William R. Jones, Jr.

Sest, Inc., Middleburg Heights, Ohio

Mark J. Jansen

University of Toledo, Toledo, Ohio

Gun-Shing Chen, Jonathan Lam, Mark Balzer, John Lo, and Mark Anderson

Jet Propulsion Laboratory, Pasadena, California

Joseph P. Schepis

Goddard Space Flight Center, Greenbelt, Maryland

The Effect of 17–4 PH Stainless Steel on the

Lifetime of a Pennzane® Lubricated Microwave

Limb Sounder Antenna Actuator Assembly Ball

Screw for the AURA Spacecraft

NASA/TM—2005-213982

October 2005
The NASA STI Program Office . . . in Profile

Since its founding, NASA has been dedicated to

the advancement of aeronautics and space

science. The NASA Scientific and Technical

Information (STI) Program Office plays a key part

in helping NASA maintain this important role.

The NASA STI Program Office is operated by

Langley Research Center, the Lead Center for

NASA’s scientific and technical information. The

NASA STI Program Office provides access to the

NASA STI Database, the largest collection of

aeronautical and space science STI in the world.

The Program Office is also NASA’s institutional

mechanism for disseminating the results of its

research and development activities. These results

are published by NASA in the NASA STI Report

Series, which includes the following report types:

• TECHNICAL PUBLICATION. Reports of

completed research or a major significant

phase of research that present the results of

NASA programs and include extensive data

or theoretical analysis. Includes compilations

of significant scientific and technical data and

information deemed to be of continuing

reference value. NASA’s counterpart of peerreviewed formal professional papers but

has less stringent limitations on manuscript

length and extent of graphic presentations.

• TECHNICAL MEMORANDUM. Scientific

and technical findings that are preliminary or

of specialized interest, e.g., quick release

reports, working papers, and bibliographies

that contain minimal annotation. Does not

contain extensive analysis.

• CONTRACTOR REPORT. Scientific and

technical findings by NASA-sponsored

contractors and grantees.

• CONFERENCE PUBLICATION. Collected

papers from scientific and technical

conferences, symposia, seminars, or other

meetings sponsored or cosponsored by

NASA.

• SPECIAL PUBLICATION. Scientific,

technical, or historical information from

NASA programs, projects, and missions,

often concerned with subjects having

substantial public interest.

• TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientific

and technical material pertinent to NASA’s

mission.

Specialized services that complement the STI

Program Office’s diverse offerings include

creating custom thesauri, building customized

databases, organizing and publishing research

results . . . even providing videos.

For more information about the NASA STI

Program Office, see the following:

• Access the NASA STI Program Home Page

at http://www.sti.nasa.gov

• E-mail your question via the Internet to

help@sti.nasa.gov

• Fax your question to the NASA Access

Help Desk at 301–621–0134

• Telephone the NASA Access Help Desk at

301–621–0390

• Write to:

 NASA Access Help Desk

 NASA Center for AeroSpace Information

 7121 Standard Drive

 Hanover, MD 21076
William R. Jones, Jr.

Sest, Inc., Middleburg Heights, Ohio

Mark J. Jansen

University of Toledo, Toledo, Ohio

Gun-Shing Chen, Jonathan Lam, Mark Balzer, John Lo, and Mark Anderson

Jet Propulsion Laboratory, Pasadena, California

Joseph P. Schepis

Goddard Space Flight Center, Greenbelt, Maryland

The Effect of 17–4 PH Stainless Steel on the

Lifetime of a Pennzane® Lubricated Microwave

Limb Sounder Antenna Actuator Assembly Ball

Screw for the AURA Spacecraft

NASA/TM—2005-213982

October 2005

National Aeronautics and

Space Administration

Glenn Research Center

Prepared for the

11th European Space Mechanisms and Tribology Symposium

cosponsored by ESA, SSIG, SSO, and CNES

Lucerne, Switzerland, September 21–23, 2005
Available from

NASA Center for Aerospace Information

7121 Standard Drive

Hanover, MD 21076

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22100

Trade names or manufacturers’ names are used in this report for

identification only. This usage does not constitute an official

endorsement, either expressed or implied, by the National

Aeronautics and Space Administration.

