Boeing’s Starliner spacecraft parachuted to a “picture perfect” landing in southern New Mexico Wednesday, capping a six-day test flight to the International Space Station that NASA’s commercial crew program manager said paves the way for the next Starliner mission to carry astronauts.
The crew capsule touched down at White Sands Space Harbor, co-located with the U.S. Army’s White Sands Missile Range, at 6:49 p.m. EDT (4:49 p.m. MDT; 2249 GMT).
Three red, white, and blue parachutes slowed the capsule to gentle landing velocity of 17.7 mph (28.5 kilometers per hour). Airbags at the bottom of the spacecraft cushioned the jolt of touchdown, ending a long-delayed demonstration mission to the International Space Station.
The Starliner’s landing occurred about four hours after the Starliner capsule undocked from the station.
The Starliner program’s first test flight in December 2019 failed to reach the station. A software programming error caused the spacecraft to burn through much of its propellant after launch, and managers cut short the test flight, which was also plagued with communications issues. The capsule safely returned to the same landing site in New Mexico.
This time, the mood was jubilant among NASA and Boeing officials.
“The test flight was extremely successful,” said Steve Stich, NASA’s commercial crew program manager. “We met all the mission objectives. Of course, today was a big one with the undocking, the separation sequence, and then the de-orbit burn, entry and landing.”
NASA’s commercial crew program managers the Starliner contract with Boeing. Since 2010, the U.S. space agency has signed a series of cost-sharing agreements and service contracts with Boeing’s Starliner program valued at more than $5.1 billion. Once certified for human spaceflight missions, the Starliner will ferry astronauts to and from the space station.
Next for the Starliner program is a test flight with astronauts.
“When I look at what happened in the flight and the kinds of things we’ll need to work through over the next few months, I don’t see any reason why we can’t proceed toward Crew Flight Test next,” Stich said.
“We have a few things to work on between now and then, but I don’t really see any showstoppers this time relative to last time, when we had challenges to the software and the comm (communications) system.”
The problems found on the 2019 test flight caused a two-year delay in the program. Last year, Boeing moved a Starliner spacecraft to the launch pad for a redo, but engineers discovered stuck valves in the propulsion module during a pre-launch checkout. Teams removed the capsule from its launch vehicle for troubleshooting, and ultimately switched the spacecraft to a new service module before preparing for another try this month.
The mission — designated Orbital Flight Test-2, or OFT-2 — blasted off May 19 from Cape Canaveral top of a United Launch Alliance Atlas 5 rocket. The spacecraft docked at the station about 26 hours later, and astronauts on the research outpost opened hatches to enter the Starliner capsule Saturday for inspections and testing.
The spacecraft departed the research complex at 2:36 p.m. EDT (1836 GMT) Wednesday, then backed away a safe distance before firing four of its rear-facing thrusters for a braking burn at 6:05 p.m. EDT (2205 GMT) to drop out of orbit.
The 58-second deorbit burn set the Starliner spacecraft on course for landing at White Sands. The capsule jettisoned its disposable power and propulsion module to burn up in the atmosphere over the Pacific Ocean. That left the reusable crew module to re-enter the atmosphere for a scorching descent, withstanding temperatures as high as 3,000 degrees Fahrenheit (1,650 degrees Celsius).
Approaching White Sands from the southwest, the Starliner spacecraft released two drogue parachutes to stabilize itself before the deployment of three large main chutes. During the last phase of the descent, the capsule let go of its base heat shield, allowing six airbags to inflate for a softer landing.
Touchdown confirmed! Starliner is back home to wrap up a test flight to the International Space Station, landing at White Sands Space Harbor in New Mexico six days after launch from Cape Canaveral. https://t.co/TcKCTaaxGr pic.twitter.com/kraJOEhl3P
— Spaceflight Now (@SpaceflightNow) May 25, 2022
After touchdown, recovery teams from Boeing and NASA approached the capsule on the desert floor. They temporarily backed off after instruments detected traces of toxic hydrazine vapor, a fuel used by the craft’s rocket thrusters. A few minutes later, officials deemed the spacecraft safe, and teams opened the hatch to begin unloading time-critical cargo packed by the crew on the International Space Station.
The cargo included hardware for tissue engineering research experiments, and three empty air tanks that will be refurbished and flown up to the station on a future mission.
Boeing’s recovery team will prepare the spacecraft for shipment across the country back to the Starliner factory and processing facility at the Kennedy Space Center in Florida. It’s expected to arrive there around June 9 to begin preparations for a future crew mission.
The aerospace contractor has another Starliner crew module that will launch on the next test flight with two or three NASA astronauts. NASA will determine the final crew complement for the Crew Flight Test in the coming months.
