Re: Atmospheric Flight to Orbit

On Mar 4, 3:54 pm, simberg.interglo...@xxxxxxxxx (Rand Simberg) wrote:
On Sun, 4 Mar 2007 18:35:25 GMT, in a place far, far away,
h...@xxxxxxxxxxxxx (Henry Spencer) made the phosphor on my monitor
glow in such a way as to indicate that:

In article <1173018446.843660.109...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Alex Terrell <alexterr...@xxxxxxxxx> wrote:
The idea is not ridiculous, but whether you can get big cost reductions
that way is unproven, at best. A rocket first stage is not particularly
costly, especially if you can recover and reuse it; it is the upper stage
that's expensive to build and maintain. And big airplanes are expensive,
and *custom-built* big airplanes are very expensive.

T-Space have argued otherwise.

T/Space, so far, is using existing aircraft... and existing aircraft paid
for by other people, at that.

As long as they continue to get support from the Air Force. If the
blue suiters pull out, but DARPA wants to continue the program, it
would be interesting to see what they do. Go to Canada, perhaps? :-)

Unless things have changed recently, the
farthest they've suggested going toward a custom aircraft is putting
longer landing gear on a 747. (And note that even a stock 747 is a $200M
aircraft, unless you can get a good deal on an old used one.)

You actually can get a good deal on a used one, but they don't have
tail doors, do they? All of the 747Fs that I'm aware of are side
loaders.

I suspect they would argue that custom
built big planes were very expensive, when prototypes were needed and
then aluminium moldings. However, carbon fibre can be formed quite
cheaply in one-offs, and the simulations can be done on computer.

Yes, if all you want is an *experimental* aircraft, it might not be all
that costly any more. Something that can be certified -- so it can carry
cargo for paying customers -- is a very different kettle of fish. Getting
a new aircraft certified costs 10-100x the cost of the prototype. (And a
big all-new design by a new company is going to be at the high end.)

That's an interesting legal question. It seems to me that if that's
its only purpose, you simply declare it a flyback first stage, and get
a launch license for it with the rest of the vehicle. No
certification required. ;-)

Yes, as involved as a launch license may be,
it is far removed from the cost of certification
--assuming of course, a reasonable concept
for the launch vehicle.

And for some launch vehicle concepts lifting first
stages with a relatively low thrust-to-weight at
takeoff such as our own, it may be possible to do
a lot of of initial testing under experimental
aircraft rules. Moreover, much of our carrier
stage is now carbon fiber, which, as Henry
(I think) points out can be relatively cheap in
one-off prototypes.


In fact, I wonder if OSC got a special type certification for
Stargazer, when they modded the Tri-Star to carry Pegasus? If not,
they're flying "uncertified" as well. With paying customers.

As I understand it, Orbital was rather sorry they
picked a certified aircraft to modify. Messing
around with a certified aircraft can be costly.

Len

.

Relevant Pages

  • Re: Atmospheric Flight to Orbit
    ... A rocket first stage is not particularly ... T/Space, so far, is using existing aircraft... ... cargo for paying customers -- is a very different kettle of fish. ... certification required. ...
    (sci.space.policy)
  • Re: FAA Revoking Standard Airworthiness Certificate DG-505
    ... The glider was purchased for private use but keeping the standard ... certification would be paramount to its resale value. ... recognized by the small aircraft directorate at the FAA in Kansas City ... agreed upon in the purchase deal, and the flip flopping of the FAA 2 ...
    (rec.aviation.soaring)
  • Re: changing operating limitations
    ... > A maximum takeoff weight ... ... distinquish between "light sport aircraft", ... aircraft", and aircraft that can be flown by sport pilots. ... would have an experimental certification. ...
    (rec.aviation.homebuilt)
  • Re: Atmospheric Flight to Orbit
    ... rocket phase in the first stage's flight. ... "suborbital rocket" definition doesn't literally apply to an orbital ... pretty definitely an aircraft and certification applies. ... It almost certainly won't be a certified aircraft. ...
    (sci.space.policy)
  • Re: Mike Melville wearing no pressure suit
    ... >> the pilot was not wearing a full pressure suit. ... >aircraft certification; lots of stuff in the FAR's don't apply to ... >type certification requirements for suborbital spacecraft similar to SS1 ... It simply doesn't apply to launch vehicles. ...
    (sci.space.history)