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#26 2014-11-01 21:04:15
- SpaceNut
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- From: New Hampshire
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Re: SS2 - status
The National Transportation Safety Board and FAA must be having a field day with the loss of SpaceShipTwo as it has crashed in a test flight with the one pilot killed and injuring the other. The identities of the pilots on board SpaceShipTwo have not been disclosed, although both are employees of Scaled Composites.
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#27 2014-11-02 12:37:08
- GW Johnson
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Re: SS2 - status
NTSB investigators don't have "field days" with anything. These are dedicated professional folks, and they will get to the bottom of it. It's the pundits, media, and political critics that are having field days.
FAA does not investigate air crashes, NTSB does. FAA may make or remake some rules based on what NTSB determines. Or maybe not.
Having two of these disasters, unrelated as they are, within days is causing quite a stir in the media. All sorts of irrelevant questions are being raised, and too many irrelevant conclusions being drawn. It's actually kind of sickening watching all that useless fuss going on.
I looked at what I could find in terms of verifiable accounts and photos, and there is not enough to draw any conclusions yet, for either Spaceship Two or the Antares rocket. I put what I could find, along with an explanation of some aspects of hybrid and solid rocket engineering, up on "exrocketman". It may be a long while before enough is known with certainty to update what I posted there.
GW
http://exrocketman.blogspot.com
"Two Commercial Spaceflight Disasters in One Week", dated 11-1-14
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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#28 2014-11-02 16:22:04
- RobertDyck
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- From: Winnipeg, Canada
- Registered: 2002-08-20
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Re: SS2 - status
In August we had a new member, a university student from Kyiv, Ukraine. She warned us about the Russian rocket engines on Antares. After the accident, she sent this to the local email list...
Hate being the "I told you" person but... I told you
I mean, about the engines that are used in this rocket.
They are the ones that were hidden for 30 years in Siberian forest before being sold to Aerojet Rocketdyne. IMO, it was only a matter of time, when they fail to notice the engine that was too damaged by inappropriate storage conditions...
Maryna
That's one hypothesis. Pardon me if I'm a bit suspicious, considering the current conflict between Russia and Ukraine. But the video did appear to show an engine explode, debris fell, then the rocket lost power and fell back to the pad. Examining remaining engines is waranted.
As for SpaceShipTwo, all I know is what's already been said in this thread. Changing engine. Vibrations of the previous engine. Thermal effects of engine exhaust on the tail. Atmospheric re-entry for an aircraft that doesn't have a heat shield. All issues worth examining. SS1 did work, but but the cube/square rule could cause problems when the design is enlarged. That is, volume and mass are expanded by the cube of the increase in length, but surface area of hull and aerodynamic surface are increased by the square. But Burt Ratan is definately capable of accounting for that. Don't know, just speculating.
This demonstrates the need to test everything. And always prepare for a test to fail.
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#29 2014-11-03 08:21:49
- RobertDyck
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Re: SS2 - status
NTSB briefing
http://spaceflightnow.com/2014/11/03/vi … ematurely/
He said the feathering system has two things the pilots must do to deploy: move the "lock/unlock" lever to the unlock position, then move the feather lever. The "lock/unlock" lever was supposed to be moved to unlock at mach 1.4, but was moved at mach 1.0. The feather leaver was not moved. However, 2 seconds after it was unlocked, the feather mechanism deployed. This was an uncommanded deployment of the feather mechanism, while flying faster than mach 1. More investigation to come.
SpaceShipTwo’s feathering system is seen deployed on a test flight in 2011.
Last edited by RobertDyck (2014-11-03 08:23:25)
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#30 2014-11-03 09:08:13
- GW Johnson
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Re: SS2 - status
I saw the same news story. Surprised to see NTSB making comments this fast, but at least it may put the kibosh on some of the media circus. I updated my posting to reflect this development, this morning.
The discussions of possible rocket failure modes are still valid, but apparently don't apply to this incident with Spaceship Two. From what I can find, the fatal ground test accident 7 years ago was an NTO tank explosion, not a hybrid motor explosion. So far, their hybrid motor has a pretty good track record in testing.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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#31 2014-11-07 13:09:47
- GW Johnson
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Re: SS2 - status
Just updating y'all on what I have heard about both failures. These are just public news releases, so who really knows the pedigree?
SS2 apparently pitched up when the tails feathered uncommanded, while under rocket power at about Mach 1 and near 50,000 feet. It completely broke up very rapidly, "ejecting" both pilots directly into the thin air, in street clothes and without oxygen, wearing chutes that require a manual ripcord pull. One managed to deploy his chute, the other did not.
Orbital believes a turbopump assembly failed on one of the two Russian antique engines, causing their rocket to lose thrust and start to fall back. That's when the range safety self-destruct was triggered.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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#32 2018-04-14 09:03:15
- SpaceNut
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Re: SS2 - status
Virgin Galactic hasn’t performed a powered flight since October 31, 2014, when VSS Enterprise experienced a catastrophic failure mid-flight. The tragic accident resulted in the death of one test pilot and severely injured another. However, Virgin Galactic has made significant progress over the last year, and powered flights are expected to resume shortly.
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#33 2020-12-10 20:28:12
- SpaceNut
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Re: SS2 - status
The company’s SpaceShipTwo will begin the flight attached to a carrier plane that will drop it upon reaching 50,000 feet. At that point, its rocket engine will engage and the space craft will head into sub-orbital space. Piloted by Dave Mackay and C.J. Sturckow, this particular flight be used as an opportunity to test out the ship’s cabin, stabilizers and controls, as well as carry payloads into space as part of the NASA Flight Opportunities Program.
While the test flight is a vital step on the way to the official launch of the $250,000-per-seat space tourism service, it will also be a milestone for New Mexico. Once the flight is complete, the state will become just the third to host a crewed space flight, after Florida and California.
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#34 2020-12-13 22:41:06
- SpaceNut
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#35 2021-02-02 10:12:16
- SpaceNut
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- From: New Hampshire
- Registered: 2004-07-22
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Re: SS2 - status
flight window starting Feb. 13 for its SpaceShipTwo Unity
Sub orbit joy rides but if performed correctly they are cheap to be had and no training would be required...
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