Virgin Galatic Spaceship Two down in the Mojave.
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This has been raised a couple of times here but to my knowledge no-one has explained what certification 'ticket' they are working towards and who will decide when the beast is fit to carry commercial passengers.
Note: in a certification regime, not only the aircraft must be certified, but also the pilots, airline, mechanics, etc. E.g., the FAA would have to make a new Category / Class and perhaps new Type Ratings for sub-orbital flight, issue new pilot exam "PTS" standards, update A&P IA requirements to work on rocket motors, issue new FAR Part 1XX for sub-orbital ops, etc.
So instead of going through a (non-existent) certification regime, SpaceShipTwo (and other manned sub-orbital flights) will go through a licensing regime instead.
Under a licensing regime, instead of certifying the aircraft, pilot, mechanic, etc., the FAA will license the launch operation.
Prior to a launch, the FAA will want to see documentation, test flight data, etc., that provides reasonable assurance that the launch will be successful. The criteria is to assure public safety and occupant safety.
Currently the FAA has issued single launch licenses (permits) -- a new launch license was required for each of SpaceShipOne's sub-orbital flights, for example.
Once launches become more routine, the FAA can issue a multiple-launch license for the launch operation.
Now that we've had an in-flight fatality, the FAA will expect even more documentation/data before issuing a new launch license.
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BTW I don't know to what extent the philosophy behind SS2 parallels that of SS1, but that craft was approached with maximum simplicity: direct control linkage (a hard landing was caused by a vacuum lock), minimum automation. Ironically, given the patriotism of the likes of SS1 pilot Brian Binnie, more a Soviet-program kind of minimalist pragmatism. When posts here have queried protections in the avionics over the past few days, I have repeatedly been reminded just how seat-of-the-pants SS1 very much seemed to be.
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Not even that. The mothership launch technology has not yet overcome the technology hurdle to achieve anything better than a brief parabolic excursion beyond the atmosphere. That is why the experimental craft of sixty years ago did not progress further and the space programme reverted to vertical launch rockets. Early ideas that the Space Shuttle might work this way were also quickly abandoned.
For a real technology progression using this launch method a true hybrid engine would be needed - a combination jet and rocket that can transfer gradually from air-breathing to purely reactive as the air density decreases. And that is a development programme which is probably beyond even Mr Branson's deep pockets.
For a real technology progression using this launch method a true hybrid engine would be needed - a combination jet and rocket that can transfer gradually from air-breathing to purely reactive as the air density decreases. And that is a development programme which is probably beyond even Mr Branson's deep pockets.
Launching from a mothership in a two-step fashion, the way Virgin does, assuming that you can add a good ramjet on top of their existing designs, lets you save some money because the mothership is fully reusable, and lets you save some weight because you don't have to carry all oxidizer that you burn up to a certain speed. But even if you can get the "spaceship" out of the atmosphere and up to, say, Mach 3 before you switch to rocket engines, you still need to go from Mach 3 to Mach 25, which means that you still need to carry a heck of a lot of fuel and only a small amount of payload.
SpaceShipTwo reportedly weighs ~10 tons (constrained by the lift capacity of the mothership), and payload to fuel ratio is way too high. You need to scale the mothership by a factor of 10, somewhere to the size of a 777, and you need to turn SpaceShipTwo into something that looks more like a classic rocket (with large separating first stage), and then it would approach being useful for actual space flight. In the present form it's firmly stuck inside Earth's gravitational well.
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I'm afraid to say "toy for the rich" is not far off the mark. That is not to belittle the engineering efforts of Burt Rutan, he is smart guy, but the programme will not amount to more than joyrides and very limited microgravity experiments.
If it helps get people interested in commercial exploitation, that's great if it leads to investment by major players, and orbital ships are what's needed for real commercial exploitation of space. Those players are investing, but in satellite launchers and ferry services for NASA, i.e. ones with a real market.
As far as "space-planes" go (i.e. SSTO) with a real chance of innovation and breakthrough in launch costs then Branson would be much better investing in Skylon Reaction Engines Ltd - Space Access: SKYLON. Skylon does not carry celebrities, unfortunately.
