NASA: No Preconceived Decision About Putting Crew on First SLS Launch
Two top NASA human spaceflight officials explained today that the study they are conducting about whether it would be feasible to put a crew on the first flight of the new Space Launch System (SLS) is just that, a feasibility study. It will lay out pros and cons, but not make a recommendation. Both said they have no preconceived decision about what the study will say.
Bill Gerstenmaier, NASA Associate Administrator for Human Exploration and Operations, and Bill Hill, Deputy Associate Administrator for Exploration Systems Development, spoke at a media teleconference this afternoon that had been announced just four hours earlier.
NASA Acting Administrator Robert Lightfoot announced last week that he was initiating a study to determine the feasibility of putting a crew on the first launch of the SLS, currently scheduled for late 2018. The existing plan is for that launch to be an uncrewed systems test of SLS and the Orion spacecraft that is being designed to take crews beyond low Earth orbit to orbit the Moon and someday go to Mars. That first uncrewed launch is designated Exploration Mission-1 (EM-1). The second flight, EM-2, scheduled for no earlier than August 2021, would be the first to carry astronauts.
The U.S. space shuttle is the only human spaceflight system ever launched that carried a crew on its first mission (STS-1 in 1981). All other human spaceflight systems flown by the United States, Soviet Union/Russia and China have had uncrewed test flights first to obtain data to better understand system performance and thereby reduce risk. Gerstenmaier spoke at a conference two weeks about the Loss of Crew (LOC) metric it uses to characterize the probability of a failure that could kill a crew. He said that at the time of the first shuttle mission, models predicted the LOC at 1 in 500 to 1 5,000. By the end of the program, after 30 years of experience that included two fatal accidents (Challenger and Columbia), they determined the actual risk for STS-1 had been 1 in 12. The risk overall for the shuttle program was determined to have been 1 in 90.
Needless to say, the decision to assess the feasibility of placing a crew on the first SLS has raised eyebrows. The media teleconference today appeared aimed at explaining that it is only a study and no decision has been made. Gerstenmaier and Hill said it would look at the advantages and disadvantages of adding a crew, including the cost and schedule implications. Gerstenmaier added that he did not know that it even would be a stand-alone study, but instead set in the context of discussions about the FY2018 budget request, a process he said would begin in a couple of weeks.
The Trump Administration plans to issue an overarching “budget
blueprint” for the government next month, but a detailed budget request
is not expected until April or May. The White House Office of
Management of Budget (OMB) writes the President’s budget request. Its
new Director, Mick Mulvaney, was sworn into office only last week. He
was a Congressman from South Carolina and a well known budget hawk
committed to reducing federal spending.
Asked whether the Trump White House asked NASA to put a crew on the first flight, Gerstenmaier replied that “the Administration team in concert with Robert [Lightfoot]” asked for the feasibility study. The overall goal, he added, was determining if crews could fly earlier than currently planned. He noted that his office already had been looking at what could be done to “enhance” EM-1 to facilitate getting data that will be needed for EM-2, such as putting crew seats in Orion and placing mannequins there to obtain radiation exposure and reentry loading data. His office briefed the Trump transition team on its activities and “they may have gotten the idea from us” to do the feasibility study. Whether or not a decision is made to add crew to the first flight, the study offers an opportunity to step back and look at the program overall and “if we’re testing the right things.”
Gerstenmaier said he feels no political pressure to put crew on EM-1 and wants to “let the data drive us to the answer.” He and Hill both said they have no preconceived decision one way or the other, but see value in the study regardless of the outcome. They expect it to be completed in about a month, but there is no set date.
EM-1 and EM-2 will use different upper stages. EM-1 will fly the Interim Cryogenic Propulsion Stage (ICPS), while EM-2 will use a more capable Exploration Upper Stage (EUS). The technical differences between ICPS and EUS are one of the reasons there is such a long gap between EM-1 and EM-2. Gerstenmaier said today that it will take 33 months to reconfigure ground facilities to accommodate the taller EUS.
ICPS is not designed to the “human-rated” safety standards required for carrying crews, however. A decision to place crews on EM-1 would require that ICPS be human-rated and a number of other hardware changes would be needed that could be expensive and time consuming. The Orion spacecraft for EM-1, for example, is not outfitted with life support systems or other hardware needed for a crewed flight.
The study will look at all of those factors and present the advantages and disadvantages, risks and benefits. Gerstenmaier has formed a team to conduct the study that includes one astronaut, although he declined to name who it is or speculate on what the position of the astronaut office as a whole might be to the idea of putting a crew on the first flight. Hill said the team has been asked to look at what it would take to send a crew of two on an 8-9 day mission around the Moon that would include one day in a high Earth orbit to check out the life support systems.
In the meantime, NASA is proceeding with its “program of record” with an uncrewed EM-1 in late 2018 and a crewed EM-2 no earlier than August 2021. EM-1 already appears likely to slip to 2019 due to facility damage from recent tornadoes at NASA’s Michoud Assembly Facility near New Orleans where SLS is being built plus delays with the Orion Service Module being provided by the European Space Agency. As for EM-2, NASA’s formal commitment is for launch in 2023, but Congress has been providing additional funding to accelerate it to 2021.
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