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The profile for IFT-6 is expected to be similar to that IFT-5, and I don't see any significant changes announced anywhere. This is strange for SpaceX, which usually makes significant changes between test flights and seems relatively unbothered by failures. Considering that IFT-5 went more or less perfectly, why would SpaceX spend their time, resources, and money (a full $90 million) do the same thing they've already done and succeeded at?

There are many things that I could imagine SpaceX could do on IFT-6. For example, they could try opening the payload door, testing an engine relight for Starship, reusing Booster 12, launching a Block 2 ship, landing Starship's upper stage, going to actual orbit, or any combination of the above. Why wouldn't they do something new for IFT-6 rather than just wasting $90 million, a vehicle, and their time?

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  • $\begingroup$ I would suspect that since the FAA license lets them redo the flight, no changes, they can quickly redo it, with a vehicle already built. That otherwise they will scrap. More data is always good. Catching it twice is much better than catching it once. $\endgroup$
    – geoffc
    Commented Oct 20 at 16:13
  • $\begingroup$ @geoffc When in the entire Starship testing campaign has SpaceX ever done the same exact thing twice, no changes (outside of Starhopper which could easily refly)? SpaceX generally makes big leaps, they aren't stagnant. I don't get the point of spending all that money, time, and resouces to do something they have already proven they could do. Why would the scrap a vehicle rather than use it for a useful purpose? $\endgroup$
    – Starship
    Commented Oct 20 at 16:20
  • $\begingroup$ the answer to "why would SpaceX continue their test campaign with this" is always going to be "because there are things to test" $\endgroup$
    – Erin Anne
    Commented Oct 20 at 17:17
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    $\begingroup$ Ship 31 is their last block 1 ship. It is expected that they aren't going to try orbiting or pretty much anything else new until block 2. Block 2 has a large number of expected changes, too many to list in comments maybe someone will list them in an answer. Not even payload testing because block 2 has a different sized payload bay. The first block 2 ship is ship 33 and it's likely not going to be ready by end of year. Meanwhile ship 31 has been static fired and is pretty much ready to go although it's expected they will probably replace the heat shield tiles which will take a few weeks. $\endgroup$
    – Steve Pemberton
    Commented Oct 20 at 20:26
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    $\begingroup$ @Starship - "Total waste" dismisses some of the comments that you have received, was that your intention? As for launching Starlinks, my guess is the Starlink deployment mechanism and/or payload door on a block 1 ship would not be exactly the same as on block 2. Not really worth designing and building a one-off version if it will only fly once. Also until a week ago it was not known if ship 31 would be making the first catch attempt, in which case that would have been the “new” thing that ship 31 would have been doing. $\endgroup$
    – Steve Pemberton
    Commented Oct 20 at 20:57

3 Answers 3

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There are many things that I could imagine SpaceX could do on IFT-6. For example, they could try opening the payload door,

They already did that. The payload door design hasn't changed, so there's no reason to expect a different result. The payload door design on Starship V2 is different, so there is no reason to expect the results to be valid for that iteration of the Starship.

testing an engine relight for Starship,

They could, but Starship V2 has significantly different engine plumbing, and Raptor 3 is a significantly different engine, so it wouldn't tell them much.

reusing Booster 12,

Super Heavy Booster 12 sustained significant damage to the engine section, which would require lengthy repairs. Also, it's not exactly a good test of reusability if all you reuse is the tanks, but you swap out or repair all the engines.

launching a Block 2 ship,

They don't have one.

landing Starship's upper stage,

That would require throwing away Super Heavy, which is the vehicle for which nailing down reusability is much more important.

going to actual orbit,

That would require demonstrating engine relight first.