Available electronically at http://gltrs.grc.nasa.gov
NASA/TM—2005-213982 1

The Effect of 17–4 PH Stainless Steel on the Lifetime of a Pennzane®

Lubricated Microwave Limb Sounder Antenna 

Actuator Assembly Ball Screw for the 

AURA Spacecraft 

William R. Jones, Jr. 

Sest, Inc. 

Middleburg Heights, Ohio 44130 

Mark J. Jansen 

University of Toledo 

Toledo, Ohio 43606 

Gun-Shing Chen, Jonathan Lam, Mark Balzer, John Lo, and Mark Anderson 

National Aeronautics and Space Administration 

Jet Propulsion Laboratory 

Pasadena, California 91109 

Joseph P. Schepis 

National Aeronautics and Space Administration 

Goddard Space Flight Center 

Greenbelt, Maryland 20771 

Abstract 

During ground based life testing of a Microwave Limb 

Sounder (MLS) Antenna Actuator Assembly (AAA) ballscrew assembly, lubricant darkening and loss were noted when 

approximately 10 percent of required lifetime was completed. 

The MLS-AAA ball screw and nut are made from 17–4 PH 

steel, the nut has 440C stainless steel balls, and the assembly 

is lubricated with a Pennzane® formulation containing a three 

weight percent lead naphthenate additive. Life tests were done 

in dry nitrogen at 50 °C. To investigate the MLS-AAA life test 

anomaly, Spiral Orbit Tribometer (SOT) accelerated tests 

were performed. SOT results indicated greatly reduced 

relative lifetimes of Pennzane® formulations in contact with 

17–4 PH steel compared to 440C stainless steel. Also, dry 

nitrogen tests yielded longer relative lifetimes than 

comparable ultrahigh vacuum tests. Generally, oxidized 

Pennzane® formulations yielded shorter lifetimes than nonoxidized lubricant. This study emphasizes surface chemistry 

effects on the lubricated lifetime of moving mechanical 

assemblies. 

1. Introduction 

The recently launched AURA spacecraft contains an 

instrument suite that includes the Microwave Limb Sounder 

(MLS), which monitors chemistry changes in the earth’s 

atmosphere. Part of the MLS instrument, the Antenna 

Actuator Assembly (AAA) mechanism, rotates the MLS 

antenna during precision scanning of the earth’s limb and is 

essentially a motor-driven Ball Screw Assembly (BSA). 

Within the BSA, 440C stainless steel balls separate a 17–4 PH 

stainless steel screw and nut. The BSA is lubricated with a 

multiply alkylated cyclopentane (Pennzane®) formulated with 

lead naphthenate but without an antioxidant. In fall 2003, the 

Jet Propulsion Laboratory started life testing a duplicate 

component at 50 °C in dry nitrogen. After approximately 

10 percent of required lifetime had been accumulated, 

lubricant darkening and visual lubricant loss on the exposed 

ball screw were observed (fig. 1). An investigation was 

initiated to determine the cause. Several areas of concern were 

examined including, but not limited to, lubricant migration, 

evaporation, and oxidation. 

2. Experimental 

2.1 Ball Screw Assembly Design 

The BSA consists of a 17–4 PH stainless steel ball screw and 

nut separated by 440C stainless steel balls. The radially 

preloaded ball screw has a 0.953 cm (0.375 in.) outside 

diameter and a 0.254 cm (0.100 in.) lead. The balls nominal 

diameter is 0.158 cm (0.0625 in.). The ball nut is supported by 

preloaded bearings that constrain it in the axial direction but 

allow rotation. When the ball nut is rotated by the motor, the 

ball screw (prevented from rotating by external linkages) 

translates freely through the nut. During rotation, the balls in 

the two ball circuits circulate between the ball screw and nut. 
NASA/TM—2005-213982 2

Figure 1.—AAA Ball Screw (at End of Stroke). 

For containment and resetting position purposes, hard stops 

are placed at both ends of the ball screw. 

Each end of the nut has a lubricant filled, Nomex felt wiper, 

which lubricates the ball screw as it extends and retracts 

(fig. 2). To reduce lubricant loss due to evaporation, a 

Pennzane® oil without an antioxidant was initially selected 

because of its ultra low vapor pressure. 

