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from the preparing-for-the-world's-biggest-belly-flop? dept.
SpaceX's next Starship starts to take shape as Elon Musk talks next steps
Less than a day after SpaceX successfully hopped a full-scale Starship prototype for the first time, the company has begun stacking the next rocket and Elon Musk is talking next steps.
[...] According to Musk, SpaceX intends to perform at least several more smaller hops (a la SN5) "to smooth out [the] launch process." It's unclear which prototype(s) will be involved in that series of hops but after SpaceX is satisfied with the state of launch operations, the plan is to "go high altitude with body flaps." Based on past comments, it's safe to assume that Musk is referring to a plan to launch a Starship to 20 km (~12 mi).
After reaching 20 km, Starship would orient itself belly down – a bit like a skydiver – and quite literally fall its way to ~1 km altitude before attempting an aggressive Raptor-powered pitch-over maneuver and last-second landing. By using Earth's atmosphere much like a skydiver trying to slow down, Starship will theoretically be able to dramatically reduce the amount of propellant it needs to land.
That high-altitude launch and landing demonstration will also be the first time a Starship truly needs aerodynamic control surfaces (i.e. "body flaps") to safely complete a flight test. According to NASASpaceflight.com info, Starship SN8 – also the first full-scale prototype to be built out of a different steel alloy – will be the first ship to receive functional flaps and a nosecone. If initial tests go according to plan, SN8 will also be the first ship to attempt a skydiver-style landing as described above. As far as full-scale aerodynamics goes, such a landing is loosely understood at best. For an orbital-class spacecraft, it's even more of a wildcard.
Regardless, just hours after Starship SN5's successful hop debut, SpaceX began stacking the first of several already finished Starship SN8 sections. Based on the assembly of past prototypes, the ship's tank section could reach its full height just a few weeks from now, while subsequent nosecone and flap installations are uncharted territory.
Previously: SpaceX Completes Static Fire of Starship Prototype, Will Hop Next
SpaceX's Starship SN5 Conducts Successful 150-Meter Flight Test
[Ed. note: Check out https://forum.nasaspaceflight.com/index.php?topic=51332.760 for developments at Boca Chica. Lots of pictures and videos of the sites (launch and construction), deliveries, component construction (e.g. nosecone, thrust ring, main body, etc.), and assembly of these components into actual Starships. And the occasional test firing or launch, too!]
(Score: 2) by Immerman on Friday August 07 2020, @03:51PM
>The rate that I think I read somewhere was 1 engine per 12 days.
Current(ish) production rate? I can see why they'd be disappointed.
Hmm, the article I read was from March, and said they were striving to keep it under $5M per engine... though perhaps that was a misunderstanding and it was $5M for all of them? That would be a bit more consistent, and a lot less expensive.
>It seems pointless. 20 km is enough to test the skydiver belly flop maneuver, apparently.
I think that's just the aerodynamic landing maneuver they're talking about testing. Reentry itself will be a whole additional set of challenges, including (probably) much higher mechanical stress on the flaps, as well as incredible thermal stress and testing of whatever shielding and/or cooling systems they decide on.
I seriously doubt there will be any customers for a SSTO flight that barely reaches orbit, unless maybe they can interest some of the current micro-launch customers. But it would allow them to both test the reentry systems and start building up a reliability record in the long interval before the engines are ready for SuperHeavy some time next year. It'd be more expensive than waiting for customers, but keep in mind that they need to not only master re-entry, but also high reusability and orbital refueling before the next launch window to Mars in two years, and last I heard they were still hoping to launch an infrastructure mission to prepare for a possible human flight in 2024. If Starship can reach orbit on its own (or at least close enough to circle the Earth once so it can return to the launch site) that buys them almost an entire extra year for testing and refinement.