Order of Kilopi
Established Member
OTRAG was killed decades ago, because France and the USSR didn't want West Germany developing rocket technology.
Its successor technology has never really got off the ground (no pun intended). I assume you are thinking of these guys:
http://www.interorbital.com/
who are universally considered clowns by people in the industry.
Order of Kilopi
Why?Originally Posted by Damburger
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Established Member
You saw the website, right?
A few years ago, they promised to put the 'first teenager in space' - not only is this a horridly irresponsible thing to contemplate, the individual they chose is now in his late twenties....
Established Member
A few years ago many site/company said they could win the X prize , only one had serious chance of winning it. And so what ?
Order of Kilopi
OK, so their advertising sucks, what about the viability of their design?
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
they have a long way to go in the field of acronym usage, which is really important with these things.
Order of Kilopi
Seriously, I'm interested in whether the concept is viable from an engineering point of view. (Taking into account the fact that almost no R&D has been put into it since the 80s.) If it was taken seriously and researched a little more, would it live up to the original tests?
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
This has been updated some time ago with more photos for folks wondering what is being talked about here.
http://www.astronautix.com/lvs/otrag.htm
A quote from Mark Wade's site above:
"Parallel staging allowed very large payload diameters up to 30 m and thrust acceleration to be limited to a maximum of 3 g to allow lighter payload and space vehicle structures."
That would allow these types of spacecraft: http://www.astronautix.com/fam/lenicles.htm
http://en.wikipedia.org/wiki/OTRAG
Order of Kilopi
This subject is certainly a blast from
the past, I remember reading about it
more than 30 years ago. It was amusing
to see that they designed the modules
with car windscreen wiper moters as
actuators next to the nozzels.
But the OPs first link indicates
development was successful with many
sub-orbital launches. So why not a
small LEO launch? Just to demonstrate
an order of magnitude reduction in
cost doing so? We are not being told
something here, right?
Established Member
What you are not being told (or choosing not to hear) is that the concept isn't particularly good and the people behind it are basically clowns.
Order of Kilopi
I was told about the clowns; I wasn't told that the concept wasn't good or particularly why it wasn't good, other than that it's currently in the hands of clowns. I want to know the engineering basis for why it isn't good (it was successful enough to tick off France, and that's always a good start).
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
I'm noy quite getting why this is a bad concept either. This description of it from one the astronautix.com article:I was told about the clowns; I wasn't told that the concept wasn't good or particularly why it wasn't good, other than that it's currently in the hands of clowns. I want to know the engineering basis for why it isn't good (it was successful enough to tick off France, and that's always a good start).
Rather reminds of the approach SpaceX has adopted with the Falcon 9, and that works quite well.Kayser's concept involved the parallel clustering of large numbers of identical propellant tank and rocket engine modules. This allowed the application of mass production techniques as used in the automobile industry.
Order of Kilopi
The Falcon 9 seems to me more inspired by the highly successful R7 rocket family, in almost all respects ranging from fuel/oxidizer to integration to engine type to basic production philosophy. The big difference is going with stacked stages with simple cylindrical construction rather than the R7's unique clustering method and resulting conical construction. That strange aspect of the R7's design is an accident of circumstances and design decisions which made sense at the time.
OTRAG is a radical departure from traditional rocket booster designs. I really like the basic idea of clustering lots of tall small diameter units, but it isn't suitable for cryogenic propellants like LOX. This means using lower performance propellants. The other big difference is the use of pressure fed thrusters. This requires heavier propellant tanks.
Order of Kilopi
Could that be resolved by using larger clusters? I've only seen a test example with 4 stacks of modules.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
Those aren't 4 stacks of modules. They're 4 modules, period. Each module is the entire height of the booster, above which the payload is placed (as well as a disposable aerodynamic faring).
Order of Kilopi
OTRAG, with its massive rocket clusters, reminds me of a liquid fuel version of the British Interplanetary Society moon rocket from the 30'sand 40's. Since OTRAG was cancelled for political and not engineering or scientific reasons, it is definitely an idea I want revived and reconsidered.
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