Micro-Space >> Ultralight Manned Spaceflight

[QuantumG]

The comedy value of this thread is high.

[Jim]

1.  If it can stand the high temperatures, high speed, and high Gs of reentry explain why it couldn't take all this during launch. Also the Umanskiy Capsule was developed so that it could bring people up as well as down if you actually read the article. 

2. I see no reason why the shtil rocket
couldn't be man-rated just like any other rocket. But lets assume that the Shtil will never be man rated. This could still very well work.

3.  The Black Brant XII costs $600,000 per launch. It has a payload of 410 kg. Even if only a One person capsule can be taken this is still 83 times less than he $50 million per seat on the Soyuz. The current reliability is 98%. This was roughly the reliability of the Space Shuttle so it should be acceptable for the Manned Missions.

1.  They are not  designed for the same environments.  Use your google fu to find out how.

2.  No,   A submarine as a pad is a non starter.

3.  learn what it takes to put a man on a rocket.

a.  Black Brant is not orbital
b.  It has over 9 g's at liftoff
b.  The upperstage is too narrow to support a capsule

[neutrino78x]

Well, it stands to reason that "ultralight spaceflight" would be possible. I mean, you can go to sea in a nuclear powered Los Angeles Class submarine, or you can go to sea in a sail driven 16 foot (5 m) sailboat. The average person cannot afford the submarine, but they can afford the sailboat.

The biggest problem you have is that all the launch systems available right now are designed to launch Big Heavy Professional Payloads.

Well that and government red tape; there does not appear to be a simple, one form, one agency method of obtaining permission to attempt such a flight. Like, if you want to fly in your Cessna, all you do is file a flight plan with the FAA. I don't know if there is an analogous process for space flight.

Isn't there a group that's trying to do a low budget spaceflight infrastructure using balloons? The same people who do those suborbital videos?

--Brian

[Jason1701]

Isn't there a group that's trying to do a low budget spaceflight infrastructure using balloons? The same people who do those suborbital videos?

That's not spaceflight and never can be.

[neutrino78x]

That's not spaceflight and never can be.

Sure it is, you go up to the limits of what balloons can support, and then you go the last little bit using a rocket. The idea is that you have eliminated the densest part of the atmosphere. It gets you up there much more slowly, but also much more cheaply (in theory).

I think that group was planning to have a big platform up beyond the maximum altitude of a 747, and you would get up there using cheap aircraft, then you would go on a rocket that launches from the platform into space.

Ah, here it is JP Aerospace. "floating to orbit".

-Brian

[douglas100]

Sure it is, you go up to the limits of what balloons can support, and then you go the last little bit using a rocket. The idea is that you have eliminated the densest part of the atmosphere. It gets you up there much more slowly, but also much more cheaply (in theory).
-Brian

If you think that going from floating high in the atmosphere to orbital velocity is the "last little bit" then you don't understand the problem.

[strangequark]

That's not spaceflight and never can be.

Sure it is, you go up to the limits of what balloons can support, and then you go the last little bit using a rocket. The idea is that you have eliminated the densest part of the atmosphere. It gets you up there much more slowly, but also much more cheaply (in theory).

I think that group was planning to have a big platform up beyond the maximum altitude of a 747, and you would get up there using cheap aircraft, then you would go on a rocket that launches from the platform into space.

Ah, here it is JP Aerospace. "floating to orbit".

-Brian

To elaborate, being in orbit has nothing to do with your altitude. Even if a balloon could take you all the way up to 400 km altitude (where the ISS orbits), you would be stationary with respect to the ground, whereas the station would be zooming past you at 17,000 mph. To actually then enter the orbit, you would have to accelerate "sideways" (tangential to the Earth) to the same velocity. 90-95% of the energy you need to get to orbit is in your "sideways" velocity.

[tegla]

To elaborate, being in orbit has nothing to do with your altitude. Even if a balloon could take you all the way up to 400 km altitude (where the ISS orbits), you would be stationary with respect to the ground, whereas the station would be zooming past you at 17,000 mph. To actually then enter the orbit, you would have to accelerate "sideways" (tangential to the Earth) to the same velocity. 90-95% of the energy you need to get to orbit is in your "sideways" velocity.

Well, strictly speaking, if you could float up to geostac orbit, you don't need sideways velocity 

[D_Dom]

Wrong again, orbit is not equivalent to altitude.
http://www.merriam-webster.com/dictionary/orbit?show=1&t=1329837549
Velocity is the defining characteristic.

[dcporter]

Well, strictly speaking, if you could float up to geostac orbit, you don't need sideways velocity 

If you magically floated up to GEO altitude, the earth would rotate out from under you, and you'd have to go really fast to the east in order to catch up (exactly as described above).

[strangequark]

Well, strictly speaking, if you could float up to geostac orbit, you don't need sideways velocity 

If you magically floated up to GEO altitude, the earth would rotate out from under you, and you'd have to go really fast to the east in order to catch up (exactly as described above).

Angular momentum would be conserved. You would maintain some sideways velocity, but it would decrease.

EDIT: In any case, the original point remains. High altitude balloons only solve a small part of the problem, and add their own extra problems. The more important boost that you get is not from altitude but from the ability to use a low pressure, high expansion ratio engine, in a near vacuum, consequently improving specific impulse.