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Siguy
2009-Apr-08, 02:29 AM
The Russian Rockot can launch a 1,950 kg payload to LEO, which is, coincidentally, the mass of a Mercury spacecraft. Now I don't think anyone would pay $13 million+ for a risky claustrophobic 34-hour one person cruise in space when you could spend $20 million on a two week journey to the ISS on a Soyuz. It's still interesting to consider "space yachts" though. How lightweight do you think a one person spacecraft capable of docking with the ISS could be using today's technology?

Larry Jacks
2009-Apr-08, 01:07 PM
It's an interesting thought exercise. I remember reading a proposal back in the 1980s for a simple spaceplane concept. IIRC, it was launched on an expendable into orbit. The single pilot depended on his spacesuit because the vehicle was unpressurized and didn't have a regular life support system. The propulsion system was simple with a lot of delta-v capacity. To simplify the design, the spaceplane portion was optimized for hypersonic (above Mach 5) and supersonic flight but used a ram-air parachute (similar to the ones skydivers use) for the final descent to landing. Now that I think of it, many of the same concepts (other than the life support) were incorporated into the X-38/Crew Rescue Vehicle concept.

Back to the OP. Mercury capsules were very small and cramped. They lacked any computers and only had attitude control, meaning they couldn't change the orbit in space. Modern materials would allow you to build a somewhat larger version of the Mercury capsule with computers and a real propulsion system with the same mass as the original. It might be a stretch to give it enough maneuvering capacity to perform a rendezvous with the ISS and you'd need a docking adaptor to actually hook up. That adapter alone could well drive up the mass considerably given the size.

KaiYeves
2009-Apr-08, 02:21 PM
I remember when I saw the Mercury capsule on display at Space Academy.

First, I went "Nobody can fit in there!"

Then I took a closer look and went "Well, maybe I could, just barely, but I wouldn't like it." (I am exactly five feet tall and rather compact.)

And then I went "But an adult man? Ouch!"

Ilya
2009-Apr-08, 04:20 PM
I remember when I saw the Mercury capsule on display at Space Academy.

First, I went "Nobody can fit in there!"

Then I took a closer look and went "Well, maybe I could, just barely, but I wouldn't like it." (I am exactly five feet tall and rather compact.)

And then I went "But an adult man? Ouch!"

An adult man in a spacesuit. Ouch indeed.

Ilya
2009-Apr-08, 04:22 PM
If you want to be truly minimalist, go with something like MOOSE (http://www.astronautix.com/craft/moose.htm). No spacecraft at all, just a spacesuit that can (theoretically) survive re-entry.

Larry Jacks
2009-Apr-08, 05:51 PM
IIRC, the Mercury astronauts were limited to being no taller than about 5' 10" or so. If they were any taller, they wouldn't fit especially when wearing a space suit. The capsule was almost as claustrophobia inducing as the space suit itself. You didn't get into a Mercury capsule, you put it on!

MOOSE has always fascinated me. If it worked, it would be the ultimate in skydiving. YEEEEE HAAA!

Trakar
2009-Apr-08, 11:18 PM
IIRC, the Mercury astronauts were limited to being no taller than about 5' 10" or so. If they were any taller, they wouldn't fit especially when wearing a space suit. The capsule was almost as claustrophobia inducing as the space suit itself. You didn't get into a Mercury capsule, you put it on!

MOOSE has always fascinated me. If it worked, it would be the ultimate in skydiving. YEEEEE HAAA!

If all you're looking for is an orbital height dive into the atmosphere, you don't really need a lot of re-entry protection. Most of the typical re-entry heat comes from bleeding off orbital or transfer orbital energies. Popping up to orbital height ballistically doesn't involve imparting near as much energy into the payload. You'l definitely go supersonic, and you'll probably want something to retard you from going too far into that regime, but such could be as simple as a small drag chute.

Van Rijn
2009-Apr-09, 01:07 AM
If you want to be truly minimalist, go with something like MOOSE (http://www.astronautix.com/craft/moose.htm). No spacecraft at all, just a spacesuit that can (theoretically) survive re-entry.

I remember the Vostok has been mentioned on BAUT before, which was essentially a small round ball, and the cosmonaut climbed out at about 7 km altitude and parachuted down seperately. The Vostok itself had parachutes, but hit the ground hard.

As far as room goes, the Gemini had a little more room per person, but there were two week Gemini missions. I doubt I could have handled that.

Van Rijn
2009-Apr-09, 01:16 AM
I remember when I saw the Mercury capsule on display at Space Academy.

First, I went "Nobody can fit in there!"

Then I took a closer look and went "Well, maybe I could, just barely, but I wouldn't like it." (I am exactly five feet tall and rather compact.)

And then I went "But an adult man? Ouch!"

You probably wouldn't have liked the Vostok 3KV. That was the one man Vostok refitted for three people:

http://en.wikipedia.org/wiki/Voskhod_spacecraft

They didn't have space suits, and it was designed to land more softly so the cosmonauts didn't have to eject first, but they had to be packed in like sardines in there.