totm nov 2023 SpaceX Discussion Thread

[Barzon]

I've heard from reliable sources that Starship needs 11 refueling flights to get 100t to TLI.

Edited May 15, 2020 by Barzon

[RCgothic]

29 minutes ago, Barzon said:

why would it be launching that often? what would it be launching? the space market cannot support even 3 or 4 M/HLVs, so why would it have enough demand to enable Starship to fly hundreds of times a year? It won't be flying hundreds of starlink batchs, because I've heard that it takes about a month to make a batch of 60 sats, which limits it to 12 Starlink launches a year and I don't think SpaceX would want to launch each sat one at a time, no matter how cheap Starship launch costs are.

And no matter how reliable Starship gets, NASA will never accept the risk of not having a LAS on crewed spacecraft.

Starship doesn't have to launch full or even half full if flying costs an order of magnitude less than Falcon9. Got a 500kg smallsat to put in orbit and $2m budget for a launcher? Starship.

3 minutes ago, Barzon said:

I've heard from reliable sources that Starship needs 11 refueling flights to get 100t to TLI.

False, it takes 300t of propellant (2-3 launches) to send 220t of starship (dry mass plus 100t) to TLI from LEO.

Edited May 15, 2020 by RCgothic

[magnemoe]

16 minutes ago, Barzon said:

why would it be launching that often? what would it be launching? the space market cannot support even 3 or 4 M/HLVs, so why would it have enough demand to enable Starship to fly hundreds of times a year? It won't be flying hundreds of starlinks, because I've heard that it takes about a month to make a batch of 60 sats, and I don't think SpaceX would want to launch each sat one at a time, no matter how cheap Starship launch costs are.

Starlink and starlink 2.0, later is way better but you need to build the antenna in space. Military will love this as in spamming LEO spy satellites. You want to test some space hardware do it in space as an secondary payload. 
Can easy see them doing passenger versions doing satellite launches kind of like many ferries between Sweden and the Baltic or Norway against Denmark and Germany is also 1-2 day cruses and he  cruse is most of their income.
No its not cheap or safe but will be way safer than climbing Everest and might not be much more expensive down the line then demand tapper off. 
 

[VoidCosmos]

11 minutes ago, Barzon said:

I've heard from reliable sources 

Who exactly? Mind posting a few links please?

[Wjolcz]

23 minutes ago, Barzon said:

reliable

I love that source! It's my favourite!

Edited May 15, 2020 by Wjolcz

[Flavio hc16]

59 minutes ago, Barzon said:

why would it be launching that often? what would it be launching? the space market cannot support even 3 or 4 M/HLVs, so why would it have enough demand to enable Starship to fly hundreds of times a year? It won't be flying hundreds of starlink batchs, because I've heard that it takes about a month to make a batch of 60 sats, which limits it to 12 Starlink launches a year and I don't think SpaceX would want to launch each sat one at a time, no matter how cheap Starship launch costs are.

And no matter how reliable Starship gets, NASA will never accept the risk of not having a LAS on crewed spacecraft.

if the cost of space goes down to 100$/kg (  an order of magnitute worse than what Elon is aiming for) you will start a craptopn of stuff launched into orbit, universities, people who can burn money, science experiments of any kind. Yopu create a market that right now we don't know.

 

48 minutes ago, tater said:

They should delay the Starlink, why trash a booster?

They will delay it, better condition both for the payload and for the recovery on the 18th, and this is an internal mission, so they can wait, i think that they want to nail that 5th reuse/landing

37 minutes ago, Barzon said:

I've heard from reliable sources that Starship needs 11 refueling flights to get 100t to TLI.

lol nope, or rather you probably misunderstood that: with 11 refuels you get 100 tons of payload back from the moon to earth.

you need 2 fully fueled starships 1crew/1cargo, each of them will need 5 refuels ( so 10 launch + the 2 ships in use). Both will go to the moon, the tanker refuels the crew starship, tankers get back home and the starship do his mission and get back home

[Barzon]

2 minutes ago, Flavio hc16 said:

if the cost of space goes down to 100$/kg (  an order of magnitute worse than what Elon is aiming for) you will start a craptopn of stuff launched into orbit, universities, people who can burn money, science experiments of any kind. Yopu create a market that right now we don't know.

