Blue Origin Thread (merged)

[JoCRaM]

The main goal is achieve reusability, once spacex achieve that, then the ratio of possible failure will drop considerably.

Is like I said before, you will feel more secure flying in a 747 that fly often, or in a new 747 which never was in the air?

That is the thing that happen with rockets right now, there is not way to fully tested them (also is very expensive even try to test them to reduce chances of failure), until you dont press the launch button nobody knows.

It was a second stage failure, I though Mr Musk had abandoned plans to reuse those.

[softweir]

The first stage's nine Merlin 1D engines keep firing at least 8 seconds after the first signs of structural damage/collapse. I know that, whilst most rockets have an onboard computer at the top that controls all the stages underneath, the F9 also has a computer inside its first stage, so that it can reenter and land on the ASDS. However, shouldn't the second stage computer have informed the first stage one about the failure, so that it would cut its engines? Could this be a sign that the two computers weren't communicating with each other?

Assuming that the two computers do communicate and that there are any known failure modes that the second stage computer can report to the first stage, that still doesn't guarantee that the SpaceX engineers had predicted the exact failure mode we saw, which they would have to do in order to program the 2nd stage computer to initiate an abort.

What we can be certain of is that the engineers will have been very conservative in choosing which (if any) failure modes trigger an abort, because of the very serious danger that they will create too many false-positives and thus generate more failures than they save. It's a nuisance if they lose a 1st stage (one that they *might* have been able to salvage *if* it landed on the barge) due to an upper stage failure, but it's BAD if they lose a payload because their computers aborted due to an "imaginary" failure!

It is quite likely the engineers chose to NOT preprogram in any abort modes once Q_max has passed. The only reason to abort a rocket is to save lives, ie people on the ground or flying the rocket. In a case like this of an unmanned rocket, they only have to worry about people on the ground, and once a rocket has gone supersonic it is so high and going so fast that a RUD event is as good as a detonation for protecting groundlings' lives - it *will* break up into small bits that *will* fall on water, not on vulnerable communities.

Once they are flying passengers things will be very different: they will have many failure modes programmed to cause aborts, all with the aim of getting the Dragon capsule away from any big, bad booms and safely down to Earth. But until then, they are unlikely to bother with post-Q_max aborts, there's no point and they could be counter-productive.

EDIT:

Not saying it happened, but what would one see in a thermal image if an anti-missile laser system were targeting during the boost trajectory? At that altitude, would there be any florescence or scatter of beam energy evident?

This is sci-fi unlikely. It's hard enough targeting a camera at a flying rocket, but aiming a laser with such precision that it can burn through the rocket is orders of difficulty harder.

If there *had* been a laser targeting the rocket, then on infrared we would have seen the rocket itself light up ahead of the exhaust trail for several seconds before it went boom. This is because it would take time for the laser to heat up the skin of the rocket sufficiently to cause structural failure. There might have been atmospheric heating effects, but we would not have seen them because the laser would be sweeping rapidly through the air, never heating any bit of air for long enough for us to see it.

Edited June 29, 2015 by softweir
Answering another post.

[Frida Space]

Thanks ^^.

Not saying it happened, but what would one see in a thermal image if an anti-missile laser system were targeting during the boost trajectory? At that altitude, would there be any florescence or scatter of beam energy evident?

Adding to what softweir already said, we have indications of faulty readings in the second stage (= we know that something went wrong inside the rocket), so there is no point in even investigating if the launch could have somehow been sabotaged. If there had been a LV failure and all telemetry/internal readings were 100% fine, then you could start looking into that hypothesis, but this is not the case.

[Kryten]

We'd also have noticed the YAL-1 being pulled out of storage and orbiting near the launchpad, given it's the only thing with that kind of capability yet built.

[RW-1]

I guess the 1st stage is so powerful that it can't be easily influenced by the stuff on top of it.

