totm nov 2023 SpaceX Discussion Thread

[CatastrophicFailure]

14 minutes ago, Starman4308 said:

Regardless of what SpaceX wants, I suspect NASA will insist on a LAS. I personally wouldn't trust a no-LAS BFR for crew transport unless they'd demonstrated a couple hundred trouble-free flights in a row, bare minimum.

With the flight rates they’re aiming for, that may not be that unreasonable. Especially with multiple tanker top offs and what not, a couple of hundred launches in a year seems not only possible but likely. 

Like @tater mentioned, the lift mass of this thing is nothing to sneeze at. A super-Dragon escape capsule on the nose probably isn’t that unreasonable either. I expect there’s going to be a lot of design refinements before this thing sees daylight, I’m sure don’t know the half of what they’ve planned yet. 

[Starman4308]

7 minutes ago, cubinator said:

That's quite likely. For a cargo or demo run to Mars, though, they'll probably have to launch the same rocket up to ten times in a row to top off the spaceship anyways, and that'd be pretty reassuring to see the rocket pull that off. And if they do that with several spaceships, that's already a lot of flights. They might be able to get that many flights in in just a few years.

And if they get that many flights in just a few years, I'll eat my hat have the vast majority of my concerns about the BFR allayed. I'm rather confident BFR will fly, I'm just not quite as sure it'll fly often enough and cheaply enough to be the Rocket of the Future (TM).

What I will say, though, is that SpaceX has the corporate agility to not stick with a bad idea once they know it's a bad idea. If it doesn't work, SpaceX will move onto their next bright idea for reducing the cost of space access. Unless they start to get seriously beaten at their own game of cheap space access, they're going to stick around for a while.

[cubinator]

39 minutes ago, Starman4308 said:

hat I will say, though, is that SpaceX has the corporate agility to not stick with a bad idea once they know it's a bad idea. If it doesn't work, SpaceX will move onto their next bright idea for reducing the cost of space access. Unless they start to get seriously beaten at their own game of cheap space access, they're going to stick around for a while.

Absolutely. The best part is that if somebody does become way better than them at cheap space travel, we still win because we get cheap space access. Musk's vision isn't necessarily "put lots of SpaceX stuff on Mars", it's "put lots of people on Mars". They've already got a lot more people thinking about trying to do that, and that's a success.

[tater]

 

[tater]

 

[CatastrophicFailure]

Aw, man. 

[magnemoe]

9 hours ago, sevenperforce said:

I definitely agree with having an ascent/landing capsule separate from the larger crew compartment, for the same reason that you wear an IVA suit during ascent and entry. I don't ever see orbital launches being a shirtsleeve environment.

The trouble with a rescue mission is that if you're going to do a rescue, then your escape pod needs to have its own robust onboard RCS system for docking, and that's tricky. Might be cheaper, mass-wise, to just go with a heat shield. 

I'm having trouble coming up with a good placement that integrates with the rest of the craft but can still leave the rest of the craft in a hurry if need be.

No the orbital rescue would be between two upper stages. Yes this leaves an speed there you has to ride the second stage down again. 
Obvious place would be on top, Perhaps extending an bit down into the ship, 

[Jaff]

I’m surprised they’ve been allowed to do that, surely Hispasat would just say sod the new fairings put the old ones on and get our sat in the sky. Test your new fairings on your own time.

 

 

[sevenperforce]

8 hours ago, tater said:

 

Well that stinketh.

[CatastrophicFailure]

2 hours ago, sevenperforce said:

Well that stinketh.

Verily. 

[Damien_The_Unbeliever]

6 hours ago, Jaff said:

I’m surprised they’ve been allowed to do that, surely Hispasat would just say sod the new fairings put the old ones on and get our sat in the sky. Test your new fairings on your own time.

 

 

Well, since up until now (and still now) there's been no real fairing recovery, if they've moved to building fairing 2.0, it's not likely that they *have* fairing 1.0s in stock.

[Jaff]

11 minutes ago, Damien_The_Unbeliever said:

Well, since up until now (and still now) there's been no real fairing recovery, if they've moved to building fairing 2.0, it's not likely that they *have* fairing 1.0s in stock.

So In that case SX aren’t honouring their contract? 

[tater]

Just now, Jaff said:

So In that case SX aren’t honouring their contract? 

SpaceX is contracting a launch, and that they iterate launch vehicles is a given, unless negotiated otherwise. Part of the lower cost is that they get some amount of experimentation. Presumably block 5 will be less this way, as the design will be gelled.

[Damien_The_Unbeliever]

Just now, Jaff said:

So In that case SX aren’t honouring their contract? 

What do you think their contract actually states? I'd almost guarantee that it's to deliver their space object safely into a particular orbital trajectory (with various particulars as to allowed variations) and not any particular launch vehicle.

As has been established, fairings cost of the order of ~5m per piece. It's unlikely they have or need spares sitting around.

[Jaff]

My point is - whoever make the satalite don’t give 2 hoots what space x do with their boosters or fairings (providing they understand the risks and mitigation of  lower costs) so all they want is their satalite in the correct position. 

 

If its beig delayed due to space x wanting to try fairing 2.0 to save themselves money then thats surely nothing to do with Hispasat and all to do with space x. Which surprises me. 

 

[sevenperforce]

24 minutes ago, Jaff said:

My point is - whoever make the satalite don’t give 2 hoots what space x do with their boosters or fairings (providing they understand the risks and mitigation of  lower costs) so all they want is their satalite in the correct position. 

If its beig delayed due to space x wanting to try fairing 2.0 to save themselves money then thats surely nothing to do with Hispasat and all to do with space x. Which surprises me. 

