Chair Force Engineer

Wednesday, February 28, 2007

TeamVision (Part 2 of 5)

Yesterday I shared my thoughts on the TeamVision approach to the Vision for Space Exploration. I decided that I would devote one post to each of the "eras" projected by the TeamVision report. Today's post relates to the second of five development spirals.

After access to the ISS has been assured through use of the Block I Orion CSM and Delta & Atlas rockets, the next challenge is to extend human presence to the moon. TeamVision does not envision taking "one giant leap" from the ISS to the lunar surface. Instead, a series of three precursor events must take place:
--Establishment of a communications node (a single satellite will probably do) in a halo orbit around the Earth-Moon L2 point (on the far side of the moon.)
--Robotic "Lunar Surface Vehicles" that would deploy rovers and determine which lunar landing sites are most worthy, from a scientific and a feasibility standpoint, of a human presence.
--A human mission to lunar orbit and back to test and validate the Block II Orion CSM (akin to Apollo 8.)

The lynchpin of Spiral 2 is a heavy-lift rocket known as Jupiter I. This rocket looks an awful lot like Direct Launcher. The only difference is that Jupiter I has an upper stage, the Integrated Common Evolved Stage. This is a 5m diameter rocket stage that should be easy to develop, using the Delta IV tooling and the existing RL-10B-2 engine. Jupiter I will be able to place 80 mT in low earth orbit, and it will launch the "Era 2" missions.

The Block II Orion CSM is an evolution of the ISS-only Orion that was developed in Spral 1. The difference is that the CM will have systems like parachutes and heat shields that are beefed up for the lunar mission, while the SM will probably employ higher-energy propellants (liquid hydrogen or methane as a fuel, and liquid oxygen as the oxidizer.) TeamVision acknowledges that NASA may decide on hypergolic propellants for the SM, in which case the Block II SM will be a lengthened version of the Block I SM. The SM engine, like its Apollo predecessor, would be used for lunar orbit insertion and trans-earth injection (I believe that NASA's current architecture uses either the earth departure stage or the LM descent stage for lunar orbit insertion.)

Interestingly, TeamVision proposes a heavy-lift rocket for placing robot rovers on the moon. With the added mass margins afforded by the Jupiter I rocket, the robot's designers can build an extremely capable rover. Even the Soviet Lunokhod rover and its lander only got a Proton rocket. There's a lot of potential for a lunar rover that could prepare a base camp for human inhabitants, or even serve as a manned rover after humans land on the moon.

So far, TeamVision is looking pretty good with its proposal for "Era 2," establishing the infrastructure for a manned lunar base and testing the lunar-capable Orion on a faster schedule and lower budget than the one NASA would use for the same task. Spiral 2 will be more expensive and more challenging than Spiral 1, but still doesn't represent anywhere near the level of challenge that went into Project Apollo (including both Saturn rockets and the unmanned precursors like Surveyor.) However, I see major storms over the horizon for TeamVision, starting with Era 3: the human lunar landing. Stay posted!

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