1950s Concept Spacecraft

[Weaver]

A thread to discuss 1950s Concept Spacecraft, by which I mostly mean the semi-realistic Werner Von Braun/Willi Ley/Krafft Ehricke stuff which, with the help of Colliers Magazine and Walt Disney, helped to get the American people 'space minded' before Apollo. There were a number of model kits of these concepts, some of them are still around today and they are, by definition, what-ifs.

What can you do to make them more credible, or alternatively to use them for other purposes, sensible or silly?

Some examples from Glencoe:

[Weaver]

Here's the Disney documentary Man and the Moon, in which the original mission of the RM-1 (lunar recon) was done as a live-action drama-documentary. It looks pretty decent for 1954, although the ship's computer will raise a chuckle or two.

Part 1: https://www.youtube.com/watch?v=NrvxQ7VNqXk
Part 2: https://www.youtube.com/watch?v=nY34CvNQ3hQ
Part 3: https://www.youtube.com/watch?v=fZd9jLzvq4Y (This is where the RM-1 is introduced)
Part 4: https://www.youtube.com/watch?v=5ufUOOPKN14

I've noticed a mistake in the Stromberg/Glencoe model. It has the cabin windows on the centreline instead of slightly above as per the grey model seen with Von Braun in the studio. This matters because the hull of the RM-1 is supposed to t be an adapted spaceplane, and all pics of the various spaceplanes show the wings being on the centreline (where they'd block the windows) too.

[kitnut617]

Interesting how the Mars Liner looks remarkably like Musk's Falcon booster.

[Weaver]

Interesting how the Mars Liner looks remarkably like Musk's Falcon booster.

Isn't it? People used to laugh at the old idea of a rocket landing on it's tail as hopelessly naive, and then SpaceX went and did it. Mind you, I still don't fancy landing a manned one on rough terrain though: Musk's boosters have fallen over more than once, plus that cliff on the box top looks awfully close...

[Weaver]

Pegasus are going to do this glorious thing in 1/350th, which will still make it 10" tall. It's a Von Braun proposal from 1952. Three of these 35 tonne monsters would take a 50-man crew for a six-week stay on the moon! Good article on it here: http://www.astronautix.com/v/vonbraunlunarlander.html

[jcf]

The Pegasus kit has been out for some time:
http://www.culttvmanshop.com/The-Moonlander-Spacecraft-1350-scale-from-Pegasus-Hobbies-_p_3693.html

Moebius has released the Kraft-Ehricke NEV:
http://www.culttvmanshop.com/Convair-Ehricke-Nuclear-Exploratory-spacecraft-from-Moebius_p_4124.html

Von Braun's First Men to the Moon, illustrated by Fred Freeman, published in 1960.

http://dreamsofspace.blogspot.com/2015/03/first-men-to-moon-1960-part-1.html

http://dreamsofspace.blogspot.com/2015/03/first-men-to-moon-1960-part-2.html

German reprint:
http://dreamsofspace.blogspot.com/2015/10/first-men-to-moon-reprint-in-german-1961.html

The blog is interesting in general:
http://dreamsofspace.blogspot.com/

[Weaver]

Moebius has released the Kraft-Ehricke NEV:
http://www.culttvmanshop.com/Convair-Ehricke-Nuclear-Exploratory-spacecraft-from-Moebius_p_4124.html

That's nice to see, because apparently Glencoe wanted to re-issue the old Strombecker kit of the same subject, but couldn't for some reason (molds too far gone to restore maybe?)

The Ehricke design I'd like to see re-released is this one, 'cos it's a half-decent design:




Images and details here: http://fantastic-plastic.com/convair-space-shuttle-by-revell.html

The booster's probably too small, and saving the upper-stage engines rather than dumping them is half the point of a re-usable shuttle, but I like the fact that it uses the spaceplane's "shadow fairing" to do something useful rather than just being an aerodynamic cover. For a more realistic version, I'd be inclined to use the shadow fairing as a pure drop tank and give the spaceplane a smaller number of larger engines which return to Earth with it. That'd put it's thrust axis off from the centre of mass, but the real Space Shuttle's engines had to deal with that issue anyway, which they did by having over 10 deg of gimballing.

