totm nov 2023 SpaceX Discussion Thread

[mikegarrison]

Musk got big cheers for his moonbase slide, but what would we do on a moonbase? It's got too much gravity to do zero-G manufacturing, but probably too little gravity to keep people healthy. There is basically nothing there that we really need. Everything on the moon is already on the Earth.

If we ever have large-scale orbital industry, then the moon could be a cheaper place to get raw materials from. But that's a long. long way away.

[tater]

Other countries have interest in going to the Moon. I think the goal is not economic, or scientific, it's honestly "adventure," the stuff he talks about at the beginning, and making the world more interesting. 

Since there are entities with money willing to pay for the Moon, you haul stuff to the Moon for them. SpaceX is just the trucking company, what they deliver doesn't matter. 

[mikegarrison]

Frankly, I see tourism as the biggest market for the moon. Maybe some astronomy outposts.

[sh1pman]

7 minutes ago, kerbiloid said:

Upd.
Also, we should assume that the most demanded good from the Earth will be hydrogen cyanide (HCN).
Because it is carbon and nitrogen.
So, building your Mun base don't forget to put huge tanks for HCN, about a half of your whole base.

I wouldn't want to be anywhere near a tank with 80 tons of cyanide...

Won't urea be a much better (and safer) alternative?

[TheEpicSquared]

17 minutes ago, mikegarrison said:

Musk got big cheers for his moonbase slide, but what would we do on a moonbase? It's got too much gravity to do zero-G manufacturing, but probably too little gravity to keep people healthy. There is basically nothing there that we really need. Everything on the moon is already on the Earth.

If we ever have large-scale orbital industry, then the moon could be a cheaper place to get raw materials from. But that's a long. long way away.

I was wondering the same. For SpaceX, I guess it's a good test of the mission architecture close to home (propulsive landing and all that), but that's about it. Tourism as well, maybe. 

However, SpaceX could haul cargo to the moon for other moon-interested companies/countries (NASA, JAXA, Russia even) and make some money with that (essentially a lunar delivery service).

Other than a quick moneymaker and testing bed for SpaceX, the moon seems to be a dead end. Their real goal is and always will be Mars, and IMO they're using the moon as a stepping-stone.

EDIT: Also, it seems to be a direct competitor to New Glenn, so maybe Blue Origin is an incentive for a moon base.

EDIT 2: Just noticed that most of what I said was already mentioned by @tater  

Edited September 29, 2017 by TheEpicSquared

[tater]

Yeah, the Moon is an oddball spot. Astronomy would be cool, but you'd not want loads of craft landing (dust) for optical interferometry. I think the technologies to build stuff (3d printers, etc) would certainly be desirable to test out. Another aspect is the general life support issues. It's ideal to test someplace where you can shield the astronauts and do longer term studies. ISRU is only really useful to the extent that it's cheaper to extract on the Moon than to bring it up. With reusable vehicles, the economics is a little more difficult (has to be even cheaper on the Moon than with expendables).

[kerbiloid]

Spoiler

13 minutes ago, sh1pman said:

I wouldn't want to be anywhere near a tank with 80 tons of cyanide...

Do you think, 80 t of hydrazine is much better?

P.S.
Though, this is not about Space-X.

 

[magnemoe]

10 minutes ago, mikegarrison said:

Musk got big cheers for his moonbase slide, but what would we do on a moonbase? It's got too much gravity to do zero-G manufacturing, but probably too little gravity to keep people healthy. There is basically nothing there that we really need. Everything on the moon is already on the Earth.

If we ever have large-scale orbital industry, then the moon could be a cheaper place to get raw materials from. But that's a long. long way away.

Lots of holes in the knowledge after Apollo, the later orbiting missions has left more questions. 
No exploring does not require bases, however if you can do ISRU it becomes easier to move around you can also export stuff to GTO or LEO, water, aluminium would be nice too. 
Moon is probably not as good an resource base as asteroids because of higher dV demands however its far closer making direct remote control practical and its easy to resupply. 
On the other hand its nothing you can export from Mars who make any sense in GTO. Mars moons is a bit more interesting as captured asteroids, an mission to them can be bundled with an Mars mission.

Add that Moon is an very nice testbed for Mars bonus in that condition is more extreme. 
Bonus in that if anything fails you can just run to the lander and return to Earth in 3 days. On Mars you have to wait for an launch window, the Mars plan require ISRU, if it don't work you are stuck. 

[AngelLestat]

Hi everyone, it has been a long time since the last time I check your comments, I saw the news today and I imagine that you might have a good discussion going on here, after reading all your comments I decided to jump on to talk of some details that may not have being mentioned yet.

