totm nov 2023 SpaceX Discussion Thread

[tater]

16 minutes ago, sevenperforce said:

If SS/SH works well enough that crewed orbital destinations are cheap, I think we might have a good business case for a small, rapidly reusable crew SSTO shuttle (or perhaps one that uses drop tanks) with fractions for full-envelope launch abort. That would be delightful. 

Yeah, any orbital destination for people doesn't need hundreds of seats a a go, something smaller would actually start to look really attractive.

I'd love to see Skylon be a thing, for example.

[sevenperforce]

Just now, tater said:

Yeah, any orbital destination for people doesn't need hundreds of seats a a go, something smaller would actually start to look really attractive.

I'd love to see Skylon be a thing, for example.

So would I, though it won't be, and I don't like having no abort modes.

A HOTOL, an air-augmented mini-Raptor spaceplane with methagox-thruster abort motors might work.

[tater]

4 minutes ago, sevenperforce said:

So would I, though it won't be, and I don't like having no abort modes.

A HOTOL, an air-augmented mini-Raptor spaceplane with methagox-thruster abort motors might work.

Abort modes are always gonna be an issue, which is why crew SS is such a long pole to me.

[Raven Industries]

23 minutes ago, tater said:

Yeah, any orbital destination for people doesn't need hundreds of seats a a go, something smaller would actually start to look really attractive.

I'd love to see Skylon be a thing, for example.

Not quite the same, but if there ends up being enough demand for such smaller flights, I could see SS being used in a sort of international/regional airport type setup. Haul large groups of people into orbit and drop them off at a hub of sorts, and then ferry individual groups to their destination with smaller craft that don't have to be built for travel to and from the Earth's surface. 

[sh1pman]

2 hours ago, sevenperforce said:

A HOTOL, an air-augmented mini-Raptor spaceplane with methagox-thruster abort motors might work.

@Spacescifi, write that down!  That’s a viable SSTO design, and it doesn’t even need an antimatter bomb pusher plate!

 

[Hannu2]

12 hours ago, sevenperforce said:

So would I, though it won't be, and I don't like having no abort modes.

A HOTOL, an air-augmented mini-Raptor spaceplane with methagox-thruster abort motors might work.

In any case general attitude must change before humans can get new significant manned achievements. We have to learn to accept that crew losses are inevitable in such extreme conditions. Pioneering work near frontiers of known world will never be safe. Before that cultural change manned activity will be boring investigation of tardigrades on LEO and endless talk of pompous "future plans" without any kind of realism.

Astronaut's attitude is not a problem. There is certainly more willing individuals for heroic but dangerous work than ever can be employed. But attitudes of politicians and funders is real problem, and that is based on opinions of average people.

[zolotiyeruki]

I just had a thought.  I'll bet the NRO would be *very* interested in SS/SH.  The resolution of satellite imagery is limited by mirror/lens diameter, and going from the space shuttle's 4.5m payload bay to SS's 9m must have some folks salivating.  Forget reading license plates, you'll be reading newspapers from orbit! (ok, I'm exaggerating a little....)

[magnemoe]

19 hours ago, sh1pman said:

@Spacescifi, write that down!  That’s a viable SSTO design, and it doesn’t even need an antimatter bomb pusher plate!

 

Or just put the methane header tank in front too, make an mini raptor, perhaps with electrical pumps rather than turbopumps as you have two Tesla batteries there anyway and that engine will be way cheaper. 
This could even let you do abort landing  on Mars or Moon then you had an base there.  

[sevenperforce]

11 minutes ago, magnemoe said:

Or just put the methane header tank in front too, make an mini raptor, perhaps with electrical pumps rather than turbopumps as you have two Tesla batteries there anyway and that engine will be way cheaper. 
This could even let you do abort landing  on Mars or Moon then you had an base there.  

Pressure-fed hot-gas thrusters might give you enough dV to do it anyway.

Have the Raptor autogenous press feed into dual-redundant maneuvering prop tanks that vent to the main tanks intermittently. In an abort, the vent lines are severed and sealed, and those tanks are used for abort and landing.