 

It doesn't matter how cheap the $/kg to LEO gets. Space hardware is expensive. A simple cubesat costs ~50k minimum, and proper satellites will cost far more than that, for the foreseeable future.

[mikegarrison]

4 hours ago, RealKerbal3x said:

[no need for LES] That's what NASA said about the Space Shuttle, and 14 people died.

Only 7 of them died during launch. The other 7 died during re-entry. (And even though the fatal damage occurred during launch, nobody realized it in time that they would have aborted the mission using a LES.)

It is also arguable that neither of the incidents was due to a hidden fatal design flaw. Both of them came from known problems that had been observed on previous flights but had been ignored.

[tater]

29 minutes ago, Barzon said:

why would it be launching that often? what would it be launching? the space market cannot support even 3 or 4 M/HLVs, so why would it have enough demand to enable Starship to fly hundreds of times a year? It won't be flying hundreds of starlink batchs, because I've heard that it takes about a month to make a batch of 60 sats, which limits it to 12 Starlink launches a year and I don't think SpaceX would want to launch each sat one at a time, no matter how cheap Starship launch costs are.

Starlink production has just started. At some point they could only make 1 Raptor a month, at some point Tesla could only make X Model 3 cars a month, now it is some multiple of that for both. Starlink production is not a limiting factor on anything going forward.

The market doesn't need to support many launches of SHLVs if the cost/launch is below even smallsat launches.

SS working at all (reusuable) eliminates all other LVs except the ones the government subsidizes to keep multiple providers around.

29 minutes ago, Barzon said:

And no matter how reliable Starship gets, NASA will never accept the risk of not having a LAS on crewed spacecraft.

I tend to think that early crew launches would have to have this, but as far as NASA is concerned, you only need to demonstrate LOC risk below their requirements, and this is possible with no LAS. The Commercial Crew requirement is 1:270, it's not like it has to have airline level safety, 1:270 is really unsafe compared to that. The Shuttle wasn't close to that.

  

11 minutes ago, Barzon said:

I've heard from reliable sources that Starship needs 11 refueling flights to get 100t to TLI.

1200t of props, so that's a reasonable ballpark to refill it. It can then push way more than 100t to TLI, though. Starship with 100t of cargo to TLI, PLUS props to return. Looks like it needs maybe 300t of props to come back from Gateway (empty). So it looks like a tanker SS could to a RT to Gateway, and drop off 100t of props at the Lunar SS. Would take 3-4 refilles of 100t to allow SS to make another RT to the lunar surface.

The Artemis plan for SS specifically mentions a tanker/depot SS staying in LEO, then tankers fill that 100%, then that vehicle fills whatever SS is actually going someplace in one go. Presumably the depot one could have tanks all the way to the nose and hold more than 1200t, as well (reducing the number of flights to refill Lunar SS at Gateway).

If launch costs are a few million bucks, then SpaceX can still be cheap for cargo to TLI even with many launches per flight to the Moon.

Still, the reality is that if they could make a SS capable of aerobraking, but without the need for Earth EDL, they could save some of that effort and tank up in LEO. Alternately it seems like a purpose built tug would make a ton of sense.

[mikegarrison]

Just now, Barzon said:

It doesn't matter how cheap the $/kg to LEO gets. Space hardware is expensive. A simple cubesat costs ~50k minimum, and proper satellites will cost far more than that, for the foreseeable future.

It does kind of matter. Part of the reason space hardware is so expensive is because it has to be designed for minimum weight. Another reason it is so expensive is because it has to be designed for maximum reliability. Both of those constraints would be reduced if it was cheaper to launch.

[Raven Industries]

6 minutes ago, Flavio hc16 said:

if the cost of space goes down to 100$/kg (  an order of magnitute worse than what Elon is aiming for) you will start a craptopn of stuff launched into orbit, universities, people who can burn money, science experiments of any kind. Yopu create a market that right now we don't know

Spoiler

 

$100/kg to LEO and we can send these things up in droves!

 

 

[Barzon]

It would be reduced yes, but not significantly. If you want stuff that works in space, it is going to be expensive.

