BROOMFIELD, Colo. — A NASA program originally intended to fly astronauts on commercial suborbital vehicles has evolved into a broader effort to enable flights by agency personnel and supporting the nascent industry.
At the Next-Generation Suborbital Researchers Conference in March 2020, then-NASA Administrator Jim Bridenstine announced a new effort, later called Suborbital Crew or SubC, to allow NASA astronauts to fly on commercial suborbital vehicles for training or to conduct research. The effort would be analogous to the Commercial Crew program to develop vehicles to transport astronauts to and from the International Space Station.
That would require, he said then, a certification process of some kind for suborbital vehicles, likely a subset of requirements NASA had established for commercial orbital vehicles. NASA followed that up with a request for information on the qualification process in June 2020, but there had been few updates on SubC since then.
At the 2023 edition of the conference last week, the manager of SubC at NASA said the emphasis of the effort had changed. “Our name is a little bit of a misnomer these days,” said Chris Gerace. “One tends to think this is about flying our NASA crew in space. It’s much broader than that.”
He said that NASA was no longer focusing on using SubC to fly astronauts for training or research. “The original intent was to provide training opportunities for our astronaut corps. These vehicles don’t really meet those needs,” he said. “The astronaut corps flies in pressure suits. Any kind of training they have they really want to have in pressure suits. They felt these vehicles, which did not incorporate pressure suits, did not fit those needs.”
NASA astronauts wear pressure suits during dynamic phases of flight on commercial crew vehicles, including launch, reentry and docking and undocking from the station, but do not wear them for other phases of flight. Neither Blue Origin nor Virgin Galactic, the two companies that operate commercial suborbital vehicles capable of carrying people, require those on board to wear pressure suits.
Instead, SubC is focused now on enabling flights by NASA civil servants, such as scientists and engineers conducting research, on suborbital vehicles. Gerace, though, said that SubC has broader goals.
“Flying NASA civil servants is really not the primary objective,” he said. “It’s really this industry, human spaceflight, wherever it takes place, and furthering that and ensuring that it is both viable and safe.”
He and others argued that NASA allowing its personnel to fly on suborbital vehicles would be an endorsement of their safety that would help companies. “If I was offering a system and had the ability to say that NASA is flying their researchers on our system, that would be a huge marketing benefit,” said Tim Bulk, chief technical officer of Special Aerospace Services, which is supporting the SubC project. He added it could have other benefits, such as with insurers.
NASA has also changed the approach of how it will determine commercial suborbital vehicles are safe enough for agency personnel. Rather than a formal certification process, like on commercial crew orbital vehicles, NASA will use a “safety case” approach where companies will explain how their vehicles are safe and the agency confirms that.
“It’s up to them to be able to describe why they’re safe, and what we’re doing within SubC, to a large extent, is a validation of that claim,” Gerace said. “NASA brings in its experts and validates that case.”
SubC is currently working with both Blue Origin and Virgin Galactic on “deep dives” into aspects of those companies’ vehicles: the escape system on Blue Origin’s New Shepard vehicle and the propulsion system on Virgin Galactic’s SpaceShipTwo. NASA is also supporting the ongoing investigation into the anomaly in Blue Origin’s most recent New Shepard flight last September.
Gerace said those deep-dive studies will continue through the end of the year and into early 2024, but did not otherwise indicate when NASA might be prepared to allow its civil servants to fly on commercial suborbital vehicles.
He also didn’t rule our eventually flying astronauts on commercial suborbital vehicles. “When they looked at their training needs, they’ve been flying astronauts to space for decades without any suborbital pre-training, so they felt that their training approach was sufficient as is,” he said of the astronaut office.
That might change, he suggested, as more civilian researchers get a chance to fly. “The experience of a suborbital flight may be very beneficial prior to going on station for six months. Things may change as we get commercial LEO destinations flying.”