Blue Origin Thread (merged)

[tater]

Unlikely.

[kerbiloid]

Just a speculation.

The pre-explosion "bang" event clearly shows that some mechanical or structural part has crashed after LOx fueling but before the test. (Maybe when got frozen, like with Challenger)
So, probably they have a problem with 2nd stage structural stability and are intensively researching if the 2nd stage still can be used at all or it needs a deep redesign.

[Nibb31]

10 minutes ago, kerbiloid said:

Just a speculation.

The pre-explosion "bang" event clearly shows that some mechanical or structural part has crashed after LOx fueling but before the test. (Maybe when got frozen, like with Challenger)

No it doesn't. The noise likely came from the scrapyard where the camera was located. It would have to have been a pretty spectactular mechanical failure to be nearly as loud as the actual explosion from 6 km away.

 

 

[monophonic]

5 hours ago, StrandedonEarth said:

How's this for a theory: A piece or fitting on the GSE became embrittled after repeated exposure to super-chilled LOX, or embrittled faster than expected.

That's my pet hypothesis. But then I am a random dude on the Internet, so don't forget the grain of salt with that.

[YNM]

What kind of tank construction do they adopt for the second stage ? Is it nearing a baloon tank ? Could they, uh... fit Centaur on it ?

[Kartoffelkuchen]

2 hours ago, YNM said:

What kind of tank construction do they adopt for the second stage ? Is it nearing a baloon tank ? Could they, uh... fit Centaur on it ?

No they can't fit a centaur on F9. Centaur is massively underpowered to compensate for gravity losses due to early S1 seperation for its recovery, that's why the second stage is that overpowered. 

[Jovus]

Given what we know (which is practically nothing) I suspect the problem didn't have much to do with the rocket itself, but rather probably originated in the launch facilities.

Which is to say that's a wild guess based on the fact that they have no data.

Too bad we'll probably never know.

[Mitchz95]

Update.

Quote

September 23, 1:00pm EDT

Three weeks ago, SpaceX experienced an anomaly at our Launch Complex 40 (LC-40) at Cape Canaveral Air Force Station. This resulted in the loss of one of our Falcon 9 rockets and its payload.

The Accident Investigation Team (AIT), composed of SpaceX, the FAA, NASA, the U.S. Air Force, and industry experts, are currently scouring through approximately 3,000 channels of engineering data along with video, audio and imagery. The timeline of the event is extremely short – from first signs of an anomaly to loss of data is about 93 milliseconds or less than 1/10th of a second. The majority of debris from the incident has been recovered, photographed, labeled and catalogued, and is now in a hangar for inspection and use during the investigation.

At this stage of the investigation, preliminary review of the data and debris suggests that a large breach in the cryogenic helium system of the second stage liquid oxygen tank took place. All plausible causes are being tracked in an extensive fault tree and carefully investigated. Through the fault tree and data review process, we have exonerated any connection with last year’s CRS-7 mishap.

The teams have continued inspections of LC-40 and the surrounding facilities. While substantial areas of the pad systems were affected, the Falcon Support Building adjacent to the pad was unaffected, and per standard procedure was unoccupied at the time of the anomaly. The new liquid oxygen farm – e.g. the tanks and plumbing that hold our super-chilled liquid oxygen – was unaffected and remains in good working order. The RP-1 (kerosene) fuel farm was also largely unaffected. The pad’s control systems are also in relatively good condition.

SpaceX’s other facilities, from the Payload Processing Facility at the Cape, to the pad and hangar at LC-39A, are located several miles from LC-40 and were unaffected as well. Work continues at Pad 39A in preparation for bringing it online in November. The teams have been in contact with our Cape Canaveral and Kennedy Space Center partners and neighbors and have found no evidence of debris leaving the immediate area of LC-40.

At SpaceX headquarters in Hawthorne, CA, our manufacturing and production is continuing in a methodical manner, with teams continuing to build engines, tanks, and other systems as they are exonerated from the investigation. We will work to resume our manifest as quickly as responsible once the cause of the anomaly has been identified by the Accident Investigation Team. Pending the results of the investigation, we anticipate returning to flight as early as the November timeframe.

Other efforts, including the Commercial Crew Program with NASA, are continuing to progress. Getting back to flight safely and reliably is our top priority, and the data gathered from the present investigation will result in an even safer and more reliable vehicle for our customers and partners.

Not much in the way of new information, but good to hear it's not related to the CRS-7 incident.

