Reaching orbit cheaply through riding airstreams

Mike Dworetsky wrote:

You get the maximum extra orbital speed taking off from near the equator
(roughly 1000 kph).

Actually that's about 1000 mph, even greater and about 6% of the
velocity needed.

The other problem is that rockets are pretty complicated pieces of machinery
and lots can go wrong that would require significant infrastructure to fix
before a launch. You would have to bring all that (people, equipment,
infrastructure, etc) along with you to the platform.

Such a 'platform', if ever built, would not be a balloon but a
real tower, which is practical to at least 100,000 ft if you can
spend enough money.

So not practical, but having a huge flying first stage that is fully
reusable and does not have to endure re-entry may be practical. It's been
discussed but not done on a large scale.

Yes, this is probably the ideal way to get to space. Wasn't it
the first concept for the Space Shuttle, that was then abandoned
for developement cost reasons? The rocket stage should probably
also be reusable.

Andrew Usher

Dear Andrew Usher:

On Jul 26, 5:32*am, Andrew Usher wrote:
Mike Dworetsky wrote:
You get the maximum extra orbital speed taking off from
near the equator (roughly 1000 kph).

Actually that's about 1000 mph, even greater and about 6%
of the velocity needed.

But still only 0.3% of the energy required, and a single propensity
for final orbital momentum.

The other problem is that rockets are pretty complicated
pieces of machinery and lots can go wrong that would
require significant infrastructure to fix before a launch. *You
would have to bring all that (people, equipment,
infrastructure, etc) *along with you to the platform.

Which could use an elevator.

Such a 'platform', if ever built, would not be a balloon but a
real tower, which is practical to at least 100,000 ft if you can
spend enough money.

Fuller's "Cloud Nines" could be used, should such be better than a
fixed terrorist target.

But such a structure (either tower or balloon) should only be the
starting point. Landings should not be attempted there.

So not practical, but having a huge flying first stage that
is fully reusable and does not have to endure re-entry may
be practical. *It's been discussed but not done on a large scale.

Yes, this is probably the ideal way to get to space. Wasn't it
the first concept for the Space Shuttle, that was then abandoned
for developement cost reasons? The rocket stage should probably
also be reusable.

I still don't understand why we don't use a catapult, for maximum
efficiency (shy of a space elevator).

David A. Smith

dlzc wrote:
Dear Andrew Usher:

On Jul 26, 5:32 am, Andrew Usher wrote:
Mike Dworetsky wrote:
You get the maximum extra orbital speed taking off from
near the equator (roughly 1000 kph).

Actually that's about 1000 mph, even greater and about 6%
of the velocity needed.

But still only 0.3% of the energy required, and a single propensity
for final orbital momentum.

The other problem is that rockets are pretty complicated
pieces of machinery and lots can go wrong that would
require significant infrastructure to fix before a launch. You
would have to bring all that (people, equipment,
infrastructure, etc) along with you to the platform.

Which could use an elevator.

Such a 'platform', if ever built, would not be a balloon but a
real tower, which is practical to at least 100,000 ft if you can
spend enough money.

Fuller's "Cloud Nines" could be used, should such be better than a
fixed terrorist target.

But such a structure (either tower or balloon) should only be the
starting point. Landings should not be attempted there.

So not practical, but having a huge flying first stage that
is fully reusable and does not have to endure re-entry may
be practical. It's been discussed but not done on a large scale.

Yes, this is probably the ideal way to get to space. Wasn't it
the first concept for the Space Shuttle, that was then abandoned
for developement cost reasons? The rocket stage should probably
also be reusable.

I still don't understand why we don't use a catapult, for maximum
efficiency (shy of a space elevator).

David A. Smith

Depends on how fast and at what altitude you would eject from the end, and
would your journey inside be in vacuum or in ambient air pressure?

If Earth was a world without an atmosphere that would work fine. I suppose
you could build one that would accelerate the upper stages to around the
speed of sound, but I would think hypersonic would be a problem due to
heating and air resistance.

Given the likely cost, a first rocket stage is probably more economic.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Dear Mike Dworetsky:

On Jul 26, 9:08*am, "Mike Dworetsky"
wrote:
dlzc wrote:
On Jul 26, 5:32 am, Andrew Usher wrote:
Mike Dworetsky wrote:
You get the maximum extra orbital speed taking off from
near the equator (roughly 1000 kph).

Actually that's about 1000 mph, even greater and about 6%
of the velocity needed.

But still only 0.3% of the energy required, and a single propensity
for final orbital momentum.

The other problem is that rockets are pretty complicated
pieces of machinery and lots can go wrong that would
require significant infrastructure to fix before a launch. You
would have to bring all that (people, equipment,
infrastructure, etc) along with you to the platform.

Which could use an elevator.

Such a 'platform', if ever built, would not be a balloon but a
real tower, which is practical to at least 100,000 ft if you
can spend enough money.

Fuller's "Cloud Nines" could be used, should such be better
than a fixed terrorist target.

But such a structure (either tower or balloon) should only
be the starting point. *Landings should not be attempted
there.

So not practical, but having a huge flying first stage that
is fully reusable and does not have to endure re-entry may
be practical. It's been discussed but not done on a large
scale.

Yes, this is probably the ideal way to get to space. Wasn't
it the first concept for the Space Shuttle, that was then
abandoned for developement cost reasons? The rocket
stage should probably also be reusable.

I still don't understand why we don't use a catapult, for
maximum efficiency (shy of a space elevator).

Depends on how fast and at what altitude you would eject
from the end, and would your journey inside be in vacuum or
in ambient air pressure?

Elevation: 2 miles (say), launched off mountains as a support.
Vacuum internally.
~1000 miles of approach "ramp", most undergound.

If Earth was a world without an atmosphere that would
work fine.

No propellant used to lift a "first stage". Ditto the rest of the
rocket.

*I suppose you could build one that would accelerate
the upper stages to around the speed of sound,

Solitons allow us to deliver at multiples of the speed of sound. Just
need a soliton (or a series) generated at the exit of the ramp.

Shorter ramps with higher accelerations for food, fuel and parts.

but I would think hypersonic would be a problem
due to heating and air resistance.

Given the likely cost, a first rocket stage is probably
more economic.

Not sure I'd agree. But then I haven't run the math. But it is
surety that it is not economic if it gets it legs cut out from under
it with each new Congress / Administration.

David A. Smith