“This is what we were hoping for — a soft, safe landing,” said NASA astronaut Butch Wilmore, who is training to fly to the space station on Boeing’s Starliner spacecraft. Wilmore called the Starliner test flight a “wonderful, successful mission.”
“We’re really pleased with the mission,” said Mark Nappi, a Boeing vice president and manager of the Starliner program. “All of the objectives of the demonstration have been satisfied. The next step is to really dig down into all the details of the mission.”
Engineers are studying why two of the Starliner spacecraft’s Orbital Maneuvering and Attitude Control, or OMAC, thrusters shut down during a burn soon after launch last week. The thrusters are made by Aerojet Rocketdyne, and generate about 1,500 pounds of thrust for major in-orbit maneuvers.
The Starliner spacecraft has 20 OMAC rocket engines, and had enough redundancy to overcome the thruster failure without any major impacts to the mission. Stich, NASA’s commercial crew program manager, said mission control test-fired the suspect OMAC engines after undocking from the station Wednesday, and telemetry data indicated the engines only produced about 25% of their expected thrust.
Engineers will analyze data from the mission to determine the most likely cause of the thruster failures. Nappi said he doesn’t expect the OMAC engine problems to force any design change to the Starliner propulsion system.
“I’m optimistic that we’ll be able to explain these and move on,” Nappi said.
Two smaller Reaction Control System thrusters also stopped working during the Starliner spacecraft’s rendezvous with the station. But those smaller rocket jets worked well after undocking Wednesday, and mission control reactivated the two RCS thrusters.
The RCS and OMAC engines were on the Starliner service module, which burned up during re-entry into the atmosphere.
Just before landing, a maneuvering jet on the Starliner crew module also appeared to stop working, Stich said. Boeing engineers will be able to get a hands-on look at that thruster.
The spacecraft’s cooling system also ran into some difficulties during the flight up to the space station. But ground controllers uplinked commands to stabilize the thermal control system, which uses two coolant loops connected to radiators to dissipate heat generated from the spacecraft’s electronics.
The navigation system on the Starliner spacecraft also took longer to configure after the capsule departed the station Wednesday.
“The things that we encountered in flight were really loss of redundancy in several thrusters,” Stich said. “We needed to learn how to manage the cooling loops. We needed to learn how to manage a little bit aligning the navigation system after we undocked today, which we did.
“Then you look at the entry sequence. That went flawlessly, and that system has to work perfectly every time, including the landing system, the parachutes, the airbag system. The cabin temperature was 70 degrees to 74 degrees, which is what we need for the crew.”
Boeing is on track to have the next Starliner spacecraft ready to fly with astronauts by the end of this year, Stich said.
But there’s a lot of work to complete before NASA clears the capsule to launch astronauts. Then officials have to find an opening in the International Space Station’s busy schedule of visiting cargo and crew vehicles, and a slot on ULA’s Atlas 5 launch schedule.
“Certainly, it could move into the first quarter of next year,” Stich said of the Starliner’s Crew Flight Test.
Nappi said Boeing and NASA are “probably several months” from firming up a schedule for the first Starliner crew mission.
The Crew Flight Test will likely last a week or two, Stich said. NASA negotiated with Boeing for an option to extend the Starliner’s Crew Flight Test as long as six months, in case the agency needs the astronauts to serve as members of the space station’s long-duration crew.
Following the Crew Flight Test, Boeing will launch six operational Starliner crew rotation missions to the station. Once the Starliner is operational, NASA wants to alternate between crew rotation flights using Boeing’s crew capsule and SpaceX’s Dragon spacecraft.
SpaceX launched astronauts for the first time in May 2020, operating under a contract similar to Boeing’s deal with NASA.
Boeing and NASA will complete software updates for the Starliner cockpit displays in the next few months. Later this summer, astronauts will participate in ground tests with Boeing’s spacesuit and the Starliner seats. A comprehensive test of the Starliner’s environmental control and life support systems is also planned this summer, according to Stich.
Engineers will also evaluate the performance of the Starliner’s propulsion system valves on the OFT-2 mission.
Stuck oxidizer isolation valves caused the Starliner’s launch delay from last year. Investigators traced the cause to corrosion generated from a chemical reaction between the valves’ aluminum housing, nitrogen tetroxide propellant vapors, and moisture that got into the propulsion system.
Boeing added a pre-launch nitrogen purge on the Starliner service module to prevent moisture from getting into the valves. Engineers are considering reducing the amount of aluminum in the valve housing for future missions, but Boeing officials believe the Crew Flight Test can go forward without a valve redesign, Nappi said.
“We are not going to rush into anything unsafely,” Nappi said. “We monitor our resources on a weekly basis. We make sure that we’re working the appropriate amount of hours, and we’re not pushing any discipline beyond our limits.”
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