Edited September 23, 2016 by Mitchz95

[Kryten]

7 minutes ago, Mitchz95 said:

Not much in the way of new information, but good to hear it's not related to the CRS-7 incident.

That's only if you assume SpaceX's analysis of CRS-7 found the right cause, which NASA among others aren't certain of. It does seem to be something in oxygen tank helium system, so it would be consistent with the alternate explanations of the CRS-7 incident.

[DerekL1963]

29 minutes ago, Mitchz95 said:

Not much in the way of new information, but good to hear it's not related to the CRS-7 incident.

Falcon's second stage has a higher proportion of total performance than is considered optimal because the first stage has to reserve delta-V for flyback and recovery.  Without a doubt this impacted the design.  And so a second failure in the second stage's helium system (even if unrelated to CRS-7) is... troubling.

[CatastrophicFailure]

Is it "normal" for helium pressurant tanks to be located inside a fuel (oxidizer) tank like that? Would it be a significant amount of reengineering to simply move the helium tanks outside? Tho I suppose that really wouldn't make much difference. 

[_Augustus_]

On 9/20/2016 at 9:14 AM, Kartoffelkuchen said:

No they can't fit a centaur on F9. Centaur is massively underpowered to compensate for gravity losses due to early S1 seperation for its recovery, that's why the second stage is that overpowered. 

Just curious, what if you put a Centaur on TOP of the second stage? How much more payload to LEO would that bring?

[CatastrophicFailure]

6 minutes ago, _Augustus_ said:

Just curious, what if you put a Centaur on TOP of the second stage? How much more payload to LEO would that bring?

None, since with those extra two or three tonnes, the Falcon couldn't get off the ground without a reduced payload. 

[Tristonwilson12]

16 minutes ago, _Augustus_ said:

Just curious, what if you put a Centaur on TOP of the second stage? How much more payload to LEO would that bring?

Centaur is 12 meters in height... the Falcon 9 fairing is 13 meters tall.... You really couldn't launch anything on top of the centaur so basically you would be launching a 45,000 Pound (fueled) Payload (the centaur).... Which Would barely get you to LEO.. (falcon 9 Can get about 50,000 pounds to LEO)..

Edited September 23, 2016 by Tristonwilson12

[_Augustus_]

10 minutes ago, CatastrophicFailure said:

None, since with those extra two or three tonnes, the Falcon couldn't get off the ground without a reduced payload. 

Falcon Heavy?

[magnemoe]

12 minutes ago, CatastrophicFailure said:

Is it "normal" for helium pressurant tanks to be located inside a fuel (oxidizer) tank like that? Would it be a significant amount of reengineering to simply move the helium tanks outside? Tho I suppose that really wouldn't make much difference. 

Not sure how common it is. 
Most common to put the pressure tanks down by the engines, its no room at top or between on falcon 9 second stage and many other stages. but with the huge vacuum engines its plenty of room at the sides. 
benefit of tank in tank is simpler piping, unlikely to be an error source by it self, an leak would also give over pressure in tank before exploding. 

 

1 hour ago, Kryten said:

That's only if you assume SpaceX's analysis of CRS-7 found the right cause, which NASA among others aren't certain of. It does seem to be something in oxygen tank helium system, so it would be consistent with the alternate explanations of the CRS-7 incident.

Analyze made sense, happened on high g load and the struts was way weaker than specified. As I remember some indications the tank hit the top of oxygen tank too. 
However its hard to be sure with no parts to analyze. 

[sojourner]

Considering all of the headaches the helium system has had over the years, I bet Musk is regretting using it. Or at least looking for a better helium system engineer.

[Kartoffelkuchen]

1 hour ago, _Augustus_ said:

Falcon Heavy?

That would already make much more sense.

3 F9 cores, a Centaur on top. I don't have any numbers now for reference, but the second stage of Falcon Heavy doesn't need to do as much work as Falcon 9's, since the seperation velocity and altitude is much greater on Heavy than on F9, and since FH is really designed to launch heavy birds to GTO, GEO, Escape trajectories, transfer orbits, Centaur makes much much more sense. Due to it's insanely high Isp you could probably double the payload to like Mars.. but yeah, we'll see what the Raptor will bring!

[DerekL1963]

2 hours ago, CatastrophicFailure said:

Is it "normal" for helium pressurant tanks to be located inside a fuel (oxidizer) tank like that? Would it be a significant amount of reengineering to simply move the helium tanks outside? Tho I suppose that really wouldn't make much difference. 