If it helps get people interested in commercial exploitation, that's great if it leads to investment by major players, and orbital ships are what's needed for real commercial exploitation of space. Those players are investing, but in satellite launchers and ferry services for NASA, i.e. ones with a real market.
As far as "space-planes" go (i.e. SSTO) with a real chance of innovation and breakthrough in launch costs then Branson would be much better investing in Skylon Reaction Engines Ltd - Space Access: SKYLON. Skylon does not carry celebrities, unfortunately.
So if I understand the sequence of events correctly - feather unlock is released early, feathers start to move.
The next bit is purely speculative on my part, but just trying to understand what might have happened.
I assume that would then result in an uncommanded violent pitch up, aircraft presents belly to airflow, pitching through 90 degrees, feathers snap off, remaining airframe breaks up?
The next bit is purely speculative on my part, but just trying to understand what might have happened.
I assume that would then result in an uncommanded violent pitch up, aircraft presents belly to airflow, pitching through 90 degrees, feathers snap off, remaining airframe breaks up?
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Originally Posted by donotdespisethesnake
I'm afraid to say "toy for the rich" is not far off the mark. That is not to belittle the engineering efforts of Burt Rutan, he is smart guy, but the programme will not amount to more than joyrides and very limited microgravity experiments.
They have spent more than $400M on the project. It's not a half hearted effort.
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I enlarged the photos. One feather is clearly visible in the debris trail, along with one of the delta wings. The other delta wing appeared to be still attached, and the fuselage largely intact. Something large was beside the fuselage- N2O tank? The rocket motor (judging by the glow) was some distance ahead. A white cloud surrounded the fuselage and trailed it. The fuselage was upside down and going backwards. I believe the camera went upside down as it tracked the ship going over, so the ship is simply falling, though in the photo it looks like it is going upwards. The trailing cloud does not look high velocity. Based on that photo, I believe pieces came off, but it didn't "explode" nor did it disintegrate. I will be very interested to hear what the pilot has to say, and how he got out. Regarding space tourism- Into Thinner Air? Rich people die like flies on Everest, why not in a sub-orbital flight if they wish? Michael Alsbury died like Scott Fischer on Everest- a leader doing something dangerous that he loved. Happens all the time, keep it in perspective. Four out of five people just died off the coast here when a wave flipped their boat. They were sport fishing for crabs, not wearing life jackets. People are not going to stop crabbing because of it, hope Branson and Scaled Composites press on too.
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All I've read is that the investigators will be looking into the actions of the crew, which is standard for any investigation.
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I don't get the sensitivity of the question over the Pilots "Piloting Qualification". It's pretty straight forward did they fly complex fast jets solo, were they qualified Test Pilots? In truth, the advances we enjoy in Commercial aviation today were hard earned by very specialist flight test Test Pilots.
It relevant to ask - did they go to Empire or USAF TPS for example. If not, why not?
It relevant to ask - did they go to Empire or USAF TPS for example. If not, why not?
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Stability of feathers against aerodynamic forces
If the hydraulics on the feathers can be overpowered by the aerodynamic forces (with the locks off) it’s odd that a system that would fail at Mach 1.02 is judged fully competent, with margin, at Mach 1.4. It seems unlikely that the aerodynamic forces would change (reduce) by a factor of many over a relatively small speed range. It also means that at lower speeds the unlock lever effectively had a label ‘move this lever to destroy the vehicle’.
If the locks were required to be in until just above the feather speed that would indicate a feather hydraulic system with low torque, but that is not the case.
At the moment the stated facts are consistent with a failed hydraulic system that could not provide the required torque when the locks were removed. If so, the fact the system was unlocked early is irrelevant.
If the locks were required to be in until just above the feather speed that would indicate a feather hydraulic system with low torque, but that is not the case.
At the moment the stated facts are consistent with a failed hydraulic system that could not provide the required torque when the locks were removed. If so, the fact the system was unlocked early is irrelevant.