But this would be for earth to orbit and back, not for landing elsewhere.

[Flavio hc16]

https://spaceflightnow.com/2020/04/27/falcon-heavy-on-track-for-design-validation-milestone-before-late-2020-launch/

 

this will be the launch that will give definitive validation for the military for falcon heavy. It's schedule for june/july and it will be a side booster droneship landing and centre core expended, the first for falcon heavy. Mass and number of satellites is unknown, but they will go for geostationary orbit

[CatastrophicFailure]

7 minutes ago, Flavio hc16 said:

it will be a side booster droneship landing and centre core expended,

Man, they just can’t catch a break on those FH center cores... 

 

But that would explain all the work that’s being done on the other drone ship in Florida lately. 

[RCgothic]

Also wow, that is a seriously hot Falcon Heavy flight! Two payloads direct to GEO.

Edited April 28, 2020 by RCgothic

[sh1pman]

GK’s attempt at working out the economics of reusable rockets by SpaceX.

 

[Wjolcz]

1 hour ago, sh1pman said:

GK’s attempt at working out the economics of reusable rockets by SpaceX.

 

I don't get it. So are they trying to prove/disprove something or just doing guesswork?

Also, where did they take the 15mln refurbishment cost from?

[tater]

2 minutes ago, Wjolcz said:

Also, where did they take the 15mln refurbishment cost from?

Someone's posterior?

[RCgothic]

I think they're trying to imply SpaceX gets unfair subsidy for its other activities because NASA pays for their new rockets.

But whoever designed those infographics is definitely not spacex material. They're awful.

[sh1pman]

31 minutes ago, Wjolcz said:

I don't get it. So are they trying to prove/disprove something or just doing guesswork?

There are two layers here. On the first one, they just try to calculate how much money SpaceX saves from reusing the first stage. The infographics could be done better, lots of repeating info, slides 2-4 could be combined into one.

On the second layer they’re implying that NASA overpays SpaceX for Dragon launches (160M vs 104M), and this allows them to set the price for commercial launches lower than the 71.5M price of a new rocket. Therefore, even without 1st stage reuse SpaceX can afford to charge significantly lower than 71.5M. 

[mikegarrison]

LOL at trying to get SpaceX to confirm or deny their numbers. I assume they are not so stupid.

Musk does have a tendency to want to show off on social media, but I doubt he will bite.

[SOXBLOX]

What I mean is that there are no missions for Starship to fly. NASA isn't about to fund anymore JWST-sized scopes, and certainly not any planet-imagers, in the near-future. The NRO is quite content already, and would much prefer to launch on proven launchers. Gateway is the only conceivable destination outside of low-earth orbit, and it may not even be built. Launches to specialty orbits are so expensive only because the current launchers are so limited; Starship would eat up the very small amount of demand there is, and would fail to make money regardless. Five sats per launch? Congrats, you just cut the price to a fifth (or less) of the original. As for colonizing Mars, Starship could *maybe* do it, but it would be losing money all the way. Keeping even an unrealistically tiny Earth-to-Mars supply chain open for any useful duration would rapidly bankrupt SpaceX. There's no money being made by a Mars colony for the first few years at least, it just eats cash. A 100 ton payload is impressive, but serves no practical purpose. What serious endeavour requires this launch vehicle?We could switch the electric grid to solar, but we don't because the effort would be a net monetary loss. We could build a maglev train system covering the continental United States, but we don't because there is no profit to be made on any realistic timescale. Even if we had all the necessary tech to put a colony on Mars today or in the next decade, we wouldn't unless there was a real economic incentive to justify the necessary effort. Elon Musk is no idiot, but at heart he is a businessman. When Starship continually fails to make money, he will retire it.

Furthermore, flying this thing with crew would be risky. When it fails (and statistically it will surely fail, being so complex) and 100 civilian passengers die on it, then what? Could the Starship program, or even SpaceX itself, recover? It would provide a massive boost to all the other launch providers, that's for sure. 