The specified minimum hardness for the balls (440C) is 

58 Rockwell C (Rc). A ball from each of the two ball circuits 

had a measured hardness’s of 55 and 64 Rc. The specified 

minimum hardness of the ball screw and nut (17–4 PH) is 

38 Rc. Measurements made on an identical unit confirmed that 

the ball screw and nut have average hardness’s of 40 Rc. The 

17–4 PH ball screw and nut hardness values are significantly 

lower than traditional ball screw materials. 

2.1.1 Ball screw life test 

The BSA was cycled as part of the AAA mechanism life 

test. The life test began in the fall of 2003 and was still ongoing at the time of this publication. The BSA continuously 

extends and retracts, actuating an antenna simulator in a 

scanning mode. The test unit is in a non-hermetically sealed, 

dry nitrogen purged environment (fig. 3). 

During the initial life test phase, the AAA mechanism was 

thermally controlled to 50 °C using an external heater. To 

shorten its duration, the life test was accelerated by 

approximately 2.7 times. Even at the accelerated speed of 

1.8 revs/sec peak, the BSA still operates in the boundary 

lubrication regime. Motor current and encoder tracking 

profiles were collected regularly to monitor performance 

degradation and visual inspections were done periodically to 

check for anomalies. 

Lubricant darkening was observed after 5 percent of the 

required life had been accumulated. After approximately 

10 percent of required life had been accumulated, lubricant 

loss became apparent. 

Shortly thereafter, the life test was suspended and an 

investigation initiated. Several areas of concern were 

investigated including, but not limited to, lubricant migration, 

evaporation, consumption, and oxidation. 

2.1.2 Ball screw life test investigation results

Lubricant samples were collected and subjected to 

Inductively Coupled Plasma/Optical Emission Spectroscopy 

Figure 2.—Ball Screw Assembly Design. 

Figure 3.—Life Test Schematic Diagram. 

(ICP-OES) for elemental analysis and Fourier Transform 

Infrared (FTIR) spectroscopy for functional group detection 

(such as the C = O bond formation, a.k.a. oxidation). Metallic 

wear and lubricant oxidation were identified. Both contributed 

to the lubricant darkening.

The metallic wear condition was mitigated after the life test 

configuration was carefully corrected to minimize the bending 

load on the ball screw, which does not occur in the flight 

configuration. The BSA’s lubricant was replaced with a 

Pennzane® oil containing an antioxidant additive. The same 

lubricant replacement process was performed on the flight 

AAA unit. Because the oil’s anti-oxidant would be lost in 

vacuum and the remaining base oil will return to ultra-low 

vapor pressure, concerns with the slightly higher vapor 

pressure of the anti-oxidant formulated oil were alleviated. 

Additionally, a change in the thermal design lowered the flight 

temperature to 35 °C and the life test temperature was changed 

accordingly. 

Each previously mentioned area contributed, in varying 

degrees, to lubricant loss in the life test mechanism. Lubricant 

loss due to tribological interactions between Pennzane® and 
NASA/TM—2005-213982 3

BSA alloys was a surprise to investigators. The following 

describes the accelerated tribological test method used to 

elucidate the lubricant and alloy interactions. 

2.2 Spiral Orbit Tribometer 

The Spiral Orbit Tribometer (SOT) facility (fig. 4) tests 

lubricants in the boundary lubrication regime. While the SOT 

is not a direct representation of the ball screw in question, it 

does provide independent tribological measurements to 

qualify lubricant/material combination’s relative performance. 

As discussed later in the paper, SOT results correlate well with 

bearing test relative lifetimes. 

The SOT facility is essentially a thrust bearing with flat 

races and a single, 12.7 mm (0.5 in.) ball. The tribometer 

simulates motions (rolling, sliding, and pivoting) seen in 

angular contact bearings. The bottom plate is stationary, the 

top plate rotates, and the ball is driven in a spiral orbit. The 

spiral’s pitch is directly related to the contact’s frictional 

force. A third plate, termed the guide plate, returns the ball to 

the original orbit diameter once per revolution. The return 

force required is measured and is directly related to the 

friction force, and therefore, the friction coefficient. Test 

acceleration is achieved by limiting the amount of lubricant on 

the ball, typically around 50 μg. A full description of the SOT 

facility can be found in references 1 to 5. 

