totm nov 2023 SpaceX Discussion Thread

[tater]

 

[kerbiloid]

Spoiler

  

4 hours ago, Nightside said:

5 hours ago, Meecrob said:

Scientology Launch System?

Now we understand why the new Human Lander System is called Dynetics...

A couple of years ago some forum users were laughing at me when I said that the most viable and probable kind of the extraterrestrial colony (not a support base, but a colony) is if some cult builds a monasterium there.

Now we can see who was right.

 

[tater]

 

[Shpaget]

7 hours ago, CatastrophicFailure said:

Needn’t be that much, SpaceX is only charging NASA around 55 million per seat. Now, with a used F9, used Dragon (which NASA won’t touch anyway), it would probably come in much less. Plus the publicity for SpaceX, I’m sure a deal could be made for a “reasonable” sum, at least in terms of movie budgets. 

Now, getting Tom Cruise’s ego into orbit, on the other hand, will require an SLS... 

Yeah, but that's per seat.

Regardless, the publicity point is kind of moot. In a market that is as small as space launch biz, being featured in a movie (or even a prominent placement) does not help. All the potential customers in the space business know about SpaceX, and the decision to use them over another one will not hinge on a Tom Cruise flick.

As for Scientology Launch System, yeah... my first thought as well (although I'll admit wasn't clever enough to thought of the backronym). I never expected NASA to put Tom Cruise and science in a same tweet. Makes me kind of sad. If it was up to me, there are some many notTomCruises out there that would get the ticket before him. blah

Speaking of static fire. What was that, one second burn? Since Elon says it was successful, I supposed that was planned, but I have to wonder, just how much data they can extract from such a short burn?

[Scotius]

2 hours ago, Shpaget said:

Speaking of static fire. What was that, one second burn? Since Elon says it was successful, I supposed that was planned, but I have to wonder, just how much data they can extract from such a short burn?

"It didn't explode!

Yay!

Great, now on to 10 second burn."

[Hannu2]

2 hours ago, Shpaget said:

Yeah, but that's per seat.

Regardless, the publicity point is kind of moot. In a market that is as small as space launch biz, being featured in a movie (or even a prominent placement) does not help. All the potential customers in the space business know about SpaceX, and the decision to use them over another one will not hinge on a Tom Cruise flick.

As for Scientology Launch System, yeah... my first thought as well (although I'll admit wasn't clever enough to thought of the backronym). I never expected NASA to put Tom Cruise and science in a same tweet. Makes me kind of sad. If it was up to me, there are some many notTomCruises out there that would get the ticket before him. blah

Speaking of static fire. What was that, one second burn? Since Elon says it was successful, I supposed that was planned, but I have to wonder, just how much data they can extract from such a short burn?

If it was 1 s at full (or high) thrust, they probably investigated ignition process. Start up process of rocket engine takes several seconds and may cause some special requirements for something.

[Lukaszenko]

4 hours ago, Shpaget said:

Regardless, the publicity point is kind of moot. In a market that is as small as space launch biz, being featured in a movie (or even a prominent placement) does not help. All the potential customers in the space business know about SpaceX, and the decision to use them over another one will not hinge on a Tom Cruise flick.

It's not for publicity in the advertising sense, where you're trying to win over customers. It's for publicity in the "hearts and minds" sense, where you're trying to win over support and inspire people to pursue space-related careers. It's more of an indirect and long-term benefit for the space industry.  

In a sense though, since the taxpayer IS the customer of NASA, it's also directly beneficial.

[tater]

NSF said the burn was ~4 sec. I didn't time it.

This is true, and likely they pay more. Maybe they don't need 2 seats, they can take a high res camera system, and mostly do fixed shots. Pay extra for the astronauts' time if they are in the shots/filming (as a other commercial contractors might for X hours of experiments done by the astronauts on their commercial payload).

Given the "set" I'd imagine it would have to be a current era story.

[Lukaszenko]

Are they really sending him to the ISS? Seems unlikely, because wouldn't he need a camera crew and all the works? Besdies, they have a mockup of the ISS on the ground and CG and parabolic flights to more or less make it convincing.

