A dark cloud on commercial crew’s horizon
by Jeff Foust
|“We will learn, make the necessary adjustments and safely move forward with our Commercial Crew Program,” Bridenstine said.|
“Earlier today, SpaceX conducted a series of engine tests on a Crew Dragon test vehicle on our test stand at Landing Zone 1 in Cape Canaveral, Florida. The initial tests completed successfully but the final test resulted in an anomaly on the test stand,” a company spokesperson said in an emailed statement. “Ensuring that our systems meet rigorous safety standards and detecting anomalies like this prior to flight are the main reasons why we test. Our teams are investigating and working closely with our NASA partners.”
More than a week later, that is the extent of what SpaceX has disclosed about the incident, or anomaly, or mishap. The company hasn’t provided additional updates about the event, or even the status of the ongoing investigation. That has become a matter of some frustration for some who believe that, as a NASA-funded program, the company should be more open.
“NASA shouldn’t enable such secrecy unless a program involves military secrets, which this one doesn’t,” argued the Orlando Sentinel in an editorial last Wednesday. The agency, it argued, should require SpaceX and the other commercial crew company, Boeing, “to be more transparent and forthcoming.”
NASA doesn’t appear to be pressuring SpaceX to provide more information. NASA administrator Jim Bridenstine, in a statement hours after the incident, said that NASA and SpaceX were working to assess the incident. “We will learn, make the necessary adjustments and safely move forward with our Commercial Crew Program,” he said.
His statement did confirm one key aspect of the incident: it took place during a test of the spacecraft’s SuperDraco thrusters, which are designed to propel the spacecraft away from its Falcon 9 launch vehicle in the event of an emergency. (The thrusters were also once contemplated to provide propulsive landings of the spacecraft on land, something that SpaceX has since deferred indefinitely in favor of splashdowns.) The thrusters use the hypergolic propellant combination of hydrazine and nitrogen tetroxide; the reddish color of the cloud appeared indicative of nitrogen tetroxide.
The incident also came up during a meeting last Thursday of the Aerospace Safety Advisory Panel (ASAP), NASA’s independent safety committee, but they offered little in the way of new details about the incident. The test took place after tests of the smaller Draco thrusters of the spacecraft were completed successfully, ASAP chairwoman Patricia Sanders said. “Firing of eight SuperDracos resulted in an anomaly,” she said, but didn’t elaborate on the details of that test or the resulting anomaly.
SpaceX is leading the investigation from the anomaly, she said, with NASA involvement, as they worked to secure the test site and collect data. She and other panel members called for patience, giving investigators time to study what happened. “We know that there’s a lot of interest regarding the recent SpaceX mishap. We are patient, and allow the teams to investigate,” said Sandra Magnus, an ASAP member and former astronaut.
While details about the accident remain scant, the implications of it are a little clearer. The Crew Dragon capsule involved in the incident was the same one that flew the uncrewed Demo-1 test flight in March. The extent of the damage it suffered hasn’t been reported, but it was likely heavily damaged, if not destroyed.
The capsule was to fly again as soon as June on an in-flight abort test, where it would have fired its SuperDraco thrusters to pull away from a Falcon 9 after liftoff. That long-delayed test was a milestone not of its ongoing commercial crew development contract but instead an earlier funded Space Act Agreement.
If that capsule in fact requires significant repairs, or is irreparably damaged, it would delay that in-flight abort test, perhaps for an extended period. That could, in turn, delay the Demo-2 crewed flight to the space station, involving two NASA astronauts.
|“Notwithstanding the recent incident, there is a large body of work yet to be completed between Demo-1 and a crewed flight,” Magnus said.|
ASAP, at its meeting last week, declined to speculate on the impact the anomaly will have on schedules. “The investigation will take time before the root cause analysis is completed, and will determine the impact to Demo-2 and the in-flight abort test,” Sanders said.
While Demo-2 was formally scheduled for no earlier than July, that flight more likely would have taken place later in the year, even before the SuperDraco anomaly. Magnus noted that SpaceX had taken a “spiral” approach to development, incrementally adding capabilities. That meant that the company still had work to do, despite the successful Demo-1 flight in March, before launching Demo-2 (see “The beginning of the end of commercial crew development”, The Space Review, March 11, 2019.)