[Flavio hc16]

2 minutes ago, Barzon said:

It doesn't matter how cheap the $/kg to LEO gets. Space hardware is expensive. A simple cubesat costs ~50k minimum, and proper satellites will cost far more than that, for the foreseeable future.

you are looking at it the wrong way around: once you make the launch cost affordable, you can afford to use off-the-shelves parts who cost way less. One example is the transponder they use on falcon 9, Boeing pays it 100k, spacex 2k or even less 

[tater]

7 minutes ago, Barzon said:

It doesn't matter how cheap the $/kg to LEO gets. Space hardware is expensive. A simple cubesat costs ~50k minimum, and proper satellites will cost far more than that, for the foreseeable future.

Nope. This is sort of a chicken and egg issue. (as was just said above)

Sats are expensive because launch is expensive per unit mass. Since you pay a lot to get to space, you make sure your vehicle is robust enough to survive, while being as small/light as possible. If mass was not an issue, you could make it robust with less cost. Alternately, you could make spacecraft just cheaper, sending more is not a problem, launch is cheap.

The other hope is that there could possibly be new markets available if costs are cheaper.

Note that cheaper cost to space is 100% internal to SpaceX until someone competes with them. SS could cost $10/kg to LEO tomorrow, but if the next cheapest is $3000/kg, they have little reason to drop the price too much unless they want new markets to open... even so, they won't change $20/kg, they might charge 1000, or 500, and pocket the rest as profit.

4 minutes ago, Barzon said:

It would be reduced yes, but not significantly. If you want stuff that works in space, it is going to be expensive.

Why?

Radiation? Put the electronics in a lead box, still cheaper than ULA.

What else?

Computer might fail so use crazy expensive one? Nah, put 5 redundant computers bought off newegg in the lead box.

Edited May 15, 2020 by tater

[RCgothic]

27 minutes ago, Barzon said:

It doesn't matter how cheap the $/kg to LEO gets. Space hardware is expensive. A simple cubesat costs ~50k minimum, and proper satellites will cost far more than that, for the foreseeable future.

At $10 per kg I could design and build a microsat in my garage and pay SpaceX to put it in orbit for me. Even at $100 per kg I could.

Edited May 15, 2020 by RCgothic

[CatastrophicFailure]

20 minutes ago, Barzon said:

It would be reduced yes, but not significantly. If you want stuff that works in space, it is going to be expensive.

Here’s another example: asteroid mining is currently not a thing because it’s just too expensive.  It’s too expensive to even go out there and just find what might be mineable. Fast forward a few years, SS is operational, each launch costs a couple million. Well now NostromoCorp can, for only a few million total, send out several dozen StarLink-based mass-produced prospector probes to go prospecting. It doesn’t matter if some of them fail, it’s even expected. It doesn’t matter if lots of them fail, heck it doesn’t even matter if most of them fail, only a few need to actually work in order to return useful data and make the mission a success, that’s an enormous risk reduction. Today, it’s several million just to study the feasibility of sending out a single probe which absolutely cannot fail because if it does the whole project is bust. 

[tater]

A bigger concern might actually be that reduced cost makes debris an even larger issue. Asteroid stuff looking better as you throw them out of SS with a kick stage and get them away from LEO, lol.

[mikegarrison]

29 minutes ago, CatastrophicFailure said:

Here’s another example: asteroid mining is currently not a thing because it’s just too expensive.  It’s too expensive to even go out there and just find what might be mineable. Fast forward a few years, SS is operational, each launch costs a couple million. Well now NostromoCorp can, for only a few million total, send out several dozen StarLink-based mass-produced prospector probes to go prospecting. It doesn’t matter if some of them fail, it’s even expected. It doesn’t matter if lots of them fail, heck it doesn’t even matter if most of them fail, only a few need to actually work in order to return useful data and make the mission a success, that’s an enormous risk reduction. Today, it’s several million just to study the feasibility of sending out a single probe which absolutely cannot fail because if it does the whole project is bust. 

What are they going to mine?

I can see only three advantages for asteroid mining:

1. No stripmining here at home.
2. Resources are already out of the Earth's gravity well (only useful if you use them in space).
3. Heavy metals that mostly sank to the Earth's core are potentially more available in asteroids (gold, iridium, etc.).

Plus there is the downside that you will have to keep sending Susan Calvin out to figure out why your robot miners are going crazy.

