SpaceX’s first orbital Starship prototype prepares for proof tests
Days after SpaceX’s first spaceship prototype made a second trip to a nearby launch site, the rocket is on its way to one of two suborbital launch rigs.
Once installed on the steel structure, Starship prototype 20 (S20) will finally be ready for – at least – two critical tests: a cryogenic proof and static fire. According to highway closures filed by SpaceX late last week, the first of those tests could apparently begin as early as Thursday, August 19, potentially giving Starship S20 at least one major milestone attempt next week.
On August 13, SpaceX Starship S20 . rolled back to the launch site a week after the rocket was sent to the pad to be briefly stacked on a Super Heavy booster – an event that appears to have been about a 50% photo opportunity, 50% test target. Neither the booster nor the ship were fully complete at the time, and both ended up needing at least another week or two of equipment and plumbing to be ready for ground testing — let alone flying. Ambitiously, the same pair — Ship 20 and Booster 4 — could be the first to attempt a true orbital Starship launch sometime later this year.
Since the second rollout, Ship 20 has more or less stayed in one place as workers continuously swarmed around the rocket on boom and scissor lifts. Visually not much has changed in the last four days, other than the installation of a handful of heat shield tiles, but the focus has clearly been around the Starship’s ‘raceway’ – a splice of pipes and wiring that makes up most of the length of the vehicle. continues. back. Virtually all missiles have them, and Starship is no different with a racetrack filled with avionics ziplines, propellant charging lines, and smaller pressure boosting and hydraulics lines.
While it is not entirely clear what specific work has been done in recent days or why it has not been done on the construction site, where CEO Elon Musk himself has said such tasks are more easily done, it is clear that Starship S20 do have a more refined raceway than any other ship before. In recent days, SpaceX has also begun installing structural elements that strongly imply that the S20 will be the first spacecraft to receive a raceway aero cover — not unlike those found on Falcon boosters — to protect the external wiring and piping during the flight. to protect flight.
Regardless, once Starship S20 is installed on one of SpaceX’s two suborbital launch pads, the vehicle will most likely be primed for a routine cryogenic proof test. To succeed, Starship will have to endure significant thermal and mechanical stress, as the tanks are filled with super-cool liquid nitrogen and pressurized to at least 6 bar (~90 psi). At this point, a Starship prototype hasn’t failed cryoproof in over a year, so the test should be fairly routine.
Oddly enough, after weeks of customizing Mount B with a series of hydraulic rams intended to simulate the thrust of Ship 20’s six Raptor engines during its cryo-proof(s), SpaceX removed all that extra hardware just before the second rollout of the Starship and now-impending installation on said mountain. Regardless of why, that decision probably means Starship S20 will move straight to static fire testing once it passes cryo-proofing. Since Ship 20 appears to be on track to be the first Starship prototype of any kind to fire more than three Raptors at once, that static fire campaign will likely be somewhat cautious, possibly starting with just 1-3 engines and then moving to four, five or even six.
SpaceX could also be careful with the wind (not unlikely as evidenced by the removal of Pad B’s unused thrust rams) and install all six Raptors and attempt to fire immediately after Ship 20 completes a cryo-proof. Based on road closures filed by SpaceX, those tests could begin on Thursday, Aug. 19 at 5 p.m. to 11 p.m. CDT. A backup window is also scheduled from 6 a.m. to noon CDT on August 20.