Space Ship Two crashes during test flight

Space Ship Two has crashed on a test flight. Seems like the hybrid motor had a destructive failure a few seconds after ignition. Apparently at least one, if not both, of the tailbooms were blown off.

One pilot got out and got his chute open. The other apparently could not get out before the main fuselage hit (has a side hatch, no ejection seats. Major problem trying to get out of a spinning/tumbling aircraft).

https://www.nbcnews.com/storyline/v...spaceshiptwo-crashes-1-dead-1-injured-n238376

Update - I have heard a first-hand eyewitness story on Space.com by an aerospace pro which indicates that both pilots got out, he got to the location where the deceased pilot landed. But the pilot who died was still in his seat. If true, that he was in a seat, rather than being an issue of getting out of the fuselage, the cockpit area may have broken off or broken up, since there's no ejection seats, and no way to get out of the side hatch while buckled into a seat. That eyewitness account of what he saw on the ground could also imply why the surviving pilot has such serious injuries (I'm glossing over a non-vehicle related piece of info that is better off not mentioned in detail).

- George Gassaway

I just read this on another news service. Easy to forget the risks our pioneers take...

Kevin

Heard that on the Radio on my way home from the Hobby Shop. Bummer.

White Knight 2, the aircraft that carries Space Ship 2, landed unharmed.

Condolences to the family of one of the test pilots.

Greg

Understand they were testing a new engine and/or fuel.

very sad news and week for space industries. i read they were using eopxy reloads??


Gesendet von meinem iPad mit Rocketry Forum

davel said:

Understand they were testing a new engine and/or fuel.

Click to expand...

It uses a Hybrid engine. Solid fuel, gaseous oxidizer. They changed the solid fuel from HTPB rubber-based to a plastic based solid. Today was the first flight to fire that engine.

https://en.wikipedia.org/wiki/RocketMotorTwo#2014_Change_of_fuel

"In May 2014, Virgin Galactic announced a change to the fuel to be used in the SpaceShipTwo rocket engine. Rather than the rubber-based HTPB—HTPB engines had experienced serious engine stability issues on firings longer than approximately 20 seconds—the engine will now use a type of plastic called thermoplastic polyamide as the solid fuel. The plastic fuel is projected to have better performance (by several unspecified measures) and will allow SpaceShipTwo to make flights to a higher altitude.[15][16][17]

As of May 2014, the new engine formulation has already completed full-duration burns of over 60 seconds in ground tests on an engine test stand.[16] However, four additional ground tests of the polyamide-fueled engine are anticipated before the SpaceShipTwo flight test could resume with the new-fuel rocket motor.[17]"


One detail I forgot to add to the first post, the pilot who survived has serious injuries, no details.

A reporter who has been extremely close to the project since the early Space Ship One days, feels even without an accident that this engine was not going to be able to perform well enough to boost it high enough to get into "space".

There have been many aircraft programs thru the years where a great design was crippled by an engine that never lived up to its performance goals.

The "engine testing" is supposed to be done on the ground to confirm the engine is reliable and safe. I wonder, now, if the hybrid at 50,000 feet has some reliability issues that ground testing could not detect. It would call for the use of a vacuum chamber, which do exist for testing engines but those facilities are very expensive and only the military/NASA have them.

- George Gassaway

Wow, major space double-whammy this week. New fuel or not, this brings the reality of spaceflight into full view....it's dangerous! And making it routine will be hard...especially for the 6hr joyrides Virgin has planned. I bet some of those folks who signed up for seats on the first flight (or any early flight, for that matter) might be second guessing themselves.

slowly I just wonder the economics vs technology in the Branson project. Rutan is gone too. I read they have trouble with staffs leaving. Hmmmm hopefully the poor pilots were not forced to fly because of some need for good news.. for Mr Branson?

By the way, injecting liquid plastic in an hybrid is a very interesting issue for us rocket and motors builders.

Gesendet von meinem iPad mit Rocketry Forum

The press conference lasted 15 minutes. No new details were released. Next press conference tomorrow. Late morning or early afternoon PDT.

NTSB and Branson will arrive very early tomorrow AM. NTSB will head investigation.

