It’s not as simple as the costs and power make it seem. Payload to LEO and TLI for SLSB1 and Starship will be similar and will most likely favour SLS from B2 onwards. The cost of the raptors is based on their reuse potential and the number of times that happens. It’s based on the F9 numbers, but that depends on how many heavy payloads are required or if the engines can be moved between vehicles. Simply, Starship needs more power (33 engines) as it’s dry weight is substantially higher than SLS whilst it’s payload is lower. The SLS was predicated upon maintaining a production line with required skills in companies and providing the right launch capacity for heavy payloads over an annual basis for a period of 10-15 years of flights.
SpaceX are working on the basis that there will be a business for a greater number of heavy payloads, especially for interplanetary missions.
Two different businesses, two different mission envelopes that just happen to have some overlaps.
I got my whole family up to watch the launch once we got past the 30min hold and we were into the final T-10 countdown. Kids were delighted - the wife, not so much.
Well, that’s not why they’re disposable in this application though- they’re being one-shotted because they had some old pre-used space shuttle engines lying around, so they decided to use them up instead
Ummm, no. They very definitely didn't have any 'spare' engines - NASA paid them $1B to 'restart production' and then you've got the cost the each engine on top of this.
Have a read of this:
https://arstechnica.com/science/2020/05/nasa-will-pay-a-staggering-146-million-for-each-sls-rocket-engine/
NASA get a lot of crap for this but it’s not their fault, their procurement and budget is absolutely drowned in politics and pork. Want the budget to do X? Fine but you have to give Y million dollars to a company in my state who gives me a load of money. The system’s designed to be dysfuncitonal
Absolutely 100%
The cost of the raptors is based on their reuse potential and the number of times that happens. It’s based on the F9 numbers, but that depends on how many heavy payloads are required or if the engines can be moved between vehicles.
No that's the actual cost of each engine.... $1m (see the above article). How else can they produce 1/day and afford to destroy a fair few in testing?
https://arstechnica.com/science/2022/11/spacex-is-now-building-a-raptor-engine-a-day-nasa-says/
Simply, Starship needs more power (33 engines) as it’s dry weight is substantially higher than SLS whilst it’s payload is lower
Nope, sorry!
SLS payload - 89T
Starship payload - 150T
https://interestingengineering.com/science/nasa-sls-rocket-behind-spacex
Two different businesses, two different mission envelopes that just happen to have some overlaps.
As soon as Starship proves it's capable (if it does!) SLS will* be binned.
(* 'Should' but probably won't)
So what's the next event for the Orion capsule that is currently sailing through space towards the moon? I presume, barring an explosion in the service module while stirring the oxygen tanks, that it just sails all the way there and meets the moon. Then what? I guess it's going to do a deceleration burn and go into moon orbit? Or does it just do the half lap and start it's journey straight back? How long before it gets there? Think I read 24 days but that seems a strangely long time, Apollo was nowhere near as long, so maybe I've confused whole mission duration with earth to moon transit time?
I hope they put lots of cameras on the capsule and we can get some cool footage!
Nope, sorry!
SLS payload – 89T
Starship payload – 150Thttps://interestingengineering.com/science/nasa-sls-rocket-behind-spacex
What you're saying clearly shows you don't know what you're talking about.
SLSB1 is 95t to LEO and 27t to TLI - that goes up to 130t/47t for SLSB2
Starship is 150t to minimum sustainable refuelable orbit - it's not LEO, it's MUCH lower. SpaceXs own website shows shows 100t to LEO with full re-use. Given Starships mass, the available power from Starship from its 3 vacuum raptors and thus the available deltaV from the engines to get from LEO to TLI means it's current usable payload to TLI is around 25>33t, which is less than for SLSB1 at the low end and MUCH less than B2. There is a plan to put 6 Raptors into Starship which will increase the dV, but this isn't confirmed. All of SpaceXs numbers are estimates at this point.
The raptors are more efficient, but mass is mass. The dry mass of SLS is 85t whereas SLS is 120t minimum.
All of these figures are from NASA's and Space X's websites.
I'm not a proponent of SLS, or a worshiper of Musk/SpaceX, but to deride the capabilities of SLS and NASA in putting it together for a specific mission target and within budgets and political constraints is no mean feat.
Have just watched the Artemis launch (twice!) with the sound turned up.
Oh my.
Less than 90 mins until the moon! Capsule approaches to 80 miles above the surface and then enters a retrograde orbit. Exciting.
Have this on in the background today.
Interesting to see the speed increase as it gets closer to the Moon with the gravitational pull.
Was at around 450mph when I watched earlier and now closer to 950mph.
Is that info on the live tracker? Tried that yesterday on my old Chromebook and it didn't seem to work.
Watching live on the NASA Youtube channel.
Aha! Think that's what it just found via space.com
Are you missing a zero from your speeds? Isn't it 4500 ish M/h?
sharkbait
Free MemberWell, that’s not why they’re disposable in this application though- they’re being one-shotted because they had some old pre-used space shuttle engines lying around, so they decided to use them up instead
Ummm, no. They very definitely didn’t have any ‘spare’ engines – NASA paid them $1B to ‘restart production’ and then you’ve got the cost the each engine on top of this.
