Launch News SpaceX Dragon V2 Pad Abort Test, May 6, 2015

[Frilock]

Uh oh. Are tinfoil hats coming into fashion around here?

 

[Hlynkacg]

I feel like many here are drastically underestimating the durability of your typical human and (oddly enough) the lethality of the alternatives. Kind of like stepping into a busy freeway to avoid getting cancer.

Uh oh. Are tinfoil hats coming into fashion around here?

Coming? They're already here.

 

[Artlav]

Kind of like stepping into a busy freeway to avoid getting cancer.

More like proceeding towards getting turned into a fine red mist to avoid using the ejection seat and spending the next few month healing broken bones.

 

[N_Molson]

Uh oh. Are tinfoil hats coming into fashion around here?

I and a few others have been around since, I don't know, almost 10 years (who remembers the M6 boards ?). There's always been a lot of scepticism around there. For me the point of this forum is the spirit of "looking a bit behind the scenes and understanding how things really work". Not blindfolded patriotism. :dry:

A few people have been saying that the Moon landing were fake and things like that. They were downed in flames quickly each time. So don't speak about tinfoil hats. You say SpaceX is a private company. Since when private companies give transparent, neutral information ? Come on.

 

[Hlynkacg]

More like proceeding towards getting turned into a fine red mist to avoid using the ejection seat and spending the next few month healing broken bones.

Pretty much.

There's always been a lot of scepticism around there. For me the point of this forum is the spirit of "looking a bit behind the scenes and understanding how things really work". Not blindfolded patriotism. :dry:...

There's also a fair bit of NASA fetishism though. An odd belief that the illusion of safety/infallability is preferable to actually doing anything.

 

[N_Molson]

"Tinfoil hats", "fetishism"... are your convinctions so fragile you really need that kind of despising vocabulary ? I feel offended, sorry. :dry:

 

[RGClark]

Based off of no hard evidence, a video and some hand-waving.

You'll forgive me if I take their word over yours

Still, it is a fair question if other crew capsules during their abort tests didn't exhibit such tumbling. I looked at the Orion abort test and it didn't have it. I tried to find one for the Apollo capsule but in the one I found it was hard to see. Also in that test the Little Joe rocket carrying it had a malfunction and disintegrated in flight so I don't know if that one would be representative anyway.
There is too the fact the tumbling only happened after the trunk was jettisoned, so it would be reasonable to ask if the streamlining characteristics offered by the trunk could be emulated by the capsule.

Bob Clark

 

[Hlynkacg]

"Tinfoil hats", "fetishism"... are your convinctions so fragile you really need that kind of despising vocabulary ? I feel offended, sorry. :dry:

I could ask you the same question. NASA's track record in such matters is hardly exemplary.

 

[RGClark]

On another forum someone noted that with the Orion abort test, the launch abort tower orients the capsule so that the heat shield faces down, which aerodynamically the capsule wants to be, before it is jettisoned.
So perhaps a simple solution would be to have the Dragon thrusters orient the capsule with heat shield down prior to engine shutdown.

[ame="http://www.youtube.com/watch?v=JLdP-L7D58g"]Pad Abort #1 PA-1 Test Launch of NASA Orion Launch Abort System LAS at White Sands - YouTube[/ame]

Bob Clark

 

[MaverickSawyer]

On another forum someone noted that with the Orion abort test, the launch abort tower orients the capsule so that the heat shield faces down, which aerodynamically the capsule wants to be, before it is jettisoned.
So perhaps a simple solution would be to have the Dragon thrusters orient the capsule with heat shield down prior to engine shutdown.

Pad Abort #1 PA-1 Test Launch of NASA Orion Launch Abort System LAS at White Sands - YouTube

Bob Clark

They can't. The Trunk puts the center of drag behind center of mass. That's why it didn't tumble until AFTER trunk jettison.

 

[C3PO]

On another forum someone noted that with the Orion abort test, the launch abort tower orients the capsule so that the heat shield faces down, which aerodynamically the capsule wants to be, before it is jettisoned.
So perhaps a simple solution would be to have the Dragon thrusters orient the capsule with heat shield down prior to engine shutdown.

The LAS doesn't use the thrusters to stabilize Orion. It's mainly the aerodynamic properties of the stack. The LES uses control ports in the tip for steering, and the solid fuel is gone by the time Orion reaches LAS separation attitude. You can tell by the 'slow' residual flames from the main solid motors.

 

[RisingFury]

I would say that SpaceX is a much more partial source than Urwumpe. The difference is that they have a huge interest saying it worked perfectly.

SpaceX might be more partial, but they have actual data. Urwumpe is basing his opinion on how it looked from the video. Not even any measurements from the video

That said, SpaceX does have an interest in saying it worked, but the data will probably be reviewed by NASA - especially for flights to ISS.

