Author Topic: We Can’t Rebuild Saturn V, But… (Read 4520 times)

Skye · « **Reply #20 on:** 03/31/2025 07:59 am »

Fair, though NG apparently can only do 20 or so tonnes to LEO w/ ASDS landing, and 25-30 expended. Ofc there is room for improvement, doubt they’ll get above 35t ASDS. W/ an LH₂ US, that’s maybe 14t to TLI (no calculation gang 💪). Not enough for either Orion or even Blue Moon.

spacenut · « **Reply #21 on:** 03/31/2025 11:22 am »

New Glenn is supposed to do about 40 tons to LEO as is. If they upgrade from 7 booster engines to 9, it would improve. Don't know if or when they will do this. It is still not Saturn V which could do 140 tons to LEO not reusable. Reusable Starship is supposed to do 150 ton payload to LEO when it gets operational. SpaceX with Raptor version 3 would improve overall thrust. Because of this they are supposed to have a tank stretch, then don't know how the Starship upper stage is to work out.

Skye · « **Reply #22 on:** 03/31/2025 11:59 am »

Nope, apparently it’s more like ~20 ASDS, ~25-35 expended for NG. Apparently this is the case. Many people on the forum have listed it as that, and SX listed NG as 34t expendable. No doubt 9 engines and subcooling propellant would increase payload, but by how much? My bet is 45, max 50t expended, 30, max 35t ASDS. Apparently they have confirmed subcooling, but considering the extremely slow takeoff on its first launch, I dunno if it could even take off w/ subcooled prop. 9 engines is basically necessary for subcooled prop. Even then with all this, it’s probably max 20t to TLI. Expended. Again, it’s not enough for Orion (26.5t) or even Blue Moon. (21.4t). Unless they use in-orbit propellant refill, I doubt they could do it until New Armstrong, and at that point, they should just land the actual upper stage, assuming it’s similar to a scaled-up SS. Speaking of SS, it’s meant to do 100t to LEO reused with V2 (V3? Depends. Apparently V3 may just be an upgraded V2, with the stretched V3 we know actually being a V4) And V3* being capable of 150-200t (recently stated by Elon as 150, but previously stated as 200. Again, this links to the previous bracketed tangent of versions)

*V3, V4, whichever one is the really stretched one.

spacenut · « **Reply #23 on:** 03/31/2025 12:38 pm »

Starship/Superheavy is still in development. I think they can reach their goals once Raptor vs 3 has all the bugs worked out. They have blown up a couple pushing them to their limits. Because Raptor 3 had increased thrust and power, it will require a tank stretch. Using Raptor 3's on the upper stage will also require a tank stretch on the Starship upper stage. Don't know how long this will take. They also have to get the heat shielding worked out as well as in orbit refueling. Making the upper stage expendable and only reusing the booster, this rocket can do about 200 tons to LEO. I always thought this would be the way to go to get it working and then work on re-entry version.

New Glenn needs some work too. It's engines have more mass than the Raptor engines for about the same thrust. I do think they are going to need 9 on the first stage. The upper stage may need 3 BE-3U's to get the most mass to orbit. New Glenn is a big rocket, but to me somewhat under powered right now. Upgrades should solve this. New Glenn, if it can get 40-50 tons to orbit with reusable first stage could provide a robust LEO and Cis-lunar program. Add a fuel depot for the upper stage and you can get a lot to the moon.

I'm hoping both will be operational within a year. Also hoping they cancel SLS and Orion, and use Blue Origin to do a lunar program eventually getting into lunar mining. The using Starship for a Mars program. Use the $5 billion or so from SLS/Orion cancellation and split about $2 billion each between the two and have a great space exploration program. Then take the $1 billion left over and help the upstart companies to get rockets developed to have competition, by having a commercial/NASA partnership. Make the companies spend about equal the money given to them by NASA to jumpstart their rocket development. Then develop in space technologies to use on the moon and Mars.

Skye · « **Reply #24 on:** 03/31/2025 01:00 pm »

I agree with your first paragraph

NG absolutely needs work, I agree, though I doubt it could ever do 40-50t to LEO with ASDS. I think that expended is feasible, but I reckon max 30-35t ASDS. BE-4 actually has less thrust and Isp than R3, and is larger and heavier. Basically, it’s inferior in essentially every way. But I doubt SX would sell them Raptors, and let’s not even go there. I agree with needing 9 engines (and subcooling!) on NG, but I doubt it needs 3 BE-3Us on the upper stage. Overall, NG is suitable for sub-20t payloads to TLI, but isn’t realistically capable of much more.

Personally, I also hope (and honestly think) they’ll both be operational by Q2 ‘26. (SS being operational as in Starlink launches. Maybe some customer payloads by then? NG the seams, but with primary payloads for a but being NASA & Kuiper launches). I also hope that they’ll cancel SLS, (and, on an unrelated note, St~~upid~~arliner) and divert the funding, though I think most of it [the $4b] should go to SX, and only a little to BO, as SS is just a more capable vehicle for all purposes, and BM could work as only a backup / rescue lander. I also agree that the $1b should go to new companies, because it’d be so nice & helpful. Stoke, RKLB, Relativity, Astra, Firefly, etc. Could really use that money. Maybe even a bigger share depending on how SX and BO do?

laszlo · « **Reply #25 on:** 03/31/2025 08:30 pm »

This all strikes me a little like the nostalgia for Model Ts and DC-3s. The older, overbuilt for simpler requirements contender always looks good while its replacement is being debugged. Superficially, the narrative is that Saturn 5 took 8 crews to the moon while Starship still can't get to orbit and is actually doing worse now that it was earlier on.

Maybe once spaceflight gets cheap enough there will be re-enactors building replicas of the Saturn 5 and flying them to the moon in Julys whose year ends in 9.