N. E. Petro, E. Mazarico, 

X. Sun, J. Abshire, 

G. Neumann, P. Lucey

Mission Study Team: GSFC 

and WFF Mission Design Labs

March 18, 2018
• Science Objectives : Focus on 

Volatiles

• Spacecraft Concept : Follow LRO/GRAIL • Mission Architecture : KISS • Concept of Operations : Map the Moon for 1 year (12 

lunations)

• New Technologies : Active 3μm lidar spectrometer, 

support a return to the Moon 

as a communications relay

MiLuV NASA/GSFC/SVS
Science Objectives

• Mapping lunar volatiles at the 3.0 and 1.5 μμm spectral absorption bands from pole to 

pole in nadir direction in day and night and in permanent darkness

–Detecting water ice on surface above 100 parts per million concentration 

–Measuring distribution of surface volatiles in areas of permanent shadow

–Mapping the global distribution of H2O/OH from pole to pole

–Monitoring diurnal cycle of surface H2O/OH frost

3 MiLuV
Mobile Volatiles?

4 MiLuV

The thermal correction (solid spectra

above), highlights the 3.0μm feature in

areas thought to be “dry” (top spectra).

The spectra of Gruithuisen Delta dome

and nearby mare surfaces (bottom

spectra) show similar 3 μm absorptions

despite differences in composition and

albedo.

Bandfield, J. L., M. J. Poston, R. L. 

Klima, and C. S. Edwards (2018), 

Widespread distribution of OH/H2O 

on the lunar surface inferred from 

spectral data, Nature Geoscience, 

11(3), 173-177.
normal

albedo

(LOLA) imaging

(Clementine)

Science Approach and Benefits

• Optimized for high spatial resolution measurements of surface spectral

reflectance/absorption

• Two bands to maximize water detection and discriminate multiple phases of

water.

– 3 μm, sampling a sensitive water band

– 1.5 μm, sampling the 1.52 μm ice band

– Reference band at 1.064 μm already measured by LRO/LOLA

– Addresses the NASA 2014 Science Plan goal to “Advance the understanding

of how the chemical and physical processes in our solar system operate,

interact and evolve”

• Benefits of active spectral reflectance measurements

– Immune to solar background and lunar thermal emission

– Uniform illumination and observation conditions (normal albedo) around the globe, 

no need for photometric

calibration.

– Definitive measurements of water abundance variations during lunar day and night

– Sensitive to 100 ppm water ice concentration 5
Measurements from previous and planned missions

6

▸ The Lunar Orbital Laser Altimeter (LOLA) 

on the Lunar Reconnaissance Orbiter 

(LRO) has shown the value of active laser 

measurements at the Moon

▸ PSRs are brighter than areas that 

receive sunlight

▸ Bright areas occur only at temperatures 

supporting surface water ice

▸ Passive spectrometer measurements near 

3 μμm show possible water ice on surface 

in polar regions and possible movement 

ice frost on lunar surface

▸ The Lunar Flashlight mission will measure 

surface reflectance to laser light from 1 to 

2 μμm 

North Polar Crater Lovelace

Permanent Shadow:

Brighter Than Surroundings

Temperature LOLA Reflectance

PSR Brighter than 

surroundings LOLA on LRO

MiLuV
Lunar Ice LIDaR Spectrometer (LILIS) concept

7

Optical Transceiver Assembly (OTA)

Ranging Electronics 

Box (REM) 

Integrated detector cooler 

assembly (IDCA)

MiLuV
Maximum Spacecraft 

Envelopes

MUSTANG 

Power System

ESPA Grande

8

ESPA

MiLuV
MiLUV ESPA Spacecraft

Fixed .5m 

antenna

MiLuV ESPA

9

Gimbaled

Solar Arrays

Instrume

nt

Star 

Trackers

MiLuV
MiLuV Flight Dynamics

• Translunar Transfer Designs

– PACE (LEO orbit deployment, 2022 launch)

– IMAP (Sun-Earth L1 Transfer deployment, 

2024 launch)

– GTO (GTO deployment into long duration 

transfers, 2020 launch that applies to any 

launch opportunity)

