Posted on 01/29/2008 10:44:28 AM PST by Freeport
Virgin Galactic expects Scaled Composites to roll out its SpaceShipTwo (SS2) carrier aircraft White Knight II (WK2) in early May for ground tests.
Construction of the four-engine, twin-fuselage prototype is 80% complete at Scaled's Mojave, California facility, said Virgin Galactic at the New York unveiling of SS2 and WK2 on 23 January.
The WK2 will have an all-carbonfibre airframe with a 42.7m (140ft) wingspan, 23.7m overall length and a tail height of 4.5m. Powered by four Pratt & Whitney Canada PW308 turbofans, the aircraft will have a range, carrying its SS2 payload, of more than 4,200km (2,270nm).
"First flight will be during the summer", and will follow a period of ground-testing, says the space tourism company's commercial director Stephen Attenborough.
Scaled's engineers had been hoping to make WK2 ready to fly at the AirVenture show in Oshkosh in July, but that is now "unlikely", says Attenborough.
Because the WK2's two fuselages will share a common cabin design with the SS2 suborbital vehicle, the carrier aircraft will be used for pilot and passenger training for the spaceship's flights.
But White Knight I is currently available for research purposes. I’ve seen at least one customer use it.
That accident, and also the failure of Elon Musk's Falcon rocket a couple of years ago, highlight the primary problem of "commercial can do it cheaper" programs.
In many cases, they "do it cheaper" by cutting corners on safety and handling procedures, QA, and so on.
While it's true that gov't programs -- especially manned flights -- can go overboard with their processes, which adds trememdously to cost, the fact is that those processes were typically developed in response to real accidents.
I've seen the mindset in lots of different situations (and been guilty of it myself): you see something and think it's stupid and wasteful, until you discover too late that there was a rationale behind it after all.
Sale!! 65 mile trips now being offered for only $10,000. I will belt you in my craft - which was made with no help from NASA - and propel you a full 65 miles and then return you safely to our starting base.
That’s 5 miles more than this contraption and a heck of a lot cheaper. What a ride you’ll have!! Total time of the excursion - 2 hours.
I’ve done this many times and never lost a passenger though I was once late due to a flat tire.
And sometimes -- a lot of times -- Sh!t doesn't happen when people follow the procedures. Like, for example, accident for which you posted the picture.
And also, I would predict, proper procedures and safety measures would have prevented the explosion at Scaled Composites.
NASA couldn't have done anything like that because they would have been required to direct the work to at least two separate major defense contractors. ;)
One of the reasons that ACTD’s work in the commercial world, is that they are much less risk averse that the Government.
FWIW, the following (from here) discusses the means by which this explosion may have occurred:
ReactivityNitrous oxide in its liquid and gaseous forms is a stable compound. Nitrous oxide is nonflammable but is an oxidizer that can support and accelerate combustion. Ignition of combustibles may be easier to initiate in a nitrous oxide enriched atmosphere. When handling oxidizers, it is important to understand fire chemistry and be aware of the unique mechanisms for ignition that can be encountered. The speed of combustion will be increased and the heat of the fire will be greater than if the combustion was in air. Nitrous oxide decomposes exothermally under high temperature (649ºC, 1200ºF) without the presence of a catalyst, and the decomposition can be self-sustaining. Within specific temperature and pressure conditions, an explosive decomposition reaction can occur. Nitrous oxide is capable of auto-decomposition, but under most conditions an ignition source is required to initiate the reaction. Experimentally, ignition energies as low as 0.14 joules have initiated decomposition. Some ignition sources that may be encountered in the workplace are static discharge, sparks from metal-to-metal contact, adiabatic heat of compression, and external heat sources (such as welding on nitrous oxide lines). Incorporating a heat sink to remove the heat can prevent propagation of a decomposition reaction. Vessel geometries and impurities can influence the chance of an explosive decomposition. Testing has shown that the decomposition reaction is limited to the vapor phase.
What it sounds like to me is, they probably didn't have a very clean environment, Nitrous Oxide concentrations may have been elevated in the room, and there was a static discharge to initiate combustion.
Well, actually, the key technologies involved were originally developed, funded, and in some cases even achieved by NASA and/or the DoD, years or decades ago.
Aircraft composites have been around for years, too.
Not to say this isn't cool stuff ... but it's not particularly revolutionary, either.
The only really "new" thing is that they're going to try to make money on it -- a business case that I think is probably based more on wishes than any realistic assessment of the customer base.
You may be correct - and I, for one, regret the loss of live and pray for those involved.
But, it is clear to me as a government contractor, this ship would not fly for thirty years if the government was building it.
The government is simply too risk averse to be an early adoptor of technology.
That would be wrong. In aerospace, especially, much of the basic research and many testbed demonstrators are developed under government auspices. As noted previously, most of the technologies for this vehicle came from government-funded sources, including the hybrid rocket (which was originally developed by American Rocket Co., using DoD and NASA funding).
Where government risk aversion really comes into play, is in fielding new technologies as they would be used in large-dollar, high-profile operational programs.
Allright, I agree with the way you said that - the government develops the new technologies, and then forgets to use them, to sum it up.
Middle Cabin is SS2 ‘space ship’
Right. Which is exactly why I posted that pic...I figured that would be your exact response.
My point, which you must concede, is that simply having "proper procedures and safety measures" would not have prevented anything at either SC or LM or anywhere.
FOLLOWING THEM MIGHT HAVE. But not guaranteed.
OTOH, the bigger and broader the bureaucracy, the more likely HUMANS will get exasperated and go around them (like removing the 24 bolts without proper paperwork.)
Humans are not computers and do not execute regulations like a CPU executes code.
Quality guys that worship the false papermill God can get carried away and there must be something equivalent to the Laffer Curve diminishing returns for process/regulations.
No use discussing with you -- your mind is made up.
“NASA would need several billion $ to make a vehicle do what Virgin/Scaled is doing for a few million $. We eagerly await their bid to open space to non government/military travel.”
Maybe but its unfair to state the so certainly. When SS1 and SS2 do is reach suborbital velocities and thus suborbital altitudes. The requires *far less* energy than orbital flight..
And I'm guessing that Scaled Composites didn't even have the procedures, and it ended up killing folks.
As for the Falcon X launch failure ... the accident report for that one is unbelievable: they had a guy crawling around the engine and tinkering with stuff -- all alone. Ridiculous, but it happened. And again, they didn't even have procedures in place.
Quality guys that worship the false papermill God can get carried away and there must be something equivalent to the Laffer Curve diminishing returns for process/regulations.
Tell it to the dead guys, sam. Or better yet, try to convince the dead guys' families.
And how many accidents has NASA had in the past 30 years?
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