totm nov 2023 SpaceX Discussion Thread

[Spaceception]

4 minutes ago, Nuke said:

i think elon may be jumping the gun here. i dont think we even are close to producing the perquisites for an interstellar mission, even an unmanned mission.

You're right on most counts, though I imagine short of an apocalypse, a government would want the prestige of following through such an ambitious mission.

Especially if it was making itself useful during the cruise - astronomical observation of the solar system and target system, studying the interstellar medium (beyond the sun's influence), or the interstellar medium inside another's stellar influence, having some of the best isolation of nearby radio sources available, and I'm sure mission designers can come up with more. They wouldn't have the probe or mission specialists twiddling their thumbs for decades doing nothing but recording status updates.

 

Yes, we're nowhere near interstellar travel at the moment, but then, so was the British Interplanetary Society when they designed Daedalus just years after Apollo 17. SpaceX can still do research too, and even go a step further than these studies and fund some technology demonstrators, or precursor missions like the Realistic Interstellar Explorer (2000-2002) probe. Maybe they don't get to it, but they can very well pass the baton.

[darthgently]

18 minutes ago, Nuke said:

you might have to do some religious engineering to make sure people get the payout down the line,  because that's really the only institution humans have ever created which has legs.

Not recommended given that religions are the one thing that members thereof take zero credit for engineering it or creating it.  That kind of being the point of most religions.  Engineered religions are probably a far more dangerous idea than a rogue AI 

[Pthigrivi]

2 hours ago, Nuke said:

4. a really stable government. administration 0 may be willing to pump billions into an interstellar spacecraft, but administration 100 may not want to spend millions building the dish to receive the telemetry later on down the line. as for the private sector look at how well pan am has maintained its fleet in 2024. pan am who? were they a thing? you see my point. you might have to do some religious engineering to make sure people get the payout down the line,  because that's really the only institution humans have ever created which has legs.

I would say the overall scientific project of learning and understanding our universe is at least as old and absolutely as robust as any religion. Astronomers in China, Egypt, and Mesoamerica may not have used the word 'science' but the motivation to understand and predict physical phenomena was there. You don't need 100% institutional stability over hundreds of years, just trust that in the future just as in the past people will be motivated to understand the universe around them. I think thats a safe-enough bet.

As to SpaceX going interstellar... I mean we know Elon. He loves big claims. They marketed Dragon as a Mars lander. By the time they actually do start colonizing mars I doubt Starship itself will be the leading proposal. I think it's a great design for mass to orbit and that form factor will be useful for decades if it's successful. It's obviously silly to compare it to anything like a working interstellar vehicle. 

Edited March 18 by Pthigrivi

[StrandedonEarth]

Falcon 9 wows the crowd (and the announcers) at a spring training baseball game in Pt St Lucie, Fl:

https://x.com/awfulannouncing/status/1768804502390358102?s=20

Edited March 18 by StrandedonEarth

[tater]

 

[tater]

 

[tater]

 

[StrandedonEarth]

Launch was a hit in San Diego, it's all over imgur...

 

E: Video clip: https://i.imgur.com/abb2NnA.mp4

E2: I have to wonder if those white dots are stars or fairing halves...

Edited March 19 by StrandedonEarth

[cubinator]

10 hours ago, StrandedonEarth said:

 

E2: I have to wonder if those white dots are stars or fairing halves...

In the photo: Right dot is possibly Jupiter, lower one is probably the first stage, and one of the fairings is visible firing RCS on the left in the middle of the plume. That's my interpretation.

[tater]

 

[zolotiyeruki]

Six weeks? Dang, they're not sitting around, are they?

[Minmus Taster]

37 minutes ago, tater said:

 

Six weeks?!?! What about the mishap investigation?

[StrandedonEarth]

1 hour ago, Minmus Taster said:

Six weeks?!?! What about the mishap investigation?

SpX: “Not enough control authority, adding more, with heaters to prevent clogs”

FAA: “Ok”

[tater]

1 hour ago, Minmus Taster said:

Six weeks?!?! What about the mishap investigation?

SpaceX decides what issues to work, and works them:

10 minutes ago, StrandedonEarth said:

SpX: “Not enough control authority, adding more, with heaters to prevent clogs”

FAA: “Ok”

This.

Some of the issues might already be in the newer vehicles as well. First mishap had 63 action items, last mishap had 17 action items, Elon said thousands of changes. My guess is that this one has even fewer than IFT-2.

IFT-1 to the investigation concluded was ~2.25 days per action item (141 days)

IFT-2 investigation was concluded in ~6 days per item (100 days).

For IFT-4 to be 6 weeks from now is ~47 days from the launch. Given ~2 weeks from closure to license leaves 33 days, so they'd need to have 5-6 action items at the previous rate of closure per action item (6 days per).

It's plausible that they have only a handful of things to address.

[Terwin]

It makes sense that being much closer to success would mean fewer things to address, and as there was no real additional hazard area for this flight, the faa is probably not terribly concerned about the mishap, so long as there is a plan to do better.