Loads of 22, 62, and 200 N, yielding mean Hertzian 

stresses of 0.75, 1.0, and 1.5 GPa respectively, were used. 

Most testing was done at 1.0 GPa. For all the tests, the ball 

speed was 100 rpm and approximately 50 μg of lubricant was 

used. Testing was done either in dry nitrogen or in vacuum. 

For vacuum tests, the vacuum level was at least 10–7 Pa and 

pump down time varied from 6 to 10 hr. The nitrogen 

environment was obtained by flooding the vacuum chamber 

with nitrogen through the vacuum pump. In this case, the front 

window of the tribometer was left open slightly, allowing the 

test to run at atmospheric pressure. 

Prior to testing, all the parts were cleaned. First, they were 

rubbed with levigated alumina powder and rinsed with 

filtered, de-ionized water. They were then rinsed in 190 proof 

ethyl alcohol and blown dry with nitrogen. Next, the parts 

were ultrasonically cleaned in hexane for 10 min. They were 

again blown dry with nitrogen and then placed in a UV/Ozone 

treatment for 15 min. The balls were rotated after 7.5 min to 

treat the entire surface. 

To lubricate the ball, a 1 mg lubricant to 1 ml hexane 

solution was made. Then, the solution was deposited on the 

ball with a syringe and the solvent evaporated, leaving behind 

the desired lubricant quantity. Weight gain, termed lubricant 

uptake, was measured on a microbalance accurate to ±2 μg. 

Three weights were averaged to obtain the lubricant uptake. 

Lifetime is reported in orbits/μg. The test terminated when 

the friction coefficient exceeded 0.28. Normalized lifetime is 

calculated by dividing the total number of orbits to shutdown 

by the lubricant uptake. In most cases, more than one test at 

Figure 4.—The Spiral Orbit Tribometer. 

each condition was done and the normalized lifetimes 

averaged.

Several material combinations were tested. In all cases, the 

ball was 440C stainless steel. Plates and guide plates were 

either 440C or 17–4 PH stainless steel. The 440C stainless 

steel plates were hardened to ~58 Rc and the 17–4 PH plates to 

44 Rc (H900 process). Since shorter life was observed using 

17–4 PH compared to 440C, a set of 440C parts was annealed 

and re-heat treated to 44 Rc to test if hardness effects 

lubricated lifetime. 

Several Pennzane® formulations were tested and are listed 

in table 1. Formulations included different lots, an anti-oxidant 

additive, a lead naphthenate (PbNp) additive, a phosphate 

additive, and some oil was deliberately oxidized before 

testing. In all cases, 99.9 percent pure hexane was used to 

make the lubricant solution. 

TABLE 1.—PENNZANE OILS USED IN AAA 

BALL SCREW TESTING

Type Additive AntiOx. Oxidized Lot 

2001A 3% PbNp No No MN030228 

2001A 3% PbNp No 8d at JPL MN030228 

2001A 3% PbNp No 66h at JPL MN030228 

2001 3% PbNp Yes No SA030324 

2001A None No No 9500924 

2001 1% Phosphate Yes No 2001 GRC 

2001 3% PbNp Yes No MN970319 

2.2.1 SOT results

Four major comparisons were made: lifetime between 

17–4 PH and 440C stainless steel; lifetime between a vacuum 

and a nitrogen environment using 17–4 PH plates; lifetime of 

several different versions of Pennzane®; and lifetime of “as 

received” oil versus oxidized oil. Because the 17–4 PH parts 

were significantly softer than the 440C parts, there was some 

concern over plastic deformation occurring during testing and 

affecting lifetime. Therefore, a set of 440C parts was softened 

to the same hardness as the 17–4 PH parts and tested. 

Additional tests were done with 440C plates that were coated 

with nickel and chromium. Table 2 and table 3 summarize the 

SOT test results. 
NASA/TM—2005-213982 4

TABLE 2.—LUBRICANT PERFORMANCE 

USING 17–4 PH PLATES 

Lubricant Env. Stress 

(GPa) 

# of 

Tests 

Average 

Life 

St. 

