Vomit Comet
Six Taylor University Physics students were selected to go up on the NASA Vomit
Comet in 2006. The spacecraft has been nicknamed the vomit comet because once the
craft has taken you into zero gravity, the contents of your stomach begin to rise which
forces you to vomit. Fifty Universities applied to do research on board the Vomit
Comet and only 13 were accepted. Taylor was the only small private school accepted
into the program. Once airborne the students tested a small satellite stabilization
attitude control system. They conducted an experiment to see whether an extended
magnet away from a satellite on a tether would align itself with the earth magnetic field.
They were also testing the tether deployment. This was in an effort to determine
whether one could extend the tether and have it stay rigid or whether it would behave
like a coil of rope.
Using NASA's Microgravity University program,
students tested initial deployment of a Nitinol tether in
zero gravity. Taylor students designed and built a
tether deployment system for TUSAT1 (a satellite
project which has given way to BUSAT). The problem
with the tether deployment is that most materials,
when deployed, meander or entangle instead of
deploying neatly to a distance far enough to achieve
the desired gravity gradient effects. Using a highly rigid
yet flexible wire called Nitinol, a nickel titanium alloy,
the wire is wound tightly and stored in the satellite as
it is launched and is still rigid enough to, theoretically,
prevent any meandering or entanglement. The
objective of the zero gravity test was to confirm
whether or not the Nitinol wire and the mechanical
apparatus can deploy with minimal meandering and no
entanglement.
Six Taylor students tested an attitude control system for
satellite projects being conducted at Taylor. One
method for stabilizing a satellite involves deploying a
tether to gain a gravity gradient. The tether is to be
deployed 100 ft, but it is the first several feet that are
the most crucial for proper deployment. It is critical that
the deployment of the first several feet is tested in zero
gravity. NASA's microgravity university granted our
student written proposal to do just that. Flying on NASA's "Vomit Comet" gave student
researchers 30 periods of 15-20 seconds of zero-gravity conditions in which to test
their experiment. Students developed an experiment, designed an electrical system and
built a safety structure that met NASA regulations.
Results of Experiment
The tether deployment was a success. The experiment showed mild meandering in
addition to jerky deployment caused by large motor step size and coding issues.
Based on the video footage and personal observation, we have come to some
preliminary results.
1. No entanglement occurred
2. Mild meandering occurred, but that can be
explained by the movement of the plane
during zero gravity
3. Tether deployment could be smoother. To
make the deployment smoother, better
stepper motors and a more accurate speed
ratio between the two motors could be
optimized
4. Internal entanglement occurred due to
incompatible motor speed ratios
For further study, the tether could be deployed again in a zero gravity environment as a
free floating experiment. This would rule out the effects of the plane on the
deployment. These results will allow for increased understanding and functionality of
future TU Satellite models.