Many SpaceX fanboys don't realize it, but ULA has enormous resources behind it from its parent companies, Lockheed Martin and Boeing. Both are aerospace and defence tech giants, with access to tech far beyond anything SpaceX has developed. If they put together a Skunk Works style team, they could build an equal or better launcher, and do it faster and cheaper. They haven't, and won't for the foreseeable future, mainly because it isn't a solution to a problem anyone is serious about solving. 

So, until there is a viable economic incentive for colonizing space or using super-heavy launchers, Starship is an answer to a question nobody is asking. By the time that question is asked, and there is a market more solid than "It's cool, so of course people will fly on it", SS will be obsolete, and rusting in a museum somewhere.

[SOXBLOX]

And as for the actual colonization of space, the first step is to make people want to leave Earth. That is, they must want to trade blue skies and zero-cost breathable atmosphere for health issues in low or zero G, dusty Mars, and life in a cramped tin can. In that case, it won't be us uber-rich first world Americans going. Probably the best way to make people move to space is to nuke not Mars, but Earth. That's right, about the only thing which could force a mass exodus would be a full-scale nuclear exchange. After which, by the way, there would be no Hawthorne, CA.

Next, you need a place to go. Building this is entirely out of the reach of whole nations, much less small companies like SpaceX. Gravity ring stations in cislunar space built with SS launches? Oh please. Get realistic, people. This isn't Star Trek, no matter how hard you shout.

 

[zolotiyeruki]

21 minutes ago, SOXBLOX said:

What I mean is that there are no missions for Starship to fly.

 

21 minutes ago, SOXBLOX said:

Many SpaceX fanboys don't realize it, but ULA has enormous resources behind it from its parent companies, Lockheed Martin and Boeing. Both are aerospace and defence tech giants, with access to tech far beyond anything SpaceX has developed. If they put together a Skunk Works style team, they could build an equal or better launcher, and do it faster and cheaper. They haven't, and won't for the foreseeable future, mainly because it isn't a solution to a problem anyone is serious about solving.

You make a good point about abort modes, but I have two counter arguments for the points above:

1) There are no missions right now that require the full capabilities of Starship.  However, that doesn't mean Starship woould be useless.  It could be used for basically every mission that every current launch platform services, at a lower cost.  Sure, smaller payloads won't use all of SS's capabilities, but it'll still be cheaper than any of the expendable launch platforms.  Who cares if the launch vehicle can handle 10x the size of your payload, if they're still cheaper than a competing platform that's sized to match your payload?
2) Boeing isn't exactly covering itself in glory lately when it comes to....well, just about anything they're involved with, and "low cost" doesn't exactly come to mind when it comes to any defense contractors, so I'll remain skeptical of Boeing and Lockmart's ability to produce a price-comipetitive launch platform, to say nothing of their desire.

[CatastrophicFailure]

30 minutes ago, SOXBLOX said:

What I mean is that there are no missions for Starship to fly.

One word answers all your questions: Starlink. Or is that two? Anyways...

SpaceX needs SS for Starlink, and Starlink will fund everything else. At least, that’s their stated plan. And that much of it makes sense, there’s billions to be made even with a tiny sliver of the global internet service market. And once SS is flying that much, it suddenly becomes cheaper than Falcon (or anything else) by orders of magnitude. Doesn’t matter if “there’s no 100 ton payloads,” if SS costs as much to launch as, say Electron, it just cheap to launch 5 tons. I know it’s a flawed analogy, but it’s cheaper to rent a 747 and reuse it than buy a brand new Cessna and throw it away. As for bigger payloads, it’s a vicious circle. There are no hundred-ton payloads because there are no hundred-ton lifters because there are no hundred-ton payloads. Create the access, and most importantly make it cheap, and now companies can build cheaper, heavier, “expendable” sats for much less than the current crop of (rightly) over-engineered billion-dollar marvels that absolutely have to work.
 

If it’s successful, Starship will be a radical change to the existing paradigm, such that it’s difficult for some people to even see. They’ll have no trouble making money off it.
 