When I buy a plane ticket, I'm buying a ride to my destination, not a slot on a particular plane. If the airline needs to switch out the plane or perform extra maintenance, that doesn't breach the contract.

The difference, of course, is that my plane ticket is very time-sensitive and I expect to be compensated in some degree if there are extreme delays. Launch purchasers are much more understanding of departure delays, since it's the nature of the business.

[PB666]

48 minutes ago, Jaff said:

My point is - whoever make the satalite don’t give 2 hoots what space x do with their boosters or fairings (providing they understand the risks and mitigation of  lower costs) so all they want is their satalite in the correct position. 

 

If its beig delayed due to space x wanting to try fairing 2.0 to save themselves money then thats surely nothing to do with Hispasat and all to do with space x. Which surprises me. 

 

That's not exactly true, if you contract with a launch service provider, particular if you have deposited money, then you want them to be there when you payload is ready to launch. If the company is offering you a low rate, but there is a good chance that they will be out-of-business (and you have to go to court to get a portion of your deposit back) then you might not choose to draw up a contract. Again as a satellite designer you need to fit your payload to the limits of the launch provider. This includes adapter limitations and fairing volume, cross-sectional area, and single dimension radial limits. Consequently once you contract you will be out of pocket if the provider cannot provide.

Thus you do care whether the service is reputable, which means you also care if they are engaged in efficient business practices. And example of how this occurs is a satellite telecommunications company. For starters you are going to be launching many satellites. Each satellite is in a collective of similar satellites. In a launch service provider you want a consistent PL circumstance (i.e. the same fairing). If that PL configuration worked with one satellite it should work with all. Insurance may cover the loss of an investment, but there are intangible losses, like getting into a new market first and establishing dominance in that market before competitors. In this case you care very much about whether your launch provider can do it cheaply, repeatedly, reliably.

[Tullius]

1 hour ago, Jaff said:

My point is - whoever make the satalite don’t give 2 hoots what space x do with their boosters or fairings (providing they understand the risks and mitigation of  lower costs) so all they want is their satalite in the correct position. 

 

If its beig delayed due to space x wanting to try fairing 2.0 to save themselves money then thats surely nothing to do with Hispasat and all to do with space x. Which surprises me. 

 

I would guess that the launch contract contains a clause that allows for a price reduction in case of massive delays due to problems on SpaceX's side.

Although I don't think that Hispasat will get anything in case of a delay of just 1 day.

[Damien_The_Unbeliever]

1 hour ago, Jaff said:

My point is - whoever make the satalite don’t give 2 hoots what space x do with their boosters or fairings (providing they understand the risks and mitigation of  lower costs) so all they want is their satalite in the correct position. 

 

If its beig delayed due to space x wanting to try fairing 2.0 to save themselves money then thats surely nothing to do with Hispasat and all to do with space x. Which surprises me. 

 

You're using you experience of mass production to try to think about bespoke products.

All space launches are bespoke, even when they follow a recognizable pattern.

[Jaff]

Isn’t the fact that space launches are bespoke the reason they’re so expensive? And therefore something SX are trying to achieve. 

[sevenperforce]

31 minutes ago, Jaff said:

Isn’t the fact that space launches are bespoke the reason they’re so expensive? And therefore something SX are trying to achieve. 

Until rapid and reusable orbital rockets become commonplace, all launches will be bespoke.

[PB666]

24 minutes ago, Jaff said:

Isn’t the fact that space launches are bespoke the reason they’re so expensive? And therefore something SX are trying to achieve. 

SpaceX is trying also to reduce the time it takes to sign a contract to launch, they appear to be doing just that. Launches have to be contracted, you cannot design an PL/Launch interface otherwise.
They don't have cushy govt set asides if that is what you are saying. The point being is that they are the interloper is going to make them a better and more competitive company . . . . they want to take the cush out of the govt set-asides and to that they need to make the recipients look poorly in comparison.

Look here funding agency
- We recycle our launch stage
- We recycle our interstage fairing
- We recycle our payload fairings
- We deorbit our second stage and don't leave anyspace junk for our SLS garbage truck to need to pick up.

We are the most environment friendly and a very cost efficient company, come launch on us. . . . .those other guys are wasteful

Not to mention
- We are buying up Methane (lowest greenhouse emissions of any fuel) from your drilling companies that are having to sell methane below cost.
- We are going to have our next launch facility just 50 miles from South Texas Shale and not to terribly far from NASA, in case you are planning to launch from our new facility.

They are also very good at building public support . . . . . .I'de be more worried about their next fantastic disaster than weather the purchasers are up at night wondering about the cost of trying to catch fairings.
One of those captivating SpaceX launches is good avertising for the launch service as well as the launched.

 

 

[DDE]

On ‎23‎.‎02‎.‎2018 at 11:34 PM, magnemoe said:

Now landing is dangerous and here an LES would be very useful. 

The hoverslam doesn't really leave much time to detect an issue and abort. We're talking an escape pod that also has more dV than a 0-0 ejection seat.

[tater]

LES systems can deal with pad failures, so they can deal with landing failures.

[StrandedonEarth]

21 minutes ago, tater said:

LES systems can deal with pad failures, so they can deal with landing failures.

If they are built to operate in such a situation, having to cancel the downward velocity and reach an altitude where chutes have time to deploy. What altitude do 0-0 LES systems need to reach? Even above that point, a landing rocket would have more downward velocity than a 0-0 abort, giving less time for chutes to open. So yeah, a landing abort system would need to be a Super-LES.

 

Edited February 24, 2018 by StrandedonEarth