Why not this shape for CEV?

The Stardust reentry capsule looks like it worked.

"http://www.nasa.gov/mission_pages/stardust/multimedia/capsule-1.html"

Why does CEV have to be a cone? Wouldn't a more efficient
shape, that could provide more useful interior space, look
more like Stardust?

- Ed Kyle

I have actually been trying to promote a saucer shape as a very good
re-entry alternative. You can control the re-entry drag by changing the
attitude. It develops lift that allows maintanence of altitude thereby
reducing G loads and heat load as well. Out in space you can point it
edge-wise to the Sun and also to the Earth thereby allowing good
thermal control. After re-entry you can glide it and get good cross
range.

zoltan wrote:
I have actually been trying to promote a saucer shape as a very good
re-entry alternative. You can control the re-entry drag by changing the
attitude. It develops lift that allows maintanence of altitude thereby
reducing G loads and heat load as well. Out in space you can point it
edge-wise to the Sun and also to the Earth thereby allowing good
thermal control. After re-entry you can glide it and get good cross
range.
Ok, but how are you going to get it up?
Even if you do it sideways, it is a lot more susceptible to
wind and minimal angle changes than the space shuttle or a sojuz.

Lots of Greetings!
Volker

On 15 Jan 2006 20:58:02 -0800, "Ed Kyle" wrote:

The Stardust reentry capsule looks like it worked.

"http://www.nasa.gov/mission_pages/stardust/multimedia/capsule-1.html"

Why does CEV have to be a cone? Wouldn't a more efficient
shape, that could provide more useful interior space, look
more like Stardust?

Isn't Apollo's more rounded heat shield meant to generate lift,
something Stardust (and Viking, and Pathfinder, and MER, and
Huygens... all of which used the same shape, if memory serves) didn't
care all that much about?

By the way, Stardust looks a lot like a truncated cone to me. The
difference between it and Apollo is that Stardust doesn't have the LM
tunnel sticking up from the middle (Apollo's was surrounded by
parachutes pre-splashdown). Stardust's chute is gone in that photo,
otherwise, it's main body is Apollo.

Brian

"Ed Kyle" wrote in message
oups.com...
The Stardust reentry capsule looks like it worked.

"http://www.nasa.gov/mission_pages/stardust/multimedia/capsule-1.html"

Why does CEV have to be a cone? Wouldn't a more efficient
shape, that could provide more useful interior space, look
more like Stardust?


yeah, but you have to be real careful not to scorch the cornmeal on the
bottom of the pan

Brian Thorn wrote:
On 15 Jan 2006 20:58:02 -0800, "Ed Kyle" wrote:

The Stardust reentry capsule looks like it worked.

"http://www.nasa.gov/mission_pages/stardust/multimedia/capsule-1.html"

Why does CEV have to be a cone? Wouldn't a more efficient
shape, that could provide more useful interior space, look
more like Stardust?

By the way, Stardust looks a lot like a truncated cone to me. The
difference between it and Apollo is that Stardust doesn't have the LM
tunnel sticking up from the middle (Apollo's was surrounded by
parachutes pre-splashdown). Stardust's chute is gone in that photo,
otherwise, it's main body is Apollo.

You're right. The cone angle does look to be about the same as
Apollo and the proposed CEV. It is the heat shield that is
different.

I suppose I am wondering why a cone won out for CEV over a
flatter side wall shape, perhaps something like Soyuz, which
could provide better interior space.

- Ed Kyle

In article .com,
Ed Kyle wrote:
The Stardust reentry capsule looks like it worked.
"http://www.nasa.gov/mission_pages/stardust/multimedia/capsule-1.html"
Why does CEV have to be a cone? Wouldn't a more efficient
shape, that could provide more useful interior space, look
more like Stardust?

The difference isn't as large as you might think. Look at that picture,
and note that the right-hand side -- the aft side during reentry -- is a
truncated cone. Extend that cone farther, and you've got very nearly the
CEV's shape. The only difference is that the heatshield surface -- the
left side in the picture -- bulges out slightly more, since it's a rounded
cone rather than a section of a sphere.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Mon, 16 Jan 2006 10:56:51 +0100, Volker Hetzer
wrote:

zoltan wrote:
I have actually been trying to promote a saucer shape as a very good
re-entry alternative. You can control the re-entry drag by changing the
attitude. It develops lift that allows maintanence of altitude thereby
reducing G loads and heat load as well. Out in space you can point it
edge-wise to the Sun and also to the Earth thereby allowing good
thermal control. After re-entry you can glide it and get good cross
range.
Ok, but how are you going to get it up?

http://au.geocities.com/psyberplasmic/ccX-6.html

Even if you do it sideways, it is a lot more susceptible to
wind and minimal angle changes than the space shuttle or a sojuz.

Lots of Greetings!
Volker
--

Christopher