SpaceX’s Starship Successfully Passes Cryo Testing

According to SpaceX CEO Elon Musk, the Starship high-altitude model SN8 has successfully passed cryo testing. The tests were meant to determine how the fuel tanks and associated hardware would hold up to the super-cold temperatures that they will have to endure when filled with super-chilled liquid rocket fuel.

SpaceX ran SN8 through its paces over the course of a few days, beginning with an apparently aborted test on October 5 and 6 in which it filled the rocket’s fuel tanks with super-cold nitrogen gas and a small amount of liquid oxygen. SN8 also moved its aft flaps under its own power for the first time.

During the first attempt to fill its tanks with nitrogen, SN8 apparently suffered a small leak near the engine mounts. SpaceX personnel noticed the link at a pressure of about 7 bar, or 100 pounds per square inch. According to a tweet from Musk, the leak was apparently due to differential shrinking, which is a common concern when handling materials in extreme temperatures. The severely cold weather on the day of the 1986 Challenger disaster is believed to have been a factor in the loss of the Space Shuttle and its crew during launch.

In this case, the rocket was never in any danger of exploding and the leak was fixed within 24 hours. The second and third tests went smoothly while SpaceX ran its rocket model through simulations of the stresses that it will go through when launched using Raptor engines.

The next test is likely to be a full rundown of how SN8 would hold up to a static firing of the Raptor engines, each of which are capable of a thrust of 440 klbf. If things go as planned, the fully operational version of Starship will make use of three Raptors that are rated for operation at sea level and three more Raptors that can operate in the vacuum of space.

The successful cryo tests mark one more milestone in preparation for a possible high-altitude test that could go to an altitude of 15 kilometers. A previous “hop test” of a test rocket sent it to an altitude of about 150 meters.

The fully operational rocket will be capable of launching 100+ metric tons of payload into low Earth orbit and will also be capable of sending payloads to the Moon and Mars. Current contracts with NASA include a customized “lunar Starship” that will be capable of sending cargo and astronauts to the Moon. Information on SpaceX’s official website also indicates that fashion mogul Yusaku Maezawa’s planned flight around the Moon on Starship is still slated for 2023.