Bob

There is no back-up for Space Ship 2. It was the only one.

legranddudu said:

slowly I just wonder the economics vs technology in the Branson project. Rutan is gone too. I read they have trouble with staffs leaving. Hmmmm hopefully the poor pilots were not forced to fly because of some need for good news.. for Mr Branson?

By the way, injecting liquid plastic in an hybrid is a very interesting issue for us rocket and motors builders.

Gesendet von meinem iPad mit Rocketry Forum

Click to expand...

Bert Rutan is 71. He retired and turned the reins over to the next generation. Most of the serious work is being done by engineers in their 20's and 30's.

No test pilot is ever force to do anything. Their not suicidal or stupid. If they were, they would not have survived long enough to become a test pilot.

The propellant composition was changed to obtain better performance. https://www.rocketryforum.com/showt...shes-during-test-flight&p=1374087#post1374087

The propellant is a solid polyamide plastic instead of solid HTPB rubber. It is not a liquid. It was ground tested many times. Today's flight was the first flight test with the new propellant.

Bob

Bob, what does "The plastic fuel is projected" means, to your opinion? if this is not a liquid (pre-heated?) form, as you say, how could this work? any ideas?

on the political side I am always suspicious when science must serve show-bizz ....after 7 years of postponing, Mr Branson shall be under terrible pressure, don't you think?


Gesendet von meinem iPad mit Rocketry Forum

The polyimide fuel is a thermoplastic which I assume means it can be injection molded into a complex solid fuel grain geometry. I believe many Hypertek and SkyRipper hybrid solid fuel grains are/were injection molded thermoset plastics.

The words "projected to have better performance" means "predicted to have better performance" or "anticipated to have better performance" in the context of the quotation.

Bob

legranddudu said:

Bob, what does "The plastic fuel is projected" means, to your opinion? if this is not a liquid (pre-heated?) form, as you say, how could this work? any ideas?

on the political side I am always suspicious when science must serve show-bizz ....after 7 years of postponing, Mr Branson shall be under terrible pressure, don't you think?


Gesendet von meinem iPad mit Rocketry Forum

Click to expand...

In the sentence, "The plastic fuel is projected to have better performance...," the word "projected" means "estimated" or "forecast." In other words, they think the plastic fuel will probably have better performance.

EDIT: Bob beat me to it...

This is really sad news.

I project that Branson is done (with this venture). Although his huge ego will make it hard to admit defeat he is probably going to have trouble with financing. Although he is wealthy this venture needs lots of cash which requires outside financeers. He is going to need a lot more cash now because the FAA is going to require much much more ground testing and certification. Hugh cash sink. Too bad.

Next up. Jeff Bezos.

I hope there is enough data that they can piece together the cause and remedy the problem.

We have had severe reminders this week of why it is called "rocket science" and why spaceflight is far from "routine".

Greg

georgegassaway said:

It uses a Hybrid engine. Solid fuel, gaseous oxidizer. They changed the solid fuel from HTPB rubber-based to a plastic based solid. Today was the first flight to fire that engine.

https://en.wikipedia.org/wiki/RocketMotorTwo#2014_Change_of_fuel

"In May 2014, Virgin Galactic announced a change to the fuel to be used in the SpaceShipTwo rocket engine. Rather than the rubber-based HTPB—HTPB engines had experienced serious engine stability issues on firings longer than approximately 20 seconds—the engine will now use a type of plastic called thermoplastic polyamide as the solid fuel. The plastic fuel is projected to have better performance (by several unspecified measures) and will allow SpaceShipTwo to make flights to a higher altitude.[15][16][17]

As of May 2014, the new engine formulation has already completed full-duration burns of over 60 seconds in ground tests on an engine test stand.[16] However, four additional ground tests of the polyamide-fueled engine are anticipated before the SpaceShipTwo flight test could resume with the new-fuel rocket motor.[17]"


One detail I forgot to add to the first post, the pilot who survived has serious injuries, no details.

A reporter who has been extremely close to the project since the early Space Ship One days, feels even without an accident that this engine was not going to be able to perform well enough to boost it high enough to get into "space".

