In the 1960’s Americans and the Russians took different approaches toward designing manned spacecraft. Apollo consisted of two modules: command and service. All the living space for the whole mission was in the command module and all the extra support equipment was in the service module. Soyuz, by contrast consisted of three modules: mission, re-entry, and service. The astronaut’s living quarters were split into a minimal capsule that was shielded for re-entry and an expanded mission space that would be used in orbit, but would be jettisoned before returning to earth.
Everything I’ve read online suggests that the Soyuz approach is superior. By minimizing the amount of stuff you need to shield for re-entry you get a big savings in weight. The three-module Soyuz system could carry more stuff into orbit with less thrust. And it’s flexible design means that its still in use decades after it was originally created.
So, since the Orion capsule is being carefully designed from scratch as a completely new manned spacecraft, why are they using the same configuration that Apollo settled on during the quick and dirty rush to the Moon in the 1960’s? (There was even an alternate Apollo proposal from GE back then that used the Soyuz configuration.) Is there some hidden advantage to the two-module configuration that I’m missing? Or is it just a case of not wanting to look like we’re copying the Russians?
I’ve read a fair bit about the Soviet philosophy of spacecraft and aircraft design, and I’d say it’s very different from how Americans have historically approached both endeavors.
Generally, the Soviets did things much more simply, to the point of being utilitarian. I believe this was out of necessity - the former USSR not having the deep pockets we did. They also had harsh weather conditions, which sometimes dictated design choices.
A good example is to compare the Korean War era MiG-15 fighter with its U.S. counterpart, the F-86 Sabre. The Sabre was a more complex machine in a few ways, and was more demanding of maintenance and operating conditions. The MiG was designed to be flown from unprepared fields by minimally trained pilots. Mechanically, it was much simpler. There were no hydraulics, for example. To overcome this, the MiG’s control stick was very long to give the pilot mechanical advantage. This is not just my reading about it by the way - I actually flew a MiG once (under instruction, not solo)!
I’ve read some accounts of current operators of both types, and they say the F-86 is much more of a maintenance hog. Great airplane - just one that was built with a different philosophy and needs more care.
Also look at the MiG-25’s design, and you’ll see how they cut every corner they could to just make it do the job with minimal outlay and complexity. I’m sure they went at spacecraft the same way.
Another factor is that the new Orion was designed to be reusable, up to 10 ten times. And although the so-called ‘reusable’ Shuttle made it horribly inefficient & expensive because its such a huge and complex machine, reusing a small command module (and only 10x) is actually a workable design.
Obama has proposed cancelling Project Constellation, of which the Orion vehicle is part, but it is still being developed by NASA to hopefully be included in Constellation’s replacement.
Question: how did the Russians get away (on the Soyuz) without the massive heat shield that Apollo used?
Does Soyuz land at a slower speed (larger parachutes)?
I always wondered why the US went for water landings, instead of on land (like the Russians).
The Soyuz reentry module does have a massive heat shield. They just leave more of the spacecraft behind, so the reentry module (and its heat shield) is relatively small. It does also have a braking rocket that fires just before landing, which makes for a reasonably soft landing on, er, land.
Three modules is a lot more complex and potentially dangerous than two modules. The only death in space was via a Soyuz capsule. Equalizing the pressure between the two cabins (orbiting and descent) fail and killed all three cosmonauts on board. Having two crew cabins adds risk, thus a simpler design is probably the better way to go.
Although the Soyuz design did maximize usable habitat space as compared to Apollo, it is hard to say whether it is a “superior” design from all standpoints. Because of the way the space is partitioned, it is harder to add crewspace, or to scale it up linearly. The Apollo is also designed for a “broad open area” blue water landing mode and stable buoyancy prior to recovery, whereas the Soyuz capsule is intended for a solid ground landing in sparse tundra and can only tolerate shallow water landing. Also realize that the Apollo Service Module (SM) is far more capable (in terms of endurance and impulse) than the Soyuz instrumentation/propulsion module (PAO). Apollo was purpose designed as a Moon landing mission transport, and later adapted for use with the Skylab program (mostly as a way to keep the Apollo/Saturn system in play), whereas Soyuz was designed as a more general purpose support craft for a wide variety of missions; the Soyuz/Almaz program is more comparable to the abortive Blue Gemini/Manned Orbiting Laboratory program, both in terms of objectives and capability.
It is interesting to note that while the Chinese Shenzhou spacecraft is essentially an upscaled clone to the Russian Soyuz (at least in terms of module organization and outer mold line), the Indian ISRO OV and the commercial SpaceX Dragon spacecraft are developed along the lines of Apollo with a service/propulsion module and a single return command/habitat module. So both very different schemes for organizing manned spacecraft functions are still in vogue, neither one being clearly held out as superior.
As for the question posed by the OP, the Apollo-inspired Orion system was specified because of the previous successful history. The original proposal, which was competed between Lockheed Martin and a Boeing/Northrop Grumman team, was respecified in mid-proposal to the Apollo OML (as pursued by the Boeing team) with the X-33-based LM lifting body concept being aborted.
A water landing was simpler & safer. The added cushioning of water allows for a higher landing speed and didn’t require as strong a capsule as a hard landing would. Both of these translate into big weight savings, and in spacecraft weight is everything.
Also, the oceans are huge targets compared to any wide, unhindered, flat landmasses. In fact, the Russians only went with land landings out of necessity. Unlike America’s two vast coastlines the USSR has amazingly little. Plus, landing on the continent fit in with their desire for secrecy, something that the US specifically didn’t want or need.
Soyuz 23 actually landed on a partially frozen lake and after the parachutes filled with water they dragged the capsule under!
True. It’s also massively more expensive. The Soviets opted for land landings for the reasons stated earlier, but it was also much cheaper.
Recovering American spacecraft after water landings necessitated calling out a rather sizable portion of the naval surface fleet. All the Soviets need is a few helicopters and trailers.