Author Topic: Dream Chaser making impressive progress ahead of CCDev-3  (Read 153107 times)

Online clongton

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #400 on: 06/27/2012 11:55 PM »
A winged or lifting body shaped spacecraft is ill suited for any kind of BEO operations. The question is not "can they safely reenter at BEO velocity", but "why should we deploy them BEO at all"?

Your asking the wrong question.   If you were riding back to earth which way would you wish to land? 

I don't think so. It's the right question. It's not a matter of g-load on a crew member or the comfort level of the re-entry. It's a matter of efficient use of volume. A BEO spacecraft must pack a lot of stuff into extremely tight spaces and crew members require habitable volume, which must be considerate of the human form. A winged or lifting body shape wastes too much volume in its shape, volume that cannot be used for crew habitation or devices or supplies to support human crew. For example five cubic meters may sound like a lot of volume but it's wasted volume if it is shaped in a form that a human body cannot fit into.

To answer your question, I would prefer the more comfortable return to surface at a 1-g load afforded by a winged or lifting body shape, but if that same spacecraft executes a long term BEO mission, I would trade the comfortable ride down, which lasts only half an hour, for comfortable living space while on the BEO mission for several months.
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I started my career on the Saturn-V F-1A engine

Offline TomH

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #401 on: 06/28/2012 12:11 AM »
To answer your question, I would prefer the more comfortable return to surface at a 1-g load afforded by a winged or lifting body shape, but if that same spacecraft executes a long term BEO mission, I would trade the comfortable ride down, which lasts only half an hour, for comfortable living space while on the BEO mission for several months.

But is it not true that on any mission that long, regardless of what is used for the launch and landing, there will be a crew habitation module in use for most of the voyage. The capsule or spaceplane will need to be in dormant mode for most of the time. Right?

Online docmordrid

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #402 on: 06/28/2012 12:22 AM »
If it's to be dormant it should be as light as possible to reduce the mission fuel requirements. ISTM that is easiest to accomplish with a capsule.
DM

Online clongton

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #403 on: 06/28/2012 12:39 AM »
If it's to be dormant it should be as light as possible to reduce the mission fuel requirements. ISTM that is easiest to accomplish with a capsule.

That is correct. All the material it takes to make the wings or lifting body shape is wasted mass in a BEO spacecraft.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Silmfeanor

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #404 on: 06/28/2012 12:45 AM »
If it's to be dormant it should be as light as possible to reduce the mission fuel requirements. ISTM that is easiest to accomplish with a capsule.

That is correct. All the material it takes to make the wings or lifting body shape is wasted mass in a BEO spacecraft.
Also, you don't have to worry about damage to the TPS as the TPS is protected in the capsule designs.
But these are old arguments and a different discussion - and there have been lots of threads.
Perhaps we should get back to the nice baby-shuttle and updates about it/her (?)

Offline mmeijeri

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #405 on: 07/08/2012 03:29 PM »
It's a showstopper. The aerobraking must be single-pass.

On a slightly off-topic note: what about an MTV? Wouldn't it be expected to have an adequate storm shelter to safely allow multiple passes? Would such a shelter be too heavy for a future beyond-LEO Dream Chaser?
We will be vic-toooooo-ri-ous!!!

Offline krytek

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Re: Dream Chaser making impressive progress ahead of CCDev-3
« Reply #406 on: 07/08/2012 04:27 PM »
As much as I love the concept, BEO Dream Chaser is probably one of the worst ideas.

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