There have been many aircraft programs thru the years where a great design was crippled by an engine that never lived up to its performance goals.

The "engine testing" is supposed to be done on the ground to confirm the engine is reliable and safe. I wonder, now, if the hybrid at 50,000 feet has some reliability issues that ground testing could not detect. It would call for the use of a vacuum chamber, which do exist for testing engines but those facilities are very expensive and only the military/NASA have them.

- George Gassaway

Click to expand...

The engine was tested many times on the ground. Other than ignition issues, a rocket motor could care less if it is operating in space or on the ground because the chamber pressure is controlled by the mass flow thru the nozzle, not the ambient exit pressure.

There are several test facilities around the US that could do a complete flight simulation, but I can't think of a reason to do it unless you need to verify specific impulse and thrust to a greater level of accuracy than you can predict from a ground level static test.

Bob

jderimig said:

I project that Branson is done (with this venture). Although his huge ego will make it hard to admit defeat he is probably going to have trouble with financing. Although he is wealthy this venture needs lots of cash which requires outside financeers. He is going to need a lot more cash now because the FAA is going to require much much more ground testing and certification. Hugh cash sink. Too bad.

Next up. Jeff Bezos.

Click to expand...

But think back to the early days of aviation. Or in the early days of jets? Early chapters in the Right Stuff show how the test pilot world exists. There is always danger in this.

Having said that, in today's cash for results world, you may be right. I hope not!


Launching rockets (or missiles in my case) is so easy a chimp could do it. Read a step, do a step, eat a banana.

Sent from my iPad Air using Rocketry Forum.

USAFmissileer said:

But think back to the early days of aviation. Or in the early days of jets? Early chapters in the Right Stuff show how the test pilot world exists. There is always danger in this.

Having said that, in today's cash for results world, you may be right. I hope not!


Launching rockets (or missiles in my case) is so easy a chimp could do it. Read a step, do a step, eat a banana.

Sent from my iPad Air using Rocketry Forum.

Click to expand...

Yes but those were government backed endeavors not private sector backed.

jderimig said:

Yes but those were government backed endeavors not private sector backed.

Click to expand...

Very true! As I said, cash is king now! Hopefully, though, it will continue on.


Launching rockets (or missiles in my case) is so easy a chimp could do it. Read a step, do a step, eat a banana.

Sent from my iPad Air using Rocketry Forum.

bobkrech said:

The engine was tested many times on the ground. Other than ignition issues, a rocket motor could care less if it is operating in space or on the ground because the chamber pressure is controlled by the mass flow thru the nozzle, not the ambient exit pressure.

There are several test facilities around the US that could do a complete flight simulation, but I can't think of a reason to do it unless you need to verify specific impulse and thrust to a greater level of accuracy than you can predict from a ground level static test.

Click to expand...

I know they ground tested the engine, but did not make that clear in my message. In any case, the one time they fly it with the new propellant, it blows up. Now it could be a totally random thing that simply did not happen on ground tests, and just randomly happened on this flight. But odds are that it was more likely it was due to the fact it was flying in the craft at 50,000 feet and not bolted to a test stand on the ground. What, I do not know.

After all, the Space Shuttle SRB's never had any problem in ground testing. Then one failed on Challenger. Of course that was not due to the conditions of flight, but due to conditions on the ground at the time of ignition (sub-zero temperature) that had never been tested. Therefore the O-Rings didn't work as designed, eventually allowing the flame leak that led to the disaster. So there's something that was never tested when the SRB's were certified for flight. I'm not suggesting cold was the problem in this case..... BUT, again the ground tests are only valid if all conditions for flight are either tested directly, or extremely detailed and accurate calculations are made to account for all variables.