[Mikki]

(Not related to recent events)

Can`t dragchutes/ parachutes or glidechutes assist SH and SS at landing and save on fuel?

The whole system starts to look bruteforcing a good idea which should be smoothed somehow.

(But who am i to ask such dumb questions ;D)

[Cuky]

6 minutes ago, Mikki said:

(Not related to recent events)

Can`t dragchutes/ parachutes or glidechutes assist SH and SS at landing and save on fuel?

The whole system starts to look bruteforcing a good idea which should be smoothed somehow.

(But who am i to ask such dumb questions ;D)

they could, but that beats the goal of rapid reuse. Parachutes need to either be repacked after landing which takes quite a bit of time. Since it would probably include removing them from the vehicle to repack they could switch them up for already pre-packed ones. But that again adds complexity and failure mode to the vehicle.

On the other hand it could include some that are used higher up and then jettisoned. But then they have failed in making a fully reusable vehicle since they throw parachutes away.

 

As for bruteforcing the landing, I guess they are searching for limits of control so that they can design the system that can precisely place the booster in a place for chopsticks to catch it.

[tater]

10 minutes ago, Mikki said:

(Not related to recent events)

Can`t dragchutes/ parachutes or glidechutes assist SH and SS at landing and save on fuel?

The whole system starts to look bruteforcing a good idea which should be smoothed somehow.

(But who am i to ask such dumb questions ;D)

Chutes for 100 and 200 ton vehicles would be HUGE (heavy). They'd also need to be cut for propulsive landing.

Starship terminal velocity is thought to be ~70m/s I think (have to watch old SpaceX animation). That's about 2 tons of propellant.

[magnemoe]

1 minute ago, Cuky said:

they could, but that beats the goal of rapid reuse. Parachutes need to either be repacked after landing which takes quite a bit of time. Since it would probably include removing them from the vehicle to repack they could switch them up for already pre-packed ones. But that again adds complexity and failure mode to the vehicle.

On the other hand it could include some that are used higher up and then jettisoned. But then they have failed in making a fully reusable vehicle since they throw parachutes away.

As for bruteforcing the landing, I guess they are searching for limits of control so that they can design the system that can precisely place the booster in a place for chopsticks to catch it.

Also unlike in KSP earth has wind, so you will move sideways with the wind velocity. One Chinese capsule went for an roll as parachutes got caught by the wind. Not an issue for an water landing but no precision landings for you  nor landing high structures like first stages. 

[Exoscientist]

On 3/18/2024 at 3:11 PM, Minmus Taster said:

Uhm... how exactly?

https://www.space.com/spacex-starship-go-interstellar-elon-musk-says

The many different approaches to nuclear fusion that are rapidly advancing suggest we will soon have fusion power, likely within 10 years. If so, then this fusion startup proposes a fusion powered rocket that could reach Mars within days and the nearest star system within 11 years:

 

  

   Bob Clark

 

[darthgently]

31 minutes ago, Exoscientist said:

we will soon have fusion power, likely within 10 years

Is there an echo in here?  J/k

Looks like an interesting approach and perhaps explains DARPA's recent talk of lunar He3 mining

[tater]

Time synced IFTs.

 

PS—taking the SpaceX thread towards fusion seems like pages and pages of off topic, better to make a thread for that, IMO.

Edited March 20 by tater

[Meecrob]

1 hour ago, Exoscientist said:

The many different approaches to nuclear fusion that are rapidly advancing suggest we will soon have fusion power, likely within 10 years. If so, then this fusion startup proposes a fusion powered rocket that could reach Mars within days and the nearest star system within 11 years:

 

  

   Bob Clark

 

The stars must be aligned or something, cuz this is the first thing I agree with you on.

[Nuke]

1 hour ago, Exoscientist said:

The many different approaches to nuclear fusion that are rapidly advancing suggest we will soon have fusion power, likely within 10 years. If so, then this fusion startup proposes a fusion powered rocket that could reach Mars within days and the nearest star system within 11 years:

 

  

   Bob Clark

 

early fusion drives wont be break even, they dont really have to be self sustaining. it will be nice to eventually tap them for electrical power, say for life support. that wont be until were at second or 3rd gen fusion power. but for now you just want fast charged particles. thus it has the same problem as any other electric thruster. its going to require some wattage. wheres do you get the power? we presently can get a few hundred kw using a really heavy bit of kit that doesn't work too far from the sun (the solar array on the iss). or we got rtgs which last decades on the order of half a kw and decreasing with age.

Edited March 20 by Nuke

[Minmus Taster]

2 hours ago, Exoscientist said:

The many different approaches to nuclear fusion that are rapidly advancing suggest we will soon have fusion power, likely within 10 years. If so, then this fusion startup proposes a fusion powered rocket that could reach Mars within days and the nearest star system within 11 years:

 

  

   Bob Clark

 

Traveling at speeds like that would get you atomized by a grain of dust. Starship is just fundamentally incapable of making a practical interstellar flight on it's own.