Matt Breihan, Jay Davis, Jack Gregory, Ashton Schrage, Sara Schuette, Lydia Whitney 12/02/2008

 The BalloonSat Octagon shall ascend to approximately 30 kilometers while recording the relative intensity of light through two photometers with two different light filters that divide the visible light spectrum into two parts, blue and red. This will determine which part of the visible light spectrum should be used to photograph objects when a satellite is at different altitudes. Octagon will also carry a digital camera to photograph the ascent/descent and internal and external temperature and humidity measuring devices to record conditions inside and outside of the BalloonSat.

Expected Discoveries ◊ An increase in the relative light intensity readings from both photometers because as the BalloonSat rises, the thinning atmosphere lets in more light. ◊ A slightly greater overall increase in the light intensity readings from the photometer with the red filter because the red filter lets in wavelengths of infrared light which is present at 30 km. The blue filter does let in ultra-violet wavelengths but the atmosphere absorbs most of these wavelengths above 30 km.

Hexagonal prism measuring 11 cm by 10 cm per side. Science experiment: Two photometers with a red filter (wavelengths 600 to 700 nm) and a blue filter (wavelengths 400 to 540 nm) Photometers connected to Basic Stamp that records readings from photometers Basic Stamp was programmed with Basic Stamp Editor v2.4, was also used to retrieve stored data after flight.

Functional Block Diagram

Proposal  Dimensions: 11 cm x 8 cm per side  Three photometers with three different filters  Photometers on top surface of BalloonSat  Heater was a triangle to fit around flight string Final  Each side was 10 cm x 11 cm  Two photometers with two different filters  Photometers placed at a 45° angle  Heater was left in original design from homework 4

Predicted  Increase in relative light readings as BalloonSat ascended; slightly more overall increase on red photometer  Internal temp. was always above 0°C Actual  Red photometer gave us five min. of data then zeros for the rest of the flight. Blue photometer gave us zeros for first two min. then data but data did not display a general increase; there was no pattern  Min. internal temp was 1.6°C

Sample of Data Photometers were programmed to take a reading every 20 seconds, total of 400 readings for each photometer. Used time stamp on photos to determine start time because the photometer switch was turned on right after the camera started to take pictures.

Reading 1 corresponds with 7:18 am Burst was at 8:52 – Reading 283 Touchdown was at 9:29 – Reading 394 Reading 400 – 9:31 am 7:18 am 9:31 am Burst Touchdown Burst Graphs of Entire Data

Zoomed in sample of data; not an overall increase in relative light intensity; no pattern at all Data is 7:34 am to 8:08 am Zoomed in graph of red photometer data, only got data for first 5 min, then zeros for the rest of the flight First 2 and half min showed the predicted increase of relative light intensity Data is 7:18 am to 7:23 am

Min. Internal Temp. – 1.6° CMin. External Temp. – °C Max. internal temp. – 38.77°CMax. External Temp. – 25.56°C Launch

Touchdown Burst Launch Min. RH – 23.4 % Max. RH – 28.7%

Pictures from camera Right after launch Ascent Right after burst Moon

More pictures Safety string moved to edge of lens after burst

BalloonSat Octagon was successfully launched at approximately 7:20 am on Nov. 15. Thought the tracking equipment was not working, we saw the balloon burst at approximately 28 km. We also saw the flight string land in a field across the highway from the caravan’s position. Once we retrieved BalloonSat Octagon and cut it loose from the flight string, we opened the BalloonSat and connected the Basic Stamp to the computer and retrieved our photometer data. We also acquired the pictures from the SD card in the camera in the car. The HOBO data was retrieved once we returned to campus.

Our photometers failed to give us usable data for the red photometer. We are confident in saying that this failure was caused by the readings maxing out the photometers. The values for the relative light intensity from the red photometer were too great for the photometers running on the program they were for the flight. The timing of this failure does not correspond with any drastic temperature change. We were not able to repeat the failure because we don’t have an infrared light source that puts out the same amount of light as the sun and the only way to repeat the failure would be to launch the BalloonSat again to see if the same failure occurs. The program has been reprogrammed to scale the photometers’ output down by a factor of 100. The photometers do take data with the new program but the only way to see of the scaling factor is enough to not max out the photometers is the launch again or put the BalloonSat under the same conditions it would experience if launched.

Photometer data was inconclusive regarding whether the amount of red light increases as altitude increases. Beginning of data followed predicted increase but only for first 3 min. There’s a lot more red light/infrared light at much lower altitudes than we thought because the photometers maxed out after 5 min. The amount of blue light/ultraviolet light does not seem to follow the predicted pattern of increasing as altitude increases. There is no pattern to our data to suggest that the amount of blue light/ultraviolet is dependent on altitude.

