totm nov 2023 SpaceX Discussion Thread

[tseitsei89]

8 minutes ago, sevenperforce said:

So what's the next big milestone for SpaceX?

First Block 5 flight?

First Block 5 reflight?

First third reflight of any orbital-class booster?

First Block 5 reflight in under 7 days?

First flight of Dragon 2?

I would say using a booster significantly more than 2 times (like 5+ times) will be a great accomplishment and a big step in reducing costs of hauling stuff in to space

Edit: Also what is important is to streamline the process of getting a landed booster back to launch shape as quickly, cheaply and reliably as possible

Edited February 8, 2018 by tseitsei89

[CatastrophicFailure]

4 minutes ago, sevenperforce said:

So what's the next big milestone for SpaceX?

First Block 5 flight?

First Block 5 reflight?

First third reflight of any orbital-class booster?

First Block 5 reflight in under 7 days?

First flight of Dragon 2?

Yes. 

[cubinator]

I still think that they should install a monolith on the Moon for the BFR test. Put a little RTG in it and have it broadcast spooky noises to anybody within a few hundred meters.

[sevenperforce]

Does anyone know why there were six sonic booms on the side booster landings?

I would have guessed four: bow shock & tail shock duplicated for each.

[mikegarrison]

46 minutes ago, sevenperforce said:

Does anyone know why there were six sonic booms on the side booster landings?

I would have guessed four: bow shock & tail shock duplicated for each.

Those grid fins may cause a shock.

[HvP]

1 hour ago, sevenperforce said:

Does anyone know why there were six sonic booms on the side booster landings?

I would have guessed four: bow shock & tail shock duplicated for each.

According to Destin Sandlin of the YouTube channel SmarterEveryDay, the sonic booms are produced by 1) the engines 2) the landing legs 3) the grid fins. Destin has some expertise in the subject considering that he is a missile flight test engineer for the Redstone Arsenal.

Headphones are suggested for the following video. Footage filmed from atop the VAB begins at 2:32 and booster landing explanation at 5:24.

 

Edited February 8, 2018 by HvP

[CatastrophicFailure]

New numbers out, via this article on SpaceFlightNow. The Tesla won't reach the asteroid belt, it'll just exceed the orbit of Mars. It will pass within 69 million miles of the red planet on Jun 8 and reach aphelion of 158 million miles on November 19. Some interesting speculation that between perturbations from Jupiter and unpredictable decomposing of components, on a scale of millions of years it may end up ejected from the solar system or hurled into the sun. 

Good thing StarMan has shades. Well, shade.

[DAL59]

https://imgur.com/vCrOo9e

 

 

Edited February 8, 2018 by DAL59

[YNM]

5 hours ago, DerekL1963 said:

My understanding, from usually reliable sources, is that certain DOD/TLA payloads require a long coast phase - and that yesterday's coast was a demonstration of FH's capability to meet those requirements.  (If you haven't figured it out yet - that's FH's raison d'être.  Gaining SpaceX solid entry into the National Security Payload business.)

Hmm... yeah. But I also heard that now they can deliver heavy payloads straight to GEO rather than GTO - "propellant-less" in the sense of they don't need extra propellant for orbit insertion.

[kerbiloid]

4 hours ago, sevenperforce said:

So what's the next big milestone for SpaceX?

Postponing of something.

[tater]

As was said, flying block 5. Specifically 7 times, because of commercial crew which requires SpaceX to fly the slightly modified F9 stack (Block 5 is an incremental modification, after all) 7 times, whereas the slightly modified Atlas Stack will have to fly exactly once before they put people on top (2 Rl-10 Centaur has only flown once in the config used for CST-100, and it flew on Atlas III, so the first "all up" stack will be the unmanned test of CST-100). SLS similarly gets to assume that it is safe because a rocket is apparently just the sum of lego parts for SLS (as long as the parts have data, then it's fine, even if the stack will never have flown).

 

[tater]

 

[Nightfury]

10 minutes ago, tater said:

 

W-WHAAT , whyy

it was "just" a big piece of metall ( i know there some other stuff) with useful data !

[Confused Scientist]

23 hours ago, Confused Scientist said:

One thing that I haven't seen much of so far is how big of a PR success this is.

Last night, the video of the launch on SpaceX's YouTube channel was the number one video on trending! Right now it's number two.

[rudi1291]

2 minutes ago, Nightfury said:

W-WHAAT , whyy

it was "just" a big piece of metall ( i know there some other stuff) with useful data !

From the article:

" things like un-safed COPVs (composite overwrapped pressure vessels) at flight pressure could have made it a ticking time bomb and hazard to navigation and marine life"

Surely blowing it up with lots of other explosive stuff is better

[sevenperforce]

12 hours ago, HvP said:

According to Destin Sandlin of the YouTube channel SmarterEveryDay, the sonic booms are produced by 1) the engines 2) the landing legs 3) the grid fins. Destin has some expertise in the subject considering that he is a missile flight test engineer for the Redstone Arsenal.

