Inspections have begun on Air Force space plane

On Dec 15, 10:41*pm, "Jonathan" wrote:
"Otis Willie PIO The American War Library"
wrote in messagenewsfbdg6pn0q2oa4bplpapggu6bu3f0v1b77@4ax .com...

Inspections have begun on Air Force space plane
http://www.spaceflightnow.com/news/n1012/12x37review

{EXCERPT} Spaceflight Now - Stephen Clark -- US Air Force and Boeing Co..
engineers will thoroughly review the performance of the first X-37B space
plane
before committing to launching...

Shouldn't it be noted that some recent prototypes, like the X-33
began as 1/3 scale of the intended final design.
And that the x-37b is about 30 feet long, and the shuttles
about 120 feet.

If the military decides to built a new 90 foot unmanned version
of the old shuttles, what would be the booster?


X-37 is not a prototype. It is just a test vehicle, an end in
itself. It is not a shuttle replacement.

On 12/20/2010 12:30 PM, Me wrote:

X-37 is not a prototype. It is just a test vehicle, an end in
itself. It is not a shuttle replacement.

They are going to build at least two of them (the second one is now
under construction) and use them both on multiple flights.

Pat

In article Q5OdnY-
hdakotatelephone,
says...

On 12/20/2010 12:30 PM, Me wrote:

X-37 is not a prototype. It is just a test vehicle, an end in
itself. It is not a shuttle replacement.

They are going to build at least two of them (the second one is now
under construction) and use them both on multiple flights.

True, but it's a reusable technology demonstrator. In order to prove
out the technologies, it necessarily needs to fly more than once.

Actually, this is a pretty smart way to go. With companies like SpaceX
trying to reduce launch costs, someone needs to figure out how to get
payload costs down. One potential way to do this is to make the
payloads reusable. In order to do that, you need a reusable orbital
vehicle on which to put those payloads.

Jeff
--
42

Me wrote:
No, this is not make payloads reusable. That was already possible
with the shuttle and it didn't provide any advantages and it
increases costs. Reconfiguration for recoverablility compromises
too many things.

Isn't Shuttle a rather extreme example of the increased costs? If so,
should it then tar all reusability?

rick jones
--
The computing industry isn't as much a game of "Follow The Leader" as
it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose."
- Rick Jones
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

On Dec 21, 8:35*am, Jeff Findley wrote:
In article Q5OdnY-
one,
says...



On 12/20/2010 12:30 PM, Me wrote:

X-37 is not a prototype. *It is just a test vehicle, an end in
itself. *It is not a shuttle replacement.

They are going to build at least two of them (the second one is now
under construction) and use them both on multiple flights.

True, but it's a reusable technology demonstrator. *In order to prove
out the technologies, it necessarily needs to fly more than once.

Actually, this is a pretty smart way to go. *With companies like SpaceX
trying to reduce launch costs, someone needs to figure out how to get
payload costs down. *One potential way to do this is to make the
payloads reusable. *In order to do that, you need a reusable orbital
vehicle on which to put those payloads.



No, this is not make payloads reusable. That was already possible
with the shuttle and it didn't provide any advantages and it increases
costs. Reconfiguration for recoverablility compromises too many
things.

Me wrote:
No, this is not make payloads reusable. That was already possible
with the shuttle and it didn't provide any advantages and it increases
costs. Reconfiguration for recoverablility compromises too many
things.

I think this is a false lesson. Sure this didn't work for the shuttle, but the
shuttle was crewed. This is un-crewed and can fly and re-fly for a fraction
of what it costs to launch the shuttle. The shuttle was a poor implementation
of an idea that the USAF has wanted since the earliest days of shuttle.

It is curious to speculate what would have happened with a military shuttle
had the Challenger accident not occurred. USAF was on a path to fly a shuttle
of their own, but it is interesting to speculate how long they would have been
able to keep it flying on their budget. Under budget constraints it is a fair
bet they would have ceased operations after only a few years anyway and turned
over their shuttle to NASA. Assuming it wasn't destroyed by a Centaur-G
Prime upper stage accident. There is no doubt grist for a great alternative
universe sci-fi / Tom Clancy story in there somewhere.

Also a pity that at least the VAFB shuttle launch facility was never made
operational. Had that also been turned over to NASA, it would have given them
a high inclination launch capability as well.

Dave

On 12/21/2010 11:10 AM, Rick Jones wrote:
wrote:
No, this is not make payloads reusable. That was already possible
with the shuttle and it didn't provide any advantages and it
increases costs. Reconfiguration for recoverablility compromises
too many things.

Isn't Shuttle a rather extreme example of the increased costs? If so,
should it then tar all reusability?

If payload weighs amount X, then using the X-37B to launch it is X plus
the 10,000 pound weight of X-37B itself. That's not the way to reduce
launch costs, because if you had just launched the payload alone you
could have either used a smaller booster or increased the payload weight
by 10,000 pounds. It's thought that X-37B carries a max payload of
around 500-750 pounds, so you pay a very high price in weight to get
your payload back.

Pat

On 12/21/2010 7:35 PM, David Spain wrote:


I think this is a false lesson. Sure this didn't work for the shuttle,
but the shuttle was crewed. This is un-crewed and can fly and re-fly for
a fraction of what it costs to launch the shuttle.

Not with an Atlas V launch every time you fly it...it puts around 750
pounds max into orbit with a launch cost of around $90-100 million.
Compared to Shuttle's launch cost per pound, that's pretty poor.
So you had better _really_ want that payload back with launch costs per
pound like that.

Pat

In article 30d1582e-7be4-496d-93d3-f5d4c99390b2
@l32g2000yqc.googlegroups.com, says...

On Dec 21, 8:35*am, Jeff Findley wrote:
True, but it's a reusable technology demonstrator. *In order to
prove
out the technologies, it necessarily needs to fly more than once.

Actually, this is a pretty smart way to go. *With companies like SpaceX
trying to reduce launch costs, someone needs to figure out how to get
payload costs down. *One potential way to do this is to make the
payloads reusable. *In order to do that, you need a reusable orbital
vehicle on which to put those payloads.


No, this is not make payloads reusable. That was already possible
with the shuttle and it didn't provide any advantages and it increases
costs. Reconfiguration for recoverablility compromises too many
things.

Shuttle is a launch vehicle *and* an orbital vehicle/reentry vehicle.
X-37 is *not* a launch vehicle. So, it can be far smaller and lighter
(no SSME's to haul back).

Shuttle is good for "lessons learned", but it's only a single data point
and we've got to be *very* careful to learn the *right* lessons from the
shuttle. One way to make sure you learn the right lessons is to fly X-
vehicles like X-37 to confirm (or deny) those "lessons" are the right
ones.

The nice thing about X-vehicles is that they're almost always relatively
cheap since you're planning on flying them a few times (to learn what
you need to learn), then you throw them away. You then incorporate what
you've learned into the next vehicle. This insures you're not locked
into a design which is sub-optimal for decades to come (like the
shuttle).

Jeff
--
42

In article
tatelephone,
says...

If payload weighs amount X, then using the X-37B to launch it is X
plus
the 10,000 pound weight of X-37B itself. That's not the way to reduce
launch costs, because if you had just launched the payload alone you
could have either used a smaller booster or increased the payload weight
by 10,000 pounds. It's thought that X-37B carries a max payload of
around 500-750 pounds, so you pay a very high price in weight to get
your payload back.

I agree an operational vehicle needs a higher payload fraction, but this
is an X-vehicle. Hopefully the lessons learned from X-37B can be
incorporated into later vehicles (X or operational) and any future
operational vehicle will have an acceptable payload.

Jeff
--
42