totm nov 2023 SpaceX Discussion Thread

[sevenperforce]

3 minutes ago, tater said:

Yeah, when I saw that mentioned somewhere, I was surprised. I think you are right about margin.

I would assume that for a very, very high-margin mission (like, 2 tonnes to LEO, where S1 can do a single-engine boostback burn and a single-engine landing burn and still hit RTLS) then RTLS would be a better choice.

[tater]

From a reddit AMA with a spacex guy:

Quote

[–]Starman2MarsSpaceX Employee[S] 112 points an hour ago 

Biggest process change was eliminating Tig welding of the thrust structure or “Octaweb” and the move to a bolted design but this made it much easier and faster to produce overall as well. Block 5 is significantly easier to produce in many areas as the technicians and manufacturing engineers worked extremely well with our design partners to incorporate design for manufacturing (DFM) solutions, based on all that we had learned from earlier vehicle builds.

 

He says they can make a F9 booster every 14 days. Merlins take a day to make.

 

[Ultimate Steve]

16 minutes ago, tater said:

From a reddit AMA with a spacex guy:

  

He says they can make a F9 booster every 14 days. Merlins take a day to make.

*jaw drops*

I wish I could make one rocket engine a day...

[Wjolcz]

Wow. They will need a big hangar to store all these stages.

[tater]

 

Stand is thought to be for testing something bigger than Falcon 9

Water tower , etc.

Edited April 24, 2018 by tater

[cubinator]

it's

 

 

 

happening

 

?

[CatastrophicFailure]

She said BFR could see full orbital flights by 2020. If this thing actually does beat SLS off the ground... 

[cubinator]

Just now, CatastrophicFailure said:

She said BFR could see full orbital flights by 2020. If this thing actually does beat SLS off the ground... 

SpaceX's timeline is likely to change soon, so SLS may still fly first. However, looking at how much more economical BFR is versus SLS in terms of Mars exploration, it's quite possible NASA could end up eating SpaceX's red Martian dust in the not-too-distant future.

[sevenperforce]

45 minutes ago, tater said:

Stand is thought to be for testing something bigger than Falcon 9

Water tower , etc.

"You're gonna need a bigger flame trench."

"Cool."

[_Augustus_]

1 hour ago, cubinator said:

SpaceX's timeline is likely to change soon, so SLS may still fly first. However, looking at how much more economical BFR is versus SLS in terms of Mars exploration, it's quite possible NASA could end up eating SpaceX's red Martian dust in the not-too-distant future.

SLS is going to be cancelled before EM-1 ever flies. It's delayed beyond belief, Block IB is now a "someday" so DSG flying on SLS is a nonstarter, and Block I makes little sense for cargo as it has significantly less payload to TLI/TMI/TJI than FH does.

[tater]

BFS and NG are pretty much a coin flip to beat SLS to space since SLS is almost certainly summer 2020, if nothing else slips. Assuming they don’t slip, lol. I’d expect bfs to slip, but I bet NG flies.

[sevenperforce]

7 minutes ago, tater said:

BFS and NG are pretty much a coin flip to beat SLS to space since SLS is almost certainly summer 2020, if nothing else slips. Assuming they don’t slip, lol. I’d expect bfs to slip, but I bet NG flies.

My prediction:

BFS flies suborbitally, then NG flies orbitally, then BFR flies orbitally, then SLS Block 1 drags its underpowered self around the moon once and dies.

[cubinator]

2 minutes ago, sevenperforce said:

My prediction:

BFS flies suborbitally, then NG flies orbitally, then BFR flies orbitally, then SLS Block 1 drags its underpowered self around the moon once and dies.

After all that, will NASA decide to make a decently capable reusable rocket?

[StrandedonEarth]

23 minutes ago, cubinator said:

After all that, will NASA decide to make a decently capable reusable rocket?

NASA needs to go back to its roots and STOP designing and building rockets (actually, they are built by contractors, presumably on a cost-plus basis, with no incentive to make things cheaper). They did the heavy-lifting pioneering work of researching different ways of getting rockets to work, much like its predecessor NACA did for airplanes. Now the commercial sector has taken the ball and is running with it. It's time for NASA to use commercially available boosters to research and develop the technologies needed for deep spaceflight, such as continuing the work on ECLSS systems and ISRU and asteroid mining systems.

[tater]

Yeah, I think that that is a better paradigm for NASA to pursue, utilize LVs that exist, and design hardware that has no economic benefit in the short term (true spacecraft, etc). If they have a compelling reason for a capability that the commercial providers don't have, or are not working on, then they could suggest what they might be willing to pay for such a service, and the providers can see what they can do to win those dollars.

[CatastrophicFailure]

51 minutes ago, _Augustus_ said:

SLS is going to be cancelled before EM-1 ever flies.