I'd assumed the engines and the grid fins would do the trick, but it's interesting that the landing legs produce enough of a transition to create a normal shock. 

10 hours ago, YNM said:

Hmm... yeah. But I also heard that now they can deliver heavy payloads straight to GEO rather than GTO - "propellant-less" in the sense of they don't need extra propellant for orbit insertion.

To be clear, they could have done this with Falcon 9 as well, albeit with smaller payloads. It takes 2.27 km/s over LEO to put a payload onto a geostationary transfer orbit, and it takes another 2.06 km/s to correct inclination and circularize in GEO. An expendable Falcon 9 can deliver 4 tonnes to Mars transfer, so it should be able to deliver a 3.6-tonne satellite direct to GEO, though in practice allowance needs to be made for boil-off as well as, potentially, a deorbit burn. Falcon Heavy expendable, in contrast, can put a 15.2-tonne satellite direct to GEO, with the same caveats applying.

If anyone is wondering, my math gives the expendable Falcon 9 an impressive 7.7 tonnes to trans-lunar injection. If the Falcon 9 upper stage could coast for 3 or 4 days, it could even deliver a little over 4 tonnes directly into low lunar orbit.

8 hours ago, tater said:

As was said, flying block 5. Specifically 7 times, because of commercial crew which requires SpaceX to fly the slightly modified F9 stack (Block 5 is an incremental modification, after all) 7 times, whereas the slightly modified Atlas Stack will have to fly exactly once before they put people on top (2 Rl-10 Centaur has only flown once in the config used for CST-100, and it flew on Atlas III, so the first "all up" stack will be the unmanned test of CST-100). SLS similarly gets to assume that it is safe because a rocket is apparently just the sum of lego parts for SLS (as long as the parts have data, then it's fine, even if the stack will never have flown).

SLS will fly once before they put crew on it. Not sure if that was your point or not, hah!

SpaceX will do a Max-Q abort test, so...really, why the concern?

19 minutes ago, tater said:

 

Has this actually been confirmed, or is it another "anonymous source" thing?

Unrelated:

What dumbassery.

[Nightfury]

Just now, rudi1291 said:

From the article:

" things like un-safed COPVs (composite overwrapped pressure vessels) at flight pressure could have made it a ticking time bomb and hazard to navigation and marine life"

Surely blowing it up with lots of other explosive stuff is better

yeah sure, but why not depressurize it before?

[Delay]

Just now, sevenperforce said:

What dumbassery.

Hopefully this disease comes to a stop soon.

Probably not; stupidity has been spreading for a few thousand years now...

[Spaceception]

15 minutes ago, sevenperforce said:

Stuff

What dumbassery.

WHHHHHY

I read some of the replies (and lost brain cells in the process), he seems to like painting himself into corners, like he acknowledged satellites, but wouldn't answer how exactly they orbited. I hope he's just a crappy troll.

[Delay]

5 minutes ago, Spaceception said:

I read some of the replies (and lost brain cells in the process)

I just looked at the comments myself... You weren't lying. He doesn't even understand that Polaris and the Sun orbit around a SMBH and therefore have similar speeds. He makes it sound like Polaris is standing still, despite the fact that "standing still" is impossible.

I would like to slam my head on the table right now, but I still need it. And my head as well, of course.

 

[sevenperforce]

12 minutes ago, Spaceception said:

WHHHHHY

I read some of the replies (and lost brain cells in the process), he seems to like painting himself into corners, like he acknowledged satellites, but wouldn't answer how exactly they orbited. I hope he's just a crappy troll.

I think he's suggesting that IF satellites exist, he should be able to see them from any video in space.

[Spaceception]

18 minutes ago, sevenperforce said:

I think he's suggesting that IF satellites exist, he should be able to see them from any video in space.

Oh.. Yeah, must've misread it. Mistake on my part.

[Guest]

Now that I think of it, it seems Elon's gone crazy

[Aegolius13]

Does anyone happen to know what the TWR of the Falcon Heavy was at launch?  Going by the mass and ASL thrust numbers on wikipedia, I get 1.63.  It did go up quickly, but that sounds pretty high.  I assume wiki's mass figure omits the payload, but then again, I doubt the Tesla was heavy enough to change the number significantly.  

[tater]

1 hour ago, sevenperforce said:

SLS will fly once before they put crew on it. Not sure if that was your point or not, hah!

No, it won't.

Falcon 9 is required to fly with everything except Crew Dragon (with crew) 7 times before crew. Fixed dev on S1 (block 5), fixed dev on S2.

CST-100 will have one flight with a fixed stack before crew, as the Centaur they are using has only flown once before, and never on Atlas V.

Orion will fly the very first time as a final stack on EM-2, as EM-1 uses a different upper stage, AND it will be the very first all-up Orion, as well.

Edited February 8, 2018 by tater