“Prior to the Demo-1 launch, because of this spiral development approach undertaken by the company, NASA and SpaceX identified configuration changes and subsequent qualification work that would be required to be completed before Demo-2 was possible,” she said, echoing comments made by NASA officials around the time of the Demo-1 mission.
“Notwithstanding the recent incident, there is a large body of work yet to be completed between Demo-1 and a crewed flight,” she said, adding it that it was too soon to speculate how the SuperDraco anomaly would affect that.
SpaceX is not the only company to suffer problems with its launch abort system. Last summer, Boeing encountered a problem with the abort system for its CST-100 Starliner vehicle. Several engine values failed to close fully when commanded, the company said at the time.
That sounded like a fairly minor problem—at least when compared to what SpaceX experienced—but it still caused significant delays for the problem. In an April 3 statement, NASA said that the company was only now “preparing to restart its Service Module Hot Fire test campaign at NASA’s White Sands Test Facility in New Mexico” now that the valve issue was corrected. “New hardware, including launch abort engine valves, have been redesigned and manufactured and are being installed on the test abort engines,” the agency said.
That statement came as NASA announced new dates for Boeing’s two commercial crew test flights: an uncrewed test now planned for launch in August, followed by a crewed test no earlier than November. Boeing had been aiming for May for the uncrewed test, but said that range issues—another Atlas 5, carrying a military communications satellite, scheduled for late June—meant that they had virtually no chance of launching in May before having to turn over the pad for that June mission.
That shorter gap between uncrewed and crewed test flights for Boeing—just three months—is feasible, Magnus suggested. “Boeing has taken a more traditional route, investing more effort prior to integrated testing to establish a more mature design from the outset,” she said, in comparison to SpaceX’s spiral approach. She added, though, that the company still faced “the submission and analysis of the required data for the final certification and verification processes.”
These events, combined, make it clear it’s highly unlikely that either company will be certified to carry NASA astronauts by the end of this year. That had been an issue for NASA, since the agency’s access to Soyuz seats was scheduled to run out by early 2020.
However, NASA has taken several steps in recent months to address that potential loss of access. That included announcing in February its intent to purchase two Soyuz seats from Roscosmos that would ensure access to the station into the fall of 2020.
|Extending the stays of two ISS astronauts, NASA said, “also allows NASA to get the most time dedicated to other research aboard the station, as U.S. commercial crew launch providers prepare for operations to and from U.S. soil and the space station.”|
In addition, NASA announced April 17 that two ISS astronauts would stay on the station for longer than the standard six-month crew rotation. Christina Koch, who arrived on the station in March, will now stay through next February, a 328-day stay that will set the record for the longest spaceflight by a woman. Andrew Morgan, set to launch to the station in July, will remain on the station until next spring, a 255-day stay,
NASA said that the extended stays would allow scientists to collect more data on the effects of long-duration spaceflights, like Scott Kelly’s 340-day stay. But, the agency added in the announcement, the extension “also allows NASA to get the most time dedicated to other research aboard the station, as U.S. commercial crew launch providers prepare for operations to and from U.S. soil and the space station.”
The third measure for maintaining access involves exercising an option that had been under study for a year to turn Boeing’s Starliner crewed test flight into an extended stay at the station, something NASA announced in early April when it reported the new schedule of test flights. NASA astronauts Nicole Mann and Mike Fincke, along with former astronaut and current Boeing employee Chris Ferguson, will spend potentially months on the station under the new plan; NASA said the exact duration of that mission will be determined later.
ASAP praised NASA for those measures, which they argued help lessen schedule pressure on the commercial crew providers. “NASA has appropriately established a contingency plan to ensure continued US crewed access to the ISS through late 2020, providing for temporal margin as they advance towards crewed flights,” Magnus said.
So, while the urgency to get commercial crew vehicles flying has faded somewhat, the urgency to find out what happened to the Crew Dragon vehicle more than a week ago persists. But just as the dark cloud from the anomaly blew out to sea and dissipated, so too should the uncertainty clouding what happened that afternoon to the spacecraft and its implications for the overall commercial crew program. Eventually.
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