It was done at least as far back as the S-IV stage of the Saturn I, so it's not exactly a "new" way of doing things.   And yes, it would take significant engineering to move them - the whole reason they're there is because cooling the helium down to cryogenic temperatures lets them put more of it in smaller and lighter tanks than would be required if the helium system were at ambient temperatures.

[_Augustus_]

50 minutes ago, Kartoffelkuchen said:

That would already make much more sense.

3 F9 cores, a Centaur on top. I don't have any numbers now for reference, but the second stage of Falcon Heavy doesn't need to do as much work as Falcon 9's, since the seperation velocity and altitude is much greater on Heavy than on F9, and since FH is really designed to launch heavy birds to GTO, GEO, Escape trajectories, transfer orbits, Centaur makes much much more sense. Due to it's insanely high Isp you could probably double the payload to like Mars.. but yeah, we'll see what the Raptor will bring!

I'm going to try to fly that in KSP and see what happens. 

[Kryten]

 You'd have to make major mods to the pads to support an LH2 stage like Centaur. I don't think ULA can sell stages to third parties anyway, the joint venture agreement that created ULA is pretty restrictive.

Edited September 23, 2016 by Kryten

[CatastrophicFailure]

2 hours ago, _Augustus_ said:

Falcon Heavy?

Again, not if you want more payload to LEO. If you want to go interplanetary like @Kartoffelkuchen said, it might be useful, but if you add fuel to the top of the rocket, you have to add thrust to the bottom to get it off the pad. Try it in KSP, make a simple 2 stage rocket + payload with a starting TWR of 1.1-1.2 (I think that's similar to F9). Size it so the payload just barely makes orbit. Then clone the second stage and make it a third stage and see what happens. 

Tyranny of the rocket equation.  

37 minutes ago, DerekL1963 said:

It was done at least as far back as the S-IV stage of the Saturn I, so it's not exactly a "new" way of doing things.   And yes, it would take significant engineering to move them - the whole reason they're there is because cooling the helium down to cryogenic temperatures lets them put more of it in smaller and lighter tanks than would be required if the helium system were at ambient temperatures.

Ah, ok. That puts some perspective to it, thanks. 

[Kartoffelkuchen]

36 minutes ago, Kryten said:

 You'd have to make major mods to the pads to support an LH2 stage like Centaur. I don't think ULA can sell stages to third parties anyway, the joint venture agreement that created ULA is pretty restrictive.

Yeah  ok well, I was just referring to the actual performance of the configuration, not about the feasibility.

 

@CatastrophicFailure I can 100% agree to what you said, just remember one thing:

SpaceX plans to increase thrust of their Merlin 1D Full Thrust engines *again*, by about 12% as far as I know, which would increase it's TWR from about 1.2 (maybe 1.15) to ~1.4, so G losses would actually be reduced, meaning that you could put a 3rd stage on a Falcon 9 plus a "resonably" sized payload I guess,  while still being able to recover the first stage (only ballistic downrange landing) and not going expendable with it. Would only make sense for interplanetary missions, such as launching a Mars probe or something. But yeah...it's a little thought experiment only.

[YNM]

On 9/20/2016 at 8:14 PM, Kartoffelkuchen said:

No they can't fit a centaur on F9. Centaur is massively underpowered to compensate for gravity losses due to early S1 seperation for its recovery, that's why the second stage is that overpowered. 

I kind of wrongly worded it (though if it could works, maybe it can save a few months ?)... My question : is F9's second stage close to Centaur, on structural terms ? I mean, for something to just broke by the cyrogenics surely some structural parts aren't working by the way it was intended to work (which, in this case, not much different than any other stage bar old Atlas and Centaur) right ?

[DerekL1963]

11 minutes ago, YNM said:

I mean, for something to just broke by the cyrogenics surely some structural parts aren't working by the way it was intended to work (which, in this case, not much different than any other stage bar old Atlas and Centaur) right ?

It wasn't "just broke by cryogenics" - it was blown apart by a near explosive internal event.  I don't think there's ever been, or ever will be, a flight worthy booster than can withstand severe overpressure of it's tankage.



This is what was left of a S-IVB stage after an external helium tank ruptured and tore the stage apart.

Edited September 24, 2016 by DerekL1963
Add picture and description of S-IVB failure.