1. Preliminary Human Asteroid Mission Design
Ian Roundhill
NASA JSC EG5
(281)
May 17, 1999
Ian Roundhill / NASA-JSC / (281)

2. Goals
Asteroids may be worthy targets as a testbed for Mars mission and/or exploration.
Produce a list of asteroids that can be reached with DVs and trip times similar to a manned Mars mission.
This study will exclude scientific considerations.
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

3. Primary Tool
Asteroid list of 650 objects from the Near Earth Objects webpage
Clearinghouse for asteroid ephemeris data chartered by International Astronomical Union (IAU)
Near Earth Asteroid Tracking (NEAT) at JPL confirmed the quality of this database.
Erthroid-Asteroid tool by Sam Wilson
Based on Earth - Mars used commonly in EG5
Similar results to Larry Kos’ (MSFC)
Modification to create ADA function call allows for large data manipulation
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

4. Assumptions Lambert targeted, patched conic trajectories
400, 500, and 600 day trip time constraints
Earth departure from km x 800 km orbit
4 propulsive maneuvers with Earth entry
Earth Departure, Asteroid Arrival, Asteroid Departure, Earth Arrival (optional)
Earth arrival DV to reduce entry speed to 13 km/s
Date Scope
Julian
Gregorian Dec 26, 2003-May 13, 2031
No Venus swingbys
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

5. Data Process Remove objects with poor orbit shapes
Produce porkchop plot
Define areas of interest
For a range of trip times
For a range of stay times
Compute round trip DV
Compute Initial Mass in High Earth Orbit
Sort based on minimum DV
Sort based on minimum mass
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

6. 1991 JW Porkchop Julian Date 2455000 June 2009 Asteroid Date
Earth Date
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

7. Sizing Methodology Single vehicle No in-situ resources
Static module masses based on Mars mission
Rocket equation engine sizing with historical mass fractions
ISP of 469 s
Cyrogenic fuels
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

8. Top Ten List
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

9. 3 Asteroids in Particular
1989 ML
Amor type
a=1.272
e=0.136
i=4.4°
1998 HG49
Amor type
a=1.2
e=0.113
i=4.2°
1991 JW
Apollo type
a=1.038
e=0.118
i=8.7°
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

10. Ian Roundhill / NASA-JSC-EG5 / (281) 483-676110

11. Ian Roundhill / NASA-JSC-EG5 / (281) 483-676111

12. Ian Roundhill / NASA-JSC-EG5 / (281) 483-676112

13. Ian Roundhill / NASA-JSC-EG5 / (281) 483-6761
107,000 kg
Transhab with TMI, Aerobrake, and TEI
Ian Roundhill / NASA-JSC-EG5 / (281) 13

14. Ian Roundhill / NASA-JSC-EG5 / (281) 483-6761
107,000 kg
Transhab with TMI, Aerobrake, and TEI
Ian Roundhill / NASA-JSC-EG5 / (281) 14

15. Ian Roundhill / NASA-JSC-EG5 / (281) 483-6761
107,000 kg
Transhab with TMI, Aerobrake, and TEI
Ian Roundhill / NASA-JSC-EG5 / (281) 15

16. Candidate 1989 ML Mission Trip Time: 550 days Stay Time: 30 days
Earth Departure
Asteroid Arrival
Asteroid Departure
Earth Arrival
DV (km/s)
July 2008
May 2009
June 2009
Jan 2010
1.38
2.63
3.44
0.05
7.50
Mass Comparisons
Post TEI
Post MOI
Post TMI
In HEO
1989 ML (mt)
Mars DRM (mt) 30 80
159
225 36 61 74
107
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

17. 1989 ML Mission Trajectory Earth Departure Asteroid Arrival
Asteroid Departure
Earth Arrival
July 2008
May 2009
June 2009
Jan 2010
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

18. Candidate 1989 HG49 Mission Trip Time: 550 days Stay Time: 30 days
Earth Departure
Asteroid Arrival
Asteroid Departure
Earth Arrival
DV (km/s)
May 2010
Nov 2010
Dec 2010
Nov 2011
1.18
1.98
2.41
0.05
5.62
Mass Comparisons
Post TEI
Post MOI
Post TMI
In HEO
1989 HG49 (mt)
Mars DRM (mt) 30 60
102
138 36 61 74
107
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

19. 1998 HG49 Mission Trajectory Earth Departure Asteroid Arrival
Asteroid Departure
Earth Arrival
May 2010
Nov 2010
Dec 2010
Nov 2011
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

20. Candidate 1991 JW Mission Trip Time: 550 days Stay Time: 30 days
Earth Departure
Asteroid Arrival
Asteroid Departure
Earth Arrival
DV (km/s)
May 2008
Dec 2008
Jan 2009
Nov 2009
2.29
0.78
0.48
0.05
3.60
Mass Comparisons
Post TEI
Post MOI
Post TMI
In HEO
1991 JW (mt)
Mars DRM (mt) 30 37 45 83 36 61 74
107
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

21. 1991 JW Mission Trajectory Earth Departure Asteroid Arrival
Asteroid Departure
Earth Arrival
May 2008
Dec 2008
Jan 2009
Nov 2009
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

22. Conclusions
Asteroids with long synodic cycles also have long launch windows
Sizes generally less than a kilometer
Very few of the 650 identified near asteroids are accessible for human Mars-like missions.
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)

23. Future Work
Ask the scientific community for an opinion of these 10 asteroids.
Conduct more extensive sizing
Variable equipment masses
Grapple devices for vehicle and EVA
Additional analysis for future discoveries
6 of top 10 discoveries since beginning of 1996
Ian Roundhill / NASA-JSC / (281) Ian Roundhill / NASA-JSC-EG5 / (281)