Dev 

MN030228 Vac 1.5 4 467 79 

MN030228 Vac 1.0 1 1600 N/A 

MN030228 

(8d Oxidation) Vac 1.0 2 593 255 

MN030228 

(66h Oxidation) Vac 1.0 4 1074 519 

MN030228 

(66h Oxidation) Nit 1.0 4 3628 2362 

SA030324 Vac .75 4 2369 1511 

SA030324 Vac 1.0 6 1219 581 

SA030324 Nit 1.0 4 3328 3252 

9500924 Vac 1.0 2 2346 806 

MN970319 Vac 1.0 1 1220 N/A 

TABLE 3.—LUBRICANT PERFORMANCE USING OTHER 

MATERIALS AT 1.5 GPA UNDER VACUUM 

Lubricant Plate 

Material 

# of 

Tests 

Average 

Life 

St. 

Dev 

2001 GRC 440C 8 2407 660 

MN970319 440C 3 4144 3280 

MN030228 440C 1 <10,000 N/A 

9500924 Soft 440C 2 2700 40 

9500924 440C/Ni Coat 4 1821 804 

9500924 440C/Cr Coat 4 4474 2886 

Figures 5 and 6 show the lifetimes of two oil lots in dry 

nitrogen and under vacuum at 1.0 GPa. To minimize surface 

chemistry effects, one test under each condition was 

performed on the same sample set. With both oil lots 

(MN030228 – without anti-oxidant and SA030324 – with antioxidant), the lifetime in nitrogen was greater than in vacuum. 

Figure 7 shows life results on 17–4 PH steel at 1.0 GPa for 

different oil lots. Statistically, there is no significant difference 

between the oils’ lubricated lifetimes. It should be noted that 

some oils had no additives, some had an anti-oxidant, some 

had lead naphthenate additive, and some had both. 

0

1000

2000

3000

4000

5000

6000

7000

1234

Test Plate Set

Life (Orbits/μg)

Vacuum

Nitrogen

Figure 5.—Lifetime of MN030228, 66 hour oxidized 

oil on 17–4 PH plates in nitrogen and vacuum. 

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1234

Test Plate Set

Life (Orbits/μg)

Vacuum

Nitrogen

Figure 6.—Lifetime of SA030324 on 17–4 PH plates 

in nitrogen and vacuum. 

0

500

1000

1500

2000

2500

3000

3500

MN030228 SA030324 9500924 MN970319

Lubricant

Life (Orbits/μg)

Figure 7.—Lifetime comparison using 17–4 PH parts at 

1.0 GPa. 

0

1000

2000

3000

4000

5000

6000

7000

MN030228 -

Vac

MN030228 -

8d Ox - Vac

MN030228 -

66h Ox - Vac

MN030228 -

66h Ox - Nit

Lubricant

Life (Orbits/μg)

Figure 8.—Comparison of lifetimes using 17–4 PH 

parts at 1.0 GPa.

Figure 8 shows the relative lifetimes of MN030228 oil, 

which does not contain an anti-oxidant and had been 

intentionally oxidized. Under vacuum, life was less for the 

oxidized oil versus the non-oxidized oil, especially the oil 

oxidized for eight days. Under nitrogen conditions, the life 

was approximately the same as the SA030324 oil, which does 

contain an anti-oxidant. 
NASA/TM—2005-213982 5

The lifetime of Pennzane® 2001 was significantly shorter 

using 17–4 PH plates compared to 440C plates under the same 

conditions. This can be seen by comparing the 1.5 GPa run 

from table 2 to the first three runs from table 3. This was 

observed independently of oil additives or test stress levels. 

Lifetime was not reduced on the softer (44 Rc) 440C disks 

compared to the hardened (58 Rc) 440C disks. 

3. Discussion 

3.1 Material Chemistry Effects 

In the boundary lubrication regime, lubricant is 

continuously consumed within the Hertzian contact zone. 

