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Surfing Satellites  |
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Surfing Satellites |
| Launch Date | 11 October 2008 |
| Launch Time | 10:28:00 AM (14:28:00z) |
| Launch Site | Wyandot County Airport (40.88863N 83.31325W) |
| Landing Site | Akron, OH (41.06013N 81.47654W) |
| Maximum Altitude | 92,401 ft (on board GPS record) |
| Ascent Rate | 330 fpm avg. to burst |
| Descent Rate | 1021 fpm avg. below 10k feet |
| Distance/Bearing | 97 miles/82° true |
| Recovered Balloon Weight | 961 g |
Special thanks to Ted (W8KVK), and Stan (K8SRB) for setting up an I-gate on the primary tracking frequency, and to the NASA Glenn Explorer Post 632 team.
| Overview |
Surfing Satellites (flight designation: Surfs Up 3) and the NASA Glenn Explorer Post 632 (flight designation: 2008A) participated in a dual launch with the mission to photograph and video balloons in flight. Additionally, both payloads carried sensors and tracking systems. The Surfs Up 3 payload had incremental improvements made based on observations and data collected during Surfs Up 2. Due to a calculation error, the Surfs Up 3 balloon was underfilled resulting in a lower ascent rate. |
| Successes | All Surfs Up 3 systems operated correctly. The Primary Tracking system delivered error-free data through out the flight at high signal strength. The Secondary Tracking system delivered error free data below 60,000 ft. The still camera recorded a total of 1370 pictures from pre-launch to power down. The video camera recorded for over two hours. The flight computer performed all primary functions including logging, flight display, and image control. The power system delivered power for over five hours. The enclosures appeared free of damage, and the internal temperature of each did not fall below 0° C. While we were not able to witness the landing, the GPS track of the descent indicates the parachute inflated and slowed the descent. |
| Data Logging and Indexing | Surfs Up 2 did not collect data during the flight and ground experiments did not re-produce this issue. Changes from Surfs Up 2 included a simplified installation of the flight computer crystal, and reduced exposure to radio energy during pre-flight. Before launch, the new flight display was used to verify logging operation. Data logging operated correctly for the duration of the flight. Over 540 kB in GPS, sensor, and imaging data was recorded. This was the second flight for the data logging and on both flights, the 256 MB SD card remained in place without extra security. For every record in each log, the flight computer added an index. The index was a rudimentary method of synchronizing all the data with date, time, and GPS location. For example, the index in the image log was used to define the location and altitude of every photograph. |
| Imaging | Because of the extended flight time, the still camera made over 1300 images. An analysis shows the flight computer requesting three images per minute up to 80,000 ft. Above 80,000 ft, the flight computer requested six images per minute indicating a successful program change and a rudimentary ability to review GPS information during flight. The video camera recorded for over two hours. However, due to the extended flight time, there is no video recording of the balloon burst or landing. The modifications to the video camera assembly provided for venting the heat from the camera, and the success indicates adequate venting. A future flight may evaluate using the camera as a source of heat. |
| New Antennas | Both antennas were modified to reduce wear due to swinging. Additionally, an antenna boom was added to the Secondary Payload moving the antenna away from the payload link lines. Neither antenna showed signs of wear on Surfs Up 3. |
| Power Supply | The power supply continued for the duration of the flight allowing the flight computer to log GPS, sensor, imaging data. The flight duration almost matched the ground based experiment designed to evaluate the power supply life. See the power supply comparison in the charts below. |
