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

[rdale]

That's what makes them money:  making it about Musk.

Well - let’s look at Twitter. Musk made it about Musk and destroyed a pretty good product while doing so.

But I’d like to go down the media path - how do they make money by making a “Musk” connection that wouldn’t be made if they didn’t mention Elon?

[alugobi]

The term 'Musk' gets more clicks than the term 'Starship'. 

[Hog]

Can someone just clarify -- does the vehicle on the pad use helium pressurization only on the ground for initial filling or is it on the vehicle overall?

There's gotta be at least one COPV of gHe in that big assed prototype SS/SH stack. Obviously attempting to exclude on vehicle stored He during operations.

[DigitalMan]

I response to the post in updates asking for feedback regarding the SpaceX webcast:

I think more Kate and John would have been good. The other dude, well, for example when he talked about Super Heavy, he goes on to say its "Super" and its "Heavy". Well, why not explain what is the scale that people use, such as medium, heavy, super heavy, etc.

I think that is enough to get an idea how to improve things.

[alugobi]

Not a twitter user, so if you're reading here:

Because they have time to fill, it's going to become repetitive, and from that it gets boring. 

Fix whatever was wrong with the Mission Control audio stream so we can listen to launch info, and skip the elementary primer on the program.

[russianhalo117]

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

It is known as a transatmospheric orbit.

[ChrisC]

Mission control audio feed https://youtube.com/watch?v=Ln8hXptcA90

Did anyone actually hear anything on that loop?  I scrubbed to a few random points during the countdown and never heard anything.  I was going to listen all the way through later today, but they've now taken that video private.

Thanks StevenO for the pointer to the SpaceX video engineer fishing for criticism.  This comment is applicable here:

Commenter: ... the sound level on the net only stream was way too quiet.

SpaceX video engineer: Concur and copy. I’ll hVe them boost BCD1 volume and compression gain.

[InterestedEngineer]

Hey. I'm finding it hard to get accurate answers about this.

In this tweet, Zack Golden mentions that this many LN2/LOX/CH4 tankers are needed to replenish the Tank Farm after this kind of WDR.

https://twitter.com/CSI_Starbase/status/1647953241001345025

Is it accurate in any way? One would think they wouldn't need as much CH4.

I have the same question. Where did the propellant go that was in the Starship and Booster tanks at the time of the scrub? Some (most I would expect) gets recycled into the tanks? Or not? My assumption is it would, so they only need to replenish what was lost due to venting, right?
Or did they really vent the whole content in Starship and Booster?

Reviving this question, haven't seen a good answer.

Why would it require more than a handful of trucks to replenish after a WDR?

[Herb Schaltegger]

Hey. I'm finding it hard to get accurate answers about this.

In this tweet, Zack Golden mentions that this many LN2/LOX/CH4 tankers are needed to replenish the Tank Farm after this kind of WDR.

https://twitter.com/CSI_Starbase/status/1647953241001345025

Is it accurate in any way? One would think they wouldn't need as much CH4.

I have the same question. Where did the propellant go that was in the Starship and Booster tanks at the time of the scrub? Some (most I would expect) gets recycled into the tanks? Or not? My assumption is it would, so they only need to replenish what was lost due to venting, right?
Or did they really vent the whole content in Starship and Booster?

Reviving this question, haven't seen a good answer.

Why would it require more than a handful of trucks to replenish after a WDR?

Most of the consumables are probably LN2 to replenish the stocks used in sub-cooling during tanking and recondensing post-scrub. The rest will be to top off the LOX and methane lost during that same process.

[meekGee]

well regardless of whether its actually broken or frozen shut, the fact is that it failed to operate when commanded which means theres a fault to it, hence a faulty valve.

No engineer in the world, especially an aerospace engineer, would describe a frozen valve as “faulty” absent a physical fault preventing actuation (a condition for which we have zero evidence).

What description would an aerospace engineer use to describe such a situation? I'm genuinely curious, and nothing is coming directly to my mind, but then again, I am not an aerospace engineer. Disabled? Inoperative? Malfunctioning? These all seem to have their own subtle connotation as well which I think rules them out just as well as 'faulty'.

Faulty is not such a bad adjective.

It was the valve that didn't work.

The reason may have been transient, the fault may have been intermittent, the design itself (valve, enclosure  procedure) is lacking or deficient since it allowed a fault to develop under normal operating conditions.

Contrast that with a valve that failed because a forklift drove over it.  In that case, it wouldn't be faulty.

[Herb Schaltegger]

well regardless of whether its actually broken or frozen shut, the fact is that it failed to operate when commanded which means theres a fault to it, hence a faulty valve.

No engineer in the world, especially an aerospace engineer, would describe a frozen valve as “faulty” absent a physical fault preventing actuation (a condition for which we have zero evidence).