MiLuV
MiLuV Transfer to Moon – GTO Deployment

Lunar Orbit

Transfer 

Trajectory 

Lunar 

Insertion

Earth

Sun – Earth line

Lunar 

Insertion

Maneuvers: GTO Periapssis Raise, 196 m/s

Injection from GTO, 833 m/s

Lunar Insertion, 1079 m/s,

Total DV = 2108 m/s

Transfer duration: ~ 169 days

Maneuvers: GTO Periapssis Raise, 196 m/s

Injection from GTO, 831 m/s

Lunar Insertion, 891m/s, 

Total DV = 1918 m/s

Transfer duration: ~ 86 days

MiLuV
MiLuV Concept

• One year in a polar, ~100 km circular 

orbit

• ~100% duty cycle

• Ride-share and

GTO orbit options 

were evaluated

• Orbit allows for

dense coverage of

the poles

• LILIS has a 100m surface spatial 

resolution from 100km

• Can we act as a com relay (yes!) 

Two maneuvers of ~ 4.6 m/s each to 

recircularize orbit

~ 13 maneuver per year

Total 1-year DV of 117 m/s

Not optimized

MiLuV
Orbit Evolution for 1-year – SK’s are needed

• Initial state at 100 km circular

• No maneuvers

• Lunar gravity set to 100x100 deg and order

• Apoapsis and Periapsis Altitude (km) • Eccentricity vs. Arg of Periapsis Evolution)

MiLuV
MiLuV Science Operations

14

Earth

Moon

Sun

Science Orbit: 

• Polar orbit, 91 – 91.5 degrees inclination, inertially fixed.

• Orbit altitude of 100km +-10 km, no more than 150km while taking data Instrument continually points within 1 degree of

Nadir

• Data is recorded on-board the spacecraft

• Attitude knowledge (reconstruction) is 1mrad, we will use the LILIS altimeter data as a tracking type to both improve orbit

determination and pointing knowledge (Mazarico et al., 2017, PSS; Goossens Thursday Poster)

Orbit Maintenance: ~Once per month a command is sent to perform orbital maintenance. Commands are uplinked to 

perform an orbit circularization maneuver which consists of two burns of approximately 4.6 m/s each.

The science instrument is turned off while the burns are performed, then science mode is resumed 

MiLuV
MiLUV Science Operations

15

Earth

Line of sight to DSN

~30 minutes com per week

Over poles

Communication Orbit: Occurs once every 84 orbits (7 

days)

• Science Instrument powers off

• Spacecraft points antenna toward DSN prior to 

orbiting the lunar north pole

• Spacecraft downlinks all housekeeping and science 

data stored from the previous 7 days. This takes 

approximately 30 minutes (1/4 orbit)

• When data is confirmed received, spacecraft points 

Nadir, turns instrument on and begins science mode 

again.

• Use navigation tracking passes, ~every other day. 

These can accommodated at any time with a +Y or -Y

patch antenna (LGA, 120o full-angle), by a yaw flip 

(180o) maneuvers (also decreases momentum 

buildup) or by doing 90o yaw maneuvers near the 

poles to give us 90N/30N (or 90S/30S) visibility of 

Earth stations.

MiLuV
MiLuV End of Mission

MiLUV: 1/16 - 1/23/18

NASA Internal Use – Do not distribute without 

permission from Noah Petro, 

<noah e petro@nasa gov>

16

2 Possible End of Mission Scenarios:

1. Enter an LRO “Frozen Orbit”

2. Deliberately De-Orbit the 

Spacecraft such that it will not strike an 

Apollo site

Both maneuvers need to be analyzed, but 

they should require approximately the 

same amount of fuel

MiLuV
Mass Summary

Note: 

Typically, a “Tailored” mass margin is assigned to each component of a CubeSat Spacecraft based on the 

TRL level and the uncertainty of the physical properties. The sum of the total of the component masses 

and margins are held up against the total allowed mass for the Spacecraft. Using this technique, a total 

margin of 0.0 is acceptable. While some mass, has been added to the components, a rigorous margin 

calculation has not been completed for this study.

