So.. Who has ever heard of OTRAG?

[Everten P.]

I have heard of OTRAG but my friends tell me it doesn't exist to which I reply "shut up"

Anyway OTRAG was a German company founded by Lutz T Kayser. There rockets ranged from the Kayser 1 to the Kayser 128 ( the number being how many tons they could get in to a low stable orbit). They all weighed 100 tons heavier then their payload. The rocket used CRPUs (Common Rocket Propulsion Units) these CRPUs had thrust control ranging from 100%-40%, this was a liqui fuel design that could not be shut down. It also did not need fuel pumps and moved the fuel by pressure alone. The design of each rocket was Danny2462 on steroids in the 70's, having a cluster of rockets that used parallel staging (as in the outer layer would decouple and the next would activate, if a rocket needed to lift more than the literal solution was adding MOAR BOOSTARS. The CRPUs were cheap and required no fancy equipment or fuel, the outside of the rocket was made of steel (but could use aluminum if necessary), they were mass produced around 1000 CRPUs a year so they were cheap and had a burn time of 280 seconds . Finally, because of its simplicity and lack of complicated parts it had a low failing chance and if it failed it could be built faster and cheaper than if a space shuttle, Orion, etc. crashed, but alas the company had made some bad decisions made by Kayser the company was torn apart by political chaos and was ended around 1980.

P.S. Since I am a scrub in this forum I couldn't put up pictures

[The Fleet Master]

I've heard about it according to my search History I always loved the idea of cheap and affordable space travel for everybody and I honestly thing this company and SpaceX had brilliant ideas.

[Vanamonde]

You should be past any limitations on posting, but we all need to link to external hosting sites to submit pictures to this forum. Is that perhaps what the problem was?

[78stonewobble]

Does raise the question, of what we could do with a decent sized factory just spitting things like that out.

[magnemoe]

Does raise the question, of what we could do with a decent sized factory just spitting things like that out.

Think the problem is that you must up in an significant quantity to get real economic of scale, think car production with assembly lines with robots.

Yes you get benefit of producing more as you can divide development and fixed costs on all the units but the real saving probably require 10 or more a day.

Things who can share production lines require less units.

[Red Iron Crown]

Their modular approach to building rocket of varying capacities was certainly interesting and different. Shame the company folded before any real progress could be made.

[Idobox]

How come nobody is looking in that type of solution anymore?

[NASAFanboy]

That gives me an idea. What if we took some of their old plans, updated them, added some of our own features, and put it on Indiegogo to start up mass production? If they can fund solar-powered roads and some guys potato salad, they can fund our modular rockets.

[KASASpace]

Didn't it turn that the country they were trying to test the rocket in try to take it over and get missiles or something?

Yes, I have heard of OTRAG, and wasn't von Braun involved?

It's a good idea lost to history, but maybe some small company could do it again?

BTW, mass production is the only "real" way to cheapen space travel. Now, if you use robots, then why must they be complicated? Simple 'bolt that" or "screw this" or "place that" machines can accomplish it, and be cheap enough to maintain. OTRAG is designed for simplicity and thus ease of construction.

[Red Iron Crown]

BTW, mass production is the only "real" way to cheapen space travel. Now, if you use robots, then why must they be complicated? Simple 'bolt that" or "screw this" or "place that" machines can accomplish it, and be cheap enough to maintain. OTRAG is designed for simplicity and thus ease of construction.

I think in this context robots means the sort of simpler automated assembly machines you describe, similar to what the auto industry uses. Definitely agree that mass production and modularity would draw down costs.

[RocketBlam]

I'm not sure where I heard of OTRAG, it may have been this thread, but I decided to try it. And it works pretty dang well.

This is my version, the KOTRAG Kayser 16. It can lift 15.4 tons into LKO (100km) with two stages. All thrust units are identical except of course the inside 4 don't have decouplers.

The stages seem very consistent. The first stage had a TWR of about 1.1, the second of about 1.2. The second stage had about 1/3rd of its fuel left at 100km orbit. So the math seems very sound.

The total cost is 102,000... whatever they spend on Kerbal. But it's 102,000 of them. That includes the payload. I'm not sure how this compares to getting 16 tons into orbit with regular staging.

Going to try a 3-stage version later. The only real problem I've encountered is that with all those rockets decoupling, the potential for disaster is high. However, some Sepratrons would fix that. Also, some struts are required, but not many, really only one per rocket.

ETA: I created a non-OTRAG version of similar DV and it was only 51,800. So saving money doesn't seem to be in the cards. But it's a fun way to get to orbit. And you can do it almost from the very start of the game. The engines are all LV-T45's.

ETAA: I've been thinking about this wrong. I don't need a 3rd stage, I need a 3rd ring. The 2nd and 3rd ring will both be part of the 2nd stage... or maybe even part of the 2nd ring will be part of stage 1, and part will be stage 2. This is giving me a headache.

Edited August 17, 2014 by RocketBlam