dcool on 13/11/2006 at 19:28
Quote Posted by Pyrian
I watched a special on the subject and realized that some of the footage basically could not have been taken in an atmosphere (dust billows), which effectively rules out filming in some earthbound desert.
Why couldn't it be taken in an atmosphere? Couldn't you take a room on earth and suck the air out? Do you mean the motion of the dust billowing implies a lower gravity? Or are you just parroting what you saw on TV?
Jonesy on 13/11/2006 at 20:14
Quote:
After they chose the new constellation program they published some crappy videos in the typical NASA style ("Hey look, we are NASA and we're the best in space industry" ). However, as I
successfully passed my physics exam, I doubt the question the whole sticky thing can fly.
Basing your arguments on whether or not a vehicle can fly (over rendered and mockup images that can change at any time) nearly 10 years before the vehicle is scheduled to be launched with actual human beings in it is idiotic beyond belief.
Also, NASA has far more aerospace engineers who are vastly more qualified than some Bulgarian who just passed his physics exam.
Let me give you an example of another time somebody made a prediction of what would happen in the next ten years:
Inline Image:
http://img.photobucket.com/albums/v463/JonesyX/PM1159.gifPyrian on 14/11/2006 at 01:03
Quote Posted by dcool
Why couldn't it be taken in an atmosphere?
Because in an atmosphere, dust - even sand, to a lesser extent - billows when churned up. Look at any video of off-roading, and compare to the footage of vehicles traversing the moon. The dirt kicked up by the moon jeep follows a simple parabola - exclusively. Even washed gravel will kick up dust when driven over like that. You could make it wet, but then it would clump and splatter.
Quote Posted by dcool
Couldn't you take a room on earth and suck the air out?
A more feasible approach, but the sheer size of the environment means that, from a cost and engineering perspective, they might as well have just flown to the moon.
Quote Posted by dcool
Do you mean the motion of the dust billowing implies a lower gravity?
No. I probably should have explained myself more thoroughly.
Quote Posted by dcool
Or are you just parroting what you saw on TV?
I've never seen a TV show give any sort of decent, intelligent response on the moon conspiracy issue. I've always found it kind of sad, because there are answers to all of the points which have been brought up - most of them so painfully obvious I spotted them immediately. But they weren't substantively challenged.
Tocky on 14/11/2006 at 03:01
Buzz Aldrin did the debunking I wanted when he knocked that dumbass on his.
Medlar on 15/11/2006 at 21:01
Why does it matter what a space rocket looks like?
Kolya on 16/11/2006 at 00:05
I thought this looked somewhat similar to the Concorde, so I looked up some data about it:
The Concorde had it's first flight in March 1969, less than ten years after that magazine was printed. With a cruising speed of 2519 km/h (Mach 2,04) it would have taken the Concorde 95min for the distance of NYC-LA (3961 km).
Written so you can understand it.
Jonesy on 16/11/2006 at 01:32
Quote Posted by Kolya
I thought this looked somewhat similar to the Concorde, so I looked up some data about it:
The Concorde had it's first flight in March 1969, less than ten years after that magazine was printed. With a cruising speed of 2519 km/h (Mach 2,04) it would have taken the Concorde 95min for the distance of NYC-LA (3961 km).
There's a certain irony in that this was the primary reason why I posted it: things change in 10 years, it seems like the design went from
space vehicle/piggyback ramjet combo platform to a (somewhat) conventional design.
Bulgarian_Taffer on 18/11/2006 at 15:02
Quote Posted by Jonesy
Basing your arguments on whether or not a vehicle can fly (over rendered and mockup images that can change at any time) nearly 10 years before the vehicle is scheduled to be launched with actual human beings in it is idiotic beyond belief.
Also, NASA has far more aerospace engineers who are vastly more qualified than some Bulgarian who just passed his physics exam.
Let me give you an example of another time somebody made a prediction of what would happen in the next ten years:
Wrong. The space shuttle was thought to be perfect. That's why the greatest engineers didn't think about emergency escape systems. Maybe they were not good enough to realise that flying on a solid rocket motor is suicidal. And it's not me who is saying this. Verner Fon Braun - the greatest rocket scientist in US has once said: Only kerosene and Oxygen for manned rockets and never use solid fuel. Look- Soyuz uses kerosene and Oxygen. Apollo once used kerosene and oxygen, as well as Gemini and Mercury. Verner Fon Braun will turn over into the grave when he sees a solid rocket motor as a first stage and a cryogen powered engine as a second stage. Emergency escape system for Ares is OK, but in case of a solid rocket motor failure it's useless because a solid rocket motor explodes very quickly so the escape system can't react immediately. I don't want to think about VAB accident- it will be worse than an in-flight accident.
I'm not against NASA, I'm against mistakes they repeat over and over again. Some techiques have proved in the past to be unstable, some not... Why do we have to return to the unstable techniques once again?
Jonesy on 18/11/2006 at 15:44
The two major accidents involving space shuttles both had nothing to do with the solid rocket boosters directly, so I fail to see your point. (frozen foam and an o-ring being the primary causes of both disasters). The escape system is of the exact same type used in the Apollo series of spacecraft (I'm not talking about the rollercoaster revision they're suggesting). There were also several different abort sequences for the shuttle, showing that they did at least perceive a chance of failure. No engineer thinks they made a perfect machine if they want to keep their job, that's why they overengineer everything. In fact, the SRBs didn't explode even in the shuttle disaster of Challenger (you can see both of them spiraling away from the explosion). The reason why Challenger disintegrated was that the integrity of the liquid hydrogen tank was compromised. You can compare that with all the major explosions stemming from the use of liquid rockets in the 60's and 70's. The direct cause was a faulty o-ring, not an explosion from the SRB.
Why do solid rocket motors explode? They explode because the pressure becomes too high inside and the casing can no longer withstand it and bursts. The heavy-duty construction of the SRB largely eliminates this possibility as long as the burn rate doesn't go out of control, which makes it different then other solid rockets. Since the fuel grain can't really shatter, as its made of rubber, this will prevent the the large increase in surface area that would cause a catastrophic overpressure. Liquid fueled engines on the other hand are the opposite, if there is a serious failure, a catastrophic explosion is the rule and not the exception. The main point about having the combustion slow down with a major pressure loss is so the crew can escape, not so much to avoid an explosion, since the SRB's heavy construction pretty much precludes this already. If you do have a serious leak, that does drop the thrust and increases abort survivability, and if its not a serious leak - then what's the problem?
The other primary reason for SRBs is cost. Building liquid fueled rockets for every single launch ala Saturn V would drive NASA into bankruptcy pretty quick.
