222222222221in"}

Figure 25. Core would break up into small sections. (Scale in inches)

![](media/image51.jpeg){width="2.7159722222222222in"
height="2.3055555555555554in"}

Figure 26. 10cm core awaiting extraction (Scale in inches).

#### 5.2.1.3 Drilling iceberg

The PDC bit was also used to drill cores inside the iceberg as shown in
Figure 27. The temperature of the iceberg was - 16 deg C while the air
temperature was -19 deg C.

The iceberg was formed from compacted snow, therefore it had a lot of
air bubbles inside it. Most probably because of these trapped air
bubbles it was virtually impossible to obtain un-fragmented ice core.
Most of the cores were of crushed ice with a few 1 cm or thicker ice
lenses. With a very high penetration rate, cuttings would pack inside
the core barrel and form what looked like a compacted snow core as shown
in Figure 28 This snow core also had some ice lenses inside it. However,
in overall the core integrity was very poor.

![](media/image52.jpeg){width="2.7083333333333335in"
height="2.0541666666666667in"}

Figure 27. Drilling into iceberg.

![](media/image53.jpeg){width="2.7180555555555554in"
height="1.382638888888889in"}

Figure 28. At high penetration rates, cuttings would pack inside the
auger to form snow ice core with few ice lenses

### 5.2.2 Auger wear.

The auger used with the PDC bit was a single scroll auger with a 25
degree pitch angle. The auger surface was coated with Nedox SF-2 by
General Magnaplate (GM). According to GM specifications, the coating
hardness can be up to Rockwell 68 on the C scale. However, this coating
was not hard enough to prevent excessive auger wear.

Visual and then microscopic examination was conducted to explain the
unusual wear of the auger along its vertical axis as seen in Figure 29.
In places where the auger flights were completely worn out, the metal
tube started to wear as well.

![](media/image54.jpeg){width="2.7118055555555554in"
height="4.166666666666667in"}

Figure 29. Auger wear was in a vertical direction.

Figure 30 shows the bit after the test. The bit had worn 2 mm on one of
its sides, indicated by the arrow. The wear essentially reached the edge
of the inner cutter.

![](media/image55.jpeg){width="2.717361111111111in"
height="2.4256944444444444in"}

Figure 30. Bit has worn 2 mm on one side (shown by the arrow).

The worn surface on the auger, as indicated by the white arrow in Figure
31 was very well polished indicating that the surface was abraded by
fine rock cuttings. On the other hand scratches on the edge of the auger
flights (indicated by the black arrow in Figure 31) are much larger and
further apart. These scratch marks were made by the edge of the flights
rubbing against the inner surface of the hole (rock). This is analogous
to using a fine sand paper, which leaves fine scratches that cannot be
seen with the naked eye and makes the surface look polished. On the
other hand a coarse grained sand paper makes much coarser scratches and
these can be easily seen by the naked eye.

The close up of the area in Figure 29 just above the beginning of the
auger flight showed a lip. This particular location of the lip at the
entrance to the auger flight might not be a coincidence. It could be
that high rate of penetration caused an excessive accumulation of
cuttings, which were not cleared in time. The cuttings would choke the
auger at the entrance to the auger flight. The bit wear as shown by the
arrow in Figure 30 is directly below this lip.

![](media/image56.jpeg){width="2.7083333333333335in"
height="2.686111111111111in"}

Figure 31. Wear on the bit and the auger flight edge was caused by
different sources.

In addition it was found that auger flights at the areas of maximum wear
had steps as shown by the arrows in Figures 29. The upper step in
particular is very well developed. These steps give also an indication
of auger choking up with cuttings.

Both the steps and the lip might be formed by the same mechanism. Once
the small imbalance in cuttings removal hydraulics forms a tiny niche,
cuttings tend to penetrate deeper and make a deeper groove. This might
be analogous to small pebbles making a hole in the rock in the river.
Rocks trapped in small cavity tend to slowly abrade the rock and make
deep holes. In that case the driving force is the flow of water.