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  • $\begingroup$ They have Ship 33, which is a block 2 ship. Why would landing the upper stage necessitate not also landing super heavy? Why would going orbit require demonstrating engine relight? $\endgroup$
    – Starship
    Commented Oct 21 at 12:45
  • $\begingroup$ @Starship Ship 33 still hasn't had its engines installed yet and still needs to undergo a WDR and static fire. IFT-6 could possibly happen as early as November, I am don't think ship 33 will be ready, unless they don't use Raptor 3 for the early Block 2 prototypes. Also, they can risk immediately going to orbit, but it is safer to demonstrate an engine relight first, because if it goes wrong, it is better to have Starship then crash in the ocean rather than having the biggest rocket ever built, flying uncontrolled with a chance of crashing anywhere on it's orbital path. $\endgroup$
    – The Rocket fan
    Commented Oct 21 at 14:38
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    $\begingroup$ @Starship well I think that answers your question. All ships except ship 26, currently have a heatshield, so unless they send S26 on IFT6, they’re probably not going to go orbital $\endgroup$
    – The Rocket fan
    Commented Oct 21 at 14:57
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    $\begingroup$ @Starship aside from "just remove the heat shield" involving a remarkable amount of effort, enormous pieces of Dragon's trunk make it down to the ground from orbit. There's no telling how big the pieces of Starship would be. $\endgroup$
    – Erin Anne
    Commented Oct 21 at 18:29
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    $\begingroup$ "SLS is bigger than starship and NASAis generally much more failure adverse." – The ICPS is tiny compared to Starship, and while the Core stage probably could go to orbit, it does not go to orbit on purpose, precisely because the RS-25 cannot relight in space. "SpaceXdidn’t do relight tests with any of their other vehicles." – The Falcon 9 upper stage is tiny compared to Starship and the Falcon 1 upper stage even tinier. And, did you forget that just last month, Falcon 9 was grounded precisely because it failed to properly deorbit? And this is on a vehicle that has flown almost 400x. $\endgroup$
    – Jörg W Mittag
    Commented Oct 21 at 22:06
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As we’ve seen, regulatory agencies don’t exactly move quickly, so if they can still do improvements and then try a sooner test flight it could make sense, rather than changing things and slogging through more delays. After all, they still need to address:

  • the damage to the engine bay of the booster during re-entry
  • the burn-through of the flap(s) on the ship during re-entry

I’m sure they can figure out a few more tweaks that would be beneficial to fly and test without fully changing the flight plan/profile. Yes, IFT-5 was quite successful (more than many expected), but it was in no way flawless.

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    $\begingroup$ Well the FAA did wind up going 1 1/2 months ahead of schedule in the end. Also IFT-4 wasn't a complete success, but SpaceX made some pretty big changes for IFT-5. $\endgroup$
    – Starship
    Commented Oct 20 at 17:11
  • $\begingroup$ Add grid fin of Super-heavy melted by Starship engines during separation. And then there's testing the new launch tower, with a flame trench instead of water deluge system. And there's streamlining everything for rapid relaunch needed for orbital refueling. $\endgroup$
    – SF.
    Commented Oct 21 at 8:51
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There are many things that I could imagine SpaceX could do on IFT-6. For example, they could try...testing an engine relight for Starship

During IFT-6, one of Starship's Raptor engines was reignited in space.

The profile for IFT-6 is expected to be similar to that IFT-5, and I don't see any significant changes announced anywhere.

In addition to the relight, according to SpaceX, IFT-6 tested "a suite of heatshield experiments and maneuvering changes for ship reentry and descent." SpaceX also made "[h]ardware upgrades for this flight [IFT-6] [which] add additional redundancy to booster propulsion systems, increase structural strength at key areas, and shorten the timeline to offload propellants from the booster following a successful catch" and "updated software controls and commit criteria for the booster’s launch and return." IFT-6 also tested "new secondary thermal protection materials" and had "entire sections of heat shield tiles removed on either side of the ship in locations being studied for catch-enabling hardware" as well as flying "at a higher angle of attack in the final phase of descent, purposefully stressing the limits of flap control."

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