The leaking LOX theory is quite popular here. Assuming it is true what caused the LOX tank to break? The rocket passed the max-Q mark so the reason couldn't be aerodynamic stress. Was it the high TWR of the nearly empty 1st stage crushing struts in the 2nd stage? Was it the preparations for 2nd stage activation? Did the payload come loose as some people in this forum think? Mechanical failure? Software problem?

From what I can see in the videos first there's a cloud coming from the top of the 1st stage or from the 2nd stage. Then the second stage seemed to receive a lot of damage, the Dragon capsule came loose. Then the cloud seems to explode and shortly after that the whole rocket was kerbalized by aerodynamic forces.

I can't image what caused the tank to break which led to this tragic outcome.

It's not a "leaking LOX theory", it's an observation of the cloud that was the first sign of something amiss in the video, myself and others commented that it appeared that we had a 2nd stage breech of a tank, so we were looking at a tank rupture. this seemed even more likely with Mr. Musk's tweet about an overpressure event in the 2nd stage prior to the mishap.

A theory existed that Payload in the trunk got loose and dropped during acceleration onto the top of the 2nd stage and ruptured it, however that doesn't explain the overpressure anomaly readings.

Unless the datasets can reveal something else, this could be several issues for them to resolve (all speculation here):

1. What caused the overpressure in the tank, this is the main one to figure out.

2. Was there a relief valve that could have vented the excess pressure and if so, why didn't that function?

3. Was there a faulty weld (or other manufacturing defect) on the tank? I include this here because while the overpressure was stated, thus we can assume it factual, what we don't know is if the tank could have held that pressure.

(the answer here is muddled, obviously it failed, however was that because #2 failed to relieve said pressure, or the defect caused the failure where without that, the tank may have held together thru 2nd stage ignition and the pressures would have began dropping during 2 stage operation ...

it will be fun watching what they give us as they investigate.

[Mazon Del]

This is sci-fi unlikely. It's hard enough targeting a camera at a flying rocket, but aiming a laser with such precision that it can burn through the rocket is orders of difficulty harder.

If there *had* been a laser targeting the rocket, then on infrared we would have seen the rocket itself light up ahead of the exhaust trail for several seconds before it went boom. This is because it would take time for the laser to heat up the skin of the rocket sufficiently to cause structural failure. There might have been atmospheric heating effects, but we would not have seen them because the laser would be sweeping rapidly through the air, never heating any bit of air for long enough for us to see it.

For anybody that has invested the resources into actually having an IR laser capable of mucking around with missile launches, that precision is actually not that hard to get. Mostly just a money problem. The airborne laser system had many problems, but precision was never (publicly) one of them.

Your info about the effects of the laser is pretty much true. Regardless of possible visibility of the beam itself in flight, you would have seen a very telltale signature on the craft itself for like 5-10 seconds beforehand.

[Nuke]

I guess the 1st stage is so powerful that it can't be easily influenced by the stuff on top of it.

The leaking LOX theory is quite popular here. Assuming it is true what caused the LOX tank to break? The rocket passed the max-Q mark so the reason couldn't be aerodynamic stress. Was it the high TWR of the nearly empty 1st stage crushing struts in the 2nd stage? Was it the preparations for 2nd stage activation? Did the payload come loose as some people in this forum think? Mechanical failure? Software problem?

From what I can see in the videos first there's a cloud coming from the top of the 1st stage or from the 2nd stage. Then the second stage seemed to receive a lot of damage, the Dragon capsule came loose. Then the cloud seems to explode and shortly after that the whole rocket was kerbalized by aerodynamic forces.

I can't image what caused the tank to break which led to this tragic outcome.

decreasing air pressure with altitude perhaps? could be a relief valve or something stuck shut so it couldn't release the boiloff o2, which would have explained the overpressure event. the difference in pressure between the tank contents and the outside environment could have caused it to rupture. helped along further if the caps were poorly designed and there was some cracking due to the launch. from the video it looks like the tank blew out.