| GPS Lock/Telemetry Loss | Surfs Up 3 successfully logged GPS data every three seconds. Post-burst GPS data indicated a loss of satellite lock, and during the final descent the GPS time, location, and altitude data appear incorrect. Also, the Secondary Tracking (on the APRS frequency) was not received above 60,000 ft (the 2008A APRS telemetry exhibited similar behavior). In comparison to Surfs Up 2, the Primary Tracking GPS assembly was not secured as well. The bulk of the payload volume contains packaging peanuts to aid in securing the payload interior components and to assist in stablizing the internal temperature. Surfs Up 3 was not filled completely with packaging peanuts, and one securing piece of styrofoam was not installed on the GPS assembly. Together, this may have allowed the GPS assembly to move during the post-burst acceleration and cause it to lose satellite lock. During descent, the GPS data appears to have valid location data but the altitude data becomes invalid about a minute before landing. In both cases, the GPS recovers and telemetry was successfully used to locate the payload. This is the second occasion where APRS telemetry was not received from above 60,000 ft. The antenna connection on Surfs Up 2 was badly damaged and was identified as the primary cause for the loss of data on the APRS frequency. Surfs Up 3 demonstrates similar behavior however the antenna shows no signs of wear. During the final minutes of the Surfs Up 3 chase, the APRS frequency was monitored for telemetry updates however, APRS traffic made it difficult to capture telemetry. Follow Up: Surfs Up 4 will secure the GPS assembly as it was in Surfs Up 2, and will use an alternative frequency for Secondary Tracking. In both Surfs Up 2 and Surfs Up 3, the Lassen iQ GPS has performed very well and will continue to be a part of flight configurations. |
| Flight Display | The Flight Display was successfully used to verify flight computer operation after the payload was closed out. The Flight Display shows sensor data, GPS data, the index, and logging status. |
| Microcontroller Crystal | The flight computer is built on an SX-48 protoboard (see Resources). The crystal mounts in a three-conductor header on the board. On Surfs Up 2, the crystal was held in place with hot glue. This may have added capacitance around the crystal and contributed to an odd start-up sequence and possibly the data logging failure. On Surfs Up 3, the crystal was held in place with the friction of the header. The start-up sequence was normal, and logging was successful. Follow Up: Investigate alternatives for securing the crystal. |
| Sensor Array Mounting | The sensor array on the primary payload is mounted vertically. After reviewing the data, the external sensors may have been affected by wind chill during the post-burst acceleration. Follow Up: Mount the sensor array horizontally. |
| Inflation Checklist | The ascent rate was low due to an incorrect calculation and the parachute weight was excluded. Follow Up: Develop an Inflation Checklist. |
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| Black = Actual Path Green = Predicted Path Map made with MapPoint Prediction made with BalloonTrack |
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| Green = Ascent Red = Descent Maps by Google Earth Looking slightly southeast; 2008A is the shorter, southern track, and Surfs Up 3 is the longer, northern track. |
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| Green = Surfs Up 3 Ascent Maps by Google Earth Looking North |
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| Red = Surfs Up 3 Descent Maps by Google Earth Looking North over Akron, Ohio |
| Launch Site |
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| Predicted Landing Site |
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| Actual Landing Site |
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| Difference from Predicted to Actual Landing Site |
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| Primary | 144.80 MHz slotted at 40 seconds past the GPS minute; every 30 seconds |
| Secondary (APRS) | 144.39 MHz slotted at 25 seconds past the GPS minute; every 60 seconds |
| Balloon Manufacturer | Kaysam |
| Balloon Type | latex |
| Balloon Size | 1500 gram |
| Neck Load | 2514 grams |
| Neck Lift | 2832 grams (neck lift should have been much higher) |
| Parachute | 5 ft |
| Peak Altitude | 92,401 ft ASL |
| Launch Conditions | light wind and clear |
| Primary Payload (Wave Catcher) 1830 g |
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| Secondary Payload 542 g |
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| Surfs Up 3 Flight Configuration | |||||||||
| The Surfs Up 3 image gallery contains photos of the launch and selected pictures taken by the on-board camera. | Surfs Up 3 Image Gallery |
| Watch the initial climb out of Surfs Up 3 from Wyandot County Airport. | Surfs Up 3 Launch (7MB) |
| Review the locations of both balloons by time in this graphic presentation. | Time Synchronized Location |
| Flight KML | Surfs Up 3 KML |
| Flight Telemetry | Surfs Up 3 GPS Data (csv) |
| Flight Metrics | Surfs Up 3 Metrics Data (csv) (temperature, pressure, humidity, power) |
| All Surfs Up 3 Charts | Surfs Up 3 Charts |
Copyright © 2007, 2008 Surfing Satellites