### 5.2.3 Cutter wear

Two new outer cutters were brazed on in Eureka and cut approximately 0.6
m in A-type rock and another 0.6 m in B-type rock. Both cutters had
their outside and top edges chipped as indicated by the arrows in
Figures 32 and 33. These chips look as if they were caused by an axial
impact i.e. bit moving up and down. The cutters showed a smooth wear on
top as seen in Figures 34 and 35.

![](media/image57.jpeg){width="1.9541666666666666in"
height="2.0236111111111112in"}

Figure 32. Front view of the first cutter.

![](media/image58.jpeg){width="1.9791666666666667in"
height="2.178472222222222in"}

Figure33. Front view of the second cutter.

Note the wear of the cutter along the outside edges indicated by two
short arrows in Figure 35. One of the inner

cutters (Figure 37) that drilled more rock shows these wear patterns
much more extensively.

![](media/image59.jpeg){width="2.7090277777777776in"
height="1.6666666666666667in"}

Figure 34. Top view of the first cutter.

![](media/image60.jpeg){width="2.7118055555555554in"
height="1.6722222222222223in"}

Figure 35. Top view of the second cutter.

Inner cutters (especially cutter in Figure 36) were chipped while
attempting to drill in basalt. These cutters were used for drilling 0.5
m of Ohio sandstone, 0.6 m of A-type rock and another 0.6 m of B-type
rock, 0.2 m of frozen water saturated silt and over 5 meters of ice.

The cutter in Figure 36 although badly fractured was still cutting the
rock. In fact, its sharp cutting edge and also uneven edge is more
aggressive than the rectangular surface of new cutters. This idea of
using PDC claw-like cutters will be followed up in months to come. The
second inner cutter shown in Figure 37 was not as badly chipped as the
first one, but showed much more pronounced wear mostly along the top and
sides. This indicates that this cutter in fact did more work than the
cutter in Figure 36.

![](media/image61.jpeg){width="2.2375in" height="1.9284722222222221in"}

Figure 36. First inner cutter.

![](media/image62.jpeg){width="2.2805555555555554in" height="1.99375in"}

Figure 37. Second inner cutter.

The extent of cutter wear was affected by how far above the bit surface
the cutter was projected. It was very difficult to braze the cutters and
still make certain that they stuck out the same lengths. Thus the
cutters that would protrude further would do the majority of the cutting
and wear faster. For example the first outer cutter in Figure 34 shows
much coarser scratch marks than the second outer cutter in Figure 35.
This means that the first cutter was rubbing against the bottom of the
hole directly, whereas the second cutter was worn by the fine rock dust
lying on the bottom of the hole. Indeed, the examination of Figures 32
and 33 shows the first cutter protruding much further out.

This uneven protrusion of cutters could also have given rise to the
excessive vibrations that were felt by the driller.

### 5.2.4 Flow lines

A close up of the bit surface in Figure 38 showed scratch marks left
behind by the cuttings moving by. The direction of rotation was from the
right to the left. These scratch marks or flow lines indicate the
direction in which the cuttings moved.

![](media/image63.jpeg){width="2.3666666666666667in"
height="2.359027777777778in"}

Figure 38. Scrach marks on the surface of the bit indicate which
direction cuttings were moving. Rotation is from right to left.

Using this analogy, if the surface of the bit were to be made from a
very soft material, like for example copper, then cuttings would by
themselves very quickly cut out most effective flow channels. In this
way the bit would be shaped to have the most efficient cuttings removal
geometry. The bit can later serve as a pattern for the final bit, which
will have to be made out of stronger material.

### 5.2.5 Lessons learned.

PDC bits can successfully drill sandstones with a high rate of
penetration. In addition, the rate of penetration can be directly linked
to the weight on bit, which might not be the case with diamond
impregnated bits. With diamond-impregnated segments, excessive weight on
bit might cause diamond fracture and eventual ceasing of drilling. With
PDC bits excessive weight on bit might also cause the fracture of PDCs.
However, even a small fragment of PDC can still effectively drill the
rock. In fact, by fracturing the PDC, the edge of the cutter becomes
more aggressive and this can enhance the rate of penetration.