[tater]

On 5/1/2020 at 5:37 PM, sevenperforce said:

I have long been a proponent of horizontal landings on thrusters. They work everywhere except Mars (because Mars needs fully-loaded liftoff). But structural integrity is an issue.

Been thinking about this more. Musk had mentioned expendable SS for deep space probes, at some point. What about expendable SS for a lunar hab?

Crew version as shown in recent renders.

Hab version oriented for horizontal landing. Steel beefed up as needed for laying on its side in 1/6 g. Total dv designed to be the ~6.1 km/s it needs. with the payload reduced to whatever the hab volume requires. Ie: the most habitable volume with structural reinforcement, ECLSS, etc installed. Since it's mostly empty space, hard to achieve SS full cargo mass (hab volume is very close to default dry mass minus payload).

A 120t dry mass SS (no cargo) only needs ~540t of props for 6350m/s (what it full SS seems to need for 150t to LEO?). Default tank size is ~1200t props, right? So you could in effect keep the dry mass the same and make half the usual tankage. Or slightly more than half with higher dry mass for laying on the side on the Moon, perhaps covered. The extra pressurized volume is mostly "nothing" so it's not much heavier than the tanks it replaced.

Make any sense? The cover parts of it with regolith (in bags)?

 

 

 

[tater]

I doodled some decks on a circle, and guestimated that the total floor area of such a horizontal SS would be ~525m² (~5,600) sqft). Maybe a little less as the bottom nose would turn into a ramp of some sort, airlocks on the side.

Still, this is a substantial habitat.

Vertical SS with 7 3m decks is more like 200m² floor area.

EDIT: I realized I made my cross section doodle 2X as big (9m radius vs dia). Amounts halved. Nose was guestimated as triangles base = hull dia at that point. Was up too later last night, sorta loopy.

Edited May 6, 2020 by tater

[CatastrophicFailure]

58 minutes ago, Lukaszenko said:

Are they really sending him to the ISS? Seems unlikely, because wouldn't he need a camera crew and all the works? Besdies, they have a mockup of the ISS on the ground and CG and parabolic flights to more or less make it convincing.

Well, that’s what the head of NASA says, and he’s a bit of an authority on such matters.  I think there’s a lot of good cinematography that could be done with just an actor and director, who’d also be operating the camera. Faking weightlessness in film is hard, doing it convincingly is even harder. Gravity did a very good job with that but there’s some things you just can’t do with only the 20-30 seconds you get on the Vomit Comet. Think one of those awesome, sweeping, single-long-takes that takes the viewer floating down the length of the entire station, saying hi to all the astronauts, looking out all the windows, etc. 

Professional filing in space isn’t entirely unprecedented, either. There was an IMAX movie done on the shuttle a while back, I forget if it had the Station. But IMAX cameras are huge, heavy and bulky, and they basically trained the astronauts how to operate them. Now, imagine what a talented director could do with just a handheld 8k+ camera that’s light years ahead of IMAX technology wise. Training astronauts to be scientists in Apollo was good, bringing along an actual scientist on Apollo 17 was even better, same idea here. 

Also, never underestimate the marketing power of a good gimmick. 

Remember Jurassic Park where the CGI got top billing but was only on screen for a few minutes? I think this will likely be similar. I’m no Tom Cruise fan, but he is a good actor, and I, not at all surprised he’s the first one to officially sign on to a project like this. I’m more interested in who’ll be running the camera. 

28 minutes ago, tater said:

Still, this is a substantial habitat.

Better yet, go full wet-workshop: vent the tanks, cut some holes, and now you’ve got a good sized garage for your rover, too.  Could even return the Raptors for reuse.

Or go full-Kerbal and stick an extra Raptor on the rover...

Also, this:

Edited May 6, 2020 by CatastrophicFailure

[magnemoe]

43 minutes ago, tater said:

Been thinking about this more. Musk had mentioned expendable SS for deep space probes, at some point. What about expendable SS for a lunar hab?

