Saudi CubeSat gets golden ticket on doomed SLS rocket

NASA will launch a Saudi satellite aboard what could be its penultimate SLS rocket on the Artemis II mission following a deal announced in Riyadh by US President Donald Trump and de facto Saudi ruler Crown Prince Mohammed bin Salman. Trump is keen to axe NASA's Moon rocket, but considering the $600 billion investment the Saudi …

[rgjnk]

'Commercial alternatives'

Let me guess, that means Musk's giant firework Starship?

SLS is a million miles from perfect but scrapping it now it's apparently ready for proper man rated missions in favour of something that definitely isn't doesn't seem that great a tradeoff.

Even worse if it subsequently means the active possibility of further moon missions gets deferred to push a Martian pipedream.

[John Robson]

Re: 'Commercial alternatives'

SLS isn't a good design... and it currently relies on SS to do the lunar side anyway.

Of course they've already gutted the Artemis program, and reduced the need for that split of duties... but SLS is pretty much in bug fix only mode.

SS/SH are in active development - they've still managed to get to where they are with a small fraction of the development cost of SLS, and they didn't start off with SRBs and main engines already designed and built (yes, I tnow they modified the SSME and the SRB design somewhat, but it wasn't a design from scratch).

The fact that SS has had two ruds (catastrophic failures) in it's last two test flights will soon be forgotten - after all there won't be an FAA soon :p

However... SLS is designed to be human rated from earth. SS isn't.

If I were to pick an apollo style "get there and get back" mission it would start and end with a dragon for the squishy, wet, payload - and likely SS/SH for the hardware - most of which can be delivered to where it's needed well in advance of the squishy payload launching.

[Flocke Kroes]

Re: 'Commercial alternatives'

SLS has cost $32B (inflation adjusted to 2024) so far. SpaceX are working hard to catch up. They were at $5B at the end of 2023. 2024 cost about $2B (according to "Funding Secured"). The cost for a working system is likely to be around $10B. I know, the comparison is silly given the vast differences in target incremental cost and cadence.

CSI Startbase has a long video about the last two RUDs and what it would take to fix the problem. (Resonant vibrations in the oxygen feed pipes cause oscillations in the engine inlet pressure to the engines and to thrust variations that create resonant vibrations in the oxygen feed pipes ...) The real fix will require a significant change to the design of Raptor 3 (which is currently exploding at McGregor). The Starships launching for the foreseeable future will be stopgaps to get test data on the heat shield but have a big chance of pogo induced RUD before they get to orbit.

Dragon has problems going to the Moon (and more on the way back). The communication system is specced for LEO. It will need something bigger for the Moon. Life support does not have the required endurance (unless docked to ISS). The heat shield is good for multiple returns from LEO. I have not seen any published data on what would happen with a much faster return from Lunar transfer orbit.

The Starship heat shield is intended to return to Earth from Mars. Perhaps one day the new and improved version will get a real test. Scott Manley did a video on how to do a flags an footprints mission with currently "available" hardware: Starship to LEO + 2x Falcon upper stages to get Orion to LLO. Very Kerbal but as he said, the Falcon's super chilled oxygen would evaporate and freeze the fuel solid before Orion got to TLI (+ how would you load the propellant? How do you get Orion out of (or in through) the Pez slot?).

[John Robson]

Re: 'Commercial alternatives'

"Dragon has problems going to the Moon (and more on the way back). The communication system is specced for LEO. It will need something bigger for the Moon. Life support does not have the required endurance (unless docked to ISS). The heat shield is good for multiple returns from LEO. I have not seen any published data on what would happen with a much faster return from Lunar transfer orbit."

Dragon was originally designed for lunar return, but the heat shield almost certainly isn't specced for that any more. It could pretty easily be tested by lobbing one into a free return trajectory on a Falcon Heavy.

In my back of a napkin proposal the Dragon isn't doing this alone, but with support from "other hardware" (likely) launched on SS/SH. The HLS version of SS will have plenty of capacity for life support etc, so the limited endurance (of ~20 person days) isn't an issue - because all the way there we'd be using the HLS support, not the Dragon.

Apollo 11 was only an 8 day mission (July 16th-24th), Michael Collins spent nearly a day alone on the command module in the middle... so that's ~3.5 days return trip.

I'm not saying that it's a good idea, or that I've done deep feasibility analysis, but that the orion/SLS bit of the task aren't the only solution to moving people to and from a lunar gateway...

[Flocke Kroes]

Re: 'Commercial alternatives'

SLS being man rated is a bit of a question mark. The heat shield 'worked' but came back with chunks missing. When NASA still had a budget and staff they researched a way to get the heat shield to wear down more evenly and this will be tested with crew on board. Artemis I flew without life support so the first zero G test will be with crew. NASA said crewed vehicles should launch at least once per year to retain institutional knowledge. SLS is promised to fly every two years so Artemis II will launch by mid November 2024. The plan was to scrap SLS block 1 after Artemis III and replace it with SLS Block 1B. Block 1B replaces the comicly under powered upper stage with a new bigger one under (slow and expensive) development. The first launch of this new stage will be with crew on top.

