OTRAG Rocket.pdf

any 6.te start going wrong statistically. In a reliability of 99% you would have at least the
first two stages also examine the probability of two engine failures.
This bill is not even considered that it will turn off when engine failure, the opposite in
order to maintain the boost symmetry. Makes you double it, then the impact.
Kayser gives true that the engines were qualified "6 Sigma". But these are only a criterion
from the production, that indicates that you have during the preparation of a committee of
about 3.4 parts per million. This does not mean that fail during the flight so few engines.
Finally, there was at 18 OTRAG launches two false starts at only 4 or one engine per
start. As the sum can be simplified to say that the OTRAG rocket engines with 100 times
more than conventional construction also provides 100 times greater demands on the
reliability of the engine. Lutz Kayser is sure that the engine is so reliable.
Already formed in the control fuel residues are immense. Each rocket must be after the
start of the horizontal plane be diverted to the vertical. When do you OTRAG this by
shutting down the engines on one side to 40% thrust. Here, too, remain fuel residues.
These are relatively large: Assuming that the same top speed as OTRAG rocket Ariane
has to reach, so expect it back, that the first stage would still have about 5,000 kg residual
fuel in the stage separation.
OTRAG was tested systems engineering
What was the OTRAG never reached the full test of a carrier. De facto, all tests are only
tests of individual engines under flight conditions. In principle, we have developed a
rocket height of the lower power class - but no launcher.
The thrust vector control of, the shutdown of engines in case of failure, the whole scheme
of hundreds of engines, the stage separation and the entire control. All this was never
tested. Not for nothing was Lutz Kayser, the financial cost of developing a launch vehicle
with 500 million DM. It is expected that there would be still some setbacks.
In other rockets there is a big step from one engine to a reliable missile. There are, in this
age of computer simulations, and even companies with decades of experience setbacks,
for example, was at the Delta III, the set after 2 miscarriages and a partially successful
demonstration launch.
In a completely new concept to me unproven technologies, the risks are very high. Today
the trend is to use less engines. Ariane 5 has only 4 engines instead of up to 10 4 in the
Ariane The Delta 4 is a maximum of 6 engines instead of up to 12 2 in the Delta This is
to reduce the reason the possibility of error.
Control
The control of the rocket as OTRAG was written by throttling an engine. It is therefore
not possible to regulate the thrust arbitrarily fine but only in fixed steps. Conventional
engines swing the other hand, their engines and can thus influence the direction of thrust
fine.