Lubricant degrades into a non-lubricating friction polymer or 

into gaseous fragments. As long as fresh lubricant is entrained 

into the contact zone, consumption occurs. This is the 

mechanism that mediates the lubrication process. When all 

available lubricant is consumed, friction and drag torque 

increase and the device eventually fail to meet mission 

requirements. Obviously, this consumption rate is affected by 

the number of contacts in a device and operating speed. Also, 

the Hertzian stress level affects the consumption rate; life 

generally decreases exponentially with increasing Hertzian 

stress (ref. 6). 

In addition to contact, speed, surface finish, and stress, the 

consumption rate is highly dependant on the lubricant and 

bearing surface chemistries. Figure 9 shows vacuum SOT 

testing for four different lubricants on 440C stainless steel. 

The results indicate a hydrocarbon based lubricant, such as 

Pennzane®, far out performs perfluoropolyether (PFPE) based 

lubricants. Additionally, the SOT relative lifetimes correlate 

well with actual bearing life tests (ref. 7), which are shown in 

the same figure. 

Another example of surface chemistry’s role in lubricant 

degradation rates involved life concerns with a ball-screw 

mechanism in the Chandra X-ray Observatory. The screw was 

made from 4150 steel, which contains 1 percent chromium; 

however, to prevent rusting before launch, the screw was 

chromium plated. The mechanism was lubricated with 

FomblinTM Z–25. SOT testing was done with FomblinTM Z–25 

and 4150 steel (1% Cr), chromium plated 4150 steel 

(100% Cr), and 440C stainless steel (17% Cr) (ref. 8). In all 

cases, a 440C stainless steel ball was used. Results, shown in 

figure 10, indicate lubricant lifetime decreases with increasing 

chromium content. 

3.1.1 The 17–4 PH versus 440C Stainless Steel

The two stainless steels used in the MLS-AAA study, 

17–4 PH and 440C, have some important chemical 

differences. 17–4 PH stainless steel is a precipitationhardening martensitic stainless steel that combines strength 

and hardness with excellent corrosion resistance. Besides iron, 

the major components are chromium (15.5%), nickel (4.5%), 

0

100

200

300

400

500

bbk kp p s s

Life (Cycles (millions) or 

Orbits/microgram)

Bearing Test

SOT

815Z 143AB 2001 Sila

Figure 9.—Lubricant lifetimes of several space 

lubricants using a SOT and bearing tester (ref. 7). 

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

4150 (1% Cr) 440C (17%

Cr)

Chromium

Life (Orbits/μg)

Figure 10.—Lifetimes of FomblinTM Z–25 in contact 

with various materials (ref. 8). 

and copper (3.25%). 440C stainless steel is high carbon and 

carbon chromium steel designed to provide corrosion 

resistance with maximum hardness and is primary steel used 

for space bearing applications. Iron, chromium (18%), and 

carbon (1.2%) are 440C’s major components. Typical analyses 

for 17–4 PH and 440C steels appear in table 4. 

TABLE 4.—TYPICAL ELEMENTAL COMPOSITION 

OF 17–4 PH AND 440C STEELS

Element 17–4 PH (%) 440C (%) 

Carbon (Maximum) 0.070 0.95–1.20 

Phosphorus (Maximum) 0.0400 0.0400 

Silicon (Maximum) 1.0 1.0 

Nickel 3.00–5.00 – 

Columbium + Tantalum 0.15–0.45 – 

Although it is not clear what chemical mechanism is 

operative in causing the increased consumption of Pennzane®

in contact with 17–4 PH surfaces compared to 440C surfaces, 
NASA/TM—2005-213982 6

both Ni and copper-chromium oxide are versatile catalysts for 

mediating reactions with hydrocarbons (ref. 9). 

3.2 Test Environment 

The test environment can play a large role in a mechanism’s 

lubricated life. For example, bearing tests with a hydrocarbon 

have shown a 5 times life increase in nitrogen gas compared to 

vacuum tests (ref. 10) and similar tests with a lead naphthenate 

hydrocarbon formulation yielded a 10 times life increase in 

nitrogen versus vacuum (ref. 12). Other researchers have 

reported differences with hydrocarbon based lubricants in 

vacuum and nitrogen (ref. 13). Spiral Orbit Tribometer tests 

have shown large differences in relative lifetimes of a 

perfluoropolyether (KrytoxTM 143 AC), where low water vapor 

concentrations extended lives by an order of magnitude 

(ref. 13). 