I think of another old classic rocket issue, the Saturn-V had some issues with frost on the outside of lines during ground tests, which hid lurking problems in flight in the first two flights. From the excellent book Chariots for Apollo:

https://www.hq.nasa.gov/pao/History/SP-4205/ch10-6.html

"What had happened to the S-II and S-IVB stages, with two of the five J-2 engines shutting down in one case and the single J-2 engine refusing to start in the other, was more of a mystery than pogo. During tests at Arnold Engineering Development Center, at Tullahoma, Tennessee, engineers discovered that frost forming on propellant lines when the engines were fired at ground temperatures served as an extra protection against lines burning through. But frosting did not take place in the vacuum of space; the lines could have failed because of this. Also, in the line leading to each of the engines was an augmented spark igniter. Next to the igniter was a bellows. During ground tests, liquid air, sprayed over the exterior to cool it, damped out any vibrations. Vacuum testing revealed that the bellows vibrated furiously and failed immediately after peak-fuel-flow rates began. These lines were strengthened and modified to eliminate the bellows.42"

I am not saying frost was a problem in this case. Just once again showing another example of how ground tests can hide problems when certain issues that actually happen in flight are not completely accounted for.

- George Gassaway

Sad news indeed. Many of us have seen what happens when a large AP motor fails.

Both Shuttle accidents were actually predicted by the Shuttle designers, and the conditions that occurred during both accidents were forbidden operating conditions that was ignored by Shuttle management.

1.) The launch the Challenger at the temperature on the pad was out of specification and not allowed. It was overridden and the o-ring failed because it was embrittled by the cold and shattered upon pressurization....

2.) Foam shedding from the external tank was not allowed and flights were not supposed to continue until the foam shedding was stopped because foam shedding could damage the Shuttle TPS. It kept happening and nothing happened so they kept launching until Columbia......

I previously replied to you that "Other than ignition issues, a rocket motor could care less if it is operating in space or on the ground because the chamber pressure is controlled by the mass flow thru the nozzle, not the ambient exit pressure." Now I just saw an NBC News video showing a photograph of what appeared to be a motor CATO, and according to the voiceover it occurred on ignition....... deja vu?......

https://www.dailymail.co.uk/news/ar...blows-testing-new-fuel-California-desert.html has a photo sequence.

Bob

bobkrech said:

I previously replied to you that "Other than ignition issues, a rocket motor could care less if it is operating in space or on the ground because the chamber pressure is controlled by the mass flow thru the nozzle, not the ambient exit pressure." Now I just saw an NBC News video showing a photograph of what appeared to be a motor CATO, and according to the voiceover it occurred on ignition....... deja vu?......

https://www.dailymail.co.uk/news/ar...blows-testing-new-fuel-California-desert.html has a photo sequence.

Click to expand...

Early on I heard in the news today that Space Ship Two had ejection seats, and their experts said it was impossible to safely eject and survive a fall "from space" because those experts did not have the real-time info to know yet at what point in the flight the problem happened, so they were thinking it had gotten way higher and would be re-entering. So with accuracy like that, a person saying the motor blew on ignition does not mean much...... deja vu?

I went by the words of a person who was close to Space Ship One's development and continuing to keep track of Space Ship Two. She reported in great detail that it ignited, burned for about 2 seconds, lost thrust or stopped, then started up about a second later and blew.

Even the photos you referred to back that up, look at the flame and plume big during that first 2 seconds, then wimpy, then boom. That's not a cato on ignition




How many times did the new version blow up ground testing? I can't find any info on this year's test firings (I'm sure they were done, but how many and how they went is the question).

It has blown up 100% of the time in flight testing. Well, something involved with the propulsion system failed, if not the engine casing itself. Such as possibly the nitrous tank overpressurizing and bursting, or the piping from the tank to the engine developing a major leak, causing a rapid cascade of problems. Even possibly POGO.

If it was human error in preparation, it would be ironic if they were not even more careful for an actual manned flight test than for ground tests.

So, again, it MIGHT be a RANDOM thing where it was horrible bad luck that it happened in the air and not on the ground. But common sense says it is more likely an issue of something that ground testing did not account for in actual flight conditions. Because the history of rocket vehicles is replete with problems and failures that occurred in flight that were not accounted for properly in ground testing.

- George Gassaway.

Not alot of acceleration loads on the motor during ground testing. Most likely a failure in the Nitrous system.

It is very sad that one person died and another was injured. Burt Rutan is undeniably arrogant though, and I'd be investigating the test & certification program.