SpaceX’s oldest Crew Dragon spacecraft launched Sunday evening on its fifth mission to the International Space Station, and engineers are crunching knowledge to see if the fleet of Dragons can safely fly as many as 15 occasions.
It has been 5 years since SpaceX launched the primary Crew Dragon spacecraft on an unpiloted take a look at flight to the area station, and almost 4 years since SpaceX’s first astronaut mission took off in May 2020. Since then, SpaceX has put its clan of Dragons to make use of ferrying astronauts and cargo to and from low-Earth orbit.
Now, it is already time to speak about extending the lifetime of the Dragon spaceships. SpaceX and NASA, which shared the price of growing the Crew Dragon, initially licensed every capsule for 5 flights. Crew Dragon Endeavour, the primary within the Dragon fleet to hold astronauts, is now flying for the fifth time.
This ship has spent 466 days in orbit, longer than any spacecraft designed to move individuals to and from Earth. It will add roughly 180 days to its flight log with this mission.
Crew Dragon Endeavour lifted off from Florida aboard a Falcon 9 rocket at 10:53 pm EST Sunday (03:53 UTC Monday), following a three-day delay as a consequence of poor climate circumstances throughout the Atlantic Ocean, the place the capsule would ditch into the ocean within the occasion of a rocket failure throughout the climb into orbit.
Commander Matthew Dominick, pilot Michael Barratt, mission specialist Jeanette Epps, and Russian cosmonaut Alexander Grebenkin placed on their SpaceX strain fits and strapped into their seats inside Crew Dragon Endeavour Sunday night at NASA’s Kennedy Space Center. SpaceX loaded liquid propellants into the rocket, whereas floor groups spent the ultimate hour of the countdown evaluating a small crack found on Dragon’s facet hatch seal. Managers in the end cleared the spacecraft for launch after contemplating whether or not the crack may pose a security menace throughout reentry on the finish of the mission.
“We are assured that we perceive the difficulty and may nonetheless fly the entire mission safely,” a member of SpaceX’s mission management crew advised the crew inside Dragon.
This mission, referred to as Crew-8, launched on a model new Falcon 9 booster, which returned to touchdown a couple of minutes after liftoff at Cape Canaveral Space Force Station. The Falcon 9’s higher stage launched the Dragon spacecraft into orbit about 12 minutes after liftoff. The four-person crew will dock on the area station round 3 am EST (0800 UTC) Tuesday.
Crew-8 will change the four-person Crew-7 crew that has been on the area station since final August. Crew-7 will return to Earth in about one week on SpaceX’s Crew Dragon Endurance spacecraft, which is flying in area for the third time.
The Crew-8 mission come residence for a reentry and splashdown off the coast of Florida in late August of this yr, wrapping up Crew Dragon Endeavour’s fifth journey to area. This is the present life restrict for a Crew Dragon spacecraft, however do not depend out Endeavour simply but.
Fleet administration
“Right now, we’re licensed for 5 flights on Dragon, and we’re taking a look at extending that life out,” mentioned Steve Stich, NASA’s industrial crew program supervisor. “I believe the purpose can be for SpaceX to say 15 flights of Dragon. We could not get there in each single system.”
One by one, engineers at SpaceX and NASA are taking a look at Dragon’s structural skeleton, composite shells, rocket engines, valves, and different parts to see how a lot life is left in them. Some elements of the spacecraft slowly fatigue from the stresses of every launch, reentry and splashdown, together with the intense temperature swings the capsule sees 1000’s of occasions in orbit. Each Draco thruster on the spacecraft is licensed for a sure variety of firings.
Some parts are already accredited for 15 flights, Stich mentioned in a current press convention. “Some, we’re nonetheless in the midst of engaged on,” he mentioned. “Some of these parts must undergo some re-qualification to make it possible for they will make it out to fifteen flights.”
Re-qualifying a element on a spacecraft sometimes includes placing {hardware} by means of intensive testing on the bottom. Because SpaceX reuses {hardware}, engineers can take away an element from a flown Dragon spacecraft and put it by means of qualification testing. NASA will get the ultimate say in certifying the Dragon spacecraft for extra flights as a result of the company is SpaceX’s major buyer for crew missions.