[AngelLestat]

It was a second stage failure, I though Mr Musk had abandoned plans to reuse those.

If you read the last Elon musk interviews his goal still is fully reusability, for now he is focus in the first stage only.. But he knows that it needs both stages and fast reusable to accomplish huge prices drop.

[sojourner]

He's said in recent interviews that reuse of the F9 second stage is off the table. SpaceX is still planning for full reuse on the BFR.

[Mitchz95]

I'm betting the second explosion is range safety charges... Uniform flames.

They said

that there was no destruct signal sent, and that the second "explosion" was probably due to aerodynamic stress.

[sndrtj]

M-Vac, short for Merlin-Vacuum, the 2nd stage engine of the Falcon 9, they basically cool everything off before it begins running since its a cyrogenic engine.

I'm just wondering, how do they chill something to cryogenic temperatures when a few instants later there's a - i expect extremely hot - flame coming out of it?

[Mazon Del]

I'm just wondering, how do they chill something to cryogenic temperatures when a few instants later there's a - i expect extremely hot - flame coming out of it?

They were prechilling the second stage engine which had not yet fired. So far it had been first stage only.

[sndrtj]

There's a change in design, basically you can't combine them.

My suggestion is to tighten (or increase) QC for the rocket and the rocket parts. Say, if every process is bound to 95% success, then an additional process (which the rule apply) will at least remove 95% from that 5% - leaving you with 0.25% chance of going wrong. Hope SpaceX and everyone else is learning out from this - maybe the shuttle did the same (24/25 success rate, then increased to 109/110 success rate).

That's probably ineffective. In basically any field, roughly 80% of problems are easily fixed by targeting the low-hanging fruit. Those remaining 20% are your bigger problem. You're going to have to spend ever increasing amounts of effort for just a tiny reward. If you were to plot effort spend vs success rate, it's probably going to be a curve that's asymptotically approaching 100%.

There is going to be a point at which further QC is more expensive in any terms than just having the occasional failure every now and then.

[Fel]

The main goal is achieve reusability, once spacex achieve that, then the ratio of possible failure will drop considerably.

Is like I said before, you will feel more secure flying in a 747 that fly often, or in a new 747 which never was in the air?

Would you feel more secure flying in a 747 that has more duct tape holding it together than nuts and bolts due to budget cuts and supervisors caring more about meeting time schedules than passenger safety, or a new 747. It's all fun and games to say "Old and Tried is better" but everytime that 747 lands it is "suppose to" be given a through field check and any problems are "suppose to" ground the flight until fully repaired. Airline regulations are "suppose to" treat every "Old and Tried" 747 exactly like a "New and Unpredictable" 747.

It doesn't matter if we get re-usability or not, it astonishes me still that we knew that Apollo 13 had problems and we STILL launched it despite knowing those problems existed because we had to stick to time schedules and decided a little "duct tape" would suffice. Unless we get better work ethic, we'll always have failure; and as failure is calculated as such (1 - 0.99999^n) where n is the number of systems that can go wrong and weren't checked in triplicate, the greatest cause for failure is not having enough time/money/manpower to sufficiently lower n.

Re-usability is akin to landing that 747 and saying "this hunk of metal is as sturdy as the titanic" then realizing a loose bolt, which should have been caught, is what caused the crash after it took off without being inspected. Even if reusable, the rocket will be stripped down to parts, fully tested (ideally, in practice probably not, have to keep that insurance premium up) then reassembled with worn parts replaced. The rocket is the same as a brand new rocket (which is good) instead of an old used rocket, protective layers failing, with a 90% failure rate.

[Albert VDS]

Why would you need to disassemble the first stage, check the components and resemble with possible new parts?

Wouldn't a static fire and all the sensors in rocket be enough?

[r4pt0r]

Well SpaceX cant launch for a few months now right? That works for me as I am a fan of ULA.

