Astronauts Victor Glover, Michael Hopkins, Shannon Walker, and Soichi Noguchi have arrived at the Kennedy Space Center in Florida for their upcoming launch to the International Space Station (ISS).
SpaceX’s Crew-1 will be the first operational, long-duration mission to the ISS onboard a Crew Dragon spacecraft and NASA’s Commercial Crew Program. Liftoff from Launch Complex 39A is currently scheduled for Saturday, 14 November 2020 at 19:49 EST (00:49 UTC on 15 November) — weather permitting.
The astronauts departed from Ellington Field near the Johnson Space Center in Houston and flew to Kennedy aboard a charter plane. Upon arrival, they were greeted by NASA Administrator Jim Bridenstine, Deputy Administrator Jim Morhard, Center Director Bob Cabana, and manager of JAXA’s International Space Station program, Junichi Sakai.
Bob Cabana greeted the crew, saying: “I can’t tell you how great it is to welcome a crew here to go to space again. I envy each and everyone of you. This whole effort to commercialize low Earth orbit, this is just a gigantic step in making that happen.”
Jim Bridenstine added, “I want to recognise what’s happened here at KSC. The transformational effort to make this a multiuser spaceport, Bob’s been leading that for over a decade. The partners we have here in SpaceX and Boeing for our commercial crew program, it’s all from his work. Thank you for that.”
“Today, we are taking another big leap in this transformation in how we do human spaceflight. NASA is one customer of many. Make no mistake, every flight is a test flight when it comes to space, but we need to be able to routinely go to the Space Station. We’re grateful to SpaceX for the Falcon 9 rocket and Dragon. We’re thankful to KSC workers and to our crew.”
Mike Hopkins, Crew-1 Commander continued: “It feels really good to be here. On behalf of the crew of Resilience, we want to say a big thank you to SpaceX and NASA and the DOD who have been working tirelessly to get us to this point. For the crew, we’re ready.”
Victor Glover, the only person without a previous spaceflight on this mission, enthused: “Today we flew here in a plane, but the plan is to leave on a rocket.”
Soichi Noguchi, reflecting on his third space flight on his third vehicle said, “Prime Crew at KSC, that’s the best part.”
Originally scheduled for 31 October, the mission was delayed 15 days to allow SpaceX to work out the problems with its Merlin engine which powers the Falcon 9. The engine suffered a problem with its gas generators during the first launch attempt for the GPS III SV04 mission in early October, initiating an auto-shutdown sequence at T-2 seconds.
Hans Koenigsmann, Vice President of Build and Flight Reliability at SpaceX later said that sensors detected an unusual pressure rise in gas generators on two Merlin engines. “When we looked at the data, we saw that two of the engines attempted to start early, and the auto abort prevented that. By doing that, it prevented a possible hard start that could have been damaging to the engine hardware.”
The Merlin engine is powered by RP-1 kerosene and liquid oxygen, one of the oldest-used mixtures in the aerospace industry. To ignite the engine, a green-colored compound known as TEA-TEB (triethylaluminium-triethylborane) is used. TEA-TEB is a pyrophoric mixture, meaning it combusts in exposure to air.
Koenigsmann added, “You need to introduce these liquids in the right order. If you do this in the wrong order, or if you happen to throw in the liquid oxygen and the RP-1 and the igniter fluid, then what would happen is… we call it a hard start. A hard start would rattle the engine in most cases but could cause damage. So in general, you don’t want that. You want a good startup.”
“If we see the pressure rise too early, then we know the liquid is in there, and it shouldn’t be there,” he said. “And software in the engine controller then stops the whole process.”
Even though no hardware problems were uncovered at the launch pad, the two engines were sent to SpaceX’s test facility in McGregor, Texas to hone in on the problem. Teams were able to analyze the engines’ startup behavior, and additional inspections found a blockage in a narrow line leading to a relief valve on the gas generator.
The vent port, which is just one-sixteenth of an inch wide, was obstructed by hardened masking lacquer. Koenigsmann described it as similar to red nail polish.
The gas generator on each Merlin engine drives a turbopump feeding RP-1 kerosene and liquid oxygen to the main combustion chamber.
Engineers at SpaceX’s McGregor test site also demonstrated that the engines performed normally after removing the blockage from the vent valve. Koenigsmann said that the issue was “very subtle,” but could’ve had some negative impact on the engine operation.
After analyzing data from previous engine testing, the team found “similar early tendencies” on two engines for the Crew-1 first stage, the two engines on the GPS stage, one on a new booster that is scheduled to launch Sentinel 6A, a NASA-ESA oceanography satellite.
The engines on the Crew-1 booster were replaced, according to Steve Stich, NASA’s Commercial Crew Program Manager.
With GPS III SV04 launching successfully on 6 November, the data from those Merlin engines will be used in the Flight Readiness Review and Launch Readiness Review, currently scheduled for 9 and 12 November, respectively.
The Flight Readiness Review will evaluate the overall readiness of all the teams and flight hardware to be cleared for launch. The Launch Readiness Review will provide one final moment to discuss the data obtained during the Falcon 9’s static fire on pad 39A, currently scheduled for Tuesday, 10 November.
SpaceX’s Crew Dragon will be the first commercially developed Crew vehicle approved by NASA to fly humans on long-duration missions at the completion of Monday’s Flight Readiness Review.
The Crew-1 astronauts will join NASA Astronaut Kate Rubins and Roscosmos cosmonauts Sergey Ryzhikov and Sergey Kud-Sverchkov as a part of Expedition 64, the current-long duration expedition to the International Space Station.
Of note, Tropical Storm/predicted-Hurricane Eta is currently threatening the Kennedy Space Center with prolonged bad weather — with a close pass to the spaceport possible on the 14th per current forecasts from the National Hurricane Center.