NASA this week told Congress it cannot afford to build a new heavy-lift rocket and spacecraft to replace the retiring space shuttle program within the timeframe and budget approved by lawmakers.
The plan to make a first launch of a new rocket and space capsule to carry astronauts by 2016 "does not appear to be possible" within the projected budget, NASA said in a report to legislators.
Four members of the Senate Committee on Commerce, Science and Transportation shot back that the plan is not optional and that the US space agency must find a way.
"The production of a heavy-lift rocket and capsule is not optional. It's the law," said a joint statement issued late Wednesday by Senators John Rockefeller, Kay Bailey Hutchison, Bill Nelson and David Vitter.
"NASA must use its decades of space know-how and billions of dollars in previous investments to come up with a concept that works. We believe it can be done affordably and efficiently -- and, it must be a priority."
The Senate committee released a copy of the NASA report, which the US space agency had not issued publicly but presented to lawmakers on January 10.
It said that NASA fears it does not have the adequate funds according to budgets outlined in the fiscal year 2011 and President Barack Obama's 2012 budget request.
"None of the design options studied thus far appeared to be affordable in our present fiscal conditions, based upon existing cost models, historical data, and traditional acquisition approaches," said the NASA report.
The US space agency said no structures match the three criteria set out by its administrator for developing a future exploration system that is "affordable, sustainable and realistic."
NASA said it would continue to study the matter and would issue another report to Congress in April.
That report will aim "to update our approach based on the plans described herein and, if necessary, modifications based on the outcome of FY 2011 appropriations and the president's FY 2012 budget request."
The final two -- or if the budget allows, three -- space shuttle flights are set to take place this year, with Discovery scheduled to launch February 24 and Endeavour on April 19, before the fleet is retired for good.
According to expert John Logsdon, the NASA report comes as no surprise, because the US space agency administrator Charles Bolden has already informed top Senators that the plan before them was unrealistic.
"Even if they got more money I don't think they could achieve it by 2016," said Logsdon, former Director of the Space Policy Institute at The George Washington University, adding that 2018 or 2020 might be more feasible.
"Something this big will require more than five years," he said.
Logsdon added that the apparent clash between senators and NASA was actually "the beginning of a dialogue."
"There is no doubt in my mind that NASA wants to build this heavy lift vehicle," Logsdon said. "It's also clear to me that based on NASA analysis they cannot do it under the conditions that have been written in the authorization act.
"So they have to go back and forth for some period of time so that Congress understands the basis of the NASA conclusion."
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