Crew version as shown in recent renders.

Hab version oriented for horizontal landing. Steel beefed up as needed for laying on its side in 1/6 g. Total dv designed to be the ~6.1 km/s it needs. with the payload reduced to whatever the hab volume requires. Ie: the most habitable volume with structural reinforcement, ECLSS, etc installed. Since it's mostly empty space, hard to achieve SS full cargo mass (hab volume is very close to default dry mass minus payload).

A 120t dry mass SS (no cargo) only needs ~540t of props for 6350m/s (what it full SS seems to need for 150t to LEO?). Default tank size is ~1200t props, right? So you could in effect keep the dry mass the same and make half the usual tankage. Or slightly more than half with higher dry mass for laying on the side on the Moon, perhaps covered. The extra pressurized volume is mostly "nothing" so it's not much heavier than the tanks it replaced.

Make any sense? The cover parts of it with regolith (in bags)?

This is an option, you will need some heavy equipment on site as you want to bury it in a pit, you also want to insulate it I assume but this can be done before launching it. You could even add floors in the tanks for an wet workshop as long as you has holes for the liquids to flow. 
Land and then use the landing engines to tip it over and slow its fall, you might want to tie down the legs on one side so it don't move forward, you could recover the engine, probably keep them around if any later lander need replacements. 
And yes make one of the tank compartments an swimming pool
You could make extensions if you want an second starship base or other bases nextby.  

[Wjolcz]

1 hour ago, CatastrophicFailure said:

Better yet, go full wet-workshop: vent the tanks, cut some holes, and now you’ve got a good sized garage for your rover, too.  Could even return the Raptors for reuse.

Was thinking about this too. The only issue I see with this is they would need some sort of tipping mechanism. I wouldn't do that with engines. Instead, they could use a steel wire crane-like design. Would require some beams and welding but it's probably doable.

Pretty sure we've discussed it already. Don't know if it was in this thread or not.

Edited May 6, 2020 by Wjolcz

[zolotiyeruki]

On the topic of filming in space, the stated $2m launch cost for SS puts zero-g filming into the budget of bigger films.  SpaceX could build a SS with a sealed, pressurized cargo bay with life support and electricity, and not much else.  Basically a zero-g sound stage.  You could put a crew up in space to film for a week!  Coming soon in The Expanse Season 10!

[tater]

I was thinking of using the 9 landing RCS engines horizontally, and landing the SS on its side, not tipping it.

Clearly the tanks could be made into hab space at some point, but honestly, the first 5,600+ square feet is probably enough for a while given the ability to send crew is ~4 per year. The same number of people as my house (4), with each person having over 100 m² to themselves.

(FIXED)

Edited May 6, 2020 by tater

[RCgothic]

So Starship could probably send two D9 Caterpillar Bulldozers to the moon in one go from a payload perspective. Got to move a lot of earth to build a moonbase!

But would you necessarily want to go solar-electric for power? Earth movers require a lot. Could you modify an internal combustion engine to run on fuel/oxidiser? Superchargers would be super-effective sucking down to vacuum. Or would a fuel/oxidiser turbine work better with exhaust to vacuum?

[magnemoe]

7 minutes ago, Wjolcz said:

Was thinking about this too. The only issue I see with this is they would need some sort of tipping mechanism. I wouldn't do that with engines. Instead, they could use a steel wire crane-like design. Would require some beams and welding but it's probably doable.

Pretty sure we've discussed it already. Don't know if it was in this thread or not.

Think the engines could work but this would be safer, you would need an A frame and a bulldozer, 

[AngrybobH]

23 minutes ago, RCgothic said:

Could you modify an internal combustion engine to run on fuel/oxidiser?

Sure, but why? Electric motors are better for the moon(lighter and have multiple possible sources of 'fuel'). Save the fuel/oxidizer for the fuel cells.

[RCgothic]

Just now, AngrybobH said:

Sure, but why? Electric motors are better for the moon(lighter and have multiple possible sources of 'fuel'). Save the fuel/oxidizer for the fuel cells.

