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SpaceshipTwo crashes shortly after Mojave test flight

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Re: SpaceshipTwo crashes shortly after Mojave test flight

#271

Post by ghostunit »

colordrops wrote: post #224
ghostunit wrote: post #202

Earlier quoted context omitted.

I find this dogma of "Eventually we will conquer space and make it accessible to all mankind" dangerous in the extreme to the actual, all-too-present predicaments we have here on real Earth such as climate change, environment devastation, fossil fuels/minerals/water depletion and the accelerating destruction of the web of life that makes possible your even being able to breathe. You are all prey to the "religion of p…

While we are off topic, this post is a fine example of "concern trolling".

Someone has to point out that you have fallen into dogmatic thinking when it comes to our "space future". There is nothing promised, nothing that can be taken for granted, nothing shown to be possible (beyond the current limits of our physics which are: getting to the moon at enormous fuel expense, and 1-way ticket to die in Mars)

Re: SpaceshipTwo crashes shortly after Mojave test flight

#272

Post by porsupah »

brent_noorda wrote: post #164
pessimizer wrote: post #90

Earlier quoted context omitted.

You're forgetting how cool it would be for rich people to burn a couple hundred thousand to fly in space for two and a half hours. It's clearly the highest expression of the human spirit, and you're a hopeless hater cynic. I wonder what the carbon footprint of space tourism is, and will be if it becomes cheaper and more popular? I feel guilty flying on a plane.

I worked out some quick math estimating 25,000 gallons just for the fuel for each tourist's 2-hour flight. Space tourism seems like the douchebaggiest idea ever created. I hope the in-flight space cocktails are worth it. http://brent-noorda.blogspot.com/2014/05/richard-branson-elo...

Perhaps Skylon is more to your liking?

Re: SpaceshipTwo crashes shortly after Mojave test flight

#273

Post by wolf550e »

jcreedon wrote: post #193
riffraff wrote: post #138

Earlier quoted context omitted.

AFAIR there is an order of magnitude of two between the prospected prices of virgin galactic and a soyuz trip.

There is also at least an order of magnitude between their maximum altitudes.

The altitude is not important.

https://what-if.xkcd.com/58/

SpaceShipTwo is meant to get to zero velocity at ~105km up. Soyuz gets to 17,450 mph at 200km up (and then catches up to the station at 400km up). Only the speed sideways is important, and there is more than one order of magnitude difference.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#274

Post by serf »

ninjaplease wrote: post #213
stcredzero wrote: post #207

Earlier quoted context omitted.

It is a nice sounding quote, though it may have factual problems until you get to programs with large numbers of iterations. Speaking of which, your username was coined by a traditional drummer/singer friend of mine. Do you know her?

It is not a nice quote, it's douchey, reductionist, and mostly nonsense. What on earth does "costs are fixed" mean? I also did not realize there was an inverse relationship between "blood" and "treasure". Are we pirates? In case you aren't trolling me, my snark was a reference to http://knowyourmeme.com/memes/in-this-moment-i-am-euphoric I don't know your friend, but my username is pretty stupid, so if she wants to t…

>What on earth does "costs are fixed" mean?

I don't think you're that simple, I think you're just trying to be derisive.

In case you're not :

Regardless of the effort involved, a value must be paid in order to form a new technology or model.

We, the people who strive to create, choose in what way we would like to pay this value. We can choose to pay for progress through time, or pay for progress through means of trial and error.

While not mutually exclusive, one methodology tends to detract from the other while serving the same purpose : the pursuit of a novel model.

The methods of payment are not mutually exclusive, the ethos behind the choice to prioritize one over the other typically (but not necessarily) is.

An off-topic example I can think of would be the drive behind early Russian aviation/aerospace versus the drive behind early United States aviation/aerospace.

Different priorities got both parties to a comparable level of technology regardless of the differing means used to get there. Free market competition rushed much of early Russian aviation and made wide use of anecdotal evidences and test piloting and created leading edge machines because of it, whereas government subsidy and large cash flows drove the US to stay on top using theory and finances instead of prioritizing the happiness of pilots and fulfilling 'stick-feel'.

(before anyone mentions it, both parties did the same stuff, they just differed in prioritization)

Both parties created fantastic machines. One paid in blood, the other in time for such achievements.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#275

Post by marze »

aptwebapps wrote: post #267
marze wrote: post #246

Earlier quoted context omitted.

