An Affordable Program of Human Missions Beyond Low Earth Orbit
- Paper number
IAC-08.A5.3.2
- Author
Dr. Robert W. Farquhar, Smithsonian Institution, United States
- Year
2008
- Abstract
In its Vision for Space Exploration (VSE), NASA has focused on a Moon base as the next logical step on the road to Mars. An alternative plan for VSE that bypasses the Moon has been proposed in an International Academy of Astronautics (IAA) "cosmic study". The IAA study calls for a three-step approach to attain the goal of a human presence on Mars. These three "stepping stones" are: 1. The establishment of a staging node in the vicinity of the Sun-Earth L2 libration point for Human missions beyond the Earth-Moon system. 2. A human mission to a near-Earth asteroid. 3. A human mission to one of the Martian moons, either Phobos or Deimos. As an initial step to expand human space activities beyond low Earth orbit (LEO), the IAA Study Team examined ways to service telescopes that were located near the Sun-Earth L2 point. One way to gain this capability would be to develop a reusable crew-transfer vehicle called the Deep-Space Shuttle (DSS). The primary components of the DSS are: * A service module with a chemical propulsion system and crew quarters that could support 3 to 4 people for flight times of up to 50 days. * A detachable, Apollo-style re-entry capsule. The Crew Exploration Vehicle (CEV) currently under development by NASA would be a logical candidate for this component. The DSS is envisioned as a one and a half stage vehicle (i.e., a core stage with drop tanks). The total delta-V capability of the DSS would be somewhere between 5 to 6 km/sec. However, the delta-V requirement could be reduced by roughly 3.2 km/sec if a expendable Earth Departure Stage (EDS) is employed. Although the DSS can transport astronauts to destinations well beyond the Moon's orbit, a larger and more capable transfer stage will be needed for flights to near-Earth asteroids, Phobos/Deimos, and Mars. To satisfy this requirement, the IAA study called for a reusable vehicle based in a halo orbit around the Sun-Earth L2 point. This vehicle termed the Interplanetary Transfer Vehicle (ITV) would be used to transfer astronauts to and from their interplanetary destinations. The ITV proposed in the IAA study would possess considerable radiation shielding and living space that would allow astronauts to travel to near-Earth asteroids and Mars in relative safety and comfort. A mission to the near-Earth asteroid, 1999 AO10 is used to illustrate the effectiveness of stationing the ITV in the vicinity of the L2 point. It is shown that an ITV operating from L2 could perform this mission for a delta-V cost of only 4.9 km/sec, which is less than half the delta-V expenditure required for an ITV based in LEO.
- Abstract document
- Manuscript document
IAC-08.A5.3.2.pdf (🔒 authorized access only).
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