National Aerospace Plane (X-30) announced 20 years ago

"Mike Swift" wrote in message
...
In article ,
David Given wrote:

[...]
SpaceShipOne only got 1/3rd the way there and that wasn't SSTO, it was
two staged, carried on White Knight.

No. No, it didn't. SS1 reached Mach 3. Orbit is about the equivalent of
Mach
25. That's 1/8 of the way.

Actually it much worse than 1/8 of the way. In terms of energy that
eight to one velocity increase takes 128 times more energy. As you can
see SpaceShipOne was far from getting to orbit.

The intention was never to get it into orbit. The question to ask yourself,
is if NASA were given the task to create a reusable vehicle to carry three
people to 50 miles altitude and back, what would *that* have cost? Ask the
same question only substitute any large aerospace contractor for NASA.

Jeff
--
Remove icky phrase from email address to get a valid address.

dan wrote:
The liquid air cycle (i.e. hotol) is less speed sensitive but
there's no easy way to carry enough cooling capacity to actually
liquify all the air you need. Best bet might essentially be a
cooled-inlet turbojet.

Alternately, there is SABRE.
http://en.wikipedia.org/wiki/SABRE

Which might be that "cooled inlet turbojet" you mentioned.

After attacking the SSTO problem
for awhile, at some point a two-stage solution begins to look more
practical.

Yes, though sometimes the SSTO looks tempting, like when you find a
very lightweight dense fuel design.

Mike Miller

Ian Woollard wrote:

mike Williamson wrote:

The big downside of wings is after you leave the atmosphere- wings push
up dry mass, and then it is very easy to lose everything that was
gained during ascent and then some; a good mass ratio is essential
particularly toward the end of the burn.

Mike

Which is another excellent reason to look at TSTO rather than STSO with
current technology.

--
Malcolm Street
Canberra, Australia
The nation's capital

In article .com,
"dan" wrote:

Exactly. Almost all the cost for the Shuttle is the maintenance needed
between flights. Some parts, like the SRBs, are completely
disassembled, stripped to bare metal (even the nuts and bolts),
inspected for cracks, and remanufactured.

Could you please give an example of an SRB segment that has been reused,
including the flight on which it was first used, and the flight on which
it was reused.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

"Bruce Hoult" wrote in message
...
Could you please give an example of an SRB segment that has been reused,
including the flight on which it was first used, and the flight on which
it was reused.

Odd request, considering that SRB segment reuse is the norm, not the
exception.

One bit of trivia. The parachutes for the SRB's have to be washed between
flights, due to their being dunked in salt water at the end of every flight.
That task must require the world's largest washing machine. ;-)

Jeff
--
Remove icky phrase from email address to get a valid address.

"Jeff Findley" wrote in message
...

"Bruce Hoult" wrote in message
...
Could you please give an example of an SRB segment that has been reused,
including the flight on which it was first used, and the flight on which
it was reused.

Odd request, considering that SRB segment reuse is the norm, not the
exception.

One bit of trivia. The parachutes for the SRB's have to be washed between
flights, due to their being dunked in salt water at the end of every
flight.
That task must require the world's largest washing machine. ;-)

There are pictures of it on the net, but I forget where.

Jeff Findley included:

"Bruce Hoult" wrote in message
...
Could you please give an example of an SRB segment that has been reused,
including the flight on which it was first used, and the flight on which
it was reused.

Odd request, considering that SRB segment reuse is the norm, not the
exception.

So give the requested example. I'm curious too.

The norm is not established by zero examples,
nor by NASA statements that say reuse is possible but
nowhere that it has happened.


--- Graham Cowan, former hydrogen fan
Boron: internal combustion, nuclear cachet http://tinyurl.com/4xt8g