SpaceX Starship : First Flight : Starbase, TX : 20 April 2023 - DISCUSSION

[whitelancer64]

Launch control box in foreground.

What is this?

A joke.

[chopsticks]

Doesn’t sound or look great:

Wonderful.  Now OSHA will shut it down for three weeks for an "investigation".

Please stop with your conspiracy theories.

Sorry if reality triggered you.  No way anybody is just going to crack a beer and give a thumbs up for Monday after something like that.

Just coming back here to remind you of "reality".

[Jimmy_C]

What could be used to mitigate the stuck valve? Replace and retest in this case? Cycling the valve? Insulation or a heater on the valve for future Starships?

[envy887]

What could be used to mitigate the stuck valve? Replace and retest in this case? Cycling the valve? Insulation or a heater on the valve for future Starships?

Do we even know whether it's a vehicle or GSE valve?

[Nomadd]

 I haven't seen the village this quiet in a while.

[EspenU]

Do we know anything about limitations to FTS batteries at this time?
As in how long can the ship remain stacked before they have to bring it down again to swap them?

[MP99]

Oh god NOOOO it's baaaaack, and with untrimmed quotes

Hahahaha!

Not to flog that semantic dead horse, but as far as I've seen, no one here has offered a calculation showing a possible post-SECO trajectory which intersects Earth's surface when calculated without taking atmosphere drag into account (given the expected SECO altitude, approximate apogee, and reentry location).

In lieu of that, I'm trusting Jonathan McDowell:
https://twitter.com/planet4589/status/1647321808658395136
https://twitter.com/planet4589/status/1647324115819278337

Rand Simberg: Has SpaceX provided a planned trajectory?

Jonathan McDowell: No, but there are enough clues in the NOTAMs, the timelines, and some FAA statements to infer one.

Simberg: To what degree of precision? (And accuracy)?

McDowell: perigee is between 40 and 60 km with fairly high confidence.
apogee is between 200 and 245 km. inclination is 26.3 +- 0.1 deg.

OK, edited to prod the dead horse *only slightly* by reporting without comment McDowell's choice of terminology:
https://twitter.com/planet4589/status/1647649762722603008

No, I would say it will be "marginally orbital". For true orbital, I require perigee > 80 km.

It's not "marginally orbital", it's "the most massive test hop, ever".

Cheers, Martin

[MP99]

Well, I thought they should do a WDR before proceeding to launch ... but I actually DON'T feel vindicated by this. But for the valve issue, everything went flawlessly and they nearly were ready to go. Was probably a low probability of going all the way to hold-down release, but prepping everything for liftoff seems reasonable. They did the truest possible rehearsal and will be more likely to be ready to go next time.

They loaded prop at the coldest time of the day.

My speculation: maybe the extra heat would have stopped it from freezing up.

Have they ever done a WDR/similar before dawn?

Cheers, Martin

[oldAtlas_Eguy]

The wind shear info in Updates. There is a brand new high tech wind shear radar system at Starbase. It can give give high accuracy up to the "minute" detailed wind shear data. These units are used at the major airports in the US and at other locations around the world. This unit at Starbase has been there since the high altitude 10km Starship flight tests.

[chopsticks]

Well, I thought they should do a WDR before proceeding to launch ... but I actually DON'T feel vindicated by this. But for the valve issue, everything went flawlessly and they nearly were ready to go. Was probably a low probability of going all the way to hold-down release, but prepping everything for liftoff seems reasonable. They did the truest possible rehearsal and will be more likely to be ready to go next time.

They loaded prop at the coldest time of the day.

My speculation: maybe the extra heat would have stopped it from freezing up.

Have they ever done a WDR/similar before dawn?

Cheers, Martin

The temperature differential between the hottest time of day vs the coldest would hardly have an impact on this IMO due to the far greater temperature differential between ambient and cryogenic.

For LOX, it's what, -200C or so? So if it was 15C this morning (probably wasn't that cold) and it gets up to 30C during the day, that's only 15 degrees of difference. To me, whether the LOX is -215 or -230 from ambient seems like it wouldn't make a difference on whether a valve freezes or not, but maybe they are that picky.. IDK

[sanman]

Does SpaceX make their own valves in-house, or do they procure them from somebody else?

[Garrett]

Well, I thought they should do a WDR before proceeding to launch ... but I actually DON'T feel vindicated by this. But for the valve issue, everything went flawlessly and they nearly were ready to go. Was probably a low probability of going all the way to hold-down release, but prepping everything for liftoff seems reasonable. They did the truest possible rehearsal and will be more likely to be ready to go next time.

They loaded prop at the coldest time of the day.

My speculation: maybe the extra heat would have stopped it from freezing up.

Have they ever done a WDR/similar before dawn?

Cheers, Martin

I think there have been multiple Starship tests on cold days/close to dawn. SN11 for example.

I don't think we know where the valve is nor what type of valve it is. Wherever it is, I suspect it will always be relatively cold because of the cold air around the rocket, regardless of the time of day.

Presumably it was a GSE valve, as the rocket would have at least single, if not double redundancy, which could have been an option (albeit risky one) to take advantage of and continue with the launch.

[sanman]

I think there have been multiple Starship tests on cold days/close to dawn. SN11 for example.