Nah, it’ll fly once. Maybe twice. Sunk costs and all that. The powers that be need it to. It may be a lumbering, foundering Titanic at this point, but like the Titanic it has a lot of momentum. Cancelling outright now that flight hardware exists is near impossible, more likely they’ll cancel any further production once SLS/NG/NA are flying and even they can no longer pull their smoke-and-mirrors game. 

 

48 minutes ago, sevenperforce said:

My prediction:

BFS flies suborbitally, then NG flies orbitally, then BFR flies orbitally, then SLS Block 1 drags its underpowered self around the moon once and dies.

Somebody really oughtta start a friendly pool or something... 

@StrandedonEarth of course, this is where I run out of likes for the day.  

 

[sh1pman]

13 minutes ago, tater said:

Yeah, I think that that is a better paradigm for NASA to pursue, utilize LVs that exist, and design hardware that has no economic benefit in the short term (true spacecraft, etc). 

It can really synergize well with SpaceX’s attitude towards making humans interplanetary species: “we provide the means of transportation, others figure out everything else”. NASA in this case can use their billions not to build a stupid rocket, but to develop the technologies needed to survive out there (something that can’t be commercialized). And then, after a decade (or two) of R&D, businesses can take over once again, using these technologies to build Moon hotels, mine asteroids for precious metals, etc. 

But I guess we're going to be stuck with SLS and LOP-G instead. Meh.

[_Augustus_]

1 hour ago, CatastrophicFailure said:

Nah, it’ll fly once. Maybe twice. Sunk costs and all that. The powers that be need it to.

Senator Shelby, one of the biggest SLS advocates, will be replaced in November. Bridenstine is not a big SLS advocate. POTUS/VP are not really SLS fans. Without Block IB, it's no longer justifiable for any kind of useful missions.

It will be cancelled before or shortly after EM-1.

[CatastrophicFailure]

7 minutes ago, _Augustus_ said:

Senator Shelby, one of the biggest SLS advocates, will be replaced in November. 

Richard Shelby? How you figure ? He was just re-elected in 2016. Senators are up every 6 years. 

[tater]

36 minutes ago, CatastrophicFailure said:

Richard Shelby? How you figure ? He was just re-elected in 2016. Senators are up every 6 years. 

He’s switching committees.

[KSK]

7 hours ago, sevenperforce said:

My prediction:

BFS flies suborbitally, then NG flies orbitally, then BFR flies orbitally, then SLS Block 1 drags its underpowered self around the moon once and dies.

This article makes a reasonably good case (political and, surprisingly, technical) for keeping Europa Clipper and it's follow up lander mission on SLS. On that basis I'm predicting four SLS flights - assuming that the schedule sketched out on Wikipedia is still current and that EM-1 remains uncrewed: EM1, Europa Clipper, Europa Lander and a crewed lunar fly-by.

At that point it could probably be retired gracefully, especially if NG and BFR are actually flying by then. Heck, from the numbers we've seen so far (assuming that they're anywhere close to reality) BFR could be used as a disposable vehicle and still come out ahead of SLS (any configuration) in cost and capability.

Whether SLS will be allowed to retire after 4 missions...? *shrug*

Edit - thinking about it, I'm not so sure that disposable vehicle comment is correct. Most of the interesting BFR missions seem to involve on-orbit propellant loading and tanker BFRs. Can't afford to throw too many of those away before SLS becomes cheaper.

Edited April 25, 2018 by KSK

[Tullius]

9 hours ago, tater said:

If they have a compelling reason for a capability that the commercial providers don't have, or are not working on, then they could suggest what they might be willing to pay for such a service, and the providers can see what they can do to win those dollars.

And what exactly does this change from NASAs usual procurement procedure, except awarding everything to one company? Orion is the result of such a competition between Lockheed-Martin and Boeing.

Any government project will see cost overruns, if you don't keep a very strict eye on the contractors to stay within budget, since the government will usually pay for any overruns.

A NASA backed BFR would also accumulate delays and cost overruns, just like SLS, since it would not be necessary for SpaceX to make do with whatever budget they could ensure, since it's practically infinite.

[tater]

NASA's own costing spreadsheet apparently produces numbers grossly higher than the private sector does. I want to say I read that F9 would have cost some multiple---approaching an order of magnitude more to develop than it actually did---under NASA costing estimates.

How does my suggestion differ from the SLS procurement? Contractors build their SLS versions first, then if accepted they get paid. If they need a dev stipend to work on a prototype, then it's a fixed budget, and very small by NASA standards (a few hundred M $). This 40 B$ dev cost by the taxpayers? Not a thing. If you want to claim a 500 M$ marginal launch cost on SLS, and bid for that project, then you build a rocket where you can make money on a 500 M$ launch cost, including all your dev costs---that the government doesn't pay for, except their cost per launch.

 

 

Edited April 25, 2018 by tater

[sevenperforce]

14 hours ago, cubinator said:

After all that, will NASA decide to make a decently capable reusable rocket?

I sure as hell hope not.