True. But it is almost pointless to compare these two programs since Apollo was so much more complex. To put it in perspective, Apollo flew on a rocket with five engines producing 1,500,000 lbf thrust each, on the first stage alone. By contrast, the Virgin motor produces 60,000 lbf thrust for 70 seconds. The Apollo program had a safety culture configured so that if anyone identified a safety issue, they became respon…

"True. But it is almost pointless to compare these two programs since Apollo was so much more complex." That's funny, because you were the one who compared them first.

"Almost pointless" due to the vast differences in scale and complexity but still worthwhile, as a contrasting example of a solid safety culture employed by the Apollo engineering and operations teams.

Although the Virgin 60,000 lbf rocket is small by the standards of Apollo, it is still an extremely challenging problem. There are no problem-free or inherently safe options, so safety needs to be engineered in from the bottom up carefully and competently. Otherwise, failures like this will not happen just once.

The engineers involved would do well to study the Apollo program and other successful complex engineering efforts such as nuclear reactors, as well as the counter examples of the two space shuttle that were lost due to management putting schedule ahead of safety.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#276

Post by Htsthbjig »

The question is : Why don't they use an unnamed vehicle for testing new fuels?

In lots of ways unmanned is actually simpler than maned, as the US army knows.

Using pilots for testing new things looks to me as extremely outdated, from the old macho days.

In the old macho days you had to sacrifice people for learning things as simple as how to control the aircraft over the speed of sound.

But today it is totally unnecessary.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#277

Post by chris_wot »

marze wrote: post #69
mixmax wrote: post #23

What this weeks events show us is that space travel is hard. Really hard. Most systems operate in extreme conditions, sometimes bordering on the improbable. Thousands, sometimes millions of horsepower in an engine smaller than a car, cryogenic liquids at -200 degrees celsius cooling a nozzle that is 3000 degrees celsius 5 millimeters away, heatshields designed to absorb obscene amounts of heat, the list just goes on…

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. What they are doing is much easier than the Apollo program, which was well managed and had no in-flight failures that resulted in loss of life, while accomplishing an infinitely harder task. This is a tragedy, obviously. But the program is about six years behind schedule, been going for 10 years. The mos…

You seem to have some sort of inside knowledge none of the rest of us have? Seriously, to say that this is a poorly managed program is something you can't provide any concrete evidence of - there has been a tragedy, but you cannot say that it was poorly managed because you don't know.

In fact, you don't even know that rubber in the hybrid engine blocked the nozzle. You can't know that - you aren't part of the investigating team. And they don't even know yet.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#278

Post by chris_wot »

marze wrote: post #275
aptwebapps wrote: post #267

Earlier quoted context omitted.

"True. But it is almost pointless to compare these two programs since Apollo was so much more complex." That's funny, because you were the one who compared them first.

"Almost pointless" due to the vast differences in scale and complexity but still worthwhile, as a contrasting example of a solid safety culture employed by the Apollo engineering and operations teams. Although the Virgin 60,000 lbf rocket is small by the standards of Apollo, it is still an extremely challenging problem. There are no problem-free or inherently safe options, so safety needs to be engineered in from the…

If there are no inherently safe options, then that tends to preclude engineering in safety. I really don't think you know what you are talking about.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#279

Post by chris_wot »

marze wrote: post #243
termain wrote: post #215

Earlier quoted context omitted.

Aviation Week reported it back in May. So, yes. I'll keep an eye out for the accident report. http://m.aviationweek.com/space/new-fuel-boost-spaceshiptwo

Well you could be right, but it is very hard to imagine that being true since the plastic hybrid has only been tested once on the ground. Doing a flight test so soon would be totally insane. In any case, the disaster was undoubtably a result of inadequate ground testing. Problems like these are almost always the result of management pushing things faster than the engineering progress warrants.

You don't know what the problem was.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#280

Post by icebraining »

venomsnake wrote: post #153
aero142 wrote: post #124

Earlier quoted context omitted.

Even though it catchy, it's still bullshit. Spending much more money and still failing miserably is a likely outcome of lots of projects.

The less you spending on safety and training, or have lax safety standards, more people will die. End of story.

Cars, planes, etc are all much safer than before while costing less. Safety mechanisms are not somehow immune to efficiency improvements.
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