By Managing editor
updated 8/5/2009 9:31:11 PM ET 2009-08-06T01:31:11

A White House panel tasked with re-evaluating NASA's plans for future space exploration has begun culling a list of potential options — one that ranges from staying the current course to taking direct aim at sending humans to Mars.

The 10-member Review for U.S. Human Space Flight Plans Committee has trimmed a larger list of 3,000 options down to about seven general scenarios, which it plans to cull even further before presenting them to President Barack Obama later this month.

"We have our work cut out for us," committee chairman Norman Augustine, Lockheed Martin's former CEO, said Wednesday during a televised meeting in Washington.

NASA's current plan is to retire its aging space shuttle fleet in 2010 after completing construction of the international space station, and replace it with a new Orion vehicle. Orion and its Ares I rocket are slated to begin operational flights in 2015 as part of NASA's larger plan to return humans to the moon by 2020. A heavy-lift Ares V rocket is also planned to launch lunar landers and other heavy cargo.

Potential options
Committee member Edward Crawley, an MIT professor, said only three of the potential scenarios under review by the committee stay within NASA's projected exploration budget, now pegged at about $80 billion total through 2020. That's about $28 billion less than what the agency expected when it chose the Orion and Ares rocket plan.

Those three options include:

  • NASA Baseline Plan: Stretch out the schedule for NASA's current Constellation program goals to build and fly Orion and the Ares rockets within the budget available, retire the shuttle fleet in 2011, and end U.S. involvement in the 16-country international space station in 2015. Rely on international partners for crew and cargo transport until Orion and U.S. commercial flights are available.

  • Space Station Focused: Retire the shuttle fleet in 2011, but extend space station operation through 2020. Rely on international partners for crew and cargo transport until Orion and Ares I rockets, or commercial flight, are available. "This would be robust utilization of the space station, but allows exploration to move off into the later distance future," said Crawley, who leads the committee's subgroup studying destinations for human space exploration. "It's a limiting case."

  • Dash Out of Low Earth Orbit: This option retains the shuttle fleet's 2011 retirement and the 2015 deadline for U.S. involvement in the space station, but eliminates the Ares I rocket entirely in order to focus on the heavy-lift Ares V rocket, which could then be used to launch Orion flights to lunar orbit, near-Earth asteroids or even planetary flybys. International partners would provide crew and cargo transport until the larger Ares V comes online. The "dash" option is aimed at launching manned missions beyond low-Earth orbit as fast as possible, "therefore it makes no sense for us to do anything other than rely on international partners and commercial [companies] for crew access," Crawley said.

More expensive scenarios
The remaining scenarios under the committee's review would likely exceed or equal the current budget planned for NASA's exploration goals, Crawley said. They range from a more direct repurposing of space shuttle technology to sending humans straight to Mars, though all could set the stage for potential in-orbit refueling capabilities.

Those options include:

  • More Directly-Shuttle Derived System: This scenario calls for flying the space shuttle through 2015 and eventually replacing it with a system that draws more heavily on the shuttle hardware, such as its external tank and twin solid rocket boosters. A potential Side-Mount Shuttle, which would use the tank and boosters to launch a cargo pod or crew capsule instead of a reusable orbiter, is one such plan. The shuttle would fly beyond 2011 at a rate of up to two flights a year, and the space station would fly until 2020. Eventually, commercial crew launch services are envisioned.

  • Deep Space: This option would retire the shuttle fleet in 2011 and extend space station operations through 2020. It suggests developing U.S. crew launch capability as a backup to services provided by international partners and commercial interests. The focus would be building a heavy-lift vehicle capability of launching astronauts on lunar orbital missions, near-Earth asteroid missions and planetary flybys.

  • Lunar Global: The shuttle replacement plans for this scenario are similar to those for the Deep Space option, but the fleet would still retire in 2011 with the space station continuing through 2020. Instead of setting up a short-duration outpost on the moon, however, the aim would be for extended stays for more exploration. "This would prepare us to take the next step to Mars, having spent some time on the moon," Crawley said.

  • Mars Direct: The final option under the committee's eye largely skips the moon and focuses on the sending astronauts directly to Mars. Like others, it includes retiring the shuttle fleet by 2011 and extending the space station through 2020. International partners and commercial companies would provide crew launch services while NASA develops a fleet of Ares V rockets to launch crew and cargo to Mars. The plan would only send humans to the moon or near-Earth asteroids in order to test hardware for the Mars mission.

With their handful of scenarios in hand, the spaceflight review committee plans to meet Aug. 12 for one final public meeting to discuss the final options before submitting a final report at the end of the month. Some committee members said on Wednesday that NASA, and the United States in general, should choose to tackle the most challenging projects in space.

Bohdan Bejmuk, a former Boeing manager leading one of the committee's subgroups, said that while flying in space is always hard, getting to low Earth orbit is slightly easier than reaching the moon, or moving out toward Mars. Buying commercial launch services to fly crew and cargo to low Earth orbit, he explained, would free NASA's top minds to target more lofty goals.

"NASA has brilliant people," Bejmuksaid. "Get attention of these brilliant people on the harder tasks, and think of buying the easier tasks from [commercial] industry. NASA would show off their skills by doing the hard stuff. ... I think that process would elevate NASA in stature in America."

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