Re:The Bremen Drop Tower
by ethagknight on Saturday September 16, 2017 @12:51PM
(#15265436)
While there are good reasons for a drop tower over an airplane, namely experiments requiring more precise control, I’m not remotely convinced that the Bremen tower was cheaper to build and operate than a Vomit Comet. For one, a 146m tall tower for which ZARM broke ground in 1988 and inaugurated the catapult in 2004; that sounds incredibly expensive. NASA uses old 727s, long out of production so a cost is difficult to assign but they were $20mm new, NASA’s planes were probably enroute to the boneyard when they acquired them.
The tower has actually been in operation since September 1990. So the time needed for construction was just 2 years and not 16 years. For the first years it was operating as a simple drop tower, without a catapult. The catapult was added later in 2004.
Construction costs according to German Wikipedia were more than 24 million DM (12.2 million euros), with a further 4.2 million euros for the catapult.
They are doing on average about 400 drops per year. The time in micro-gravity is 4.74 sec for a simple drop and 9.3 sec with the catapult. (source: Wikipedia)
According to my estimations this amounts to about 18.72 hours of micro-gravity in 24 years.
That's still expensive, but not outrageously so.
zero-G planes are only mostly zero-g. They fly a parabolic trajectory, so their body actually rotates about the center of mass while flying.
Also, their weightlessness is not as well controlled as a drop tower's.
The cost you've listed is for a single passenger.
You know what's more expensive to build and operate than a pressure controlled tube on the ground? A pressure controlled tube with jet engines operated by pilots.