Dream Chaser, any chance of this actually being flown?

Reading the recent press stuff from nasa, although I cannot quite put my
finger in on it one gets the serious feeling that Boiing and Space X are
getting preferential treatment to some extent. The lifting body idea is not
new of course but obviously requires more money to get it to be viable as a
robust design, and they seem to be behind in the 'race' so to speak.
Brian

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From the Sofa of Brian Gaff Reply address is active

In article , says...

Reading the recent press stuff from nasa, although I cannot quite put my
finger in on it one gets the serious feeling that Boiing and Space X are
getting preferential treatment to some extent. The lifting body idea is not
new of course but obviously requires more money to get it to be viable as a
robust design, and they seem to be behind in the 'race' so to speak.
Brian

I'd say it's very hard to tell at this point who NASA favors. There are
certainly those within NASA who believe that the one true way for
astronauts to return to earth is to land on the runway at Edwards AFB or
(even better) at the former space shuttle runway at KSC.

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

I think anyone who is not an astronaut by first choice might appreciate not
being landed in a tin can in the see or the middle of nowhere as the
Russians do.
Having heard a recording of a Soyuz re-entry it seems to be quite a ride,
with lots of bangs thuds buffeting, and other noises and quite a large
amount of g's, and the rather undignified roll over after the landing
rockets fire.

Brian

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From the Sofa of Brian Gaff Reply address is active
"Jeff Findley" wrote in message
...
In article , says...

Reading the recent press stuff from nasa, although I cannot quite put my
finger in on it one gets the serious feeling that Boiing and Space X are
getting preferential treatment to some extent. The lifting body idea is
not
new of course but obviously requires more money to get it to be viable as
a
robust design, and they seem to be behind in the 'race' so to speak.
Brian

I'd say it's very hard to tell at this point who NASA favors. There are
certainly those within NASA who believe that the one true way for
astronauts to return to earth is to land on the runway at Edwards AFB or
(even better) at the former space shuttle runway at KSC.

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

In article , says...

I think anyone who is not an astronaut by first choice might appreciate not
being landed in a tin can in the see or the middle of nowhere as the
Russians do.
Having heard a recording of a Soyuz re-entry it seems to be quite a ride,
with lots of bangs thuds buffeting, and other noises and quite a large
amount of g's, and the rather undignified roll over after the landing
rockets fire.

Somewhat true, at least for the final touchdown. But, Dragon V2 solves
the final touchdown problem by soft landing the capsule on landing gear
via rocket propulsion (Super Draco engines). The only commercial crew
design which uses parachutes and air bags for touch-down (or splash-
down) is Boeing's CST-100 capsule.

If given the choice between a gliding landing on a runway in a lifting
body or propulsive vertical landing, I'd personally choose the vertical
landing. But I'm not the NASA Astronaut Office who's been landing
gliders for decades, so they may have another preference.

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

So what about a capsule with inflatable wings like a hang glider. OK I have
seen pictures many years ago of tests of this idea and apparently, then it
was felt far too complex and error prone.
Brian

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From the Sofa of Brian Gaff Reply address is active
"JF Mezei" wrote in message
eb.com...
On 14-08-25 13:48, Jeff Findley wrote:

If given the choice between a gliding landing on a runway in a lifting
body or propulsive vertical landing, I'd personally choose the vertical
landing. But I'm not the NASA Astronaut Office who's been landing
gliders for decades, so they may have another preference.

Can you elaborate on your preference ?

Both techniques involve a "only one shot to land". And contrary to the
unar landers where the crew are in control o craft for minutes and see
descent slowing down etc, the capsules are in free fall (with
parachutes) with engines firing only at last minute to slow down to
landing speed. Miss that and you land rather hard.

In a glider scenario, I suspect the crew have much more time to get into
a controlled approach and failing this, they can bail out if they
realise the landing will fail.


However, I guess from the hot re-entry phase, a capsule gains advantages
over a glider whose attitude must remain within a very narrow set fo
acceptable numbers of face total destruction. A capsule is more
forgiving and self adjusting.

In article om,
says...

On 14-08-25 13:48, Jeff Findley wrote:

If given the choice between a gliding landing on a runway in a lifting
body or propulsive vertical landing, I'd personally choose the vertical
landing. But I'm not the NASA Astronaut Office who's been landing
gliders for decades, so they may have another preference.

Can you elaborate on your preference ?

Both techniques involve a "only one shot to land". And contrary to the
unar landers where the crew are in control o craft for minutes and see
descent slowing down etc, the capsules are in free fall (with
parachutes) with engines firing only at last minute to slow down to
landing speed. Miss that and you land rather hard.

Actually on Dragon V2, parachutes are there only for a backup landing
method (i.e. launch abort which uses Super Draco fuel to escape the
booster would leave no fuel reserve for propulsive landing). On a
normal landing, Dragon V2 lands by firing the Super Draco engines.

But your point is still valid. There is only enough fuel for "one shot
to land". I don't think it's designed for extended hover.

In a glider scenario, I suspect the crew have much more time to get into
a controlled approach and failing this, they can bail out if they
realise the landing will fail.

Lifting bodies tend to have horrible L/D ratios, like the shuttle, so
they'll suffer many of the same problems. Bailing out of the shuttle
was only an option if you were still very, very high up in the air. The
thing flew like a brick and there simply wasn't time to bail out at "the
last minute". Remember the M2-F2 lifting body crash which was used in
the opening sequence of The Six Million Dollar Man? Not a good day for
lifting bodies.

However, I guess from the hot re-entry phase, a capsule gains advantages
over a glider whose attitude must remain within a very narrow set fo
acceptable numbers of face total destruction. A capsule is more
forgiving and self adjusting.

Depends on the details. Dragon V2 and CST-100 will both fly hypersonic
lifting reentries similar to that of a lifting body. The advantage of
the lifting body during hypersonic reentry is that it can have higher
hypersonic L/D than a capsule and therefore more cross-range and lower G
loading during that phase of the flight. But you have to temper that
with the fact that the lifting body needs to hit a long runway with a
precise speed, altitude, and heading, where the capsule can come down on
pretty much any flat surface, or even water, in an emergency.

In short, the pilot of the lifting body has many more variables to
contend with and if things go bad near the runway, there is no time to
bail out and I don't believe Dream Chaser will have e-seats (which carry
with them their own dangers).

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

In article , says...

So what about a capsule with inflatable wings like a hang glider. OK I have
seen pictures many years ago of tests of this idea and apparently, then it
was felt far too complex and error prone.

This sort of thing was investigated for Gemini (e.g. Rogallo paraglider
wing), but was never fully developed.

NASA's Amazing Gliding Gemini Capsules
http://tinyurl.com/njajkey

From above, the first two pilots who tried to land the TTV (Gemini Test
Tow Vehicle) landed in the hospital. The first pilot (Charles Hetzel)
had to eject and broke a rib. The second manned test landed so hard (30
feet per second) that it was considered a controlled crash and the pilot
(Don McCusker) was in the hospital from the shock of the landing. The
third piloted test (Jack Swigert) was successful, but came far too late
for the technology to be incorporated into the fast paced Gemini
program.

That test program wasn't terribly successful.

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