For start, I really like way more this new design that the last, way more realistic and practical as many of you mention.
I imagine what it can done a vehicle like this for the space business or exploration. How cheaper could have been the JWTelescope if would not need to be folded between other things.

Of course, they still need a big design, not because mars require it..  because it could not be fully reusable if does not reach to that minimum size. For example the heatshield mass which depend on the surface but it becomes negligible to respect the volume (amount of fuel), but it seems that even considering that, they are way on margin with respect to mars reentry (that animation is the thing that I enjoy most), we also have to take into account that it returns almost empty, otherwise the volume/surface ratio "density" would be an issue instead a benefit.

I like the idea to change all efforts to this vehicle instead continue developing the falcon9, although this will remain operational for a long time.

One things that was kinda crazy was the idea to use this vehicle as a faster transport between cities on earth.  Like many of you mention..  even if they manage to solve the launch and reentry vibrations, I doubt they can solve the g-forces in a confort way for normal people, but it may be an audience in search of adrenaline.
There is a bigger issue with this idea..  sonic boom and sound pollution like we can see in this video:

   The sonic boom is originated way far above, maybe at 5 km of height, so is not an issue of the cameraman proximity, so the launch facility should be way far from any city, and if it take you at least 1 hour to reach the launch site and 1 hour in destination, then the 35min of travel lost meaning. 

But I guess this vehicle does not depend on this local application to achieve profits.

PD: I like how they solve the docking and refuel system between other things.  Also.. it would be a second stage variant to sent expendable missions to the outer planets or venus?

Edited September 29, 2017 by AngelLestat

[magnemoe]

18 minutes ago, mikegarrison said:

Frankly, I see tourism as the biggest market for the moon. Maybe some astronomy outposts.

Moon would be an nice tourist destination, trip time match well with an holiday. 
An moon hotel would be even cooler, with an large dome you could not only jump high but fly with strap on wings, you could run on water in the pool at least if wearing large boots or jump out of water like an dolphin if wearing flippers. 

[TheEpicSquared]

About the point-to-point idea, is it, in a purely technical aspect, possible for the ship to glide down using its wings to a runway landing? I’m pretty sure that even if it’s possible, it won’t be used because you would need landing gear sticking out of the heatshield, and we know that that’s a no-go for SpaceX. 

Maybe glide it onto a giant bouncy castle?  

[HebaruSan]

Some of the 30 minute trip time would be spent in free fall, right? Any forecasts as to how long? I wonder whether that's a net positive or negative for attracting customers.

[tater]

His note about marginal costs in the talk was interesting. he put the marginal launch cost below F9 and even F1.

What do with think the marginal costs of a reused F9 are? 30 M$? Less? If they could actually operate a rocket cheaper than F9, then the size just doesn't matter, even a little. Launch Koreasat (~1400kg) with BFR? Why not, still cheaper than F9.

I'm sure we won't see the math on that, but if it's true, that part is kind of a big deal. I saw people at NSF saying it might cost 1-2 M$ to fuel the thing up.

 

[AngelLestat]

8 minutes ago, magnemoe said:

Moon is probably not as good an resource base as asteroids because of higher dV demands however its far closer making direct remote control practical and its easy to resupply. 

Also.. moon is not good for refuel and go..  because you waste almost the same dv to leave the moon than to leave low orbit, so a captured ice asteroid in low orbit would be way more usefull in that matter.

[Guest]

Just now, HebaruSan said:

Some of the 30 minute trip time would be spent in free fall, right? Any forecasts as to how long? I wonder whether that's a net positive or negative for attracting customers.

Depends on the average chunder quotient.

[mikegarrison]

26 minutes ago, magnemoe said:

On the other hand its nothing you can export from Mars 

Mars isn't about exporting things from Mars to Earth. It's about colonization.

Eventually, if there are enough people, Mars would become an economic trading partner with the Earth. China and the US trade a lot of stuff with each other, but almost none of it is raw materials that don't exist in the other country. Instead, it's mostly manufactured goods, intellectual property, and raw materials that one country or the other has specialized in (so that the cost to ship them is less than the cost to duplicate the specialization).

16 minutes ago, tater said:

His note about marginal costs in the talk was interesting. he put the marginal launch cost below F9 and even F1.

What do with think the marginal costs of a reused F9 are? 30 M$? Less? If they could actually operate a rocket cheaper than F9, then the size just doesn't matter, even a little. Launch Koreasat (~1400kg) with BFR? Why not, still cheaper than F9.

