Deniz Bertuna, Tyler Drake, Jason Hohl, Gavin Kutil, Ryan Quakenbush, Gauravdev Singh Soin October 18, 2007

 Objective The objective of our team mission is to test and build a satellite that will be sent to approximately thirty kilometers and measure light intensity at different atmospheric levels and take high quality images. The team wishes to further the studies of light intensity being performed by Professors Brown and Fesen in their efforts to create a low budget, high quality, near space platform for astronomical purposes.  Expected Results Our main goal is to gain data of light intensity of the sky further to promote the research of Professors Brown and Fesen in hopes of advancing the field of low cost near space astronomy.

 Level 0  (Objective Requirements- Derived from Mission Statement)  Construct a BalloonSat in order to improve or understanding of light intensity between the altitudes of 15 and 30 kilometers with a budget of $200.00, and a weight less than or equal to 800 grams by November 10, 2007  Measure light in the infrared frequency in nanometers at different atmospheric altitudes.  Track the temperature (˚C) of the photodiode to correctly evaluate dark current noise effects on data.  Obtain high quality images of the curvature of the earth at 30 kilometers.  Keep the inside of the BalloonSat above 0 ˚C

 Level 1  (System Requirements- Derived from Level 0)  The Balloonsat, excluding the photometer, must be maintained at an optimal temperature of 25 ˚C.  The balloonsat must be connected to an inverted plastic tube will be fixed through the center of the balloonsat. The rope, which is tied to the balloon, is threaded and knotted through the tube.  Balloonsat must be carried by a latex balloon filled with helium, carrying a parachute deploying on burst, and capable of carrying a net payload of twelve kilograms

 Level 2  (Subsystems Requirements- Derived from Level 1)  2.1) The photodiode circuit is connected to the Basic Stamp, where all of the data from the photometer will be stored.  2.2) The Basic Stamp will be preprogrammed to record the data in the proper format.  2.3) The camera will be connected to the power source via a switch. The operation of the camera will be controlled by a timing circuit which will be programmed to take photographs at regular intervals of one minute.  2.4) The HOBO will consist of two sensors, one recording external temperature of the balloonsat and the other recording internal temperature in ˚C.  2.5) The heating unit must operate properly to ensure that the subsystems (excluding the photodiode) will function even though the exterior of the balloonsat will experience temperature extremes of -70 ˚C. Insulation will also be used to keep the BalloonSat above the required 0 ˚C  2.6) In order for the balloon to reach its desired altitude of 30 kilometers, each system has to obey the 800 grams weight limit. The balloon will also carry a parachute, to ensure a soft landing velocity of nearly 100 kilometers an hour, and a GPS tracking system to help the team recover the balloonsat.

 Construct a BalloonSat to test light intensity at high altitudes.  Measure light in the infrared frequency.  Record temperature of the photodiode.  Obtain high altitude photographs

 -Low dark current silicon photodiode  -OPA129 Integrator  -OPA27 op amp voltage follower  pF Panasonic metalized polypropylene film capacitor  -DIP-packaged reed relay  -LM335 temperature detection circuit  -4.1 inch PVC pipe with a diameter of inch  -1 x 1/18 aluminum bar  -Plano-convex lens of 30mm diameter and 25mm focal length  -HOBO  -Digital Camera with timing circuit  -Foam Core  -Condensation Gel Packets  -Insulation  -BASIC Stamp The BASIC Stamp has been ordered and received. Nothing else will needed to be ordered.

 In order for our group to have a successful flight and collect substantial data, several tests will need to be performed on both our satellite structure and its inner components. Our group established a detailed day-by-day test schedule to ensure a successful mission. Most importantly, our group needs to test our photodiode because our data will not only reflect our success as a group but also will provide data for the further studies of Dr. Brown and Dr. Fesen. Our group aims to have complete confidence in both our structural and subsystems designs. With that in mind, our group will conduct multiple tests using different conditions. From there our group will utilize this information and apply that to out separate designs for best performance. The way that the group will determine which tests were more successful than others will be by means of video photography. With that the data can be analyzed and then properly utilized.

 6.1 Stair Test The stair test will be implemented to test the structure of the BallonSat. If the parachute of the balloon fails, the payload needs to survive a harsh landing, which is what the stair test is designed to do. 6.2 Whip Test To simulate the flight the BalloonSat will experience once the balloon pops at its maximum altitude. By attaching a cord to the satellite it will be spun around to simulate flight. 6.3 Drop Test Incase the parachute fails to deploy, the satellite will be put to very high velocities, so the payload will be dropped from a height of twenty meters to simulate the landing force it could experience. 6.4 Cooler Test The payload will experience extreme cold temperatures during flight; by making sure all the experiments function properly, the BalloonSat will be placed in a cooler of dry ice for three hours to experience how long it will be in flight in these extreme temperatures  6. 5 Photometer Testing and Calibration The photodiode must first be calibrated to record accurate data. The current plan involves exposing the photodiode to a know wavelength in a completely dark room to learn the variation constant. This can most easily be done with various colors of light or a laser pointer. Testing on the photometer will mostly involve the circuit and basic stamp functioning compatibly together.

 Subsystems test  Cooler/ heater  Light/ photodiode  Electrical  HOBO  BASIC stamp  Camera and timing circuit  Heater

 We have tested our BalloonSat’s structure. Through recreational activities of kicking, punching, wearing it as a shoe, soccer, football, and dropping from various heights.  As we expected, our structure held form from all that we did.  This was a preliminary prototype to see the basic structure of what our final BalloonSat will look like.

 The main expectations are to formulate an average value of light intensity at various altitudes to further promote the research of Professors Brown and Fesen in hopes of advancing the field of low cost near space astronomy.  Collect temperature and humidity readings at increasing altitudes during the duration of the flight.  Take High quality images of the horizon at the balloons maximum height.