SpaceX successfully launched three Falcon 9 rockets at a brisk pace over the weekend, putting 67 Starlink satellites into orbit within three days of the Federal Aviation Administration giving it approval to resume launches following a rare mid-flight failure on July 11.
SpaceX kicked off its return to flight by launching 23 Starlink internet satellites from the Kennedy Space Center early Saturday, followed by a second Starlink launch from Cape Canaveral Space Force Station early Sunday, which put 23 more high-speed relay stations into orbit. The third Falcon 9 launched a few hours later from Vandenberg Space Force Base in California.
All three flights appear to have gone off without a hitch.
NASA is counting on Falcon 9s to launch a Northrop Grumman Cygnus resupply ship to the International Space Station on Aug. 3, followed by a SpaceX Crew Dragon flight to carry three agency astronauts and a Russian cosmonaut to the lab around Aug. 18.
The second stage planned for use with the manned flight, known as Crew 9, will be tested in the coming days at a SpaceX facility near McGregor, Texas, to verify that the company’s corrective measures will not have unintended consequences.
SpaceX
“It’s going to go through a second hot fire stage around July 30, and that’s really going to be to verify some of the new modifications that the vehicle will have as a result of the anomaly,” Steve Stich, NASA’s commercial crew program manager, said Friday.
“We have followed the FAA’s investigation step by step. SpaceX has been very transparent, our teams have been integrated into the investigation and have followed all the changes on this thruster.”
The space agency has yet to officially authorize the launch of these flights, but SpaceX’s successful return to flight this weekend will undoubtedly play a role in the final decision.
Boeing engineers also had a busy weekend, successfully testing 27 maneuvering thrusters on the company’s aircraft. The Starliner capsule is now docked with the International Space Station.
The tests verified the proper performance of the reaction control system (RCS) thrusters, which had previously experienced problems, and confirmed that known helium leaks in the capsule’s propulsion system had remained stable and had not worsened.
Tests suggest the thrusters will function properly when the ship eventually returns to Earth.
“The single-pulse firings were designed to confirm the performance of each thruster,” Boeing wrote in an update. “Between each firing, the team reviewed real-time data and all thrusters operated at maximum thrust values.”
“The helium system also remained stable,” the company said. “In addition, an RCS oxidizer isolation valve that was not fully closed previously was actuated several times during (Saturday’s) testing and is now operating normally.”
Launched June 5 on the spacecraft’s first manned test flight, the Starliner crew — Commander Barry “Butch” Wilmore and co-pilot Sunita Williams — was originally scheduled to spend about eight days in space.
The mission is now nearly two months long due to work to resolve thruster issues and five helium leaks, one detected before launch and four that developed during the capsule’s rendezvous with the space station.
NASA is expected to hold a major evaluation later this week to assess the test data and determine the spacecraft’s readiness to return Wilmore and Williams safely to Earth.
William Harwood/CBS News
As for SpaceX and the Falcon 9, the company blamed the July 11 failure on a crack in an upper stage sensor line, caused by a loose bracket and metal fatigue, which led to a liquid oxygen leak.
The leak, in turn, caused extremely low temperatures in the engine’s plumbing, slowing the flow of a fluid needed to restart the powertrain for a second, planned “burn.”
Instead, the engine suffered a “hard start” that damaged several components, preventing the rocket from reaching its intended orbit. While the stage remained intact, the Starlinks it was carrying into space were released into a much lower orbit than intended and subsequently burned up in the atmosphere.
Sarah Walker, a SpaceX official, said Friday that the “sensor line” was not needed and would simply be removed from downstream rockets. She added that the data provided by the line was available from other telemetry sources aboard the rocket.
As for Crew Dragon flights, she added, the second stage engine only fires once, and the leak that derailed the Starlink launch would not have been a factor in a manned flight. In any case, the leaked connector will be removed.
“I have absolute confidence in the team and in the integrated approach NASA is taking to respond to the situation,” said Nick Hague, Crew 9 co-pilot and veteran of the Russian Soyuz launch failure. “And I look forward to hanging on to the rocket when the team decides it’s time to go.”
He said the crew was training at SpaceX headquarters in Hawthorne, California, the day after the Starlink launch anomaly “and from the beginning they brought us into the conversation and told us everything they knew.”
The Federal Aviation Administration, which is responsible for granting launch licenses in the United States, has approved SpaceX’s analysis of the failure, concluding that “no public safety concerns were involved.”
“This public safety decision means the Falcon 9 vehicle can resume flight operations while the overall investigation remains open, provided all other licensing requirements are met,” the FAA said in a statement.
In addition to providing an update on SpaceX’s near-term plans for the Falcon 9, Walker also addressed an unexpected issue with debris from Crew Dragon trunk sections that managed to survive the heat of reentry to hit the ground.
The trunk section, equipped with solar cells, helps power the Crew Dragon in space and transports external station payloads into orbit in an unpressurized environment.
Before re-entering the atmosphere, the trunk is jettisoned. The crew capsule, equipped with a heat shield, then fires its braking rockets to leave orbit and make a precisely targeted splashdown in the ocean. The trunk continues its low orbit and eventually re-enters the atmosphere in an uncontrolled manner.
Early in the program, engineers concluded that the entire trunk would burn up completely upon reentry. But on several occasions, relatively large, charred pieces of trunk debris survived reentry and struck the ground.
The returning Crew Dragon astronauts and the recently launched Dragon resupply ships have all returned to landings off the coast of Florida, either in the Gulf of Mexico or the Atlantic Ocean.
Walker said SpaceX now plans to move all Crew Dragon cargo and capsules to the Pacific Ocean off the West Coast. Sections of the capsule will now be jettisoned after the deorbit rocket launches, ensuring that they reenter the atmosphere in roughly the same area as the crew and cargo capsules, which is well out to sea.