T.R | Title | User | Personal Name | Date | Lines |
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301.1 | | VINO::DZIEDZIC | | Sun Jun 21 1987 20:50 | 8 |
| Responding to your related topic, the current development in subs
is toward "negative buoyancy" vessels, ie, ones which sink without
some power thrusting them upward. The cans with air in them don't
have the same degree of manuverability (compare an airplane with
a hot air balloon).
Not that this belongs in this notes file, but . . .
|
301.2 | | MONSTR::HUGHES | Gary Hughes | Mon Jun 22 1987 13:13 | 20 |
| Some random thoughts about .0...
The general philosophy with getting things into space has always
been to get it above the lower layers of the atmosphere as quickly
as possible to avoid using excessive reaction mass in fighting
aerodynamic drag.
There is probably some value in challenging that.
The X-15 program was intended to explore high speed, high altitude
flight. The fact that it could have been made into an orbital vehicle
was somewhat incidental (that doesn't mean that it should have been
ignored however).
There used to be high altitude sounding rockets launched by balloon,
Farside probably being the largest. They seem to have been replaced
by bigger convnetional rockets. The balloon launch seems to have
been a neccessity brought about by the available rocket motors.
gary
|
301.3 | Building a bridge to get there | EDEN::KLAES | The Universe is safe. | Mon Jun 22 1987 13:29 | 8 |
| While we're at it, why don't we just build one of those "space
elevators" - huge transportation towers that reach hundreds of miles
above Earth's surface - to deliver materials into Earth orbit?
But that's another Topic in itself.
Larry
|
301.4 | | REGENT::POWERS | | Wed Jun 24 1987 10:01 | 11 |
| > While we're at it, why don't we just build one of those "space
> elevators" - huge transportation towers that reach hundreds of miles
> above Earth's surface - to deliver materials into Earth orbit?
Because space elevators need to be mass-centered in geosynchronous orbit,
meaning the entire structure has to be well over 23,000 miles long (to reach
enough past the geosynch point to counterbalance.
The alternative of a real tower 200 miles tall is interesting, but
then you don't automatically have orbital velocity just by reaching the top.
- tom]
|
301.5 | hear say | MTBLUE::BARNABY_GALE | | Mon Sep 14 1987 00:38 | 4 |
| seems to me NASA was toying with the idea of a shuttle with jet
engines that would take off from a runway,once in low earths orbit
it would jetison the 2 engines which would be remote controlled
back to earth and the shuttle would then launch itself into orbit.
|
301.6 | use rocket engines only ? | VIDEO::OSMAN | type video::user$7:[osman]eric.six | Wed Sep 16 1987 16:38 | 18 |
| Why bother to be elaborate by jettisoning your jet engines. Just leave
them intact and use rocket engines when you've taken off.
o Better yet, attempt to use same engine housings for both
engines !
o Better yet, use same fuel for both engines
o (maybe better yet), use rocket engine to take off with, but
use runway instead of vertical. Then you'd only need one kind
of engine.
Of course, this might be too hot for blowing in airport mechanic's
face as you taxi out, so another idea might be helicoptor blade
to lift craft vertically, and then rocket engines start at
safe altitude.
/Eric
|
301.7 | wild ideas! | SAUTER::SAUTER | John Sauter | Thu Sep 17 1987 08:25 | 17 |
| re: .6--
Ack! The art of jet engine design is fairly mature, and the art
of rocket engine design is getting there. The two beasts are very
different: making one engine do both would result in a very inefficient
engine, by today's standards, I expect.
I have trouble imagining a helicopter with enough lifting capacity
to carry a rocket capable of enough delta-V to achieve orbit. The
big rockets are brought to Kennedy Space Center by barge because
they cannot be carried by any existing airframe. The shuttle can
be carried by a modified Boeing 747, but only after it has dropped
its External Tank.
(In fact, I think the big rockets are barged to KSC in pieces and
assembled there. Can anybody confirm this?)
John Sauter
|
301.8 | He's not heavy, he's my rocket! | TUNER::FLIS | | Thu Sep 17 1987 09:00 | 13 |
| re: .7
The 'big' rockets are barged to the cape (eg: Saturn V), but because
they are too *large*, not due to their weight. The first stage
of the Saturn had a dry weight of 286,600 lbs (this is with the
engines and shrouds installed) Sounds high, but the engines are
not shipped installed and they are the heaviest part of the stage.
The second stage has a dry weight of only 78,750 lbs, not much
more than the 3rd stage (at 24,900) which *is* flown in on the pregnant
guppy.
jim
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301.9 | Have you heard of HOTOL | PION::COSCONNOLLY | Gerry with G not jerry with a J | Thu Oct 22 1987 10:13 | 6 |
| re .0 and all jet engine replies
Have you heard of HOTOL !!!!!!!!!!!!!!!!!!!
Gerry
|