totm nov 2023 SpaceX Discussion Thread

[CatastrophicFailure]

[sevenperforce]

4 minutes ago, CatastrophicFailure said:

Is that an image of FH from last year?

I thought the new FH would have Block 5 legs.

[CatastrophicFailure]

27 minutes ago, sevenperforce said:

Is that an image of FH from last year?

I thought the new FH would have Block 5 legs.

Yup. AKAIK, it’s still in the hangar, not sure if the TEL is in there yet. 

[RealKerbal3x]

The FH launch is happening 11:36pm my time...luckily it’s half term holiday next week so I don’t need to go to school the next morning. I’ll just watch Star Trek until the webcast starts

[tater]

 

[sevenperforce]

1 hour ago, tater said:

 

I love how many updates we get.

[tater]

 

[CatastrophicFailure]

3 hours ago, tater said:

 

Oh good, he’s no longer “Jung Musk.”  Interesting to have such a problem, tho, I wonder why that wasn’t an issue with the test stand plumbing?

 

[sevenperforce]

Just now, CatastrophicFailure said:

Oh good, he’s no longer “Jung Musk.”  Interesting to have such a problem, tho, I wonder why that wasn’t an issue with the test stand plumbing?

 

Different feed path from the tanks.

[magnemoe]

Just now, sevenperforce said:

Different feed path from the tanks.

Might also be different valve as the test stand does not have to think about weight, guess the valve on the test stand is out in the open and tank is insulated. 
On the hopper and starship you will have valve close to an un-insulated tank with lots of stuff who limited airflow. 
The pre-valves is typicaly an butterfly valve, an plate who rotate inside the piping and can shut of flow fast, the next is slower but can fine adjust the flow. 

It make me think of the plumbing of starship, you will have header tanks. Is all fuel and oxidizer flowing trough the header tanks?
This is easiest but will add pressure drop because of the convoluted path and turbulence. or is it an bypass option? You will need valves between main and header tanks anyway as you want to keep the fuel tank in vacuum to insulate the header tanks so bypass just adds two more. 

[tater]

 

[CatastrophicFailure]

 

Confidence still high enough for the 7th despite the static fire delay that they’re putting out NOTAMs? 

ohpleasephpleaseohplease... 

[sh1pman]

This guy. Is going to launch rockets with people in them. To space.

 

[Ultimate Steve]

yes

[CatastrophicFailure]

30 minutes ago, sh1pman said:

This guy. Is going to launch rockets with people in them. To space.

This guy. Has a sense. Of humor. 

...we all hope...

[Cunjo Carl]

NASA is seriously considering using a Falcon Heavy together with an ICPS (Boeing's second stage for the Delta IV) for the EM-1 mission in order to lift the Orion capsule and European Service Module for a lunar flyby. Bridenstine talks about the idea and the difficulties involved during this town hall meeting. The video starts when the discussion moves to SpaceX-y things, and that particular suggestion is at about 36:00.

"Talk about strange bed fellows." NASA's Administrator, Jim Bridenstine.

 

Edited April 3, 2019 by Cunjo Carl
wording fix

[CatastrophicFailure]

19 minutes ago, Cunjo Carl said:

NASA seriously considers using a Falcon Heavy together with an ICPS (Boeing's second stage for the Delta IV) for the EM-1 mission in order to lift the Orion capsule and European Service Module for a lunar flyby. Bridenstine talks about the idea and the difficulties involved during this town hall meeting. The video starts when the discussion moves to SpaceX-y things, and that particular suggestion is at about 36:00.

Haven’t seen the video but I’ve been following the discussion on Twitter. My understanding was, the idea was considered but rejected, both due to the difficulty of building an adapter between the FH US and the ICPS and all the pad plumbing such would require, and also that it wouldn’t allow Orion to brake into Münar orbit, just a flyby. 

Im a bit confused on that last part, honestly. Would the FH US burn all the way to depletion and still need a kick from the Delta stage to get the payload in orbit? This is the planned profile with SLS anyway, right? Would the ICPS really need that much more of its own fuel just to make orbit?

ETA: tho, seeing the big ol’ ULA badge on a Falcon was a bit of a whut. moment... 

Edited April 3, 2019 by CatastrophicFailure

[Cunjo Carl]

35 minutes ago, CatastrophicFailure said:

Haven’t seen the video but I’ve been following the discussion on Twitter. My understanding was, the idea was considered but rejected, both due to the difficulty of building an adapter between the FH US and the ICPS and all the pad plumbing such would require, and also that it wouldn’t allow Orion to brake into Münar orbit, just a flyby. 

Im a bit confused on that last part, honestly. Would the FH US burn all the way to depletion and still need a kick from the Delta stage to get the payload in orbit? This is the planned profile with SLS anyway, right? Would the ICPS really need that much more of its own fuel just to make orbit?

I haven't been following the conversation, I just heard what he said in the video. It sounds like he's considering the idea as a ... maybe a fall back plan is the right feeling. He still has his bets on the SLS, but he thought the FH-ICPS had enough continuing merits for the long term mission (I believe here meaning entry into NRHO orbit with the hoped-to-be Gateway) to be worth seriously considering. It certainly has its difficulties, and he discusses a few of the problems in the video. He also mentions that he hadn't run these things by his lead rocket scientist, who was wearing a decidedly blank and dubious smile.