That Starlink money, in turn, will finance SpaceX’s more “altruistic” goals of colonizing Mars. If that’s even possible at all, I guarantee you’ll have no trouble finding volunteers, even if that pool declines as price goes up. Whether all that’s a good idea is another thread, but this is SpaceX’s plan. 
 

40 minutes ago, SOXBLOX said:

Many SpaceX fanboys don't realize it, but ULA has enormous resources behind it from its parent companies, Lockheed Martin and Boeing.

Boeing, sadly, can’t find its own S with both hands and a map right now. 

41 minutes ago, SOXBLOX said:

SS will be obsolete, and rusting in a museum somewhere.

Stainless doesn’t rust. 
 

 

16 minutes ago, zolotiyeruki said:

You make a good point about abort modes

On that note, it’s worth pointing out that the very first airliners were deathtraps too. Once again, it’s a chicken-egg thing. Rockets don’t have airliner-like reliability because they don’t have airliner-like logged hours because they don’t have airliner-like reliability. Or cost. Both of which SS is being built to address. If Starship is eventually flying multiple times a day, then the hours needed to problem solve and reach that kind of reliability can actually be achieved, and Starship won’t be flying any great numbers of people until it’s demonstrated that kind of reliability. 

[tater]

1 hour ago, SOXBLOX said:

What I mean is that there are no missions for Starship to fly. NASA isn't about to fund anymore JWST-sized scopes, and certainly not any planet-imagers, in the near-future. The NRO is quite content already, and would much prefer to launch on proven launchers.

A few things, right now, even with cheap launch via SpaceX (substantially cheaper than competitors for US gov launches), ULA gets thrown bones because the government rightfully wants more than one provider. Once Blue Origin is flying, there will be 2 competing providers that actually compete. That will drive prices down in a way that has not had to happen so far, because ULA can't be any cheaper than they are right now. BO with reuse will be able to compete.

If prices were to come down, everything changes.

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Gateway is the only conceivable destination outside of low-earth orbit, and it may not even be built. Launches to specialty orbits are so expensive only because the current launchers are so limited; Starship would eat up the very small amount of demand there is, and would fail to make money regardless. Five sats per launch? Congrats, you just cut the price to a fifth (or less) of the original.

Starship would indeed eat up all the demand, the question becomes at what point do they decide to try and create new demand by lowering prices? Assume they actually make it work, and a flight costs a few million bucks. Single digit millions SpaceX cost for 150t to LEO, and maybe they mark it up 100% to 10 million. That's $67/kg. People can start experimenting with new business models at those kinds of prices.

That said, SpaceX isn't building SS to do this, it's for their own purpose, Mars (something I personally think is goofy).

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As for colonizing Mars, Starship could *maybe* do it, but it would be losing money all the way. Keeping even an unrealistically tiny Earth-to-Mars supply chain open for any useful duration would rapidly bankrupt SpaceX. There's no money being made by a Mars colony for the first few years at least, it just eats cash. A 100 ton payload is impressive, but serves no practical purpose.

I actually don't disagree regarding Mars. I just don't see it. That said, if they could demonstrate a flight to Mars (and more importantly BACK), they could potentially sell it to the only people who could write a check for it, NASA.

 

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What serious endeavour requires this launch vehicle? We could switch the electric grid to solar, but we don't because the effort would be a net monetary loss.

Space based solar might actually work if launch costs were low enough. Way up the thread there is a talk by an outfit working on 2 sided solar panels that also function as flat panel microwave antennas. Limited use case, but not impossible.

 

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We could build a maglev train system covering the continental United States, but we don't because there is no profit to be made on any realistic timescale. Even if we had all the necessary tech to put a colony on Mars today or in the next decade, we wouldn't unless there was a real economic incentive to justify the necessary effort. Elon Musk is no idiot, but at heart he is a businessman. When Starship continually fails to make money, he will retire it.

nah, that is the part I think people miss, he's making money to build SS, not building SS to make money.

 

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Furthermore, flying this thing with crew would be risky. When it fails (and statistically it will surely fail, being so complex) and 100 civilian passengers die on it, then what? Could the Starship program, or even SpaceX itself, recover? It would provide a massive boost to all the other launch providers, that's for sure. 