In the SOT tests performed, both the 66 hour oxidized oil 

lot and the SA030324 lot, which contains an anti-oxidant, had 

a 3 times longer life in nitrogen compared to vacuum. All 

these results indicate that life testing done under nitrogen is 

not an accurate representation of the life that can be expected 

from the same mechanism operating in orbit. 

4. Conclusions 

1. The unique surface chemistry associated with the 17–4PH 

stainless steel alloy results in an accelerated rate of 

lubricant consumption for Pennzane® formulations in 

boundary/parched lubricated contacts. 

2. Life tests run at atmospheric pressure in dry nitrogen do 

not simulate the on orbit environment and may result in 

an over estimation of orbital lifetime of moving 

mechanical assemblies. 

3. Partially oxidized hydrocarbon lubricants may lead to 

lower orbital lifetimes. 

5. Lessons Learned 

Space mechanism designers utilizing lubricated mechanical 

moving assemblies made of alloys other than conventional 

bearing steels, such as 440C or 52100; need to verify that 

mission lifetimes will not be compromised by adverse 

lubricant/alloy interactions. Additionally, life test 

configurations that do not reflect the orbital/operational 

environment should be thoroughly evaluated for applicability 

and test accuracy. 

References 

1. Kingsbury, E., “Tribology of Slow Rolling Bearings,” 

Mater. Res. Soc. Sym. Proc., 140, 437–442, 1989. 

2. Jones, W.R., Jr. et al., “A New Apparatus to Evaluate 

Lubricants for Space Applications-The Spiral Orbit 

Tribometer (SOT),” SAE Int. Spring Fuels & Lub. Meet. 

& Expos., paper 2000–01–1828, June 2000. 

3. Pepper, S.V., Kingsbury, E., and Ebihara, B.T., “A 

Rolling Element Tribometer for the Study of Liquid 

Lubricants in Vacuum,” NASA TP 3629, October, 1996. 

4. Pepper, S.V. and Kingsbury, E.P., “Spiral Orbit 

Tribometry-Part 1: Description of the Tribometer,” Trib. 

Trans., 46, 1, pp 57–64, 2003. 

5. Pepper, S.V. and Kingsbury, E.P., “Spiral Orbit 

Tribometry-Part II: Evaluation of Three Liquid Lubricants 

in Vacuum,” Trib. Trans., 46, 1, 65–69, 2003. 

6. Jansen, M.J. et al., “The Effect of TiC Coated Balls and 

Stress on the Lubricant Lifetime of a Synthetic 

Hydrocarbon (Pennzane® 2001A) Using a Vacuum Spiral 

Orbit Tribometer,” Proc. Intern. Tribo. Conf., 1433, 

Nagasaki, Japan, Oct., 2000. 

7. Bazinet, D.G. et al., “Life of Scanner Bearings with Four 

Space Liquid Lubricants,” Proc. 37th Aerospace Mech. 

Symp., NASA/CP—2004-212073, 333–341, May, 2004. 

8. Pepper, S.V. and Kingsbury, E.P., “Destruction of 

FomblinTM Z–25 by Different Bearing Metals,” Proc. 4th 

Int. Rolling Element Bearing Symp., 1997. 

9. Fuson, R.C., “Reactions of Organic Compounds,” John 

Wiley & Sons, Inc., New York, 641, 1973. 

10. Carré, D.J. and Bertrand, P.A., “Effect of Test 

Atmosphere on Moving Mechanical Assembly Test 

Performance,” Proc. 37th Aerospace Mech. Symp., 

NASA/CP—2004–212073, 357–361, May, 2004. 

11. Carré, D.J., Bertrand, P.A. and Lince, J.R., “Lead 

Naphthenate Tribochemistry Under Vacuum and Gaseous 

Nitrogen Test Conditions,” Trib. Lett., 16, 3, 207–214, 

2004. 