Still, he explains that "It would require time, it would require cost and there is risk involved.  But guess what, if we're going to land boots on the moon in 2024, we have time and we have the ability to accept some risk and make some modifications. All of that is on the table."

Straight out of the horse's mouth. Not sure what else to say!

35 minutes ago, CatastrophicFailure said:

ETA: tho, seeing the big ol’ ULA badge on a Falcon was a bit of a whut. moment... 

Right? I love it! Almost could have been the April Fools joke. Original image credit appears to be a Reddit user by the name of DoYouWonda.

" To everyone thinking this is a Franken-rocket, you’re right. As are many rockets. The Falcon Heavy is 3 Falcon 9s, the Delta IV Heavy the same. The OmegA is nothing but restocked existing pieces. SLS is a shuttle derived launcher with boosters, core stage, main engines, and upper stage from different rockets. " DoYouWonda

 

Edited April 3, 2019 by Cunjo Carl

[sevenperforce]

1 hour ago, Cunjo Carl said:

"To everyone thinking this is a Franken-rocket, you’re right. As are many rockets. The Falcon Heavy is 3 Falcon 9s, the Delta IV Heavy the same. The OmegA is nothing but restocked existing pieces. SLS is a shuttle derived launcher with boosters, core stage, main engines, and upper stage from different rockets."

 

It's also easy to forget just how big a rocket Falcon Heavy actually is. FHB5 carries 154% as much liquid propellant as the core of the SLS and boasts 251% as much thrust.

[DDE]

9 hours ago, sh1pman said:

This guy. Is going to launch rockets with people in them. To space.

Sounds like you’re finally having a Roscosmos moment.

Edited April 3, 2019 by DDE

[RealKerbal3x]

3 hours ago, CatastrophicFailure said:

 

That looks...uh, ridiculous!

What’s the combined mass of the Orion and the ICPS? That does look on the limit of a fully expendable FH’s mass to LEO.

[Cassel]

6 hours ago, CatastrophicFailure said:

Haven’t seen the video but I’ve been following the discussion on Twitter. My understanding was, the idea was considered but rejected, both due to the difficulty of building an adapter between the FH US and the ICPS and all the pad plumbing such would require, and also that it wouldn’t allow Orion to brake into Münar orbit, just a flyby. 

Im a bit confused on that last part, honestly. Would the FH US burn all the way to depletion and still need a kick from the Delta stage to get the payload in orbit? This is the planned profile with SLS anyway, right? Would the ICPS really need that much more of its own fuel just to make orbit?

ETA: tho, seeing the big ol’ ULA badge on a Falcon was a bit of a whut. moment... 

What about this statement that they could use crew Dragon?
Would they be able to take Orion to Earth's orbit without a FH second stage?

edit:
What if Orion would take off without crew and abort system? The crew would have been delivered with the help of Dragon?

Edited April 3, 2019 by Cassel

[AVaughan]

1 hour ago, RealKerbal3x said:

What’s the combined mass of the Orion and the ICPS?

Quoting what I wrote elsewhere, 

Quote

According to https://www.spacex.com/falcon-heavy falcon heavy can lift 63,800 kg to LEO, or push 26,700 kg to GTO. That suggests two options.

1. Launch Orion + the SM on a FH, use the F9 second stage plus some of the SM's dV for the TLI burn. (Wikipedia says Orion and the SM have a wet mass of 25848kg). I've seen various figures for the service modules dV, but since TLI is about 700m/s more dV than GTO, then even the lowest dV of 1300m/s should be plenty for a Lunar flyby, and might be enough for the DRO. This option would probably require a custom payload adapter and fairing, or alternatively it might be possible to modify the SLS's spacecraft adaptor design and mount that on a F9 second stage, and use the SLS fairings.

2. Launch Orion + the SM + the ICPS on a FH to LEO. (Using wikipedia wet mass figures, total mass of Orion + SM + ICPS is about 56,560kg). Again you would either need a custom payload adaptor and fairing, or alternatively to modify the SLS's interstage design and mount that on a F9 second stage. In addition SpaceX would probably need to add liquid hydrogen plumbing and infrastructure to the pad and launch tower, so option 1 is probably better. But as you say, ultimately this is a political issue, so politicians will vote for what they think will help them most in the next election.

 

[RCgothic]

ICPS on top of the falcon second stage looks wrong. And mass to LEO includes fuel residuals, it's not literally how much weight you can have in the payload section.

How do ICPS and FUS stack up DV wise? In terms of thrust? Could ICPS be a straight replacement for FUS? That seems a bit more feasible as all the weight is going on top of FS1, which is used to having the weight of stages above it.

Edited April 3, 2019 by RCgothic

[Rakaydos]

38 minutes ago, RCgothic said:

ICPS on top of the falcon second stage looks wrong. And mass to LEO includes fuel residuals, it's not literally how much weight you can have in the payload section.

How do ICPS and FS2 stack up DV wise? In terms of thrust? Could ICPS be a straight replacement for FS2? That seems a bit more feasible as all the weight is going on top of FS1, which is used to having the weight of stages above it.

From what brigstene said, FH plus FUS plus EUS and Orion could just barely do a flyby, and FH plus FUS plus ICPS plus EUS and Orion could manage the full mission, if the Orion is lightly loaded. It was rejected for 2020 because of GSE problems, but he's explicitly keeping it on the table for 2024, as a stick to threaten SLS with.