SpaceX Tuesday...

[Beati Dogu]

Meanwhile, both fairing recovery boats now have their big spider arms attached, so perhaps we'll see a dual fairing recovery later this month.

The next Falcon 9 flight is likely to be on Oct 17th and will carry 60 more Starlink satellites.

[anonymous-user]

The speed of development and manufacturing is quite breathtaking.

[Art0ir]

Tim did an interview with Elon that's worth a watch (on restricted internet atm or I'd post)

[shalmaneser]

Beati Dogu said:

The Super Heavy is supposed to be 9 m (30 ft) in diameter and 68 m (223 ft) in height.

For an idea of the scale, here's the dummy first stage of the SLS rocket arriving at the Kennedy Space Center:



It's actually slightly smaller that the Super Heavy - with a width of 8.4 m (27 ft 7 in) and height 64.6 m (212 ft).

It's remarkable they've taken 20 years to build a fuel tank, really. Especially since they had a working one already attached to the shuttle!

Beati Dogu said:

He seems to like stainless steel now. Being 2% the cost of the equivalent carbon fibre doesn't hurt.

The super heavy booster is more of a known quantity in terms of operation. A scaled up Falcon 9 booster really. The Falcon 9 body is mostly aluminium-lithium alloy. The black interstage is carbon fibre now. The fairing and legs are carbon fibre with an aluminum honeycomb. The grid fins used to aluminium, but got a bit melty sometimes and are now titanium.

Interesting that he doesn't think it'll need a re-entry burn like the Falcon 9. Wouldn't surprise me if that changes.


Edit: They have a web page for Starship now:

https://www.spacex.com/starship

Scroll down for more.

Edited by Beati Dogu on Monday 30th September 21:09

So a stainless booster it is! Exciting, hope it looks as good as that on the launchpad!

[MartG]

shalmaneser said:

It's remarkable they've taken 20 years to build a fuel tank, really. Especially since they had a working one already attached to the shuttle!

Not quite that simple - the SLS core stage has to accept longitudinal loads from the engines at its base as well as the mass of the payload at the top of it, together with the loads exerted by the SRBs - this required a complete redesign of the structure compared to the Shuttle ET which had loads applied differently due to the side-mounted Shuttle

[Eric Mc]

It's a bit disingenuous to call the core of the SLS a fuel tank. It is, of course, mostly a fuel tank (like all rockets) but changing what had been 100% a fuel tank into a functioning rocket - and making it bigger - is rather complex.

I'm not sure they chose the right path, mind you.

[Beati Dogu]

More engine info from Elon:

Raptor cost is tracking to well under $1M for V1.0.

Goal is <$250k for V2.0 is a 250 ton thrust-optimized engine, ie <$1000/ton

[MartG]

Beati Dogu said:

More engine info from Elon:

Raptor cost is tracking to well under $1M for V1.0.

Goal is <$250k for V2.0 is a 250 ton thrust-optimized engine, ie <$1000/ton

Contrast that to the $40million NASA paid for each RS-25 SSME back when they were new, never mind how much they've spent refurbishing, upgrading, and recertifying them since The new ones NASA has ordered are thought to cost around $60million each, and four of them will be discarded in each SLS flight.

[Beati Dogu]

Crazy isn't it?

Each RS-25 costs the same as an entire Falcon 9 flight.

[MiniMan64]

MartG said:

Beati Dogu said:

More engine info from Elon:

Raptor cost is tracking to well under $1M for V1.0.

Goal is <$250k for V2.0 is a 250 ton thrust-optimized engine, ie <$1000/ton

Contrast that to the $40million NASA paid for each RS-25 SSME back when they were new, never mind how much they've spent refurbishing, upgrading, and recertifying them since The new ones NASA has ordered are thought to cost around $60million each, and four of them will be discarded in each SLS flight.

How do they justify that cost against what Space X manage to do?

[RobDickinson]

MiniMan64 said:

How do they justify that cost against what Space X manage to do?

