A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Policy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Dream Chaser, the SUV of spacecraft?



 
 
Thread Tools Display Modes
  #1  
Old January 29th 14, 10:32 PM posted to sci.space.policy
Anonymous Remailer (austria)
external usenet poster
 
Posts: 28
Default 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.

  #2  
Old January 30th 14, 05:25 AM posted to sci.space.policy
Bob Haller
external usenet poster
 
Posts: 3,197
Default 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......

  #3  
Old January 30th 14, 01:51 PM posted to sci.space.policy
Jeff Findley[_4_]
external usenet poster
 
Posts: 411
Default Dream Chaser, the SUV of spacecraft?

In article .at,
says...

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.


I'm not sure it's all that much "roomier".

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.


It's not really "winged", like the space shuttle was. It's a lifting
body. Quite a bit of difference. It's heritage can be traced back to
the 1960's when the US and USSR both were researching, and flying,
lifting body designs. Both countries flew test vehicles to space and
back.

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.


Never say never. My bet is that the road ahead of Dream Chaser is going
to be much more bumpy than the road ahead of Dragon and CST-100, just
because there is a wealth of experience with manned capsules. But, it's
very unclear which approach will win out in the long run.

Lifting bodies have not yet been flown manned to LEO and back, so there
is a large unknown there. At this point it time is it *not* clear
whether a capsule or lifting body will ultimately be safer. This is why
competition is a *good thing*. Innovation is enhanced by competition.

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
  #4  
Old January 30th 14, 09:51 PM posted to sci.space.policy
Jeff Findley[_4_]
external usenet poster
 
Posts: 411
Default Dream Chaser, the SUV of spacecraft?

In article ,
says...

Jeff Findley wrote:

In article .at,
says...

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.


I'm not sure it's all that much "roomier".


Pressurized volume of Dream Chaser is over 50% more than Dragon.


But how much of that is really usable? From the (few) drawings I've
seen, most of the space is taken up by seats for the crew, much like
Dragon. I deliberately chose a word like "roomier" because of this
issue. If you have pointers to decent pictures or drawings, I'd
appreciate a hyperlink. :-)

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.


It's not really "winged", like the space shuttle was. It's a lifting
body. Quite a bit of difference. It's heritage can be traced back to
the 1960's when the US and USSR both were researching, and flying,
lifting body designs. Both countries flew test vehicles to space and
back.


Actually, it's 'winged' exactly like the Space Shuttle was, which was
also a lifting body, but bigger. Lifting bodies are twitchy little
things to fly, especially at low speeds. Remember that scene at the
beginning of The Six Million Dollar Man? That was a real film of a
lifting body, the M2F2, that got just a little too twitchy on landing.
The pilot actually survived and returned to flight status.


I'll give you that one. The "stablizers" on Dream Chaser are rather
large and might as well qualify as wings.

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
  #5  
Old February 1st 14, 04:31 PM posted to sci.space.policy
Bob Haller
external usenet poster
 
Posts: 3,197
Default 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
  #7  
Old February 1st 14, 10:29 PM posted to sci.space.policy
Bob Haller
external usenet poster
 
Posts: 3,197
Default 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


  #8  
Old February 2nd 14, 03:40 PM posted to sci.space.policy
Robert Clark
external usenet poster
 
Posts: 1,150
Default Dream Chaser, the SUV of spacecraft?

On Wednesday, January 29, 2014 4:32:49 PM UTC-5, Anonymous Remailer (austria) wrote:
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.


The abort capability is to be provided by the Dream Chaser's onboard hybrid engines:

Sierra Nevada's 5-year partnership with NASA - Progress on Dream Chaser.
June 22, 2012 by Chris Gebhardt
http://www.nasaspaceflight.com/2012/...-dream-chaser/

Bob Clark
  #9  
Old February 2nd 14, 07:47 PM posted to sci.space.policy
Bob Haller
external usenet poster
 
Posts: 3,197
Default 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....
  #10  
Old February 3rd 14, 02:12 AM posted to sci.space.policy
Brad Guth[_3_]
external usenet poster
 
Posts: 15,175
Default Dream Chaser, the SUV of spacecraft?

On Sunday, February 2, 2014 6:40:12 AM UTC-8, Robert Clark wrote:
On Wednesday, January 29, 2014 4:32:49 PM UTC-5, Anonymous Remailer (austria) wrote:

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.




The abort capability is to be provided by the Dream Chaser's onboard hybrid engines:



Sierra Nevada's 5-year partnership with NASA - Progress on Dream Chaser.

June 22, 2012 by Chris Gebhardt

http://www.nasaspaceflight.com/2012/...-dream-chaser/


Bob Clark


An exploding butt rocket with an expanding fireball moving out at 5 km/sec, or even 2.5 km/sec, is going to be a tough fail to outrun.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Giant leap in race to replace space shuttle? Dream Chaser gets big boost. [email protected] Policy 0 January 31st 13 07:13 PM
Eclipse Chaser--How Contact Ernie Pianni (sp?) W. Watson Amateur Astronomy 0 October 27th 07 12:59 PM
GROND Takes Off: First Light for Gamma-Ray Burst Chaser at ESO La Silla (Forwarded) Andrew Yee[_1_] News 0 July 11th 07 05:36 PM
Rosetta comet-chaser takes a close look at planet Mars (Forwarded) Andrew Yee Astronomy Misc 0 February 25th 07 06:03 AM
what TPS on Dream Chaser? Joe Strout Policy 6 June 30th 06 02:52 PM


All times are GMT +1. The time now is 09:28 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.