4 hours ago, Tullius said:

Any government project will see cost overruns, if you don't keep a very strict eye on the contractors to stay within budget, since the government will usually pay for any overruns.

A NASA backed BFR would also accumulate delays and cost overruns, just like SLS, since it would not be necessary for SpaceX to make do with whatever budget they could ensure, since it's practically infinite.

The proposal is not "NASA-backed BFR" but rather "NASA-funded BFR launch" where NASA buys a payload delivery service and supplies the payload but doesn't directly fund the launch vehicle.

With F9, NG, BFR, and to a lesser extent Vulcan, we are beginning to see the possibility of LV-agnostic payload services. NASA needs to say "We don't care how it gets there; we just want to know who can put this payload into this orbit at this time while satisfying our reliability assurance criteria."

7 hours ago, KSK said:

This article makes a reasonably good case (political and, surprisingly, technical) for keeping Europa Clipper and it's follow up lander mission on SLS. On that basis I'm predicting four SLS flights - assuming that the schedule sketched out on Wikipedia is still current and that EM-1 remains uncrewed: EM1, Europa Clipper, Europa Lander and a crewed lunar fly-by.

Europe Clipper could be delivered direct to Jupiter, more cheaply, and sooner, with two reusable Falcon Heavy launches. Or one F9 launch and one Atlas V launch.

But since NASA probably wouldn't buy distributed launch for Clipper, then yeah, it might fly on SLS. EM-1 and Clipper, if EUS is developed. If they only fly ICPS, Clipper will more likely fly on an Atlas V 551 and just do a longer transit. SLS will never fly a Europa Lander, since the lander will not be designed (let alone built) until well after Clipper arrives.

Quote

Whether SLS will be allowed to retire after 4 missions...? *shrug*

Edit - thinking about it, I'm not so sure that disposable vehicle comment is correct. Most of the interesting BFR missions seem to involve on-orbit propellant loading and tanker BFRs. Can't afford to throw too many of those away before SLS becomes cheaper.

Flying the spaceship disposable would not quite beat SLS simply because the upper-stage mass ratio is remarkably poor compared to the EUS. But if you fly the booster disposable as well, you blow SLS out of the water. Especially Block I with ICPS.

Elon said BFR (before the recent stretch) could put 250 tonnes into orbit by expending both the booster and the upper stage. With the stretch and engine uprating, you're probably looking at 275 tonnes. Clipper is under ten tonnes; 265 tonnes of propellant at 375 seconds Isp is enough to deliver Clipper direct to Jupiter, including the insertion burn.

12 hours ago, _Augustus_ said:

It will be cancelled before or shortly after EM-1.

After, I'm sure. I agree that it's gotta fly at least once.

39 minutes ago, tater said:

How does my suggestion differ from the SLS procurement? Contractors build their SLS versions first, then if accepted they get paid. If they need a dev stipend to work on a prototype, then it's a fixed budget, and very small by NASA standards (a few hundred M $). This 40 B$ dev cost by the taxpayers? Not a thing. If you want to claim a 500 M$ marginal launch cost on SLS, and bid for that project, then you build a rocket where you can make money on a 500 M$ launch cost, including all your dev costs---that the government doesn't pay for, except their cost per launch.

Yeah, that's just stupid. EDIT: By which I mean, the $40B dev cost is stupid, not dev stipends and cost per launch.

Quote

 

 

This will be a re-use of the Zuma booster. 

Edited April 25, 2018 by sevenperforce

[Tullius]

56 minutes ago, tater said:

NASA's own costing spreadsheet apparently produces numbers grossly higher than the private sector does. I want to say I read that F9 would have cost some multiple---approaching an order of magnitude more to develop than it actually did---under NASA costing estimates.

How does my suggestion differ from the SLS procurement? Contractors build their SLS versions first, then if accepted they get paid. If they need a dev stipend to work on a prototype, then it's a fixed budget, and very small by NASA standards (a few hundred M $). This 40 B$ dev cost by the taxpayers? Not a thing. If you want to claim a 500 M$ marginal launch cost on SLS, and bid for that project, then you build a rocket where you can make money on a 500 M$ launch cost, including all your dev costs---that the government doesn't pay for, except their cost per launch.

And you really think that there is a single company out there that is dumb enough to jump on such a project?

If NASA wanted to let a private company develop a new rocket, it is going to look much more like the commercial cargo or commercial crew programs: The project gets divided into multiple milestones and the companies get paid for reach each one of them separately. This gives you much finer control over costs, since you can stop and rethink how a certain milestone can be reached if costs explode. However, if at some point the companies decide that a certain milestone cannot be reached with the given amount of money, either NASA increases the budget or the project has to be given up.

Part of the reason why the commercial cargo and crew programs have been so successful at keeping costs down was the fact that SpaceX wanted to offer Falcon 9 also on the launch market outside of the program. And Orbital ATK and Boeing had to make sure to keep costs down, since otherwise SpaceX would get the whole programs.