I don't think we know where the valve is nor what type of valve it is. Wherever it is, I suspect it will always be relatively cold because of the cold air around the rocket, regardless of the time of day.

Presumably it was a GSE valve, as the rocket would have at least single, if not double redundancy, which could have been an option (albeit risky one) to take advantage of and continue with the launch.

Maybe they need to cycle these cryo valves on & off even during the filling process, just to keep them moving and "limber" -- just have them on a rotational schedule. Or do they already do that?

[MP99]

What were people's thoughts on the section of today's SpaceX broadcast that talked about the Starship missions they're working on:

Starting at 20:40
https://www.youtube.com/live/L5QXreqOrTA?feature=share

It felt to me that they went into some depth on Polaris, Dear Moon, and Dennis Tito. Then they followed it with a brief mention of Artemis III and the preceeding test mission, and didn't even mention Artemis IV.

Am I just being over-sensitive, or should there have been more acknowledgement of NASA's faith in them, and their collaboration on the HLS programme?

Cheers, Martin

[whitelancer64]

What were people's thoughts on the section of today's SpaceX broadcast that talked about the Starship missions they're working on:

Starting at 20:40
https://www.youtube.com/live/L5QXreqOrTA?feature=share

It felt to me that they went into some depth on Polaris, Dear Moon, and Dennis Tito. Then they followed it with a brief mention of Artemis III and the preceeding test mission, and didn't even mention Artemis IV.

Am I just being over-sensitive, or should there have been more acknowledgement of NASA's faith in them, and their collaboration on the HLS programme?

Cheers, Martin

Artemis IV is ~2028. That's a long ways out, and they were talking about the near-term flights with humans on board. I got the impression they were emphasizing that these flights will ensure success on Artemis III.

[wannamoonbase]

What were people's thoughts on the section of today's SpaceX broadcast that talked about the Starship missions they're working on:

Starting at 20:40
https://www.youtube.com/live/L5QXreqOrTA?feature=share

It felt to me that they went into some depth on Polaris, Dear Moon, and Dennis Tito. Then they followed it with a brief mention of Artemis III and the preceeding test mission, and didn't even mention Artemis IV.

Am I just being over-sensitive, or should there have been more acknowledgement of NASA's faith in them, and their collaboration on the HLS programme?

Cheers, Martin

Maybe you don’t want to tell the world this is going to land people on the moon if there are concerns that it could air burst on a global video feed

[Slothman]

Well, I thought they should do a WDR before proceeding to launch ... but I actually DON'T feel vindicated by this. But for the valve issue, everything went flawlessly and they nearly were ready to go. Was probably a low probability of going all the way to hold-down release, but prepping everything for liftoff seems reasonable. They did the truest possible rehearsal and will be more likely to be ready to go next time.

They loaded prop at the coldest time of the day.

My speculation: maybe the extra heat would have stopped it from freezing up.

Have they ever done a WDR/similar before dawn?

Cheers, Martin

I think there have been multiple Starship tests on cold days/close to dawn. SN11 for example.

I don't think we know where the valve is nor what type of valve it is. Wherever it is, I suspect it will always be relatively cold because of the cold air around the rocket, regardless of the time of day.

Presumably it was a GSE valve, as the rocket would have at least single, if not double redundancy, which could have been an option (albeit risky one) to take advantage of and continue with the launch.

If it was a pressurization issue, does it make sense that it would be a GSE valve? I would think that in this case there would be a valve on the vehicle at the end of the propellant line. They wouldn't want to pressurize the tanks with the vehicle valve open.

I'm assuming here that the issue was a frozen-open valve. If it was frozen closed, the redundant valves on the vehicle would be able to take over. On the other hand, maybe even with redundancy, they wouldn't want to fly it. However, they absolutely couldn't fly it if it was frozen-open.

[cplchanb]

Well, I thought they should do a WDR before proceeding to launch ... but I actually DON'T feel vindicated by this. But for the valve issue, everything went flawlessly and they nearly were ready to go. Was probably a low probability of going all the way to hold-down release, but prepping everything for liftoff seems reasonable. They did the truest possible rehearsal and will be more likely to be ready to go next time.

quite the irony that this scrub was due to faulty valves as well  People were chirping SLS for it left right and center lol

[meekGee]

A minimum 48 hour recycle to 7 am CST is 4/20.

What? Today is 4/17. Forty eight hours is two days. That’s 4/19.

T-0 today was 8:20. Next T-0 will likely be 7:00. That would be a 46 hours and 40 minutes recycle on 4/19. Not juvenile enough to understand this?

During the Stream they said "Wednesday".

Because someone missed the same point as Herb.

Coming from a guy named "Herb" the irony is thick.  (Not a stoner either... but c'mon, it was sitting right there)

More on topic, I'd have given 90% chances of a scrub today for a variety of reasons.  Hopefully the pressurization issue is easy to fix and they can make a proper go and at least light off some engines on the next shot!

[EDIT] Fixed to quote the right post!

And I didn't see it!

Even if they launch on 4/19, if they cross the international date line, will they land on 4/20?

[jedijeff123]

No, because they will be crossing back into Hawaii, which is the same day as the rest of the US. If they were splashing it down in the lagoon on Kwaj, it would have worked out though!