No, that's exactly what that had. The RS25D engines used in this launch were old-stock shuttle engines that have all been flown before. I think the confusion is that as I mentioned they're also making new ones. The prices you mention are for those.
This is why it's so daft- they committed to using the RS25 since it already existed, but then once committed they had to make more, and they always knew that'd be necessary (unless, of course, teh program failed or was cancelled or totally rebuilt partway through, which to be fair was always possible- I do wonder if people were assuming that was going to happen and so went with an option that'd be good for that but not good if it succeeded?).
But, it did offer maximum politics and pork.
This was a bit quick - didn't it take Apollo like a week?
4 days 6 hours 45 minutes for Apollo 11 according to Google. Think they spent a little longer in earth orbit as they had to reorder themselves, service module, capsule,lem (I think). But the lem was tucked under the sm and capsule, ontop of the Saturn v, during launch.
I Imagine that everyone on this thread has already seen this, but if not there is a wonderful video on YouTube discussing the computer used for the 1969 (Apollo 11) landing. It is difficult to image how basic it was and how hardcore the astronauts were in staying cool and landing with it. The video says 1hr 21 but if you are short of time then
16:28 start of discussion on landing
19:50 start of the landing. Typing 37 into the computer to tell it to load a program and then 63 for the loading program
48:00 the actual landing and what goes wrong and how cool they are
60:00 the end of the main talk
But really, just sit back and watch the whole thing. It's a different world
It's not on Netflix currently (was) nor included in prime but there to rent, 'hidden figures' is a great film about the maths, and the development of the maths, and beginning to use mainframe computers, and the unrecognised at the time black ladies behind some important parts, in NASA and Apollo.
I think I watched the second half of hidden figures then my wife came in and I made her watch it from the start.
Aha! dirkpitt was right....and so was I. just watched a bit more from today on you tube and the orion capsule WAS dong about 450Mph, increasing to about 900Mph on approach, and WAS ALSO doing about 4500 MPH an hour later when I had a look during the OPF, Outbound Powered Flyby.
Re The Apollo Guidance Computer. I'm sure some of you will have seen this series of youtube videos, where a bunch of people restore one, and get it plugged into a moon lander simulator:
Apollo Guidance Computer Part 1: Restoring the computer that put man on the Moon - YouTube
Also, this book is a good read, written by one of the people who wrote the code for part of the landing sequence. We'd call him a software engineer now, but I don't think that term existed then!
Sunburst and Luminary: An Apollo Memoir: Amazon.co.uk: Don Eyles: 9780986385933: Books
Interestingly, some later software written by Don Eyles is still being used in the ISS!
Interesting thread all 🙂
I've added that Don Eyles book to my Christmas list.
On that note, I loved the BBC podcast 13 minutes to the moon: https://www.bbc.co.uk/programmes/w13xttx2 - great interviews, analysis etc. They did another one about Apollo 13 which is also worth a listen.
Just seen this https://www.independent.co.uk/space/japan-steam-propel-moon-spacecraft-b2234128.html
It's Something from Japanese space agency that hitched a lift on Artemis. For me the steam propellant isn't nearly as interesting as the purpose and journey of the craft. It's on route to earth/moon Lagrange point 2, taking 1.5 years to get there (using little fuel). Lagrange points are where gravity and centrifugal forces balance and an object just...'sits'. So studying EML2 as a possible location for a spaceport with easy, low fuel access to earth orbit, lunar orbit, and on to the rest of the solar system seems intriguing to me! Maybe not a great route for astronauts, but as a cargo route I guess it has a lot going for it.
And after one lap in the retrograde orbit, it's on its way home!
That last short burn kicked Orion out of its retrograde orbit and the craft did another lunar flyby at 130km altitude yesterday, when it did it's last major engine burn to kick on and start the Earth transit. All seemed to go well again and it's set for capsule separation, re-entry and a splash down in the Pacific in a few days. The biggest remaining question seems to be re-entry. This will be far faster than any previous manned (capable) craft and a real test for the heat shield. It needs to withstand 3000C! If it fits well then as Artemis 2 will be crewed and 3 will land on the lunar surface!
The biggest remaining question seems to be re-entry. This will be far faster than any previous manned (capable) craft and a real test for the heat shield.
I've read that Orion will be coming in to re-entry much faster than other craft in the past. Is this just to test the heat shield or is there another reason?
I guess that if the heat shield has a significant margin of error built in then it may well be able to withstand re-entry trajectories that are steeper than planned ie something has gone a bit wrong.
I’ve read that Orion will be coming in to re-entry much faster than other craft in the past. Is this just to test the heat shield or is there another reason?
It's not much faster than the Apollo missions. Spacecraft coming back from the moon have a much higher reentry speed than those returning from low Earth orbit (gravity and all that).
Artemis is currently 18000 miles from Earth, travelling at 10000 mph and accelerating.
It's home! Splash down happened as planned off the Baja peninsula of California. Whoop whoop!
The Crazy Journey of Artemis 1:
Great explanation of the path Orion took, and why. Seeing the sketch relative to earth, particularly with no moon on the sketch, makes for confusion then. 'oh that's really cool' moments.