totm nov 2023 SpaceX Discussion Thread

[Exoscientist]

9 hours ago, darthgently said:

Apparently the downcomers in any rocket of this design are very sensitive to hard landings which results in fuel and oxidizer mixing.  The starship in the bellyflop tests that landed hard on legs, then went RUD after a pause was downcomer failure.  The booster tipping over onto the water would have put a big strain on the even longer downcomer

 

 According to SpaceX after soft water landing the Superheavy was not expected to explode. This was found by a reader on Reddit in SpaceX’s environmental impact statement:

It would be contrary to what SpaceX notes in their 2023 PEA revaluation documents though.

After the landing burn ends, the flight plan is for Super Heavy to impact the water vertically and intact. Then, within several seconds, Super Heavy would tip over and impact the water horizontally. The landing would impart forces onto the liquid oxygen (LOX) tank and methane tank; however, the tanks’ structural capabilities allow it to withstand these forces. Therefore, the tanks would remain intact, and there would be no resultant interaction between the LOX and methane. Super Heavy is expected to remain intact.

  That was a very large fire that erupted up the side of the rocket after the landing burn. Remember that large fire visible on the outside is stemming from fuel burning on the inside of the engine compartment. 

  Bob Clark

Edited July 7 by Exoscientist

[darthgently]

This is interesting.  If I'd guessed I'd have guessed wrong.  Apparently, if I'm reading this right, SpaceX still buries everyone even without Starlink payloads

 

 

[tater]

Chart needs a key.

[darthgently]

1 hour ago, tater said:

Chart needs a key.

I kept digging and couldn't find one.  QC issues everywhere

[Meecrob]

On 5/29/2024 at 11:31 AM, mikegarrison said:

Of course they were serious.

No. Elon is a funny guy. He was making a joke out of seeing how many people believe it.

Did I forget to tell you science and spaceflight guys Elon posts on this board all the time under a pseudonym. We know he is autistic to some degree. There is a character around here posting 'spergy  things all the time. Remember the man knows how to excrement post.

Edited July 11 by Meecrob

[mikegarrison]

On 7/9/2024 at 10:28 AM, darthgently said:

I kept digging and couldn't find one.  QC issues everywhere

It's pretty obvious that the dark blue is Starlink upmass. Light blue must be everything else. Lavender is probably "scheduled".

[Meecrob]

On 5/28/2024 at 10:51 AM, mikegarrison said:

it is contradicted by what SpaceX themselves said during and after the flight, where they said they lost control of the vehicle.

Yes but, Elon is excrement posting in real life!

[Meecrob]

On 6/6/2024 at 9:34 AM, Codraroll said:

They just passed a coastline. Winder where that is? I'm not good enough at geoguessing to tell

It's called get an atlas.

On 6/6/2024 at 9:46 AM, Codraroll said:

By the way, for those of you who know your stuff ... are the re-entry fireworks green at this altitude for the same reason that the aurora is green? Or is it because of the camera settings?

No camera effects, thats what the camera saw. They might use specific lenses and all that, but there is no after-effects added.

Edited July 11 by Meecrob

[Meecrob]

On 6/6/2024 at 10:09 AM, DAL59 said:

Is Starship watertight? 

Well it holds cryogenic fuel and oxidizer. I'm pretty sure its water tight.

[Meecrob]

On 6/24/2024 at 4:49 PM, mikegarrison said:

Also,  making 1000 Starships a year?

Airbus makes 45 A320s a month, which is a little more than 500 per year. Musk thinks the demand for Starships is going to be 2x higher than the demand for A320s?

Not right now. Give it some time.

On 6/26/2024 at 1:56 AM, Exoscientist said:

On the other hand, a Raptor still did explode on both booster landing attempts.

  Bob Clark

Looks like we got ourselves a regular Sherlock Hizzolmes here.

[Meecrob]

On 7/7/2024 at 4:37 AM, Exoscientist said:

The fact the explosion was large enough to create a mushroom cloud of that size is disturbing. That is not something SpaceX would want to reveal for a landing attempt of the Superheavy on land.

Oh no! I'm not sure the solid ground can withstand an explosion. I mean nowhere near as well as water. No phase changes going on there amirite?

On 7/7/2024 at 2:12 PM, Exoscientist said:

  That was a very large fire that erupted up the side of the rocket after the landing burn. Remember that large fire visible on the outside is stemming from fuel burning on the inside of the engine compartment. 

Yeah we get it, you think these things are fragile. They are not, its solid steel. I'm sure it can handle a wussy fire. Get real, buddy

Edited July 11 by Meecrob

[Ultimate Steve]

After some anomalous looking icing and venting and possibly leaking during the first second stage burn, Falcon 9 S2 experienced a RUD during a perigee raise burn. Starlinks may not survive.

Full flight replay here:

https://x.com/i/broadcasts/1gqGvNkwZPgGB

I don't think we have video of the RUD.

First Falcon failure or partial failure (to be determined, deciding factor is probably if the Starlinks survive) since 2016 I think.