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Regarding the "qualified test pilot non-debate". There's always been more or less subtle conflicts between pilots with different backgrounds. Hearsay has it that Chuck Yeager questioned Neil Armstrong's abilities because he was not only a pilot, but also a qualified engineer. (and to the best of my knowledge, none of of them attended any "test pilot school"). If the scaled pilots were not qualified, I have no doubt at all that the NTSB will uncover that. If there ever was a red herring, the question about the pilots qualifications is a prime example.
Last edited by deptrai; 5th Nov 2014 at 05:46.
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it’s odd that a system that would fail at Mach 1.02 is judged fully competent, with margin, at Mach 1.4.
I can see that the tail boom is of a horn balance design. Is it possible that this could contribute to the feather 'self-deploying' once unlocked given the right aerodynamic pressure?
Also I believe the actuator is pneumatic. Would this provide less resistance to 'self-deployment' than hydraulics?
Thinking about it some more, the pressure on the horn wouldn't need to deploy the feather but could place enough pressure either side of the pivot to break the boom about that point.
Also I believe the actuator is pneumatic. Would this provide less resistance to 'self-deployment' than hydraulics?
Thinking about it some more, the pressure on the horn wouldn't need to deploy the feather but could place enough pressure either side of the pivot to break the boom about that point.
Last edited by Hadley Rille; 5th Nov 2014 at 09:53.
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@funfly
The video of the 2013 second powered flight does not suggest a significant climb during the powered phase of that flight. The unlock call on that flight occurs during powered flight and before the pull-up that reduces the speed to near zero.
I think you will find that the dynamic surface pressure on the aircraft control surfaces under maximum thrust at Mach 1.02 would have been considerably higher than at a higher altitude at Mach 1.4 and where the scenario may also have been in a re-entry state, i.e. reduced thrust.
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I am afraid this will delay the program, it is a pity because I always believed that this project could create new scenarios and boost the aeronautical sector if finally a civilian airlines was able to conquer the space.
I read an article in an aviation news pubblication saying the technology of SpaceshipTwo is in reality 30 years old and it a military technology developed by B.A.S. to deploy special troops through high area of atmosphere quickly around the World but it was finally dismissed because it was unstable and after many flights it could simply explode. It looks this news was classified but than declassified 10 years ago.
I read an article in an aviation news pubblication saying the technology of SpaceshipTwo is in reality 30 years old and it a military technology developed by B.A.S. to deploy special troops through high area of atmosphere quickly around the World but it was finally dismissed because it was unstable and after many flights it could simply explode. It looks this news was classified but than declassified 10 years ago.
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Deptrai - I think you are missing the point, apart from being high handed and more than a little conceited. The question of the suitability of the Pilots is not at issue. Its essentially down to their training and relevant experience, I happen to know a couple of Test Pilots whom are also engineers and they had to eat a lot of in working their way through the various flying programs and into Empire Test Pilot school. The skills and Piloting knowledge gained was significant.
As you say the NTSB should be looking into the adequacy of their Training, SOPs and standards discipline etc. but its good to discuss the issues on here.
As you say the NTSB should be looking into the adequacy of their Training, SOPs and standards discipline etc. but its good to discuss the issues on here.
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Deptrai - I think you are missing the point, apart from being high handed and more than a little conceited.
Internet forums tend to make disagreements escalate quickly. I'll offer my sincere apologies, and a beer.
Internet forums tend to make disagreements escalate quickly. I'll offer my sincere apologies, and a beer.
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Originally Posted by deptrai
Regarding the "qualified test pilot non-debate". There's always been more or less subtle conflicts between pilots with different backgrounds. Hearsay has it that Chuck Yeager questioned Neil Armstrong's abilities because he was not only a pilot, but also a qualified engineer. (and to the best of my knowledge, none of of them attended any "test pilot school"). If the scaled pilots were not qualified, I have no doubt at all that the NTSB will uncover that. If there ever was a red herring, the question about the pilots qualifications is a prime example.