[Mazon Del]

And of course, on the discussion of 100% reliability rates, there is the issue of the unknown unknowns. You can only solve problems you are aware, or can conceive, exist. You might have quintuple checked every piece of hardware and interaction it may have with every other piece of hardware. The software might have proven itself in hundreds of thousands of software simulations and many thousands of real tests. But if a bird flies right above that rocket and punches a hole in it...well, all that effort was for naught now wasn't it?

- - - Updated - - -

Well SpaceX cant launch for a few months now right? That works for me as I am a fan of ULA.

That is a fair opinion to have, but I am admittedly quite curious, what makes you a fan of the ULA over someone like SpaceX, Blue Origins, etc?

[Kryten]

Well SpaceX cant launch for a few months now right? That works for me as I am a fan of ULA.

ULA manifest is full anyway, this doesn't help them.

[Soda Popinski]

I'm just wondering, how do they chill something to cryogenic temperatures when a few instants later there's a - i expect extremely hot - flame coming out of it?

Typically, the rocket is cooled by running the fuel / oxidizer through tubing in the bell. That continues while the rocket is firing.

[softweir]

Would you feel more secure flying in a 747 that has more duct tape holding it together than nuts and bolts due to budget cuts ...

Very unhappy. But that's at the extreme opposite end of the spectrum of quality control and expense that we are discussing, so not really relevant to the discussion.

[r4pt0r]

That is a fair opinion to have, but I am admittedly quite curious, what makes you a fan of the ULA over someone like SpaceX, Blue Origins, etc?

Well Lockheed Martin I have loved since I watched a series of documentaries on them, about Skunkworks and their X-plane programs. Also the military craft they've created I absolutely adore(my namesake the F-22, the F-117, the smooth looking F-16 is a cutie as well). I also later found out that my grandpa who was an air force mechanic in Vietnam, worked on the SR-71 when he was stateside postwar.

The Boeing B-17 is one of my favorite planes of all time, and was the one that got me into RC planes.

But beyond simple nostalgia for the aircraft that captured my imagination, I have a soft spot for big corporations who cooperate in the name of profit.

I do find the almost religious support for SpaceX a little strange. I would ask the same question back, "What makes you a fan of SpaceX?"

[Lukaszenko]

I think SpaceX has its fans because it's not a big corporation just going after profit, but it's a man following a dream (or at least it seems like it). The fact that a lot of people (especially on this forum) share in that dream, certainly also helps.

Edited June 29, 2015 by Lukaszenko

[softweir]

You didn't ask me, but I'll give my answer anyway:

SpaceX have rocked the boat and have made other corporations look to see if they are playing their best game. When mega-corporations have divided a market up between them they tend to settle into very similar ways of doing business which aren't, necessarily, the best ways to progress technology. Any kind of outside competition makes them get a bit more imaginative, which generally (not always, but usually) is for the good. If nothing else, it will make the executives lend a more favourable ear to any out-of-the-box ideas that come up from the R&D departments.

The BIG thing I like about SpaceX is that they are committed to reusability in space launches, and have come very close to making the dream of affordably reusable low-mass launchers look very much more plausible than ever. I have no idea if their ideals are realistic, but they are trying, and creating new technologies in the process. It makes space fun again, in a way that has been lacking since the retirement of the space shuttle.

Whether SpaceX manage to change the game and if they survive the process is unforeseeable. But they are making interesting waves.

[Nibb31]

The fanboyism is annoying, whether its for SpaceX, Apple, Ford or your favorite washing powder. These are corporations, not football teams.

[sojourner]

Even if reusable, the rocket will be stripped down to parts, fully tested (ideally, in practice probably not, have to keep that insurance premium up) then reassembled with worn parts replaced. The rocket is the same as a brand new rocket (which is good) instead of an old used rocket, protective layers failing, with a 90% failure rate.

Not even close.