Spacecraft Dry Mass Total 68.028 MPL MiLUV Design

Mass of Helium Pressurant 6.4 (Helium is proportional to Fuel Mass)

Total Dry Mass 74.428

Mass of Green Propellant 39.7

Propellant Mass Fraction 0.542

(Fuel/Dry M)

Delta V from available fuel 1000 

m/s

Delta V req. for Lunar Orbit 800 m/s Upper bound for candidate rideshares polar LEO, L1, Lunar 

Insertion flyby

Delta V for Station Keeping + 130.8 8.4 m/s/month x 12 months + 30 m/s EOM

EOM m/s

Total Delta V req

Mass Fraction for Req. Delta V

930.8

m/s

0.48

Margins are included in the performance requirements

Minimum Mass of Fuel Req.

Mass Margin for Fuel

35.15

11.4%

Mass Limit of ESPA 320

Total Launch Mass 114.128 Dry Mass + Fuel Mass

Mass Margin for ESPA 64.3%

17

All

masses

listed are

in units of

kg

MiLuV
MiLuV Cost Estimate • MiLUV initial cost estimation was completed using two separate techniques: parts cost times rule of

thumb and a bottoms up labor estimate

– Parts cost rule of thumb reduced to 2.5x due to higher TRLs of Proton 400K and MUSTANG

• Neither cost estimate includes science data analysis or reporting

• DSN costs could be reduced depending on

desired mission ConOps; current costs

reflect more of a worst case daily contact

usage

• MUSTANG avionics cost could be reduced

by an additional $200K depending on

options desired and test approach

• Custom MUSTANG board cost could

potentially be reduced from $1M depending

Bottoms Up Labor and Parts Cost Esti

FTE

FTE for S/C Bus @$200K 64.5

mate

$M

12.90

on complexity

$M

12.90

Parts Cost 12.23 12.23

DSN Ops 4.31 4.31

Instrument 40.00 40.00

Total for Spacecraft 69.43

With 30% Margin 90.26

 and test methodology

Parts Cost Rule of Thumb x2.5

$M $M

Parts ROT 12.23 2.5 30.58

DSN Ops 4.31 1 4.31

Instrument 40.00 1 40.00

Total for Spacecraft 74.88

With 30% Margin 97.35

18 MiLuV
MiLuV Findings/Outcomes

• To produce a near-Class D mission, parts selection, processes, and 

procedures will have to be maintained at a higher level than a normal 

CubeSat. This will require an especially vigilant QA system, who 

understands the training and education required.

• Our philosophy was not to go for the cheapest with CubeSat technology 

but instead use as robust parts as doable for this form factor (e.g., 

MUSTANG)

• Spacecraft design is “Single String”, meaning the failure of any one 

subsystem could likely cause a mission failure

• Subsystem power requirements are large for the S/C surface area, the 

mass of propellant is relatively large compared to the mass of the 

spacecraft, the bus will be exposed to “soak back” heat from the 

thrusters for long periods of time, and the telescope is sensitive to 

thermal gradients. This will require additional thermal analysis and 

testing. 19 MiLuV
MiLuV Findings/Outcomes Continued

• An increase of approximately 5 kg in the quantity of fuel required for the mission will 

exceed the volume of the ESPA standard and require an ESPA Grande rideshare. 

• The Propellant tank will likely need to be custom designed for this mission. A slosh 

analysis will need to be performed, along with design and verification of a propellant 

management system to ensure that the fluid dynamics of the fuel do not interfere 

with the ACS maneuvers 

• Green Prop systems have been flown on rideshares, however, they are still 

relatively new and must be designed to the satisfaction of the prime mission. Green 

propellant systems are still in their developmental stage. The green propellant 

nozzles have not been used with the propulsion system.

• If an SLS lunar flyby is selected as the rideshare, the high lunar encounter velocities 

will require the propulsion system to be precise. 

• SmallSat Integration teams may require training in contamination control.

• DSN may not be available for every desired Com Orbit, the con Ops will need to be 

flexible to get data back in a timely manner

20 MiLuV