The effectiveness of the drill in terms of the drilling effort and
induced vibrations can be easily assessed using a hand held drill. For
example drilling in B-type rock was much harder than in A-type rock. It
might be beneficial to actually test the newly made drill bits in this
way prior to using them in the drilling fixture. By testing many bits in
various formations, the driller can build up an expertise and later
could very rapidly assess the performance of different bits in the same
formations. The downside of the manual drilling is that the driller gets
tired and sometimes it seems that the drilling effort is higher even if
it is not. In addition the big disadvantage is that no numerical
information can be obtained. To quantify the weight on bit in the field
the driller can stand on a scale, for example a regular bathroom
weighing scale, and read off how much the scale moves during drilling.
The difference between the readings would be the actual weight on bit.

When coring in a sandy gravel material, there is a high risk that stones
may wedge permanently inside the core barrel. This needs to be avoided.
A solid stem auger might be a choice for these formations as long as the
stones themselves are smaller than the width of the auger flights.

Cutters on the drill bits should be able to be replaced very easily in
the field without using welding, soldering or brazing. This is not
relevant to Mars. However, the equivalent lesson for Mars is that we
must have inter-changeable bits.

Since the angle at which the drill was penetrating the rock was
controlled by the driller, sometimes it happened that the drill was
rubbing against the side of the borehole. Therefore, every so often
gauge cutters need to be added to the auger flights to prevent excessive
auger flight wear.

In conclusion the PDC bit effectively cuts sandstone, frozen muds free
of pebbles and ice. For hard rocks most likely a diamond-impregnated bit
will have to be used. In addition a drill may need the ability to deploy
a non-coring auger to deal with unconsolidated materials overlying
bedrock or ground ice. These bits may represent a minimal inventory of
bits to be taken to Mars.

##### 5.3 Contamination Assessment

Based on the results from 2003 the same technique used to assess
contamination of the permafrost/ground-ice cores during the drilling
process (See Juck et al. 2004. Appl. Environ. Microbiol. *in press*) was
also used for the M/ADD drill in September 2004. In this methodology,
fluorescent microsphere tracers are painted onto the inside of the drill
bit and core barrel prior to coring (Figure 26). This experiment began
halfway through the time in Eureka once Lyle Whyte (McGill University)
had arrived to join the team.

The procedure was first attempted on sandstone samples using the small
hand drill and core apparatus that was developed by Kris Zacny from UCB,
Figures 20, 22. and 27.

![](media/image64.png){width="2.717361111111111in"
height="1.8118055555555554in"}

Figure 26. Fluorescent microspheres being applied to the bit and core
barrel of the UCB drill

Core labeled with microspheres from 6 sandstone cores (\~ 7.5 inches
depth) were retrieved (Figure 26) and stored in sterile sample bags by
Lyle Whyte, Figure 28.

![](media/image65.png){width="2.717361111111111in"
height="1.8118055555555554in"}

Figure 27. Sandstone core awaiting extraction and curation

![](media/image66.png){width="2.717361111111111in"
height="1.8118055555555554in"}

Figure 28. Core samples in sterile bags

Microsphere transfer from the drill bit to the cores was confirmed
visually on site and later back at the Weather Station (Figure 29) with
a hand held UV trans-illuminator light source.

![](media/image67.png){width="2.717361111111111in"
height="1.6541666666666666in"}

Figure 29. Fluorescent beads transferred from drill bit to core samples
glow in UV light

The same procedure was applied successfully with the M/ADD drill with 2
samples consisting of \~6 inches of core from the 3^rd^ sandstone
drilling site.

We also attempted the procedure with the ice core drill at the ice berg
site (Figure 30). Only 1 core of size \~7 cm was successfully retrieved
from the first drilling attempt. Subsequent iceberg cores were generally
broken and

![](media/image68.png){width="2.717361111111111in"
height="1.3583333333333334in"}

Figure 30. Painting the ice coring drill with fluorescent beads

fractured, sometimes completely shattered. Especially the first part of
the core (i.e. the top portion that had stayed in the drill the
longest); the bottom portion of the iceberg core was generally in the
best shape but we could not visually see microsphere transfer to these
cores. We encountered the same problem with Kris Zacny's drill as well,
where iceberg cores were generally completely shattered. There are
extensive gas bubbles in the iceberg ice which may have weakened the
strength of the cores and resulted in the fracturing and shattering
during the drilling procedure.