The Dragon fleet is flying extra usually than SpaceX or NASA initially anticipated. The most important cause for that is that Boeing, NASA’s different industrial crew contractor, is working about 4 years behind SpaceX in attending to its first astronaut launch on the Starliner spacecraft.
When NASA chosen SpaceX and Boeing for multibillion-dollar industrial crew contracts in 2014, the company envisioned alternating between Crew Dragon and Starliner flights each six months to rotate four-person crews on the International Space Station. With Boeing’s delays, SpaceX has picked up the slack.
The Boeing delays have been good for SpaceX within the sense that NASA has awarded contract extensions to hold the Crew Dragon program by means of the top of the 2020s. NASA has bought 14 operational Crew Dragon flights from SpaceX, in comparison with six Starliner flights from Boeing. On Sunday evening, SpaceX launched the eighth operational Crew Dragon flight for NASA, and the thirteenth crew flight on Dragon general.
While SpaceX is flying astronauts for NASA, the corporate can also be launching all-private crews to orbit by means of offers with the Houston-based firm Axiom Space and billionaire Jared Isaacman, who plans to carry out the first industrial spacewalk later this yr.
Business is booming, however SpaceX is reaching certification limits on the Dragon spacecraft quicker than anticipated.
SpaceX has 4 human-rated Dragon spaceships, plus three Dragons designed for cargo missions. A fifth Crew Dragon is on observe for completion later this yr, and can most likely make its first flight in early 2025, in response to Stich. SpaceX officers have mentioned this would be the closing Crew Dragon spacecraft the corporate will construct, and the fleet of 5 capsules will probably be sufficient to fulfill demand for Dragon missions till the next-generation Starship automobile is able to take over.
It will probably be a minimum of a number of years, and probably longer, till Starship is licensed for human launches and landings. Until then, Dragons will proceed launching on Falcon 9 rockets, even when some satellite tv for pc missions shift to Starship.
SpaceX has flown a few of its reusable Falcon 9 boosters as many as 19 occasions, almost double the rocket’s unique life expectancy, and is taking a look at certifying Falcon 9s for as many as 40 launches and landings.
Stich mentioned NASA and SpaceX may choose an intermediate variety of flights, someplace between 5 and 15, after they re-certify the Dragon spaceships. A later spherical of testing and evaluations may finally get to SpaceX’s 15-flight purpose. “I want to get out to seven to 10 flights for Dragon, however we’ll see the place we get,” he mentioned.
There are some elements, like warmth defend materials and parachutes, that SpaceX nonetheless wants to switch after every flight.
It’s all the time the valves
During preparations for the Crew-8 mission, SpaceX technicians swapped out valves contained in the spacecraft’s propulsion system that appeared to indicate indicators of corrosion. The valves management the stream of propellant to the Draco thrusters wanted to maneuver the spacecraft in orbit, and to the extra highly effective TremendousDraco engines that might solely fireplace within the occasion of a launch abort.
“We’ve had some valve corrosion within the oxidizer valves, each on the low strain facet which is used on orbit, after which the facet for aborts,” Stich mentioned.
The Draco and TremendousDraco thrusters eat a hypergolic combination of propellants. Hydrazine is the gasoline and nitrogen tetroxide is the oxidizer, and the propellants ignite after they are available in contact with each other. Stich mentioned technicians changed a number of forms of valves within the oxidizer facet of the propulsion system, together with tank isolation valves, Draco manifold valves, and throttle valves for the TremendousDraco abort engines.
“All these were related to corrosion,” Stich said. “I would say all of them were done out of an abundance of caution.”
Engineers monitor how the valves cycle throughout checkouts between flights. “If the timing begins to look somewhat uncommon, we’ll go in and change these valves,” Stich mentioned.
SpaceX
Bill Gerstenmaier, SpaceX’s vp of construct and flight reliability, mentioned the valve points may have one thing to do with put on and tear over the course of Crew Dragon Endeavour’s 4 earlier area missions. But it most likely has extra to do with environmental components, he mentioned.
