AC3 Testbed orbit lifetime

0018-EX-ST-2008 Text Documents

Aerospace Corporation, THE

2008-04-18ELS_89599

Aerocube 3 Lifetime Analysis John McVey & Alan Jenkin April 14, 2008 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. 1

Background • The analysis provided in this report will determine if the Aerocube 3 mission orbit is compliant with U.S. Debris Mitigation Standard Practice of an on-orbit lifetime less than 25 years – If the orbit lifetime is greater than 25 years, then a drag device will need to be incorporated • At the request of Dave Hinkley (Mechanics Research Office), a long-term orbit evolution analysis was performed J.P. McVey, A.B. Jenkin; Astrodynamics Dept. 2

Long-Term Orbit Propagation Tool • Used two independent tools for verification of results: LIFETIME 6.0 and TRACE • LIFETIME 6.0: Low Altitude Orbit Decay and Maintenance (developed by George Chao) – MSISE-00 atmosphere model – J3-J4 Earth gravity model – Sun and moon gravity – Solar radiation pressure • Precision integration code TRACE (used to verify select LIFETIME runs) – Developed by Aerospace (TRACE is used throughout the industry, but we used the most recent Aerospace version) – MSISE-86 atmosphere model – 16 x 16 modified WGS-84 Earth gravity model – Sun and Moon gravity – Solar radiation pressure (assumed reflectivity coefficient = 1.3) J.P. McVey, A.B. Jenkin; Astrodynamics Dept. 3

Orbit Propagation Inputs • Area and mass estimation – Mass: 0.825 kg – CubeSat 10 cm on each side, assumed tumbling – Also considered a drag enhancement device: a 1-meter diameter balloon • Considered 95, 50, and 5 percentile levels of solar flux (F10.7) and geomagnetic index (Ap) – For LIFETIME, used NASA Marshall Space Flight Center monthly predictions released March 2008 (based on NOAA data) – For TRACE, used NASA Marshall Space Flight Center predictions every 3 months due to program restrictions for long-term propagation. • AeroCube 3 orbit was taken from TACSAT-3 launch trajectory supplied by Orbital Sciences Corporation – Taken from DEPLY_CTD event – Steve Hast provided conversion to classical orbital elements in ECI J.P. McVey, A.B. Jenkin; Astrodynamics Dept. 4

Aerocube 3 (no balloon) Orbit Lifetime 95th Percentile • With an 95th percentile atmosphere assumption (high solar activity), the orbit lifetime shown in TRACE and LIFETIME differ a bit due to the 3 month gap in atmospheric predictions in TRACE where LIFETIME is modeling the fluctuations every month. The result is a longer orbit lifetime prediction by TRACE . In this case, the LIFETIME prediction should be more accurate. • LIFETIME = 465 days of orbit life • TRACE = 516 days of orbit life 500 TRACE Perigee TRACE Apogee 450 Apogee/Perigee Altitude (km) LIFETIME Perigee LIFETIME Apogee 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 5

Aerocube 3 (no balloon) Orbit Lifetime 50th Percentile • For a 50th percentile atmosphere assumption. TRACE and LIFETIME agree quite well because the fluctuation in solar activity from month to month is not as large as the 95th percentile. • LIFETIME = 698 days of orbit life • TRACE = 712 days of orbit life 500 TRACE Perigee TRACE Apogee 450 Apogee/Perigee Altitude (km) LIFETIME Perigee LIFETIME Apogee 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 700 800 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 6

Aerocube 3 (no balloon) Orbit Lifetime 5th Percentile • For a 5th percentile atmosphere assumption. TRACE and LIFETIME agree quite well because of the low fluctuation in solar activity. • LIFETIME = 1051 days of orbit life • TRACE = 1028 days of orbit life TRACE Perigee 500 TRACE Apogee LIFETIME Perigee 450 LIFETIME Apogee Apogee/Perigee Altitude (km) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 700 800 900 1000 1100 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 7

Aerocube 3 w/Balloon Deployed Orbit Lifetime 95th Percentile • For a 95th percentile atmosphere assumption. TRACE and LIFETIME agree quite well because the time is short enough to more accurately model the solar activity. • With the balloon deployed, the orbit lifetime is dramatically decreased compared to the non-deployment. • LIFETIME = 21.1 days of orbit life • TRACE = 21.4 days of orbit life 800 TRACE Perigee TRACE Apogee Apogee/Perigee Altitude (km) 700 LIFETIME Perigee LIFETIME Apogee 600 500 400 300 200 100 0 0 5 10 15 20 25 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 8

Aerocube 3 w/Balloon Deployed Orbit Lifetime 50th Percentile • For a 50th percentile atmosphere assumption. The balloon will help decay the satellite in a little over a month. • LIFETIME = 32.1 days of orbit life • TRACE = 32.1 days of orbit life 600 TRACE Perigee TRACE Apogee Apogee/Perigee Altitude (km) LIFETIME Perigee 500 LIFETIME Apogee 400 300 200 100 0 0 5 10 15 20 25 30 35 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 9

Aerocube 3 w/Balloon Deployed Orbit Lifetime 5th Percentile • For a 50th percentile atmosphere assumption. The balloon still decays the satellite in a little over a month. • LIFETIME = 40.1 days of orbit life • TRACE = 40.4 days of orbit life 700 TRACE Perigee TRACE Apogee Apogee/Perigee Altitude (km) LIFETIME Perigee 600 LIFETIME Apogee 500 400 300 200 100 0 0 5 10 15 20 25 30 35 40 45 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. Time (days) 10

Conclusions • The Aerocube 3 satellite is predicted to remain on-orbit until the end of 2009 at the earliest to mid-year of 2011 at the latest. – This complies with U.S. Debris Mitigation Standard Practice of an on-orbit lifetime less than 25 years. – The Aerocube 3 mission will be approaching solar max in 2011 – A drag device will not be needed for this mission in terms of meeting U.S. Debris Mitigation Guidelines. • If a drag device such a balloon is deployed, this will dramatically decrease the orbit lifetime from hundreds of days to about one month in time. • LIFETIME and TRACE results agree fairly well Cases: LIFETIME TRACE Orbit Lifetime (days) 95 Percentile 465 516 Orbit Lifetime (days) 50 Percentile 698 712 Orbit Lifetime (days) 5 Percentile 1051 1028 Orbit Lifetime (days) 95 Percentile w/Balloon 21 21 Orbit Lifetime (days) 50 Percentile w/Balloon 32 32 Orbit Lifetime (days) 5 Percentile w/Balloon 40 40 J.P. McVey, A.B. Jenkin; Astrodynamics Dept. 11


Document Created: 2008-04-18 07:34:28
Document Modified: 2008-04-18 07:34:28
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