Friday, November 13, 2009

Ten Questions for HSF Committee - Question 1

Are beyond-LEO exploration and fitting the budget really incompatible?

Two of the goals in the Committee's charter were to fit the budget and to enable beyond-LEO exploration. However, only two of the options presented by the Committee fit the budget, and neither of these options enable beyond-LEO exploration in a meaningful time frame. I will ignore the first of these two options, the budget-constrained Program of Record, since it doesn't keep the ISS, encourage commercial space, or include international participation, violating many of the Committee's goals. It also completes Ares 1 after the ISS is deorbited, leaving it nowhere to go. Finally, it starts lunar exploration far, far in the future.

As the Committee states, the Program of Record "offers little or no apparent value".

The Committee's Option 2 fits the constrained budget while allowing technology development, a longer ISS lifespan, and commercial support of the ISS. It removes Ares 1, but delivers an "Ares V Lite" in the late 2020's, with actual use of the Ares V Lite happening much later. Essentially beyond-LEO exploration is not viable under this plan, either, although some useful non-exploration activity can be expected with Option 2.

Given that this option attempts to fit the constrained budget while enabling beyond-LEO exploration, why was it encumbered with the high development cost and long schedule of Ares V Lite? Why was it required to reach the lunar surface, when the Deep Space (Flexible Path) options depicted elsewhere in the report involve a lower cost of entry? The report states:

In the process of developing these options, the Committee conducted a sensitivity analysis to determine whether any reasonable exploration program (e.g., with different heavylift vehicles, or a different exploration destination) would fit within the FY 2010 budget guidance. The Committee could find none. In addition, the Committee tried to develop a variant of the Flexible Path that fit within the FY 2010 budget, and such a variant looked no more promising than Option 2, with the first missions beyond low-Earth orbit in the late 2020s.

This analysis led the Committee to its finding that human exploration beyond low-Earth orbit is not viable under the FY 2010 budget guideline. It would be possible to continue the ISS and a program of human activity in low-Earth orbit within this budget guidance, and to develop the technology for future exploration, but the budget limitation would delay meaningful exploration well into the 2020s or beyond.

It would be good to see the analysis behind these conclusions. What if only the early Flexible Path destinations such as lunar orbit and Lagrange points were considered? What if, to match these easier destinations, an easier heavy lift option such as the Phase I EELV HLV, or no HLV at all (just refueling and/or assembly) were used? The tradeoffs in terms of reduced cost and shortened schedule versus losing or postponing more difficult destinations should be spelled out.

Such information would be valuable for an Administration that might be considering no budget increase, or perhaps only a modest budget increase, for exploration.

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