The 100 people on a flight thing... yeah, not seeing that for a long time. That said, either reusable rockets get safe, or we are stuck on this rock forever with no more than a handful of people willing to take combat or test pilot level risks to leave flags and footprints. Someone has to make this work, at some point, or we're Earth bound indefinitely.

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Many SpaceX fanboys don't realize it, but ULA has enormous resources behind it from its parent companies, Lockheed Martin and Boeing. Both are aerospace and defence tech giants, with access to tech far beyond anything SpaceX has developed. If they put together a Skunk Works style team, they could build an equal or better launcher, and do it faster and cheaper. They haven't, and won't for the foreseeable future, mainly because it isn't a solution to a problem anyone is serious about solving. 

Yeah, no.

They are not about that, they are about harvesting money from the taxpayers. The SLS debacle is a demonstration of exactly what Boeing is after. Milk NASA for as much as possible, doesn't matter if it's never done, it's not about doing anything, the longer it takes, the longer they get paid.

 

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So, until there is a viable economic incentive for colonizing space or using super-heavy launchers, Starship is an answer to a question nobody is asking. By the time that question is asked, and there is a market more solid than "It's cool, so of course people will fly on it", SS will be obsolete, and rusting in a museum somewhere.

The super heavy part is simply wrong here. The mass to LEO or of the rocket doesn't matter at all. All that matters is the cost for a typical payload. If that cost is less than competitors by enough, anyone would be a fool to use any other LV. If SpaceX can fly it nearly empty for less than a maxed out Vulcan or NG, then they are cheaper.

1 hour ago, CatastrophicFailure said:

If Starship is eventually flying multiple times a day, then the hours needed to problem solve and reach that kind of reliability can actually be achieved, and Starship won’t be flying any great numbers of people until it’s demonstrated that kind of reliability. 

Also a chicken and egg thing. Starlink would be done in a few flights, then once again there is nothing to do. Sure, some test missions to the Moon and Mars, but then...

Space Force is actually a serious possibility. The AF/SF wants a rocket that works like a plane. An operational space vehicle. Gas it up, and go. I'd not sell that possibility short. First unmanned, then after enough flights maybe they look into a crew version (would have to have an abort/escape system of some kind, IMO). Airline safety... Man, I just don't see it for a long, long time. It would take decades to get to 10% of the number of airline flights in the US on a single day.

That said, if they could manage crew safety somehow... tourism is the killer app, IMHO.

Edited April 29, 2020 by tater

[CatastrophicFailure]

37 minutes ago, tater said:

That's $67/kg. People can start experimenting with new business models at those kinds of prices.

Exactly. For that much, I'd sure a heck be throwing a cubesat up, just because I could. At prices even approaching that, it becomses practical from a business perspective to "throw stuff at space and see what sticks."

[tater]

Here's the interesting solar power talk:

He is suggesting this using Atlas 551 as the LV. At the mass they are confident of achieving, they would need 58 launches to get to power at $1.77/kWh. That's of course only a number the US military might pay at a base in the middle of no place in AK, or something. Atlas 551 is ~153 million a pop. So 870t at a total cost of 8.874 B$.

Assuming that SS can get only 87t to MEO (150 to LEO) with no refilling. That's 10 SS flights. If they charged the same per launch as Atlas 551, that's 1.53B$. That drops the price per kWh to 30 cents. Still 3X what I pay at home. Of course MUsk has said that SS would be able to fly for a couple million a flight, but they need some markup, clearly. If they charged 50M$/flight, then the power cost is now competitive with what I pay at home.

So space based power might actually be doable with launch costs cheap enough. A few years ago I would have said, "yeah, space based solar was debunked years ago" but that's simply not true now, it might be possible.

I don't think this is a killer app for SS, what I am really getting at is that lower cost opens up possibilities that have been discounted, or no one ever seriously considered. Asteroid mining is another. The current entry costs are absurdly high to test anything... not at $67/kg they aren't, and the spacecraft doesn't need to be perfect for that cheap a price, if it fails, iterate and send another.