What description would an aerospace engineer use to describe such a situation? I'm genuinely curious, and nothing is coming directly to my mind, but then again, I am not an aerospace engineer. Disabled? Inoperative? Malfunctioning? These all seem to have their own subtle connotation as well which I think rules them out just as well as 'faulty'.

Faulty is not such a bad adjective.

It was the valve that didn't work.

The reason may have been transient, the fault may have been intermittent, the design itself (valve, enclosure  procedure) is lacking or deficient since it allowed a fault to develop under normal operating conditions.

Contrast that with a valve that failed because a forklift drove over it.  In that case, it wouldn't be faulty.

But it still would be accurately described - in the absence of data as to root cause - as “failed.”

Similarly, a cryogenic fluid valve is not “faulty” if it is exposed to fluids other than those with which it is expected to operate; if it is supplied with an over-current of the electrical power with which is it is actuated or alternately, an over-pressure of the pneumatic fluid which operates it. The valve is not faulty if there are contaminants in the fluid causing it to bind, freeze up or actuate sluggishly and out of specification … et cetera.

But if commanded and it fails to actuate, is is still “failed” even though not “faulty.”

[TomH]

well regardless of whether its actually broken or frozen shut, the fact is that it failed to operate when commanded which means theres a fault to it, hence a faulty valve.

Sorry, but it is the above conclusion which is faulty. The problem could be procedural, as in sequence of events, or timing. Such an adjustment could eliminate the problem, just as was the case with the Amos-6 mission. A change of sequence and timing in loading the supercooled prop solved the problem. In other cases, additional insulation and/or heaters have solved similar problems.

The valve itself is not faulty. An adjustment to the physical and temporal conditions related to and surrounding the valve need to be adjusted. The valve itself requires no change.

[TomH]

Anything sacred about 7 am, as opposed to 9 am?

I would note that (in general) weather is calmer in the early morning. As the sun rises, its angle moves closer to vertical, it has less atmosphere through which to travel (less and less coming through sideways). The increasing thermal solar gain heats the surface of the ground and water, thus inducing more air currents. In simple terms, it tends to be calmer at 7 than at 9.

[matthewkantar]

Is it me or has bickering about semantics become a trend here? With what "faulty" means, how long 48 hours is, what "orbital" means, and others, going on for pages and pages, it feels like being trolled.

[FutureSpaceTourist]

https://twitter.com/maxar/status/1648093238417317895

Today’s #satellite image (April 17, 2023) of the @SpaceX Boca Chica launch facilities in Texas with a view of the #Starship and Super Heavy rocket on the launch pad. Today’s scheduled launch of the most powerful rocket ever constructed was scrubbed. Stay tuned! 🚀

[chopsticks]

Is it me or has bickering about semantics become a trend here? With what "faulty" means, how long 48 hours is, what "orbital" means, and others, going on for pages and pages, it feels like being trolled.

Not just you. It seems like people are often arguing about the definitions of words when it's pretty clear that people do in fact understand each other. It's tiresome, like kids bragging about how much smarter they are than the next kid.

[sdfasdfasd]

Is it me or has bickering about semantics become a trend here? With what "faulty" means, how long 48 hours is, what "orbital" means, and others, going on for pages and pages, it feels like being trolled.

It is solved on other sites by threading comments, so those who enjoy it can go down their silly rabbitholes but normal people can just skip over those threads. It also makes quoting much less necessary.

Unfortunately this site seems to use technology from the 90s that cannot do comment threads.

[catdlr]

In the attached screengrab from engineering cameras under the booster in the OLM I see what appears to be frosted tubing extending from the launch mount to each engine.  They are put in after the explosion in December and are not part of the LN2 stage zero connectors for engine spin-up.  What are these for? Are they directly connected to each engine and how are they disconnected at launch or do they just tear off at launch?

According to CSI Starbase, the booster can not launch with these lines connected (see clip below)

https://youtube.com/clip/UgkxG_I_eJnWZqaPOx4ZD0NByythzo6_wtk0

[woods170]

In the attached screengrab from engineering cameras under the booster in the OLM I see what appears to be frosted tubing extending from the launch mount to each engine.  They are put in after the explosion in December and are not part of the LN2 stage zero connectors for engine spin-up.  What are these for? Are they directly connected to each engine and how are they disconnected at launch or do they just tear off at launch?

Those are flex lines and are torn off at launch. Temporary thing. Only applies to B7. On B9 et al. a different solution is applied.

[catdlr]

In the attached screengrab from engineering cameras under the booster in the OLM I see what appears to be frosted tubing extending from the launch mount to each engine.  They are put in after the explosion in December and are not part of the LN2 stage zero connectors for engine spin-up.  What are these for? Are they directly connected to each engine and how are they disconnected at launch or do they just tear off at launch?

Those are flex lines and are torn off at launch. Temporary thing. This only applies to B7. On B9 et al. a different solution is applied.

Thanks, I added a clip from CSI Starbase that mentions that the booster can't launch like that.  But if they are designed to tear away, then I'm good