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Dream Chaser, the SUV of spacecraft?
Why is Sierra Nevada Corporation (SNC) calling the Dream Chaser the SUV of space? Because it's roomier than the cramped Dragon and CST-100 capsules? That may be, but with those you will at least have a fair chance of making it back alive. Let's face it, a winged vehicle is too dangerous for space travel due to the energies involved. I've claimed before that Dream Chaser has no hope of surviving an in-flight explosion of the booster rocket, which will rip its wings off and doom the vehicle and crew. With a capsule, there's a fair chance you might survive. People are asking why SNC is booking an Atlas 5 for a demonstration flight without demonstrating both an on-pad abort or an in-flight abort (preferably at Max-Q). I believe Dream Chaser could work, but it can never be safe and therefore has to be discarded, just like Shuttle. |
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Dream Chaser, the SUV of spacecraft?
nasa has stated publically that launch abort is required for all manned launchers.
so you get dream chaser to make some unmanned cargo deliveries to iss then do what dragon is doing, test for launch abort escape...... |
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Dream Chaser, the SUV of spacecraft?
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Dream Chaser, the SUV of spacecraft?
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Dream Chaser, the SUV of spacecraft?
the earth is mostly oceans. so how is dream chaser going to land on the ocean?
capsules are unique they can land anywhere |
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Dream Chaser, the SUV of spacecraft?
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Dream Chaser, the SUV of spacecraft?
On Saturday, February 1, 2014 4:07:37 PM UTC-5, Fred J. McCall wrote:
bob haller wrote: the earth is mostly oceans. so how is dream chaser going to land on the ocean? capsules are unique they can land anywhere Not so much, Bob. If your capsule lands on water, you need some really big ships to recover you or you sink. Note that the first thing recovery teams did with capsule water landings was affix floatation and stability collars. They sort of have to be prepared for water landings. They also have to be specially designed for land landings, else they crack open like big eggs when they hit and all those soft humans die. Jesus, all those airliners can't land on water, either!!! What were we thinking??????? -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn soyuz normally lands on ground but can land in water... apoll capsules included flotation devices so presumably so would all capsule systems... divers would add more flotation once they arrived at the vehicle most airliners that dich in water have heavy losses.... capsules can survive a ballistic re entry, any winged vehicle would break up under those g loads;9 |
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Dream Chaser, the SUV of spacecraft?
On Saturday, February 1, 2014 8:57:50 PM UTC-5, Fred J. McCall wrote:
bob haller wrote: On Saturday, February 1, 2014 4:07:37 PM UTC-5, Fred J. McCall wrote: bob haller wrote: the earth is mostly oceans. so how is dream chaser going to land on the ocean? capsules are unique they can land anywhere Not so much, Bob. If your capsule lands on water, you need some really big ships to recover you or you sink. Note that the first thing recovery teams did with capsule water landings was affix floatation and stability collars. They sort of have to be prepared for water landings. They also have to be specially designed for land landings, else they crack open like big eggs when they hit and all those soft humans die. Jesus, all those airliners can't land on water, either!!! What were we thinking??????? soyuz normally lands on ground but can land in water... How nice for it. So what? Given the one real experience with a manned one making an accidental water landing, I'll leave that to you, Bob. Water landing of Soyuz is for EMERGENCIES ONLY. apoll capsules included flotation devices so presumably so would all capsule systems... divers would add more flotation once they arrived at the vehicle No, ALL capsule systems would not, because that stuff is extra weight and volume that you don't want to carry unless you're planning a water landing. most airliners that dich in water have heavy losses.... Yeah, and yet we fly them anyway. Getting the point yet? capsules can survive a ballistic re entry, any winged vehicle would break up under those g loads;9 Jesus, I wish you'd learn something before you bloviate so stupidly. Apollo max g was around 7.2 g coming back from the moon. Aerobatic planes hit 12 g and the wings stay on and nothing breaks up. Same for modern fighter aircraft. Hell, even some WWI aircraft could take 7 g. well a some soyuz have done a ballistic re entry of over 30Gs the capsule and crew survived even apollo capsule could land on ground in a real emergency. geez when did the shuttle ever break up on re entry? capsules are safer, and should be designed to land on land or water in a real emerrgency.... |
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Dream Chaser, the SUV of spacecraft?
In article ,
says... bob haller wrote: well a some soyuz have done a ballistic re entry of over 30Gs the capsule and crew survived Cite? Normal Soyuz reentry peaks at 5g or less. A particularly sharp reentry will get you up between 8g-10g. TMA-11, for example, took a little over 8g for a couple of minutes. He's very likely mis-remembering the Soyuz abort that happened due to a Soyuz launch vehicle failure. Let me look it up... http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39 Soyuz 7K-T No.39 was intended to be the second mission to take cosmonauts to the Soviet Salyut 4 space station for a 60-day mission. ... Only three of the six locks holding the stages together released and the third stage's engine ignited with the second stage still attached below it. ... At the time when the safety system initiated separation the spacecraft was already pointed downward toward Earth, which accelerated its descent significantly. Instead of the expected acceleration in such an emergency situation of 15 g (147 m/s²), the cosmonauts experienced up to 21.3 g (209 m/s²). Despite very high overloading, the capsule's parachutes opened properly and slowed the craft to a successful landing after a flight of only 21 minutes. And there you go, Bob's memory is a complete disaster, as always. The crew on this flight was very lucky, since the capsule exceeded the maximum design deceleration. :-( Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer |
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Dream Chaser, the SUV of spacecraft?
On 2/02/2014 8:07 AM, Fred J. McCall wrote:
bob haller wrote: the earth is mostly oceans. so how is dream chaser going to land on the ocean? capsules are unique they can land anywhere Not so much, Bob. If your capsule lands on water, you need some really big ships to recover you or you sink. Note that the first thing recovery teams did with capsule water landings was affix floatation and stability collars. They sort of have to be prepared for water landings. They also have to be specially designed for land landings, else they crack open like big eggs when they hit and all those soft humans die. It seems to me that either a capsule has a relative density less than one, and will float indefinitely, or it has a relative density greater than one, and will sink immediately. It's unlikely in the extreme to have a relative density greater than one, but so close to it that there's time for flotation devices to be attached. In practice, it's obvious that the capsules had relative densities much less than one, given that they remained largely above the surface of the water. Of course, all bets are off once you open the hatch, allowing the possibility of water ingress, which is no doubt the reason for the flotation devices. Sylvia |
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