“I believe it’s extra how can we hold the atmosphere pristine across the valve and stop that (corrosion),” Gerstenmaier mentioned. “We could make some design modifications on the valves sooner or later to work on that space.”
Valve issues are nothing new for SpaceX or just about another area firm.
Boeing had hassle with corroded valves within the Starliner spacecraft. Investigators traced the reason for that drawback to the response of nitric acid with moisture that seeped into the propulsion system. SpaceX apparently detected proof of valve corrosion early, earlier than it manifested right into a extra major problem like that which grounded a Starliner take a look at flight for almost a yr. Gerstenmaier mentioned SpaceX added purges to the propulsion system to forestall contamination from increase on the valves.
Epps lastly in orbit
Jeanette Epps, a mission specialist on the Crew-8 mission, waited almost 15 years to fly in area after NASA chosen her as an astronaut in 2009.
She was set to grow to be the primary Black astronaut to fly a long-duration stint on the area station in 2018, when she was coaching for launch on a Russian Soyuz spacecraft. But NASA changed her with a backup crew member, and the company by no means publicly said a cause for the crew change.
It’s uncommon however not unprecedented for NASA to take away an astronaut from a crew quickly earlier than launch, nevertheless it’s normally for medical causes, like an sickness an harm. In these circumstances, NASA sometimes withholds particulars from the general public as a consequence of privateness issues, however the company has recognized a medical subject as the rationale for changing a crew member.
That was not the case for Epps. Some individuals outdoors the company theorized Epps may need been faraway from her flight for political or racial causes, however Ars has reported that didn’t seem like the case.
Epps, a former CIA know-how intelligence officer, returned from Russia to NASA’s astronaut coaching base in Houston to await one other project. In her public remarks after NASA eliminated her from the Soyuz crew, She was clearly dissatisfied. “It is one thing that I stay with day by day,” Epps mentioned in 2018.
But she declined to “speculate” publicly on the rationale for NASA’s resolution. She mentioned she handed all of her NASA and Russian coaching for the mission. “I did not have any medical circumstances or something like that,” Epps mentioned in 2018. “And I did not have any household points in any respect, both.”
NASA did make Epps eligible for future flight assignments pretty quickly after she misplaced her Soyuz seat. In 2020, NASA added Epps to the crew slated to fly Boeing’s Starliner crew capsule on its first operational mission to the area station, however NASA later reassigned her to coach for a SpaceX launch after continued delays on Boeing’s Starliner program.
She would doubtless have flown on SpaceX’s Crew-5 mission in 2022. But NASA and Russia’s area company signed a long-planned barter settlement to permit SpaceX’s Dragon spacecraft to start ferrying Russian cosmonauts to and from the area station and provides US astronauts seats on Russian Soyuz flights. That meant a Russian cosmonaut took the open seat on the Crew-5 mission.
Epps was final member of NASA’s 2009 astronaut class to fly in area. Some astronauts within the 2009 class have already flown twice. In January, she advised reporters she stored her spirits up by persevering with to coach. Despite the lengthy wait to get into area, Epps is among the many few astronauts who’ve educated to fly on Soyuz, Starliner, and Dragon.
“I’ve been fairly busy over the previous few years nonetheless coaching, nonetheless working towards the purpose of going to the area station,” Epps mentioned.
Matthew Dominick, the Crew-8 commander, can also be a first-time area flier. He was a US Navy take a look at pilot who flew F/A-18 fighter planes earlier than NASA chosen him for the astronaut corps in 2017. Michael Barratt, the Crew-8 pilot and a flight surgeon, is a veteran of two earlier flights to the area station, one on a Soyuz and one other on an area shuttle.
Russian cosmonaut Alexander Grebenkin, one other spaceflight rookie, rounds out the crew. He was a radio communications engineer and served within the Russian navy earlier than becoming a member of Russia’s cosmonaut corps.
March 3, 2024: This story was up to date after the launch of SpaceX’s Crew-8 mission.