Updates SpaceX Falcon 9 F5 CRS SpX-2 through CRS SpX-12 Updates

[Urwumpe]

WIRED: An Analysis of SpaceX’s Falcon 9 Crash Landing

 

[Evil_Onyx]

That looks to me like the legs failed as well, in that video.

 

[Urwumpe]

That looks to me like the legs failed as well, in that video.

Could be a secondary effect, if the stage landed on just one before engine shutdown.

 

[Thunder Chicken]

Barge eye view...

https://vid.me/e/i6o5

edit: pos HTML interface wont let me post video, see link.

Here's the Youtube version, if it matters.

Man, that RCS was putting up a good fight. It does look like one of the legs got overloaded so a crash was pretty much guaranteed, but they were really close to pulling it off.

 

[RisingFury]

They almost made it! I give them 90% on the next attempt.

 

[Urwumpe]

Here's the Youtube version, if it matters.

SpaceX CRS6 BARGE LANDING (view from gopro) - YouTube

Man, that RCS was putting up a good fight. It does look like one of the legs got overloaded so a crash was pretty much guaranteed, but they were really close to pulling it off.

One engine nozzle has also been damaged during the landing and before the explosion already - that was no 90% landing.

 

[fsci123]

We're missing something here. Nobody has explained how that barge keeps surviving these explosions. An investigation needs to be called.

 

[Urwumpe]

We're missing something here. Nobody has explained how that barge keeps surviving these explosions. An investigation needs to be called.

Some lot of steel and some lot of paint?

After all, any aircraft carrier deck is build to lower standards.

 

[Thunder Chicken]

We're missing something here. Nobody has explained how that barge keeps surviving these explosions. An investigation needs to be called.

Welded steel plate is mighty tough stuff and easy to repair. Take a ship out into the North Atlantic in February and you'll see how tough it is. Look up the Sea Witch / Esso Brussels tanker accident in NY harbor December 1973. Though both ships were heavily damaged by the explosion and fire, both were salvaged.

Some weld patches and paint, maybe a few fittings, and JRTI will be ready for another "landing".

 

[dman]

They almost made it! I give them 90% on the next attempt.

I give it 5.5 - did not stick the landing........

 

[RisingFury]

One engine nozzle has also been damaged during the landing and before the explosion already - that was no 90% landing.

All of the damage is purely as a result of sideways landing. I think by next attempt they'll tweak the autopilot to be more predictive and stabilize the rocket sooner.

We're missing something here. Nobody has explained how that barge keeps surviving these explosions. An investigation needs to be called.

A rocket explosion isn't a bomb. It's not designed to penetrate and the explosion is also a lot slower.

A bomb made out of dense material, is long and has a high impact velocity. The explosive is also already pre-mixed with oxidizer.

A rocket explosion seems devastating, but there's no supersonic shockwave and a lot of energy is lost to heat and light.

You can see the debris doesn't go flying into oblivion:

https://www.youtube.com/watch?v=BhMSzC1crr0&feature=youtu.be

Don't get me wrong - I wouldn't stand anywhere near. But I'm not made of steel...



The video shows to things:
1.) Fire after the explosion, so the fuel burns slowly and after the fact.
2.) The rocket seems to be relatively on track, but the autopilot decides to make a radical correction quite late.

There's probably a decent amount of damage on the barge, but I'd bet a lot is fire related.


Edit:
Just noticed an interesting piece flying off from the explosion to the left. It's trailing a line of smoke and acting as if it's under propulsion. It starts at about 20 seconds into the video and the video cuts out before we see what happens with the piece.

 

[Andy44]

It looked like the vertical speed was fine to me. Looks more like it wasn't level at touchdown. And in that deck video the landing gear doesn't appear to be bent, though it's hard to see through the smoke. and that gallant little jet on the nose, struggling mightly to save the ship...alas.

 

[MaverickSawyer]

Edit:
Just noticed an interesting piece flying off from the explosion to the left. It's trailing a line of smoke and acting as if it's under propulsion. It starts at about 20 seconds into the video and the video cuts out before we see what happens with the piece.

Saw that, too. Looks like the RCS propellant tank, given that it seems to generate the same plume as the cold gas thrusters at the top of the stage.

 

[Cosmic Penguin]

In other (not newsworthy ) news, the CRS-6 Dragon will arrive in port of ISS in about 4 hours from now, where the 6 on board are waiting for terminal navigation and cargo unloading.

 

[Urwumpe]

Just noticed an interesting piece flying off from the explosion to the left. It's trailing a line of smoke and acting as if it's under propulsion. It starts at about 20 seconds into the video and the video cuts out before we see what happens with the piece.

Yes, and it is accelerating pretty slow and separated late, while spiralling. It looks like a pressurant tank or similar in its behaviour to me.

 

[BrianJ]

Unless they can modify the engine to throttle down more, that's not an option - with a near-empty stage, its minimal acceleration is above 1g.

You're right. Extra fuel only really helps if you can throttle down below 70% - which my simulated Falcon can. I'll have to see about that
Cheers,
Brian

 

[fraxudemspas]

We're missing something here. Nobody has explained how that barge keeps surviving these explosions. An investigation needs to be called.

Jet fuel can't melt steel beams.

 

[Urwumpe]

Jet fuel can't melt steel beams.

Actually, it really can't melt them.

But then, making steel soft and plastic is enough. What many volunteer fire fighters here learn very early in their training: A 300 year old timber frame house collapses much later in a fire, than a 3 week old steel factory hall.

But for the deck of such a barge, you just have to remember that we have previous technologies that had already been designed for surviving the impact of many tons of jet fuel and metal: Aircraft carriers. Especially after the first Kamikaze attacks, the USA had learned how strong the deck of a carrier has to be.

Even launching V-2 rockets was already attempted from the decks of US carriers. Only partially successful, but the deck was always good enough for the job.

https://www.youtube.com/watch?v=Eug0uV5ko0s

 

[Cosmic Penguin]

In other (not newsworthy ) news, the CRS-6 Dragon will arrive in port of ISS in about 4 hours from now, where the 6 on board are waiting for terminal navigation and cargo unloading.

Already bolted to CanadaArm-2 at 10:55 UTC.

 

[fraxudemspas]

The landing platform is back in port. Not much left of the first stage, as expected.