[kitnut617]

Seems like another Musk use, the massed engines on the Falcon Heavy

[Weaver]

It's always tempting from an economic/industrial point of view to build one engine design and then mount more and more of them to get higher thrust rather than designing a new, bigger engine. However there's an interesting trade-off point where the cheapness and redundancy of using multiple engines is overtaken by the complexity and the chance of at least one failing. Where this trade-off point lies depends on the nature of the engines and the vehicle. For CTOL aircraft with jet engines it seems to be at about four, because cost and complexity are important in relatively mass-produced vehicles, and the consequences of losing 25% of your power (with no damage to other engines) are tolerable. In a rocket, margins are usually so tight that a 25% loss would be catastrophic, but on the other hand, failures are more often explosive, so having fifty engines to insure against the failure of one of them may not work if that failure results in an explosion that takes out another six. Also, a rocket has no good abort options. If a commercial airliner flying from London to Karachi experiences an engine problem and lands safely at Hamburg, that's not the end of the world. Once a rocket is launched however, the ONLY acceptable outcome is for it's payload to achieve orbit: getting 90% of the way there then falling back due to an engine failure is still a 100% loss.

Von Braun's Moon Lander is more in the nature of a VTOL aircraft. The key safety point with these is that you do NOT want asymmetric thrust to occur when you're in vertical flight at low altitude. There are only two solutions to this: a) have one engine (Harrier) so that if it fails, you drop onto your undercarriage in a flat attitude, or b) have so many engines (many unbuilt projects) that if one of them fails, the asymmetric thrust is still within the ability of the RCS system to compensate for it. In between the two, you have a 'fail-dangerous' zone where loss of one engine results in the aircraft rolling or pitching as it falls, with terminal consequences. However the Moon Lander has some other considerations to take into account. On the one hand, a 100% failure and a safe-but-hard landing aren't an acceptable outcome, because that still leaves you stuck on the Moon with time-limited life-support. That might seem to argue in favour of the many-engines solution, but on the other hand, the relative unreliability of rocket engines, and the explosive nature of their failures, might simply doom you to a quick death in a fireball rather than a slow death as the air runs out.

There are no 'right' answers to any of this. All designers can do is calculate the percentage chances of failure in each component and the consequences of those failures, and design accordingly. The veracity of those calculations depends as much on experience as theory however, and in the early 1950s, rocketry was still a very 'young' game.

[Weaver]

Nice illustration of the Bottle Suit design seen in the various Disney films, attached to the RM-1 and the Space Station:



Images from the Cyberneticzoo blog, which has a lot more info here: http://cyberneticzoo.com/teleoperators/1954-bottle-suit-wernher-von-braun-walt-disney-american/

In many ways this is an admirable design, and a decent response to the problems inherent in designing traditional 'soft' spacesuits. You can critique quite a few things about it though, although all could be fixed with relatively modest redesign:

1. Lack of comprehensive reaction control jets. The Bottle Suit has roll/yaw/pitch control via gyros, but it's only propulsion comes from the (presumably 'cold') HTP rockets at top and bottom. This means it has no 'translate' ability in the forwards/backwards and left/right planes without changing attitude first. That might be acceptable (just) for a simple transport device, but for one that's intended to perform intricate work in close proximity to other craft, it just won't do. Imagine you're working on some part of the space station when you find yourself very slowly drifting away from it, probably as a result of pushing on it slightly with one of the waldos. What you want to do is fire a quick RCS pulse to arrest this motion, but in the Bottle Suit, you'd have to first pitch 90 deg downwards, then fire the one rocket, then the other, then pitch up again and hope you were now at the right distance. It might be a cliché to stick Apollo-style thruster quads all over things, but honestly, they're a damned good design that hard to beat, and this thing needs them acutely.

2. There doesn't seem to be much volume allocated for life support equipment and supplies. Even a real-life astronaut's backpack is still pretty big.

3. When the Bottle Suit's in the airlock and the inner door is open, you've got a 5lb thrust HTP rocket pointing straight into the crew compartment...

4. I don't like the way that the Bottle Suit forms the outer door of the airlock. If it gets damaged or dented and can no longer form that seal, then the inner door can't be opened, the man in the suit will die inches from his colleagues, and they will have no more ability to leave the ship without depressurizing all of it. The Bottle Suit airlock needs inner and outer doors, with the latter preferably not being blocked by the in-place suit.

[jcf]

The multiple engine notion goes back to Hermann Oberth and his The Rocket into Planetary Space, 1925.


He also used the basic concept in the design of the Friede in Fritz Lang's "Frau im Mond".

[Old Wombat]

If it works, why not?

[Weaver]

If it works, why not?

The nearest it came to being tried was the Soviet N-1 (Saturn V equivalent), which conspicuously didn't work...