Members of NASA’s independent panel of aerospace safety advisers voiced concerns last week about the quality control issues that “apparently have plagued” Boeing’s Starliner crew capsule program, while urging NASA to monitor closely. SpaceX’s plans to reuse Crew Dragon spacecraft on astronaut flights to the International Space Station.
A pilotless test flight of Boeing’s CST-100 Starliner spacecraft in December ended prematurely after a programming error in the capsule’s mission timer caused the spacecraft to burn too much fuel shortly after separating from its rocket Atlas 5.
The unexpected fuel consumption left the Starliner capsule with insufficient propellant to complete its flight to the space station.
The Starliner safely landed in New Mexico two days later, but ground crews identified another software problem in a propulsion controller that governs the thrusters in the spacecraft’s service module, which launches from the crew module. Starliner before re-entering the atmosphere. Mission control plugged in a software patch shortly before reentry, eliminating the risk that the misconfigured powertrain controller could have caused the scrapped service module to crash into the crew module after separation.
There were also problems with Starliner’s communications system during the pilotless demonstration mission, known as the Orbital Flight Test, or OFT.
An independent review team that investigated issues during the OFT mission issued 80 recommendations for Boeing and NASA engineers to address software issues, the communications issue, and the lack of management oversight in oversight that contributed to problems on last year’s test flight.
Donald McErlean, a seasoned aerospace consultant and member of NASA’s Aerospace Safety Advisory Panel, said July 23 that Boeing is making progress to resolve technical problems. Boeing plans to fly a previously unplanned second Starliner orbital flight test to the space station later this year, followed by a crew flight test in the first half of 2021 with a three-person astronaut team on board.
“However, despite this progress, which is definitive and indeed measurable, the panel remains concerned about the quality control issues that have apparently affected Boeing’s commercial crew program,” said McErlean, a former chief engineer at the U.S. Navy aviation programs.
Boeing performed a cushion abort test on a Starliner crew capsule last November, one month before the Orbital Flight Test. One of the capsule’s three main parachutes failed to deploy after a successful test of the spacecraft’s abort engines, and Boeing traced that problem back to a missing pin on the parachute rig.
“We realize that the CCP (Commercial Crew Program) has been working with the security and engineering communities to address these issues, but this is an issue that the panel will continue to watch closely as OFT and then CFT are conducted.” McErlean said.
The panel recommended that NASA’s Commercial Crew Program “maintain a balance” between setting and achieving milestones on schedule and ensuring that managers make appropriate technical decisions, according to McErlean.
Boeing developed the Starliner spacecraft under contract with NASA, which seeks to stop relying exclusively on Russian Soyuz crew capsules to transport astronauts to and from the space station. NASA awarded Boeing a $ 4.2 billion contract, and SpaceX received a $ 2.6 billion deal in 2014 to complete development of the Starliner and Crew Dragon spacecraft.
Public-private partnerships were designed to end the United States’ dependence on the Russian Soyuz spacecraft to transport the crew to and from the space station.
While Boeing still has at least two Starliner test flights, one with no crew members and one with astronauts, before the capsule is declared operational, SpaceX is nearing the end of the Crew Dragon development program. The human classification capsule was first launched with astronauts on May 30 on the Demo-2 mission, and it delivered NASA test pilots Doug Hurley and Bob Behnken to the International Space Station the next day.
Hurley and Behnken are scheduled to leave the station on August 1 and leave the Florida coast on August 2, completing a mission spanning more than two months. Once the Dragon Crew returns to Earth, SpaceX and NASA engineers plan to formally certify the SpaceX crew capsule for regular crew rotation missions to the space station, beginning with a late launch. September from the Kennedy Space Center that transports four astronauts to the research complex in orbit for a six-month expedition.
The mission slated for launch in late September, known as the Crew-1, will be followed by at least five other Crew Dragon operational missions through 2024.
NASA said last month that it will allow SpaceX to reuse the Crew Dragon spacecraft and Falcon 9 thrusters for NASA astronaut missions. NASA says SpaceX could begin reusing Crew Dragon vehicles and the early stages of Falcon 9 in manned launches that begin with the second post-certification mission, or Crew-2.
Crew-2 is scheduled for launch in February 2021. The Crew-1 mission, SpaceX’s first operational astronaut flight, is scheduled to fly with a new Crew Dragon spacecraft and a Falcon 9 rocket.
Each of SpaceX’s operational crew’s rotational flights to the space station will carry up to four astronauts, including NASA space flyers and space station international partners.
NASA has assigned astronauts Mike Hopkins, Victor Glover, and Shannon Walker to the Crew-1 mission. Japanese astronaut Soichi Noguchi will join American astronauts on the Crew Dragon spacecraft.
“You are seeing the beginning of the rotating use of commercial crew systems in transporting our astronauts to the ISS,” said McErlean.
At the public safety panel meeting on July 23, McErlean said SpaceX is currently planning to restore and reuse the Crew Dragon spacecraft that is flying on the Demo-2 mission on the Crew-2 mission next year. That crew capsule was named Dragon Endeavor by Hurley and Behnken shortly after its launch in May.
SpaceX also aims to reuse the Falcon 9 rocket assigned to the Crew-1 mission again at Crew-2 launch next year, McErlean said.
“So in this case, Crew-2 will fully utilize SpaceX’s reuse philosophy,” said McErlean. “Although the reuse has been successful in previous releases, the use of pre-flown hardware for a human space flight mission is unique, and will create additional work for NASA, which must meet human certification requirements.”
Boeing also plans to reuse the Starliner crew capsules on multiple flights. Unlike the crew Dragon, which splashes into the sea, the Starliner parachutes to a padded airbag landing on the ground.
McErlean, representing the safety advisory panel, said NASA must also keep up with SpaceX’s philosophy of “constantly evolving vehicle designs” with an “ongoing formal safety-related process” to ensure modifications remain. within the agency’s human qualification certification requirements.
“With the completion of the Demo-2 mission and the appropriate vehicle changes driven by the data collected during that mission, NASA will have essentially completed the certification process required for NASA personnel flying on SpaceX hardware.” McErlean said. “However, it is the opinion of the panel that, given SpaceX’s approach to hardware upgrades, NASA has to decide by what processes it will continue to monitor vehicle and system changes to ensure those changes still remain in one position. certified security guard for human space flight operations. “
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