Starship Orbital Test Flight - 4/20 Launch

[charliemagpie]

Is that why Expanse is still on my IMDB watch list, its on the backburner.

Twice over the years I've rewatched the first few episodes, it got interesting then lulled. It got superseded by new shows, and then nearly forgotten.

But whenever I go through my list , I say "I should watch that"... now I will. TX

 

[SparkChaser]

And that's what ultimately destroyed it as the tanks were purged of pressure. The last frame of video that SpaceX has from the winglet camera shows the booster tank folding as the rocket crumples. from the aerodynamic load from the Starship mated atop it.

-Crissa

You can see the venting of all the tanks as it flips over. I think they blew holes in the tanks to decompress them. That would have weakened it considerably.

 

[JBee]

You can see the venting of all the tanks as it flips over. I think they blew holes in the tanks to decompress them. That would have weakened it considerably.

Yeah well apparently that was the flight termination system (FTS) that blew those vent holes into it. But I think they were expecting greater destruction from the FTS than they got, and because of the relatively high altitude and low air density, together with the high speed inertia of a still full 1400ton Starship the empty booster was really hanging on to the Starship and not the other way around. That resulted in some unusual manoeuvres as the the booster ran out of fuel and everything got top heavy and it didn't separate. It actually took a full minute for it to explode after they triggered FTS, which is not really according to spec. Their saving grace was that it was at 36km altitude at the time, and so it had time to ignite and explode, but closer to the ground the results would have been different. It might or might not of exploded early after FTS was triggered at a lower altitude, but I dare say the next one will be 2-3x as large, or at least a few laps of detonation cord wrapped around the tanks to shear them in half and ignite the remaining fuel.

The thing to remember here is that Starship itself is designed to survive high speed orbital re-entry, with heat shield, and a freefall dive all the way back to the ground for the flip landing. So it's quite possible for it to crash intact onto the ground. In this case of course it was far out to see straight after launch, but it also has a downrange glide capability, so loosing control of it, is never a good idea.

 

[Crissa]

We also don't know if they didn't just wait for the tanks to empty to destroy it. More crumple, less bang.

-Crissa

 

[JBee]

Yeah, I was thinking that when listening to some commentators as well, It would be a fairly serious omission for SpaceX and the FAA not to have ensured the FTS was capable enough for complete disassembly of both parts of the vehicle, plus contigencies.

I'm not sure if they want more or less explosion, I think the primary goal of the FTS is lots of small bit rather than big ones, so I suppose a larger explosion, but distributed along it's length would be better to create smaller fragments?

I remember with our BVLOS UAV competitions, our FTS had to do a hard right rudder, and nose down with motor cutoff switch. The result was a uncontrolled dive into the ground that demolished the aircraft on impact, and anything in its way. So what we did with our quadplane was make it a two stage affair, where on our own failsafe it would go into hover mode and slowly descend to the ground undamaged. Then when the Challenge ground staff ordered a FTS, it would nose dive into a spin in crash. We had to use ours once and we recovered the plane intact...and nobody got hurt either. It did a bit of field mowing though.

Our little battery powered 3kg airframe was competing against 50-60kg fuel powered aircraft, and all of those had a simple spin and crash FTS, and that with 10's liters of fuel onboard in a open field over 30km away...not ideal, and we told the organizers as much too.

 

[Sirfun]

Multiple high-res angles of the launch (including one hit by concrete and glitched). You can see the moment the dust changes as the concrete breaks.

Also, you can see how it looks to have watched it live, and how noisy it truly was five miles away.




-Crissa

WOW, that was some amazing video. Thanks for the post.

 

[CyberGus]

Joe got a thermal tile as a souvenir!

 

[SparkChaser]

I'll have to get in touch with my friend that was there in the control room. A few rounds and maybe he will let me in on what happened.

 

[Sirfun]

Joe got a thermal tile as a souvenir!

That would be my little piece of history!

 

[CyberGus]

That would be my little piece of history!

I'd pay 500 $DOGE

 

[JBee]

I can't believe you Texans were in the state and didn't go to watch it!
Here was me on the other side of the planet hoping that it would be delayed until I come over next week!