Did Mercury and Gemini use the same capsule?

[dotancohen]

I've been looking for information on the design of the Mercury and Gemini capsules. I know that Mercury was a single seater and Gemini a two seater, and I know that the retro rockets were completely different. But other than that the two capsules seem very similar. Was the Gemini capsule a derivative of the Mercury capsule? Is the style (even the ribs on the bodywork) just the best way to get the job done, resulting in a similar appearance for completely different projects (Like the STS and Buran orbiters)?

For that matter, why is the bodywork ribbed? Is it to dissipate heat on reentry? It sure looks like the _opposite_ of what one would expect from an aerodynamic viewpoint, at least for launch.

Thanks!

 

[russ_watters]

Googling the dimensions will tell you they are not the same capsule. Yes, the design is similar because the design constraints are similar, plus the people who designed them were the same people! I wouldn't use the Buran and Space Shuttle as an example, though, as the Buran was likely an actual copycat design. Note that our capsules and the Russians' capsules look nothing alike.

The ribs are for expansion when heated, so they don't deform (the SR-71 was also ribbed) and the capsule was not designed to be aerodynamic. The purpose of the shape was to dissipate heat and slow it down.

 

[dotancohen]

Googling the dimensions will tell you they are not the same capsule. Yes, the design is similar because the design constraints are similar, plus the people who designed them were the same people! I wouldn't use the Buran and Space Shuttle as an example, though, as the Buran was likely an actual copycat design. Note that our capsules and the Russians' capsules look nothing alike.

I did understand that it was not the _exact_ same capsule, but even my Ford Focus has different dimensions than the Mazda 3, even though they are both based on the same chassis. That is why I figured that it may be a derivative design. I did not realize that it was the same people who designed them both! I wonder did they start with a blank sheet of paper and come to similar conclusions for Gemini, or did they start with some Mercury components and build from there.

The ribs are for expansion when heated, so they don't deform (the SR-71 was also ribbed) and the capsule was not designed to be aerodynamic. The purpose of the shape was to dissipate heat and slow it down.

Thanks, I did not know that the Blackbirds were also ribbed. That is interesting, I remember once reading about how they would expand, in fact I think that they leaked fuel when cool on the ground. They would heat up the airframe then refuel in flight.

 

[Ophiolite]

For technical details on just about any aspect of manned space exploration you cannot do better than http://astronautix.com/" .

The specifics on http://astronautix.com/project/mercury.htm" can be found via the links.

 

[dotancohen]

Thank you Ophiolite! That is a great site!

It also pretty much confirms what I had suspected: "Gemini was conceived as an 'upgraded Mercury' "