More work ahead for Crew Dragon after test flight

KENNEDY SPACE CENTER, Fla. – As SpaceX prepares to launch its Crew Dragon spacecraft on its first test flight, the company and NASA recognize that much work remains to be done before the spacecraft is ready to carry astronauts.

In a statement released Feb. 28, NASA and SpaceX officials said they were planning to launch the Crew Dragon spacecraft on a test flight known as Demo-1 or DM-1, which will demonstrate the systems of the unmanned spacecraft on board . The mission is scheduled to be launched on a Falcon 9 at 2:49 am on March 2 of Launch Complex 39A, with an 80% chance of an acceptable climate.

A late hurdle that NASA and SpaceX had to overcome was a concern of Russia, one of the partners of the International Space Station, about the risk the spacecraft posed to the station if its computers failed to function properly. Roscosmos issued a dissenting opinion about Crew Dragon's flight software during a flight readiness analysis on February 22, and NASA later worked to address those concerns.

"We agreed with Roscosmos yesterday in a protocol on the approach," said Joel Montalbano, deputy manager of NASA's ISS program. These steps include closing hatchways at the station and the three-person crew there ready to enter the Soyuz docked at the station if the Dragon Crew collided with the station because of a software flaw, a scenario he described as "very remote ". .

The Crew Dragon spacecraft approaches the ISS differently from the Dragon cargo version, said Hans Koenigsmann, vice president of building and flight reliability at SpaceX. The Dragon charge approaches the base station until it is close enough to be captured by the robotic arm of the station. The Dragon Crew will position itself in front of the station and will move along the speed vector to dock at the station.

"You basically have to actively accelerate and brake to get to the station" with the approach of Crew Dragon, he said. In contrast, with Dragon's approach to charge, "if you do nothing, you will fall slowly and move away from the station."

For the Demo-1 mission, the Dragon Crew will approach 150 meters from the station before the station crew sends a withdrawal command to retreat to a distance of 180 meters. "This is all part of the tests we do to ensure the safety of the space station," Montalbano said. The spacecraft will also stop at a distance of 20 meters for the final test before coupling.

Crew Dragon's ability to safely dock with the station is just one of many tests the spacecraft will undergo on a scheduled flight to last about six days. "From NASA's point of view, we're really looking forward to seeing the orbiting performance, how systems are going to work together," said Kathy Lueders, manager of NASA's commercial crews program.

"This is an invaluable exercise to learn in the space environment how these systems will be working and then make sure these systems are ready for when we put our teams on them," he added.

How close to Crew Dragon is to people who fly is a matter for debate. Pat Forrester, chief of NASA's astronaut office, said it was "very exciting" to be back at the Kennedy Space Center before the release of Demo-1. "It will be more exciting when we get back to the DM-2," said the crew's test pilot. "While much progress has been made, we still have a lot of work to do and we look forward to teaming with SpaceX to do it."

Koenigsmann said there is "still some work to be done" on the Crew Dragon elements before the Demo-2 mission. The life support system will need to be expanded to the Demo-2 mission, he said as an example of change, and the software will be upgraded between the two missions.

"There are a lot of details that we have to address, but overall it's the same vehicle," he said.

Another issue, first reported in a briefing on February 22, is with Draco's propellants from the probe after the thermal vacuum test. "For the complete environment in which we expected this mission to be originally operated, the Dracos did not like that environment," Lueders said, with temperatures getting too low.

For Demo-1, the mission was changed to avoid such low temperatures, including the one-day approach to ISS after launch. Finally, the heaters will be added to the propellant's propellant lines so it will not be a problem for Demo-2, she said.

Other changes in the spacecraft are likely to depend on the outcome of Demo-1. Lueders said the spacecraft is heavily equipped to measure its performance and will also have on board a mannequin – nicknamed "Ripley", in honor of the character of the film. Foreign film franchise – to study the conditions a human would experience on the spacecraft.

The Demo-2 mission is slated to be launched in July, according to NASA's current commercial flight test flight program, although most industry watchers expect it to fall by the end of the year. Koenigsmann, asked if the July date was still viable, said that this would depend on what changes need to be made to the Crew Dragon after Demo-1.

"There's really a lot of ingenuity in both teams," he said of NASA and SpaceX, citing the short-term solution to the issue of the propeller as an example. "For something similar, I would expect us to find a similar operational solution."