Space Grant Consortium - University of Wisconsin - Green Bay

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Figure 8: Anticipated Altitude for Dart
Design Versions
The following sections describe in detail the development of our competition entry. Our rocket
went through four revisions to accomplish the following tasks:
1) Proof of viability of concept
2) Gather Drag Coefficient data
3) Proof of viability of small diameter (1.5-inch) dart
4) Competition Entry
These four versions are discussed in the following sections.
Version I: “Green Bean” Based on preliminary estimations, this version was designed in
September 2009. Eventually nicknamed “Green Bean”, this iteration of the boosted dart was
expected to serve as a proof of concept, verify the mathematical models, and gather performance
data. In order to cut costs and reserve a larger portion of the budget for the final design and any
contingencies, some elements of “Green Bean”, such as the dart fins, were taken from currently
available supplies instead of purchasing their optimized equivalents.
The dart itself was designed around a 2.1-inch (54mm) airframe. At the time, it was felt that this
diameter would provide a good balance between low drag and ease of flight preparation (the
loading of parachutes, etc).
This version of the boosted dart was flown at the Midwest Power rocket launch in October, 2008.
During testing, flight instability was discovered. Because the dart’s fins were from existing
supplies (to avoid purchasing them), they were larger than necessary, and as a result CP of the
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