 

[Urwumpe]

I would say that SpaceX is a much more partial source than Urwumpe. The difference is that they have a huge interest saying it worked perfectly.

Still, he is right, I should provide data to back my opinion up with facts.

But on the other hand ... does SpaceX argue in public with more data than a tweet? Do the SpaceX fanboys have better facts?

Even if you claim that SpaceX has a rocket and I don't : give a 12 year old KSP player the same money that SpaceX got from NASA and investors and he would do it as well. Others managed more for less after all.

---------- Post added at 03:42 PM ---------- Previous post was at 03:39 PM ----------

That said, SpaceX does have an interest in saying it worked, but the data will probably be reviewed by NASA - especially for flights to ISS.

NASA is the third biggest investor into SpaceX after Musk and Google. Its hardly impartial by now.

 

[RisingFury]

I never said that humans in the capsule would be fine. I said SpaceX is claiming it. Unfortunately they don't release data, but you have to think they have people looking it over.

That said, NASA might not be impartial, but they are (for the most part) strict when it comes to safety (a few exceptions there). I trust that they'll review the data fairly before allowing any flights to ISS.

 

[Urwumpe]

I never said that humans in the capsule would be fine. I said SpaceX is claiming it. Unfortunately they don't release data, but you have to think they have people looking it over.

That said, NASA might not be impartial, but they are (for the most part) strict when it comes to safety (a few exceptions there). I trust that they'll review the data fairly before allowing any flights to ISS.

yes, there are 17 known exceptions to the rule of safety in NASA. :tiphat:

also much worse is whenever NASA mixes with business.

 

[N_Molson]

NASA is the third biggest investor into SpaceX after Musk and Google. Its hardly impartial by now.

This is still, again and again the biggest misunderstanding in this affair : SpaceX is not designed to be a NASA competitor. The whole idea of the COTS program was precisely to unload NASA of "domestic" tasks like ferrying people to LEO, so that it can focus on a manned Mars program and robotic missions (two sectors probably equally important). And - on background - ULA deals with the defense-related programs. The current situation in the USA is, to sum up, the following, and I don't see why its difficult to understand :

NASA : Science, R&D (partnerships with Universities & Engineering schools, "sub-offices" like the excellent JPL), Space Exploration, Robotic Missions.

COTS (SpaceX, but also others) : ISS resupply (cargo and crews) in order to avoid the (very) embarassing dependance on Russia, commercial satellites, space tourism (including suborbital flights, maybe later specific small stations aka "space hotels", etc...) and other activities in LEO.

ULA : works with NASA for robotic missions launch and deployment, with the Air Force for all defense-related program (X-37B, classified "communications" satellites...).

And it seems to me it makes sense that way. But for some reason, people keep getting overenthusiast over SpaceX achievements. Because they have a very agressive maketing and PR service. But I don't see why this "branch" of the space program would be more exciting than the others. Well than the space exploration one at least, as defense satellites are not over-exciting things.

Notice that while we speak, New Horizons is currently reaching Pluto. We are finally going to see how it looks like, and scientists will gather precious data that could really help knowing better how objects get ejected from the Oort cloud and what kind of minerals (potential ressources in a far future) are really there. That's pretty cool, no ?

 

[Donamy]

I think it would be possible to have the helmets of the astronauts automatically secured in the case of an abort, with something like the HANS device that NASCAR uses now.

[ame="http://en.wikipedia.org/wiki/HANS_device"]HANS device - Wikipedia, the free encyclopedia[/ame]

 

[RGClark]

They can't. The Trunk puts the center of drag behind center of mass. That's why it didn't tumble until AFTER trunk jettison.

You might have to jettison the trunk to do it while the thrusters are still firing.

Bob Clark

 

[Urwumpe]

I think it would be possible to have the helmets of the astronauts automatically secured in the case of an abort, with something like the HANS device that NASCAR uses now.

HANS device - Wikipedia, the free encyclopedia

That only works if you only need to rotate your head. This is not really a good option in a spacecraft. For example during an pre-launch abort, you might have to leave your seat quickly and want to avoid the extra time for releasing the HANS.

If you have a couch like in Soyuz, a lot of the trouble can be avoided, but at the price that a part has to be customized for you and has to move with you if you take another seat.

There is no perfect solution, its always a compromise between the many risks and risk reductions. But then, its always better to start at the cheap solutions. A small software patch is expensive in absolute terms, but cheap over the whole life cycle.

 

[Astro SG Wise]

"I doubt that this would not kill astronauts by breaking their neck." This may or may not be true. It does look pretty crazy, but the astronauts can barely move their neck in that helmet as it is anyway, let alone having their helmet secured to the seat. Secondly, I agree with who said it first. The tumbling reminds me of any number of random roller coaster theme rides. Either way, they have a much better chance of survival than sitting on the rocket :lol:.