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Old June 1st 17, 11:27 AM posted to sci.space.policy,sci.physics
Fred J. McCall[_3_]
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Default US Military's XS-1 Space Plane Will Be Built by Boeing (Video)

"Robert Clark" wrote:


================================================= =================================
"Jeff Findley" wrote in message
...

In article ,
says...

"The U.S. military's new XS-1 space plane will be built by Boeing, and
it's called
the Phantom Express.

The Defense Advanced Research Projects Agency (DARPA) announced today (May
24) it
had selected Boeing for the next phase of its XS-1 project, known as the
Experimental Spaceplane, after an intense competition among aerospace
companies.
The XS-1 is aimed to be a completely reusable military space plane capable
of
launching 3,000-lb. (1,360 kilograms) satellites into orbit 10 times in 10
days.
The spacecraft could dramatically reduce the cost of launches to $5
million per
flight, DARPA officials said."

See:

http://www.space.com/36985-darpa-xs-...m-express.html


Big waste of money, IMHO. XS-1 is a VTHL winged launch stage powered by
SSMEs. It looks like a slightly warmed over version of Boeing's failed
bid for NASA's X-33 contract.

To be fair, I'd expect they're bidding what they know. Rockwell
International, the company who built the space shuttle orbiters, was
bought by Boeing many years ago. So, it doesn't surprise me that their
vehicle looks the way it does.

But expecting this to launch 10 times in 10 days and be cheap to operate
is a stretch, especially with the SSMEs powering the thing. The SSMEs
are being assembled from components that Aerojet Rocketdyne isn't using
for SLS, so that is a bit sketchy. My guess is they're not going to be
up to the latest "block" version of the SSME.

Jeff


Bob, cut the following line out of your replies, as it will cause most
newsreaders to simply delete everything after it since you don't quote
things.

--


"--" conventionally indicates 'end of article' and most newsreaders
stop copying when they see it.

================================================= ============================

Good point about the SSME's being used. Actually for a booster dense
propellants such as kerosene or methane are preferable. You could use
hydrogen for an upper stage based on the Boeing X-37, however. Then you
could have a fully reusable system.


The whole system as currently designed relies on a 'high energy' upper
stage powered by LH2/LOX, so the use of those propellants on the lower
stage just makes no sense at all.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw