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Comment by Laremere | Hacker News Reader

No.

This is the second integrated flight test. Even if this flight fully meets all of its goals, it won't /really/ be a successful launch by standard measures.

Starship (the top part) has successfully completed several suborbital hops, including a "bellyflop". So in that sense, yes.

This upcoming test involves launches with both Starship and the Super Heavy Booster. Succeeding the current mission goals would be the booster soft(ish) landing in the ocean near the launch site, and the Starship obtaining a parabolic arc before surviving reentry to crash into the ocean near Hawaii.

To really have a "success" by standard measures under their belt, SpaceX will need to target having Starship actually orbiting with a test payload (probably Starlinks). After that "success", they're likely to still have secondary mission failures with landing the booster, and deorbiting and landing Starship.

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Gotcha! So this test criteria this weekend may not be to reach orbit, but just test out heavy booster and getting starship correct trajectory.

If they crash into the ocean do you know if they are supposed to be recoverable or will they sink?

It is not supposed to be recoverable for reuse.

Best case, they get to test the new sound dampening, armored pad, armored pad cooling, igniting all the engines on the pad, booster launch, staging, booster fly back, booster descent, booster landing (though not on anything solid). If that works they have a booster floating in the Gulf of Mexico they need to clean up.

For Starship they get to test staging, engine in vacuum, bellyflop control from very high altitude to sea level. Apparently all the way to sea level. They do not appear to be planning the reignition and flip. They may set the record for "most powerful bellyflop".

All the excitement is in the first 9 minutes of the flight. A little over an hour later the Starship's "orbit" will intersect too much atmosphere and will re-enter for about 12 minutes.

As for why not to try landing the Starship on water, I think they'll play with all their available fuel mass in vacuum. Those engines haven't operated there yet.

I'd be surprised if they haven't tested at least one engine in vacuum. You can build a test apparatus for that. Only learned how when I saw this video: https://www.youtube.com/watch?v=hrLyzpTV7GU

The planned nominal trajectory for the first flight (and, I presume, this one as well) set Starship up for re-entry without a deorbit burn, so they're not planning to properly enter orbit at all. This is to avoid the prospect of an uncontrolled re-entry after orbital decay if something went wrong while it was in orbit, or worse if it got up there and the tanks exploded. Elon doesn't ordinarily choose to be cautious like this, so it probably wasn't entirely his choice.

(They'll be putting out enough energy to demonstrate that it could enter orbit, but the trajectory that they'll be putting it into is an "orbit" that intersects the atmosphere.)

Starship will crash into the ocean at terminal velocity off Hawaii (with no belly flop maneuver to stop descent right above the ocean), there may be some floating bits but not recoverable in any significant sense. The booster will do a landing burn, they will most likely sink it in the gulf and not attempt to tow it back to port.

https://www.spacex.com/launches/mission/?missionId=starship-...

I just did a short search for the SLS test launches, but couldn't find anything. Is this SpaceX fail fast approach to test incrementally, and SLS was just launched the first time with payload, or did I just miss the test launches of that system?

It's a different development approach.

NASA with SLS spent a much longer time and much more money to build ONE rocket, which HAD to succeed. It uses well-established technology and pushes few boundaries.

SpaceX philosophy is to build fast, launch, and iterate on unproven, innovative ideas.

Also SpaceX is building a rocket mass production pipeline rather than a one off mostly custom unit.

Yes, a very good point. The goal is not "build a rocket". It's "build a factory for building many rockets".

The Artemis 1 launch was the first (and only) test launch of the SLS. It was successful, and yes, they launched it with expensive payload, the Orion capsule, which was also tested successfully. On the other hand, the SLS development was and is probably a lot more expensive than for Starship, while being much less technologically advanced.

The new era of dirt cheap space launch costs starts when SpaceX successfully launches 100 tons to LEO on a previously used booster and starship, then lands them again. Given how few flights are scheduled from Boca Chica it's fair to assume it will be at least a year before that, possibly longer.

However, in so far as the raptor engines have flown, the belly flop maneuver has been validated, and the full stack has flown, once they're landing the booster and starship following successful payload deliver we could say that the new era started when raptor first flew.

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