It has been 325 missions since the last Falcon 9 failure. I'm not sure what rocket comes in second place for success streak, but wow, that is quite a streak that may not be beaten for some time.

[CatastrophicFailure]

1 hour ago, Ultimate Steve said:

First Falcon failure or partial failure… since 2016 I think.

2015 someone said. Perigee is likely 138km, extremely not norminal. 
 

 

[Ultimate Steve]

2 minutes ago, CatastrophicFailure said:

2015 someone said. Perigee is likely 138km, extremely not norminal. 

Well then you get into the gray area as to where Amos 6 stands in the failure spectrum. I personally count it as a full failure even though it occurred during prelaunch testing. CRS-7 was indeed 2015 though.

[tater]

Yeah, it was leaking during the burn (the constant icing, presumably LOX?).

[Deddly]

It was nevertheless a very interesting and beautiful sight to watch the ice crystals form, gently fall off and then get blasted away by the rocket exhaust. 

[cubinator]

So what would be the time of day to go watch for falling satellites? 7PM/7AM? It's not dark then, but such things are pretty bright sometimes.

[Deddly]

I would imagine it would take quite a few orbits for them to come down, wouldn't it? 

[cubinator]

2 minutes ago, Deddly said:

I would imagine it would take quite a few orbits for them to come down, wouldn't it? 

I dunno, Celestrak has a "click to estimate decay date" for a Starlink that says yesterday (because perigee < 150 km) and another that says tomorrow.

https://celestrak.org/NORAD/elements/table.php?GROUP=last-30-days&FORMAT=tle

[mikegarrison]

15 hours ago, Ultimate Steve said:

It has been 325 missions since the last Falcon 9 failure. I'm not sure what rocket comes in second place for success streak, but wow, that is quite a streak that may not be beaten for some time.

Atlas V has never had a failure.

[Cuky]

11 minutes ago, mikegarrison said:

Atlas V has never had a failure.

According to Wikipedia it had one partial failure in 100 launches.  And that is still as many lunches in 22 years as Falcon does in like 13-14 months

I just hooe that this failure won't cause too long of a delay for them

[Deddly]

7 hours ago, Cuky said:

According to Wikipedia it had one partial failure in 100 launches. 

I had forgotten about this so I checked. It was the launch of June 2007. There was a fuel leak in the upper stage and the engine shut down early, resulting in a lower orbit than intended. The payload was able to compensate and the flight was claimed a success. 

I guess the definition of success becomes unclear when the payload itself has the ability to change its orbit. I suppose it's like getting a ride to the hospital; if you are unconscious and the ambulance drops you off outside the doors, that would be a huge failure on their part. But if you are able to walk in on your own two feet thanks to the care they gave you on the way, well... they got you most of the way, so it was a success, I guess? But both eventualities would lead to a thorough investigation. 

 

[RCgothic]

2 hours ago, Deddly said:

I had forgotten about this so I checked. It was the launch of June 2007. There was a fuel leak in the upper stage and the engine shut down early, resulting in a lower orbit than intended. The payload was able to compensate and the flight was claimed a success. 

I guess the definition of success becomes unclear when the payload itself has the ability to change its orbit. I suppose it's like getting a ride to the hospital; if you are unconscious and the ambulance drops you off outside the doors, that would be a huge failure on their part. But if you are able to walk in on your own two feet thanks to the care they gave you on the way, well... they got you most of the way, so it was a success, I guess? But both eventualities would lead to a thorough investigation. 

 

I guess that's why JMcD scores non-nominal but usable orbits 0.75 of a success, and orbital but unusable 0.4.

[mikegarrison]

1 hour ago, RCgothic said:

I guess that's why JMcD scores non-nominal but usable orbits 0.75 of a success, and orbital but unusable 0.4.

Not even that. IIRC, the satellites on that 2007 flight reached their own orbit, but had to use more thruster fuel than desired, which may have meant a shorter active life. But they were NRO sats, so of course no one would say.

Anyway, the mission was still officially counted as a success, because the payload reached its desired orbit.

I guess my point in bringing up the Atlas V record was that I found it a little annoying for someone to be wondering who has the second-best record besides Falcon, when it is actually quite arguable that Falcon does not have the best record of the current launch platforms. I mean, yeah, you could argue whether 100 launches with every payload reaching the desired orbit is better or worse than 350+ launches with at least three times a payload was completely lost. But I think that never losing a payload is probably better, at least when the number of launches is within the same order of magnitude.

Edited July 13 by mikegarrison

[Deddly]

2 hours ago, mikegarrison said:

Not even that. IIRC, the satellites on that 2007 flight reached their own orbit, but had to use more thruster fuel than desired, which may have meant a shorter active life. 

To me, that exactly matches the definition of "Non-nominal but usable orbit." 

Edit: Presumably, the Starlink satellites would also be able to use the orbit if their thrust were high enough. But a RUD seems more of a failure to me than a premature cutoff, even if it's being ditched in the ocean either way.