The new plan cancels SLS for Artemis IV+, ends the new upper stage, the new boosters required when NASA runs out of old space shuttle parts and the new mobile launch platform required SLS Block 1B. The old mobile tower was so heavy it damaged crawler transporter and the road to the launch site. The new bigger tower should get designed any decade now. The plan also cans the Lunar space station. That only existed because SLS could not get Orion to low Lunar orbit. Obama tried to cancel SLS but lacked the support to get it done. We are about to find out what happens when Trump threatens congress's favourite supply of pork. It needs votes from 60 senators so some Democrats will need to be convinced/bribed/deported. The same probably goes for a bunch of Republican senators given how much bi-partisan support SLS/Constellation/Shuttle has had over the decades.

Artemis IV has a (fictional) launch date of September 2028. The none of big components (SLS block 1B, new mobile launch tower, Starship HLS and the space suits) will be ready by then. This gives plenty of time for some commercial options to turn up.

The most obvious is Starship. This can easily be man rated by firing any government official who questions its safety. Less obvious is RocketLab. They have talked about man rating Neutron. Blue Origin (pause until yu stop laughing) were hiring staff to design a crew capsule a couple of years ago. There is even the ridiculously expensive option of getting Orion to LEO with New Glenn then launching something to push it from LEO to LLO. Stoke aerospace have been working on a re-usable upper stage. It might be possible to adapt this into a crew vehicle (probably for LEO only).

SLS's low capacity, low flight rate and enormous price (>$4.2B per launch) has always been a barrier to a sustainable presence on the Moon. I will be happy for it to die. The only downside of Trump killing it is that there may not be enough of the United State left to support the population at a level above starvation let alone a return to the Moon.

[John Robson]

Re: 'Commercial alternatives'

Letting it die is a rather negative outlook. In the same way that I support Boeing's efforts with Starliner, I also support having a second, working, heavy lift vehicle (whether SLS ever meets that target is a different question).

Whether that should be something so designed by committee as SLS is a completely different question, but I don't see many other alternatives being proposed - New Glenn is probably going to be a better bet than SLS at this point, but it's less demonstrated than even SS/SH.

But at the moment... SpaceX is dominating the market through technological superiority. Yes there are things they can't do, but those are higher energy deployments which are very low volume compared with LEO and GTO missions.

Their testing methods are not conventional, so people forget that they're testing and get really focussed on ruds (they are rather pretty after all).

When does SLS expect to be reusing first stage engines, or indeed a whole first stage?

Don't bother answering, it's deliberately a trick question: They're very different beasts - with different design goals.

[David Hicklin]

Re: 'Commercial alternatives'

What happens when StarShip is still RUDing in 10 years time? Ariane ??

[John Robson]

Re: 'Commercial alternatives'

Let's hope it isn't.

Another flight coming up soon. Let's see what happens, isn't testing fun!

[Potemkine!]

de facto Saudi ruler Crown Prince Mohammed bin Salman.

He's the guy who ordered the assassination and dismemberment of a journalist working for the Washington Post, isn't he ?

Such a nice guy. Money can buy everything it seems.

[Andrew Scott]

salman

just the kind of gut trump likes. he also likes kim jong un. i think he had a relative poisoned in an airport. loves putin and probably has people he'd like to defenstrated like putin has, and maybe will. it sounds like the supreme court has said that he could order it to be done if it was in his capacity as president.

[Burgha2]

Starship will never be practical

It's starting to look a lot like his tunnels

"Recent reports indicate that the actual payload capacity of Starship might be closer to 50-100 metric tons, rather than the 150 metric tons initially targeted"

https://www.spacedaily.com/m/reports/Starship_Unpacking_the_Complexities_of_SpaceXs_Two-Stage_Vision_999.html

"A NASA official said Artemis will need 20 SpaceX Lunar Starship launches per moon landing."

https://www.nextbigfuture.com/2023/12/nasa-says-up-to-20-spacex-starship-refueling-launches-per-moon-mission.html

None of this is sounding practical at all.

[John Robson]

Re: Starship will never be practical

Assuming that they don't change anything... R3 will be a substantial upgrade, and other changes are in progress.

[druck]

Re: Starship will never be practical

Less practical even than rebuilding the Saturn V.

Irony is you could ship the one at the Johnson Space Centre off to a workshop in Shenzhen, and they'd make you half a dozen exact copies for 1/1000th of an SLS - one of them might even work too.

[mr.K]

Predicting the future

After reading the above comments, it seems to me that people have strong opinions about the future. However, it also appears that these opinions are not the same, and thus I am unsure as what to believe. I wonder, is this unique to the future, or are people not aligned in their opinions about current and past events as well?