If we could do this over, we would have started working on the main science experiment, the photometers, sooner and tested them more. The programming for the Basic Stamp ended up being a lot more work that we thought and therefore we had less time to test the photometers. When testing the photometers, we would have tested them with a wide range of light sources to make sure that the photometers would take correct measurements with a wide variety of light sources and in different conditions. Although it is unlikely that we would have been able to test under the exact light intensity conditions the BalloonSat went through during flight, more testing would have allowed us to understand how the photometers worked earlier. To get different results, we could have used different light filters and compared different parts of the electromagnetic spectrum. We could have also programmed the photometers to be more or less sensitive and changed the scaling factor of the photometers.

 BalloonSat Octagon should be stored in dry, low humidity conditions at room temperature. The batteries should not be stored connected to any hardware in case a battery leaks.  To activate BalloonSat Octagon for flight, one must replace all batteries, 3 9V for the heater, 1 9V for the Basic Stamp/photometers, and 2 AA for the camera.  Once the batteries are replaced, one must secure the camera into position. To accomplish this, slide the ends of the plastic holder into the slots in the insulation. The ends can then be glued to the insulation.  The HOBO will need to be reprogrammed so that it takes data during the flight.  The number of readings the photometer takes and the time between readings can be adjusted by changing the Basic Stamp program.  Once everything is reprogrammed, one can tape the lid closed with aluminum tape. The two on/off switches will need to be switched to the on position and secured with aluminum or electrical tape. The momentary switch for the camera needs to be pressed once.

Level 0 Requirements: O1) Team Go Go Gadgets shall construct a BalloonSat to launch on a high altitude balloon that will ascend to 30 kilometers, cost less than $150, and weight less than 1000 grams by Nov. 15, O2) Team Go Go gadgets shall measure and record relative light intensity readings through the use of two photometers with different wavelength filters. O3) Team Go Go Gadgets shall use a HOBO data logger to measure and record internal temperature, external temperature, and humidity readings for the duration of the flight. The internal temperature shall not drop below 0°C through the use of a heating element. O4) Team Go Go Gadgets shall use a Canon camera to photograph the ascent and descent of the BalloonSat. Level 1 Requirements: From O1- S1) BalloonSat Octagon shall comply with the weight limitation by making the BalloonSat as small as possible but still allowing room for all of the necessary equipment. S2) BalloonSat Octagon shall comply with the cost limitation by not wasting parts or ordering many more of one part than is necessary. S3) BalloonSat Octagon shall be completed by Nov. 15, 2008 by Team Go Go Gadgets following the schedule set at the beginning of class and completing tasks in an efficient manner. From O2- S4) BalloonSat Octagon shall have two photometers placed at 45 degrees to measure the relative light intensity at the BalloonSat Octagon ascends. S5) The two photometers shall have filters, one blue and one red, placed over them to divide the visible light spectrum into two. S6) A Basic Stamp shall be used to record the relative light intensity readings from the photometers. S7) The Basic Stamp shall be connected to s laptop with BASIC Stamp Editor software on it to retrieve the data from the Basic Stamp after launch and recovery. From O3- S8) The HOBO data logger shall be programmed to measure and record the internal temperature, external temperature, and humidity readings for the duration of the flight. S9) A heater shall be used to ensure the internal temperature does not fall below 0°C. S10) The HOBO shall be connected to a computer with BOXCAR software on it to retrieve the data readings after launch and recovery. From O4- S11) A Canon camera’s firmware shall be programmed to take pictures at a set interval for the duration of the flight. S12) After launch and recovery, the SD card from the camera shall be connected to an SD card reader to retrieve the pictures from it. Requirements Flow Down

FRP compliance The internal temperature was kept above 0°C during the flight The total weight did not exceed 1000 grams (actual: 728 grams) The design included the use of a HOBO data logger and Canon camera The design included an additional science experiment (photometers) BalloonSat was made out of foam core The flight string tube was in the center of the BalloonSat and was a non-metal tube The BalloonSat had contact information and an American flag on the outside

Mass Budget

Don’t procrastinate. Time is always against you no matter what anybody says. Get started early and don’t take a break until the end of the semester. Make sure that you meet at least once a week and try to meet at the same time, in the same place so everyone knows what’s happening when. Don’t be afraid to ask questions. A lot of this class deals with things that no one knows about at the beginning. If another group is having similar problems as you, work together to try and solve them. TEST! Test everything more than you think is necessary. Test different sub-systems separately and together. Test things again even if they worked right the first or second time. Work together as a team. Make sure that everyone gets along because it will be a long, hard semester if there is any tension within the group and you won’t get to fully enjoy your success. Do something fun and interesting as a science experiment but make sure that you are not getting in over your head. You do need to be able to understand everything that you put into your BalloonSat, so don’t try to do something that you don’t understand just because it seems really fun.