Edited May 15, 2020 by mikegarrison

[Shpaget]

27 minutes ago, tater said:

snip

Exactly. The price drop Elon promises, if delivered, will bring about a paradigm shift in space hardware design. I can't help but compare it to relatively recent changes in electronics hobby scene. It used to be all about analog circuits, 555s and opamps to maybe get a half arsed AM radio. Now, you slap an Arduino in a Tupperware box and presto! You have have a data logging, wifi enabled, internet connected, RFID triggered, video call supported, lullaby singing, laser pointer swinging cat food dispenser. 20 years ago that would be a multimillion dollar project that would require a team of skilled engineers to pull off, now it's just a few clicks on ebay and a few more on github. Soldering iron optional. I expect similar change in space hardware too. If $ to LEO drops to sub three digit ballpark, you can expect to see sats built from "household" items. Need a solar panel? Why spend tens of thousands on superthin gallium arsenide cells when you can climb to your roof and take the much bigger polycrystalline silicon stuff for a fraction of the price and more output. Who cares if they have 5 mm thick glass on them and are mounted in steel frame? Launching that extra mass is basically free.

Grab the lead acid battery from your car, while you're at it. No need to splurge on li-ion stuff.

[mikegarrison]

5 minutes ago, Shpaget said:

Exactly. The price drop Elon promises, if delivered, will bring about a paradigm shift in space hardware design. I can't help but compare it to relatively recent changes in electronics hobby scene. It used to be all about analog circuits, 555s and opamps to maybe get a half arsed AM radio. Now, you slap an Arduino in a Tupperware box and presto! You have have a data logging, wifi enabled, internet connected, RFID triggered, video call supported, lullaby singing, laser pointer swinging cat food dispenser. 20 years ago that would be a multimillion dollar project that would require a team of skilled engineers to pull off, now it's just a few clicks on ebay and a few more on github. Soldering iron optional. I expect similar change in space hardware too. If $ to LEO drops to sub three digit ballpark, you can expect to see sats built from "household" items. Need a solar panel? Why spend tens of thousands on superthin gallium arsenide cells when you can climb to your roof and take the much bigger polycrystalline silicon stuff for a fraction of the price and more output. Who cares if they have 5 mm thick glass on them and are mounted in steel frame? Launching that extra mass is basically free.

Grab the lead acid battery from your car, while you're at it. No need to splurge on li-ion stuff.

Physics still applies. It won't be "basically free", just not as crippling.

[tater]

 

[RCgothic]

Today's not done yet, but a test for of SN4 is looking increasingly unlikely:

 

[CatastrophicFailure]

2 hours ago, mikegarrison said:

can see only three advantages for asteroid mining:

1. No stripmining here at home.
2. Resources are already out of the Earth's gravity well (only useful if you use them in space).
3. Heavy metals that mostly sank to the Earth's core are potentially more available in asteroids (gold, iridium, etc.).

Exactly. 

Theres a staggering amount of theoretical wealth in some metallic asteroids, it’s not that far off to say there’s literally chunks of precious metals on the surface just waiting to be scooped up. Tho I think the market for things like iridium and cobalt, other metals that will be essential in the coming widespread adoption of EVs will be more lucrative, especially as environmental and humanitarian concerns continue to grow around their extraction here at home. The rub is making retrieving such from deep space actually profitable. At the current cost of things, it simply is not. With the paradigm shift Starship could bring, well, it might be. Part of that is just figuring out if it’s even worth perusing in the first place. But whatever one’s own opinions on the matter, there are currently several outfits who do think it’s worth investigating, even with today’s costs. 

[CatastrophicFailure]

Bleh. And I’ll be stuck in training all day. 

[sh1pman]

3 hours ago, CatastrophicFailure said:

Here’s another example: asteroid mining is currently not a thing because it’s just too expensive.  It’s too expensive to even go out there and just find what might be mineable. Fast forward a few years, SS is operational, each launch costs a couple million. Well now NostromoCorp can, for only a few million total, send out several dozen StarLink-based mass-produced prospector probes to go prospecting. It doesn’t matter if some of them fail, it’s even expected. It doesn’t matter if lots of them fail, heck it doesn’t even matter if most of them fail, only a few need to actually work in order to return useful data and make the mission a success, that’s an enormous risk reduction. Today, it’s several million just to study the feasibility of sending out a single probe which absolutely cannot fail because if it does the whole project is bust. 

Also, I read somewhere that space-based solar power (microwave power transmission to Earth) can become a very profitable and competitive field, if launch prices drop significantly.