All microsphere labeled sandstone and iceberg cores were stored and
archived by Lyle Whyte; these cores will be returned to Montreal where
microsphere penetration into the interior of the cores will be assessed
by fluorescent microscopy. In addition, Dr. Whyte's lab will attempt to
detect and characterize microbial populations within the sandstone and
iceberg core samples by using a combination of culture independent and
culture dependent microbiological method- ologies. Existence of
microbial life within the sandstone cores from depth would have
important astrobiological implications and especially for the further
development and utility of a prototype Mars drill.

##### 6. Mars Drilling Team eArchive

A web-based \"Mars Drill Technology eArchive\" (eArchive) has been
published at no cost to the project by the Texas Space Grant Consortium
(TSGC). In its current form, it serves as a restricted-access archive of
Mars drilling technology professional papers, and related reports and
correspondence, prepared by project scientists. Examples of the web
site's navigation pages are set forth in Figures below.

Plans call for the expansion of the eArchive into an outreach tool,
containing age-appropriate content to grades 6-14 education audiences
and the general public. Topics are to include drill design, development,
demonstration and use in pursuit of NASA\'s goal to \"Follow The Water\"
and other Mars Exploration Program subsurface exploration objectives.
Some of the articles will be written by project scientists and edited,
where needed, by TSGC\'s professional educator-writers to optimize
audience access and ensure alignment with pertinent education standards.
Other articles will be written by TSGC educator-writers with the project
scientists providing factual oversight.

POC: Burke O. Fort, Texas Space Grant Consortium (512/471-7225)

Archive at the University of Texas
![](media/image69.pct){width="5.936805555555556in"
height="5.672916666666667in"}

![](media/image70.pct){width="5.93125in" height="5.581944444444445in"}

![](media/image71.pct){width="5.930555555555555in"
height="3.1756944444444444in"}

![](media/image72.pct){width="5.929861111111111in"
height="5.267361111111111in"}

##### 7. Plans for FY 2005

###### JSC-BHI

With the Mk II drill proven to be functional under Arctic permafrost
conditions the focus of FY 2005 will be fourfold:

1.  demonstration of the new anchor mechanism in the lab and in the
    field

2.  design, fabrication and test of an automatic core break-off and
    capture device

3.  automation of the drill following demonstration of capability using
    the UCB laboratory drill

4.  accumulation of additional field experience toward multi-meter
    penetration in rocks of different hardness ranging from sandstone to
    basalt

###### 

###### In the last case field work will be carried out in locations that are relatively convenient to Houston as compared to Eureka. Funding permitting, however, a four person team will return to Eureka for final testing in permafrost conditions.

###### 

###### UC Berkeley and Ames

Additional work will be carried out at UCB to determine experimentally
the optimum flight angle of the auger, the number of auger flights and
the choke length. The extent of the experimental work will depend on the
amount of available funds.

The UCB team has developed two bits that will be tested in silt/sand/ice
mixtures and in various rocks to determine their effectiveness. The
first one is a self-healing hybrid bit (a combination of PDC cutters and
diamond impregnated segments) that could potentially penetrate any
formation and a second bit is a PDC bit.

The effectiveness of introducing gas puffs to assist cuttings removal
will be tested under martian conditions while drilling in dry, frozen
rocks i.e. with no subliming water ice blowing the cuttings out. The bit
and the rock core temperature will be closely monitored.

Working with ARC, the loop between the drill control and measured
operating parameters will be closed to permit the automation of the UCB
laboratory drill. When this is working effectively the capability will
be transferred to the M/ADD drill at JSC. See section 3 above.

If time and funds permit additional work will be carried out at UCB to
investigate cross-contamination issues under martian conditions.