Earlier this month, NASA disclosed that the White House asked the agency to consider flying astronauts on the maiden launch of the massive Space Launch System rocket, known as Exploration Mission-1 (EM-1), instead of using it as a test flight. On Friday, senior managers at the agency told reporters during a teleconference that they were "encouraged" by the opportunity to study this possibility, but they were also carefully weighing the risks against the rewards.

“We recognize this will be an increased risk," said William Gerstenmaier, associate administrator of NASA’s Human Explorations and Operations Mission Directorate. "We take that increased risk, and we take it against the benefits we gain by doing this, and we say, ‘Is that something that is worthwhile for us to go and do?' Then we have an agency-wide discussion on whether this is an appropriate risk for us to take.”

The study should be complete in about a month, Gerstenmaier said. During the call, he and NASA's lead manager for the SLS rocket and Orion spacecraft, Bill Hill, provided some additional information about the mission. It will fly just two astronauts, instead of four or six, on an eight- or nine-day mission into lunar orbit and back. The flight plan will also include multiple opportunities to return to Earth earlier if some unexpected problem occurs.

Timeline

Under NASA's existing plan for EM-1, the agency plans to launch the SLS rocket with an uncrewed Orion vehicle (and unfinished life support systems) in late 2018 or early 2019. Then, crew would fly on the second launch of SLS (EM-2) with a finished version of Orion in 2021 or later. Gerstenmaier said he was only in favor of putting crew on EM-1 if that mission could be flown before the end of 2019. "If we went much beyond that we might as well just fly crew on EM-2," he said.

In making the decision to fly crew on the initial launch of SLS, the agency would not only be taking on additional risks in terms of crew safety, it would also be dealing with additional costs. "From our previous assessment, we know it’s going to take a significant amount of money—money that would be required fairly quickly," Hill said during the teleconference.

While NASA officials would not specify those costs, one informed source told Ars that a preliminary estimate of these costs is about $500 million. The money is needed to qualify the SLS rocket's upper stage for a crewed flight as well as to cover substantial work to add life support systems, to finalize displays to the Orion spacecraft, and to finish work at the Kennedy Space Center launch pad on a crew escape system.

Risks

At this point NASA's biggest concern is crew safety. Historically, with the rockets used during Mercury, Gemini, and Apollo spacecraft launches, NASA flew at least one uncrewed test flight before astronauts went into space. NASA did fly the space shuttle with crew on its maiden mission, but that was largely because the configuration of the vehicle made it difficult to launch and land without a commander and pilot.

The space shuttle made its initial flights with a rather crude system of ejection seats (which were later removed). Gerstenmaier said he had more confidence in the combination of Orion and SLS, because the spacecraft has a full-fledged launch abort system to get the crew to safety in the event of an emergency. If the EM-1 flight carries crew, NASA would bring forward an in-flight test of this abort system to early 2019. During this test, an Orion mock-up will reach speeds of up to 600mph and attempt an abort during the moment of highest aerodynamic loads after launching on a first stage booster from a Peacekeeper missile.

There has been some question about the extent to which NASA has been pressured politically into accelerating the first crewed flight of Orion. Right now, the baseline plan would preclude a human launch during President Trump's first term in office. According to Gerstenmaier, the White House team asked NASA's acting administrator, Robert Lightfoot, to perform the feasibility study—but no more. "From my perspective I don’t see this as pressure to go do this," Gerstenmaier said. "This is something we’re going to evaluate, we’ll trade it back and forth in the study and see what the results look like coming out the other side."

Would there be rewards other than pleasing the White House? During his remarks, Hill seemed to suggest so. If the EM-2 flight profile can be flown on the EM-1 mission, it would open up more ambitious options for crew flights with EM-2, he said. Flying crew on EM-1 may also improve morale at NASA, which hasn't supported an Orion launch since a flight test in 2014 on a Delta IV Heavy rocket. Flying crew sooner would reinforce NASA's message that SLS and Orion represent the beginning of a real exploration program, rather than one that seems to be in perpetual development.