I'm sure we won't see the math on that, but if it's true, that part is kind of a big deal. I saw people at NSF saying it might cost 1-2 M$ to fuel the thing up.

 

He was talking cost/ton. That's what I meant about the scale issues. To get the low cost/ton numbers requires a reasonable load factor in the payload bay. A 777 across the Pacific is hella expensive per person if there is only one passenger on board. But it's pretty reasonable with an 80% load factor.

Edited September 29, 2017 by mikegarrison

[kerbiloid]

Spoiler

26 minutes ago, AngelLestat said:

a captured ice asteroid in low orbit would be way more usefull in that matter.

They call it Minmus.

 

18 minutes ago, mikegarrison said:

Mars would become an economic trading partner with the Earth.

Rocks for food.

[tater]

37 minutes ago, mikegarrison said:

Mars isn't about exporting things from Mars to Earth. It's about colonization.

Eventually, if there are enough people, Mars would become an economic trading partner with the Earth. China and the US trade a lot of stuff with each other, but almost none of it is raw materials that don't exist in the other country. Instead, it's mostly manufactured goods, intellectual property, and raw materials that one country or the other has specialized in (so that the cost to ship them is less than the cost to duplicate the specialization).

Mars never becomes a trading partner with Earth, there is nothing they have that Earth needs.

I suppose if they somehow have money, then they buy stuff from Earth, and return money. However it is they get money.

 

Quote

He was talking cost/ton. That's what I meant about the scale issues. To get the low cost/ton numbers requires a reasonable load factor in the payload bay. A 777 across the Pacific is hella expensive per person if there is only one passenger on board. But it's pretty reasonable with an 80% load factor.

Yeah, that might make sense... I was thinking marginal launch cost, not per kg. But it might still be what I was thinking. All other rockets have the entire cost of the rocket as part of the marginal cost.

What's the difference in marginal cost between flying a full 777 across the pacific, then using it for more flights, vs the same flight, then desrtroying the plane once the passengers disembark?

Edited September 29, 2017 by tater

[Elthy]

Cost/ton wouldnt see the Falcon 1 on the top of the chart, though.

[tater]

Ninjaed.

[sevenperforce]

6 minutes ago, Elthy said:

43 minutes ago, mikegarrison said:

He was talking cost/ton. That's what I meant about the scale issues. To get the low cost/ton numbers requires a reasonable load factor in the payload bay. A 777 across the Pacific is hella expensive per person if there is only one passenger on board. But it's pretty reasonable with an 80% load factor.

Cost/ton wouldnt see the Falcon 1 on the top of the chart, though.

Precisely. Falcon 9 beats the heck out of Falcon 1 for cost/ton. Falcon Heavy moreso.

43 minutes ago, mikegarrison said:

He was talking cost/ton. That's what I meant about the scale issues. To get the low cost/ton numbers requires a reasonable load factor in the payload bay. A 777 across the Pacific is hella expensive per person if there is only one passenger on board. But it's pretty reasonable with an 80% load factor.

Chartering a 777 across the Pacific for a single passenger is cheaper than buying a Cessna, flying it to the end of its range, and crashing it nose-first into the tarmac.

[mikegarrison]

10 minutes ago, sevenperforce said:

Chartering a 777 across the Pacific for a single passenger is cheaper than buying a Cessna, flying it to the end of its range, and crashing it nose-first into the tarmac.

Actually, it's probably not. You can buy a Cessna for what, $100K? Less?

21 minutes ago, tater said:

What's the difference in marginal cost between flying a full 777 across the pacific, then using it for more flights, vs the same flight, then desrtroying the plane once the passengers disembark?

Depends on the 777. You can get them used for around $10M, if you are looking for an early 777-200. Brand new is more like 20x that.

23 minutes ago, tater said:

I was thinking marginal launch cost, not per kg.

Well, maybe he did mean that. I don't know. He didn't really hand out any spreadsheets to back up his pretty pictures.

[SuperFastJellyfish]

You can buy a used Cessna 152 for $20k-$30k.  I'd post a link, but the mobile version I'm on won't paste it cuz reasons.

[mikegarrison]

25 minutes ago, tater said:

Mars never becomes a trading partner with Earth, there is nothing they have that Earth needs.

There is nothing on an empty Mars that Earth needs. But once there are people there, people generate value. The economic value in Mars is that, eventually, it  can be self-sustaining for people to live there. It won't be Mars that provides the value, it will be the people living on Mars who do.

[CatastrophicFailure]

The comparison is new Cessna vs charter existing 777. A new Cessna is gonna run you upwards of $300k, maybe more. At that price point, the charter just might win out.