Space Grant Consortium - University of Wisconsin - Green Bay

Dividing up the budget. After performing a bit of searching it was found that building
an entirely custom rocket would be more than the budget could handle. However, it could easily
afford buying a lot of “semi custom” parts and then assembling them together. Thus, just over a
third of the budget was designated for major structural parts for the rocket. The next part that was
considered was electronics. The first was an altimeter that would deploy the upper stage, and the
other electronics were tracking devices for the rockets. Both of these were deemed extremely
critical, therefore almost half of the budget was allotted to these parts. This left over a decent
amount of budget to use on a practice launch and various other miscellaneous parts and tools
needed.
Predicted Performance
Maximum altitude. Maximum altitude: 7730 Feet
Maximum acceleration. Maximum acceleration: 1490 Feet/Second/Second
Acceleration versus Time:
Methods used to calculate above. In order to make the above calculations three major
methods were used. The first involved using RockSim to automatically calculate the above
predictions. The second involved finding an exact analytical solution, using Mathematica, to
solve the differential equation modeling the forces on the rocket after maximum velocity was
achieved. Inputs to the model consisted of the rocket’s CD and its maximum velocity just after
motor burn out. Both of these variables were taken from the RockSim program. The last
calculation made was using MATLAB. A small program, based on an open source code, was
written to simulate the rocket’s flight computationally. Each of the different methods produced
slightly different flight paths. Ultimately a weighted average was taken of the three to use as the
predicted maximum altitude and acceleration noted in sections 5.1 and 5.2.
Post Flight Evaluation
Verified Launch Events.
Flight. The following is an account of the launch to the best of the team’s knowledge:
The rocket launched from the pad extremely straight and perpendicular to the ground. The dart
separated correctly, immediately after motor burnout. The parachute opened almost instantly
after motor burnout. The dart disappeared out of sight less than a second after separation. The
parachute separated from the booster body. All three fins could be seen falling separately from
the body. A radio tracking signal was heard as parts of the booster were falling to the ground.
After two minutes, no radio tracking signals were ever heard again.
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