A sweeping review of Nasa's human spaceflight program has concluded that the agency has an unsustainable and unsafe strategy that will prevent the US from achieving a human landing on Mars in the foreseeable future.
The 286-page National Research Council report, the culmination of an 18-month investigation mandated by Congress, says that to continue on the present course under budgets that don't even keep pace with inflation "is to invite failure, disillusionment, and the loss of the longstanding international perception that human spaceflight is something the United States does best".
The report makes a case for sending astronauts back to the moon. That's an idea that has been vocally opposed by President Barack Obama. Obama killed the Constellation program, which had been backed by President George W. Bush and would have included a return to the moon.
The key argument against the Constellation program was that it didn't pencil out — that there wasn't nearly enough money dedicated to the program to achieve the lunar landing it envisioned. But now the NRC committee has delivered essentially the same assessment of the Obama Administration's current Nasa program of record. If the goal is Mars, the committee said, the current strategy isn't going to work.
"Absent a very fundamental change in the nation's way of doing business, it is not realistic to believe that we can achieve the consensus goal of reaching Mars," committee co-chair and former Indiana Governor Mitch Daniels said Wednesday morning in an interview.
Nasa spokesperson David Weaver said the agency welcomed the report, and characterised it as being "consistent with the bipartisan plan agreed to by Congress and the Administration in the Nasa Authorization Act of 2010 and that we have been implementing ever since."
Weaver added, "Nasa has made significant progress on many key elements that will be needed to reach Mars, and we continue on this path in collaboration with industry and other nations."
The NRC's Committee on Human Spaceflight also probed the philosophical question of why we send humans into space to begin with. That question incited the formation of the US$3.2 million (NZ$3.8m) review effort, which was funded by Nasa.
The committee concluded that the purely practical, economic benefits of human spaceflight do not justify the costs involved, but said that the aspirational nature of the endeavour may make it worth the effort.
The committee unsurprisingly identified Mars as the "horizon goal" of the agency. The report said the US should pursue international collaborations that would include China — currently treated as a space rival and not as a potential partner. Nasa officials are not permitted to speak to their Chinese counterparts, a policy the committee criticised.
The report sees three potential pathways to get to Mars, two of which involve a return to the moon. A lunar landing and habitat would help develop technologies that could later be used on a Mars mission, the report said.
"This committee found a number of compelling reasons to include the moon as a stepping stone on the way to Mars," co-chair Jonathan Lunine, a planetary scientist at Cornell, said in an interview. "From the point of view of a destination — scientific, technical, and also in terms of our international partners — it is attractive."
The third pathway, which doesn't involve a return to the moon, is essentially the one that the Obama Administration has chosen, which includes, as a major step, the Asteroid Redirect Mission (ARM). The NRC report is not bullish on the idea.
Nasa wants to grab a small rock passing close to the Earth in its natural orbit, and then redirect it to a new orbit around the moon. Astronauts would visit the rock and take samples, a mission that could double as an early shakedown cruise for the Orion capsule being developed by Nasa in tandem with a heavy-lift rocket called the Space Launch System (SLS).
The asteroid mission has been politically controversial — Republicans in Congress tried but failed last year to forbid Nasa to do it — and it has technical challenges, not least of which is the difficulty in identifying an asteroid that could be plausibly captured by a robotic spacecraft.
The NRC report says that mission involves the creation of a large number of "dead end" technologies that don't get the US closer to a Mars landing.
There is also a safety issue in play. The current plan calls for long gaps between launches of the SLS — four years in some cases.
"The current program to develop launch vehicles and spacecraft for flight beyond LEO [low earth orbit] cannot be sustained with constant buying power over time, in that it cannot provide the flight frequency required to maintain competence and safety, does not possess the 'stepping-stone' architecture that allows the public to see the connection between the horizon goal and near-term accomplishments, and may discourage potential international partners," the report states.
John Logsdon, professor emeritus of George Washington University's Space Policy Institute, said the report had a familiar ring to it.
"They go through all this negative analysis and still conclude we ought to go to Mars. No one ever says 'let's lower our ambitions'. It's always 'increase the budget,' not 'lower ambitions'," he said.
As for going to Mars: "It's a dream. It's been a dream forever. And will remain a dream unless something changes."
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