They dont need too, Congress oversee spending and this money goes to jobs with little regard for outcome

[shalmaneser]

MartG said:

Not quite that simple - the SLS core stage has to accept longitudinal loads from the engines at its base as well as the mass of the payload at the top of it, together with the loads exerted by the SRBs - this required a complete redesign of the structure compared to the Shuttle ET which had loads applied differently due to the side-mounted Shuttle

Eric Mc said:

It's a bit disingenuous to call the core of the SLS a fuel tank. It is, of course, mostly a fuel tank (like all rockets) but changing what had been 100% a fuel tank into a functioning rocket - and making it bigger - is rather complex.

I'm not sure they chose the right path, mind you.

I was being flippant really but it does highlight that the SLS is just massive slice of congressional pork.

[Beati Dogu]

They're going with welded steel for the Super Heavy boosters' grid fins too, which are diamond shaped in the animation they showed BTW.

That'll save a load of cash and time.


I like how they're using 4 Tesla model S/X battery packs in the nose to drive the fin actuation motors (also Tesla). Nice repurposing there.

The rocket is back in two parts again, while they fit it out.

[Chester35]

Beati Dogu said:

Crazy isn't it?

Each RS-25 costs the same as an entire Falcon 9 flight.

But some engines have so far been in orbit multiple times. And does the cost actually matter when one B2 bomber costs $2.1b ? The USA has 21 of those and about to upgrade to the B21.

Edited by Chester35 on Saturday 5th October 18:20

[Chester35]

MiniMan64 said:

MartG said:

Beati Dogu said:

More engine info from Elon:

Raptor cost is tracking to well under $1M for V1.0.

Goal is <$250k for V2.0 is a 250 ton thrust-optimized engine, ie <$1000/ton

Contrast that to the $40million NASA paid for each RS-25 SSME back when they were new, never mind how much they've spent refurbishing, upgrading, and recertifying them since The new ones NASA has ordered are thought to cost around $60million each, and four of them will be discarded in each SLS flight.

How do they justify that cost against what Space X manage to do?

NASA budget is $21.5b which is tiny in comparison to spending on the DOD. I'm surprised people are squibbling over a few million here or there to be honest. I'm glad you lot were not posting when Saturn V was about to go to the moon .

What matters is who can win the race....

[RobDickinson]

What race?

And costs do matter, nasa could do a st ton more stuff if it left the rocket building to others.

[Flooble]

I kind of feel that only US taxpayers really get to complain (or not) about SLS. But the rest of us should be grateful that the US is prepared to stump up that kind of money to advance science.

[MartG]

Chester35 said:

Beati Dogu said:

Crazy isn't it?

Each RS-25 costs the same as an entire Falcon 9 flight.

But some engines have so far been in orbit multiple times. And does the cost actually matter when one B2 bomber costs $2.1b ? The USA has 21 of those and about to upgrade to the B21.

Edited by Chester35 on Saturday 5th October 18:20

We were talking about the new-build RS-25s, at $60m a pop, not the ex-Shuttle ones - and comparing the cost with the B-2 ( or the possible replacement ) is like comparing oranges with screwdrivers i.e. utterly meaningless

[Beati Dogu]

I don't think NASA had much say in SLS and it was largely imposed on them by Congress as a corporate welfare and jobs program in certain key states (Louisiana, Alabama, Texas, California, Florida mostly). It's certainly not in NASA's gift to cancel the program.


NASA administrator, Jim Bridenstine, has been critical of the SLS program & its endless delays before.

Take this interview with him a few days ago by The Atlantic's Marina Koren:


Koren: Have you thought about a future in which private companies leapfrog NASA in the effort to go to the moon?

Bridenstine: I think it would be fantastic if they could do that.

Koren: And what if they’ve done that before SLS is ready?

Bridenstine: I’m for that. And if they can get to the moon, we want to use those services. Our goal is to be a customer, not the owner and operator of all the equipment. But right now, if we’re going to get to the moon in 2024 with humans, SLS and Orion are the way to do it.

https://www.theatlantic.com/science/archive/2019/1...


So there you have it. If the likes of SpaceX and Blue Origin can build their large and capable spacecraft, NASA would definitely beat a path to their door.

[Zad]

It is more about keeping ahead of the Chinese / Russians than anything scientific, surely? Always was, always will be. No votes in science, many votes in keeping a cold war going.