totm nov 2023 SpaceX Discussion Thread

[tater]

 

[Beccab]

5% increase over the previous F9 record, which was already higher than its specifics

[sevenperforce]

7 hours ago, Beccab said:

5% increase over the previous F9 record, which was already higher than its specifics

Impressive.

Any indication why? This is the Gen 2 Starlink group; is this a lower shell or a particularly easy inclination?

[Beccab]

38 minutes ago, sevenperforce said:

Impressive.

Any indication why? This is the Gen 2 Starlink group; is this a lower shell or a particularly easy inclination?

Out of necessity, probably. Not sure where they got the additional performance, the inclination seems similar to many before this launch to me

 

Also! 

 

[RealKerbal3x]

 

[Lukaszenko]

38 minutes ago, Beccab said:

Out of necessity, probably. Not sure where they got the additional performance, the inclination seems similar to many before this launch to me

They probably skimmed it off the entry burn of the booster. There's plenty there, at the expense of a hotter and riskier reentry, which they might be willing to try.

[JoeSchmuckatelli]

https://www.cnn.com/videos/us/2023/01/25/glowing-spiral-appears-hawaii-satellite-launch-cprog-orig-aw.cnn

 

 

Edited January 28, 2023 by JoeSchmuckatelli

[tater]

 

 

[CatastrophicFailure]

Prolly old news but… 

 

 

 

[Minmus Taster]

5 hours ago, CatastrophicFailure said:

Prolly old news but… 

 

 

 

If Artemis wasn't obsolete before it's plain irrelevant now

[tater]

7 hours ago, CatastrophicFailure said:

Prolly old news but… 

250t expendable. Hmm.

1 hour ago, Minmus Taster said:

If Artemis wasn't obsolete before it's plain irrelevant now

Artemis is the program, and Starship is the Human Landing System, so it's still pretty relevant.

Assume an 80t LSS, and assume the 250t number is cargo, not vehicle (maybe a SS with no fins, tiles, etc... like LSS).

Expending SH puts it in LEO with 250t of residual props (5252 m/s of dv).

Expend a second vehicle, and our LSS is in LEO with 500t of props now (7342 m/s).

A third and it can fly from LEO to the lunar surface and back to lunar orbit with residuals.

3 more, and 1 of those can fly to LLO as a tanker so LLS (and maybe the tanker) can come home.

[CatastrophicFailure]

4 hours ago, tater said:

250t expendable. Hmm.

That could put a nuclear reactor on Pluto. 
 

just sayin… 

[JoeSchmuckatelli]

I want to see it fly before we start trying to figure out how many D7 Plutonium Dozers it can ferry to Mars

[tater]

Starlink coverage is now 9:15 Pacific.

And now later still (can't trust youtube placeholder):

 

Edited January 30, 2023 by tater

[tater]

 

 

[tater]

We need ~12.2 km/s for a LEO to LEO round trip for HLS.

So assume HLS is 80t dry and has 10t of cargo. with 1200t of props, that's 9873 m/s.

It lands with a wet mass of 249t.

Leaves 10t of cargo so it's now 80t dry, wet mass 239t.

That's 4058 m/s. Return to LEO requires ~6100. But it can actually get to LLO, and back to the surface with what it has. Now in LLO with ~59t of props.

Can't believe this number, but our 80t HLS needs to have a wet mass ready to leave the moon of... 420t to reach LEO propulsively.

So what would it need to carry in LEO to land with that extra 171t of props (landed mass 430t)? 2250t. That's a decent stretch, almost 2x the props in SS right now. So a double tankage stretch makes little sense to carry to the surface and back. Why not take a regular sized (another HLS?) to LLO, instead? If a regular SS, it could at the least aerobrake, if not direct entry (the latter will take a while with crew to be safe). if an HLS, then what can we do?

So anyway our nominal 80t HLS (LSS, whatever) is back in LLO with ~2 km/s of dv (wet mass 139t, 59t of which is props). We only need to bring it 111t for it to fly back to LEO.

A second HLS sent to LLO (80t dry, no cargo) would get to LLO with 6181 m/s dv remaining (343t residual props). It can get back to LEO with 170t of props, leaving it 173t of props it can transfer to the first HLS. Both can return to LEO with margin, or the first HLS can do yet another RT to the surface.

If the second HLS also had 10t cargo it gets there with 336t of props. That's enough for HLS2 to transfer 111t to the first HLS to return to LEO, and still fly back to the moon and back to LLO—with margin.

2 HLS could swap constant crews on the moon in this fashion, with commercial crew vehicles meeting it in LEO to provide transport from and back to Earth.

 

 

[tater]

 

[tater]

Seems like an expendable SS/SH lunar hab would be a good idea.

250t expended to LEO... We put the props in the nose for this concept, staging off the normal SS tank section after TLI. We can get a 47t payload to the surface of the Moon in 1 launch. From an Artemis standpoint, whatever lander they like, lol (maybe larger if some other lander, I'm assuming 378s I_sp for Rvac). But a 47t lander is 250t wet in this case. Assuming methalox, that's only ~3 SS rings worth of props. We have ~9-10 rings of volume to play with in the payload section (counting the taper). So the top of the nose is props. 15t of lander~8t of decks. 23 of our 47t used up.

So we need whatever mass the methalox landing engines are—in the nose with cosine losses—within the remaining 24t of mass. Goal is our Starship payload section on the moon with the deck right on the surface. Basically LSS minus all the normal SS tankage. Bottom floor for rover and airlocks. Upper 2-3 floors (~63 m² per floor) for crew/cargo.

Since crew arrives on a habitat (LSS), this provides backup consumables, and emergency shelter, etc.—and it's a 1 launch vehicle.

Alt concept: land the 47 ton SS payload nosecone but with props/engines at the bottom. You could land 20t of cargo—and the top of the nose could be an ascent vehicle that can still get 14t to LLO (including vehicle mass). I assumed the ascent vehicle is hypergols, so storable. So we land a 1 launch hab (with large rover included), and a second cargo/ascent vehicle version. LSS problems can result in the crew hunkering down in the permanent hab, then leaving via the emergency ascent vehicle to meet up with their ride home (another LSS, which can ferry crew from LLO propulsively with no retanking in LLO required).

Like those^^ but wearing a pointy hat

Note that Mars Direct habs were 8.4m in dia. We'd add an extra deck, so 3 floors, rover/ramp on bottom, then props and landing engines in the more curved part.

Ascent vehicle version moves generic cargo up a couple rings, and the nose is a Dragon pressure vessel (Dragon XL?) with some tanks, Dracos, etc.

2 single launch events send a rover, many tons of cargo, a habitat, and an emergency ascent vehicle that can take a crew to LLO or Gateway.

 

Edited January 31, 2023 by tater

[Nuke]

On 1/26/2023 at 7:12 AM, tater said:

 

if you stare into the void long enough, it stares back.

[tater]

Odd.

 

[tater]

20 min vent happened. Stream likely goes live a few minutes before.

 

[tater]

Nominal so far

[JoeSchmuckatelli]

48 minutes ago, tater said:

20 min vent happened. Stream likely goes live a few minutes before.

 

Never gets old, does it? 

[linuxgurugamer]

Just now, JoeSchmuckatelli said:

Never gets old, does it? 

Was a beautiful launch and landing

[Beccab]