Because earth movers require a lot of energy, and it may be easier to provide that power from a dense fuel source if you want to prepare a base quickly, rather than wait ages between recharges that are individually only able to accomplish a small amount of work due to limited battery capacity.

[CatastrophicFailure]

25 minutes ago, RCgothic said:

Got to move a lot of earth to build a moonbase!

*moon. 

26 minutes ago, RCgothic said:

But would you necessarily want to go solar-electric for power? Earth movers require a lot. Could you modify an internal combustion engine to run on fuel/oxidiser? Superchargers would be super-effective sucking down to vacuum. Or would a fuel/oxidiser turbine work better with exhaust to vacuum?

This is exactly what ULA’s ACES concept does, run hydrolox boiloff through a combustion engine for power. Probably not practical for the kind of moon-moving equipment a moonbase would need, electric would be simpler, less cooling requirement, and near the poles solar is much more feasible. 

Coincidentally NASA already has an in with a guy who builds electric powered equipment and the hardware to land it...   

2 minutes ago, RCgothic said:

Because earth movers require a lot of energy, and it may be easier to provide that power from a dense fuel source if you want to prepare a base quickly, rather than wait ages between recharges that are individually only able to accomplish a small amount of work due to limited battery capacity.

Doing it on the moon also cuts the required loads to 1/6th, and with Starship as cargo ferry, mass is suddenly much less of a concern. Land a Starship that’s just full of batteries, have it constantly trickle charge from some huge solar arrays and boom, Lunar Supercharger. 

[RCgothic]

16 minutes ago, CatastrophicFailure said:

*moon. 

Coincidentally NASA already has an in with a guy who builds electric powered equipment and the hardware to land it...   

Doing it on the moon also cuts the required loads to 1/6th, and with Starship as cargo ferry, mass is suddenly much less of a concern. Land a Starship that’s just full of batteries, have it constantly trickle charge from some huge solar arrays and boom, Lunar Supercharger. 

Lol, yes, moon.

Does it reduce the requires loads to 1/6 though? If you want to bulldoze through a rock it might be harder because your bulldozer weighs less and therefore has less traction.

Edited May 6, 2020 by RCgothic

[tater]

A cross brace here and there would likely suffice to shore up SS on its side in lunar gravity.

Even within the prop tanks. Enter tank somehow, install pillars (telescopic that cranks open and locks). Now it could be covered or not, but not at risk of collapse, regardless.

If there is payload margin, the nose/ramp section could have a rover within at the expense of some floor space.

Some regolith could be pushed against the sides before hand. Bottom deck, deepest under regolith is windowless and has sleeping bathing facilities (~300m² area). next deck could be covered the same way, depending on how high regolith is piled. Top levels are exposed.

Perhaps the inner wall/ceiling surfaces (think car headliner for the top floor) could be made to store water?

4 minutes ago, RCgothic said:

Does it reduce the requires loads to 1/6 though? If you want to bulldoze through a rock it might be harder because your bulldozer weighs less and therefore has less traction.

Moar Tesla battery packs! Cybertruck, but with the bed stacked with battery packs.

[CatastrophicFailure]

10 minutes ago, RCgothic said:

Does it reduce the requires loads to 1/6 though? If you want to bulldoze through a rock it might be harder because your bulldozer weighs less and therefore has less traction.

I honestly don’t know, I’d be real curious to hear from someone who ran the numbers. Your dozer weighs less, but the rock also weighs less. Seems to me like it’d be a net reduction in the amount of energy needed to do anything. 

[RCgothic]

1 minute ago, CatastrophicFailure said:

I honestly don’t know, I’d be real curious to hear from someone who ran the numbers. Your dozer weighs less, but the rock also weighs less. Seems to me like it’d be a net reduction in the amount of energy needed to do anything. 

The rock weighs less, but if it's firmly anchored you need to shear through it. Same energy to do that anywhere in the solar system.

A solar farm with a load of multi-purpose swap-in battery packs for an electric vehicle is probably most efficient.

Still, a Kerolox supercharged diesel engine would be cool.