12. John, P.J., Cutler, J.N., Sanders, J.H., “Tribological 

Behavior of a Multialkylated Cyclopentane Oil Under 

Ultrahigh Vacuum Conditions,” Trib. Lett., 9, 3–4, 167–

173, 2001. 

13. Pepper, S.V., “Effect of Test Environment on Lifetime of 

a Vacuum Lubricant,” Proc. World Trib. Conf., 

Washington, D.C., USA, September, 2005. 
This publication is available from the NASA Center for AeroSpace Information, 301–621–0390.

REPORT DOCUMENTATION PAGE

2. REPORT DATE

19. SECURITY CLASSIFICATION

 OF ABSTRACT

18. SECURITY CLASSIFICATION

 OF THIS PAGE

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this

collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. Z39-18

298-102

Form Approved

OMB No. 0704-0188

12b. DISTRIBUTION CODE

8. PERFORMING ORGANIZATION

 REPORT NUMBER

5. FUNDING NUMBERS

3. REPORT TYPE AND DATES COVERED

4. TITLE AND SUBTITLE

6. AUTHOR(S)

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION/AVAILABILITY STATEMENT

13. ABSTRACT (Maximum 200 words)

14. SUBJECT TERMS

17. SECURITY CLASSIFICATION

 OF REPORT

16. PRICE CODE

15. NUMBER OF PAGES

20. LIMITATION OF ABSTRACT

Unclassified Unclassified

Technical Memorandum

Unclassified

National Aeronautics and Space Administration

John H. Glenn Research Center at Lewis Field

Cleveland, Ohio 44135–3191

1. AGENCY USE ONLY (Leave blank)

10. SPONSORING/MONITORING

 AGENCY REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546–0001

Available electronically at http://gltrs.grc.nasa.gov

October 2005

NASA TM—2005-213982

E–15304

WBS–22–228–11–10

12

The Effect of 17–4 PH Stainless Steel on the Lifetime of a Pennzane®

Lubricated Microwave Limb Sounder Antenna Actuator Assembly Ball

Screw for the AURA Spacecraft

William R. Jones, Jr., Mark J. Jansen, Gun-Shing Chen, Jonathan Lam,

Mark Balzer, John Lo, Mark Anderson, and Joseph P. Schepis

Lubrication; Space tribology; Liquid lubricant; AURA

Unclassified -Unlimited

Subject Categories: 23 and 37

During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw

assembly, lubricant darkening and loss were noted when approximately 10 percent of required lifetime was completed.

The MLS-AAA ball screw and nut are made from 17–4 PH steel, the nut has 440C stainless steel balls, and the assembly

is lubricated with a Pennzane® formulation containing a three weight percent lead naphthenate additive. Life tests were

done in dry nitrogen at 50 °C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated

tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane® formulations in contact with

17–4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable

ultrahigh vacuum tests. Generally, oxidized Pennzane® formulations yielded shorter lifetimes than non-oxidized

lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

Prepared for the 11th European Space Mechanisms and Tribology Symposium cosponsored by ESA, SSIG, SSO, and

CNES, Lucerne, Switzerland, September 21–23, 2005. William R. Jones, Jr., e-mail: William.R.Jones@grc.nasa.gov,

Sest, Inc., 18000 Jefferson Park Road, Suite 104, Middleburg Heights, Ohio 44130; Mark J. Jansen, e-mail:

Mark.Jansen@grc.nasa.gov, University of Toledo, MIME Department, 2801 W. Bancroft Street, Toledo, Ohio 43606;

Gun-Shing, e-mail: Gun-Shing.Chen@jpl.nasa.gov, Jonathan Lam, e-mail: Jonathan.C.Lam@jpl.nasa.gov, Mark Balzer,

e-mail: Mark.Balzer@jpl.nasa.gov, John Lo, e-mail: C.J. Lo@jpl.nasa.gov, and Mark Anderson, e-mail:

Mark.S.Anderson@jpl.nasa.gov, NASA Jet Propulsion Laboratory; and Joseph P. Schepis, e-mail:

Joseph.P.Schepis@nasa.gov, NASA Goddard Space Flight Center. Responsible person, Mark Jansen, organization

code RST, 216–433–6054.