News Changes to the SpaceX BFR rocket.

[diogom]

Isn't it, um, standard procedure for the FAA to ground after an unsuccessful launch? Same happened after the suborbital hops.

 

[statisticsnerd]

I don't think a Starship orbital flight test is happening in 2023 and I seriously don't think a moon landing in Starship is happening in 2025, or possibly even ever. SpaceX jumped the shark here.

Yeah, a Moon landing in 2025 is highly unlikely. Starship may not even reach orbit until then, but I believe that it will probably land on the Moon at some point.

Although blowing out a gaping hole under the launch pad during the OFT was pretty stupid, SpaceX isn't usually incompetent. They have accomplished some pretty amazing things such as reusable boosters, Starlink, sending astronauts and cargo to the ISS, and sending a Tesla into space.

Orbital refueling and landing on the Moon shouldn't be insurmountable hurdles.

 

[Thunder Chicken]

Isn't it, um, standard procedure for the FAA to ground after an unsuccessful launch? Same happened after the suborbital hops.

Yes, but there will probably be an environmental review as well.

 

[statisticsnerd]

Yes, but there will probably be an environmental review as well.

Raining chunks of concrete on endangered sea turtle habit isn't a good look. This is their nesting season too.

 

[evp143]

The launch have shown that the material experiencing an extreme loads and what else could expect at full 'boster 7' thrust?! After all there is no construction material that can bear (resist) such pressures and heat without protection ('Big bang concrete' test

).

 

[RisingFury]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

 

[Urwumpe]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

Thats a bit jumping to conclusions.

 

[evp143]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

it’s a much easier task for Starship than taking off the Earth but debris and dust could be a problem not only for ship

 

[jedidia]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

It's a lot easier on the moon, obviously, but you're probably going to need a train line to the base, because you'll need quite a few km of spacing...
Incidentally, how powerfull are the DGs engines, exactly?

 

[Pioneer]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

Looking back at the Starhopper tests, those didn't seem to kick up enormous amounts of debris. Also it was mainly the insane amount of thrust from the first stage that caused the crater, not the upper Starship stage. The latter will also be landing mainly in lower-gravity environments too.

 

[jedidia]

The latter will also be landing mainly in lower-gravity environments too.

It has to be noted though that that also makes it easier for debris to fly around...

 

[Urwumpe]

It has to be noted though that that also makes it easier for debris to fly around...

Thats why it is good if its lighter than SuperHeavy and has the final landing engines on top....

 

[Max-Q]

It's looking like there's no way Starship can really land on the Moon or Mars without debris destroying it.

It's the difference between 33 sea level raptors on the SuperHeavy booster, and 3 sea level and 3 vacuum raptors on Starship.
That's less than 18% of the thrust. They really do need a flame deflector for SuperHeavy, but not for Starship.

 

[Thunder Chicken]

It's the difference between 33 sea level raptors on the SuperHeavy booster, and 3 sea level and 3 vacuum raptors on Starship.
That's less than 18% of the thrust. They really do need a flame deflector for SuperHeavy, but not for Starship.

Something to consider is that escape velocity on the moon is something like 2.4 km/s, which is less than the gas exhaust velocity coming out of these engines, and there is no drag on the regolith particles once they are ejected by the exhaust. It's likely that some regolith is going to be sent into widely variable lunar orbits on every launch, and who knows how long that debris will stay in lunar orbit. And NORAD won't be able to track the bigger bits like they do on Earth. Managing debris ejection on the moon is kinda a big deal because, if done, poorly, it isn't impossible that they Kessler Syndrome themselves out of lunar operations.

 

[GLS]

Nice video with several views and good sound (if you don't count the shouting and screaming)

 

[Thunder Chicken]

Nice video with several views and good sound (if you don't count the shouting and screaming)

It appears that the two outboard engines that were next to each other that were inoperative at launch didn't just fail to light, but they lost their engine bells. I wonder how much rocket debris they are going to find scattered around the pad (and the county).

 

[jedidia]

Managing debris ejection on the moon is kinda a big deal because, if done, poorly, it isn't impossible that they Kessler Syndrome themselves out of lunar operations.

Huh... That had never occurred to me, but it's an interesting thought. I guess somebdy's gonna have to build a landing pad...

 

[steph]

Huh... That had never occurred to me, but it's an interesting thought. I guess somebdy's gonna have to build a landing pad...

In the long run, of course. But even launching from the bottom of a crater means most fragments impact the landscape, and what's left is at a high angle/eccentricity, so it will impact the moon on the return trip. And any lunar base would need a form of micrometeor protection anyways

 

[Linguofreak]

Something to consider is that escape velocity on the moon is something like 2.4 km/s, which is less than the gas exhaust velocity coming out of these engines, and there is no drag on the regolith particles once they are ejected by the exhaust. It's likely that some regolith is going to be sent into widely variable lunar orbits on every launch, and who knows how long that debris will stay in lunar orbit. And NORAD won't be able to track the bigger bits like they do on Earth. Managing debris ejection on the moon is kinda a big deal because, if done, poorly, it isn't impossible that they Kessler Syndrome themselves out of lunar operations.

Also true of the Apollo LM.

But any trajectory that leaves the lunar surface is going to have a periapsis below it, so any debris that isn't ejected from the moon outright should reimpact within an orbit. I suppose for a very low angle launch (if it isn't caught by terrain), a masscon along the ground track might tweak the orbit so that the Pe is above ground, and it might survive multiple orbits, but other masscons might tweak the Pe back down, or it might encounter higher terrain as the moon rotates under the orbit (Pe altitude is still likely to be very low).

So the majority of the debris hazard to spacecraft from a launch from the lunar surface will be to spacecraft in orbit at or shortly after the time of launch (including the launching spacecraft itself). Long term Kesslerization is unlikely.

 

[steph]

Also true of the Apollo LM.

But any trajectory that leaves the lunar surface is going to have a periapsis below it, so any debris that isn't ejected from the moon outright should reimpact within an orbit. I suppose for a very low angle launch (if it isn't caught by terrain), a masscon along the ground track might tweak the orbit so that the Pe is above ground, and it might survive multiple orbits, but other masscons might tweak the Pe back down, or it might encounter higher terrain as the moon rotates under the orbit (Pe altitude is still likely to be very low).

So the majority of the debris hazard to spacecraft from a launch from the lunar surface will be to spacecraft in orbit at or shortly after the time of launch (including the launching spacecraft itself). Long term Kesslerization is unlikely.

Yeah, I mean, given the amount of stuff that gets thrown around by impacts, the moon should have had rings by now