Global Space Balloon Challenge Launch on April 23

The “Medford High Altitude Eclipse Team” from North Medford High School (NMHS) launched their contribution to the Global Space Balloon Challenge on April 23 at the Earth Day event at the ScienceWorks hands-on science museum in Ashland, Oregon.

The launch was part of a series of practice events for a project sponsored by NASA that will attempt to image the total eclipse of the Sun on August 21, 2017 from a balloon flying at 100,000 feet. The video images will be sent in real-time to the NASA television network.

The Earth Day launch was carried out by ten NMHS sophomore students supported by their Astronomy Teacher and four adult mentors. The students will be working on the Eclipse project for the next 18 months and this will form the basis of their senior projects.

The equipment used for the Earth Day launch included a Kaymont 1000 balloon, Rocketman parachute, Xaiomi YiCam camera, SPOT Tracker and 3 Arduino-based flight “computers.” The balloon ascended to 26,674 meters (87,513 feet) before bursting. The payload then descended and successful landed near Merrill, Oregon, some 66 miles from the launch point. The NMHS team successfully retrieved the payload, which was in perfect condition. During the descent of the payload (at about 40,000 feet), the team also tested a radio-driven flight termination unit, which also worked well.

Achievements

  • This flight was our most successful to date
  • Improved team communication and error reduction using flight checklists managed by a student flight director
  • Great support and sponsorship from the ScienceWork hands-on science museum in Ashland
  • The “reverse” parachute design worked well
  • The new manufactured payload container approach was lighter and easier to use
  • The new flight computer units (IMU and FTU – see below for details) worked well
  • Improved use and accuracy of flight simulation software
  • Great PR from local television station (NBC channel 5) and local newspaper (Medford Tribune). The newspaper article can be found at:http://www.mailtribune.com/article/20160418/NEWS/160419659

Key Action Items

  • Continue to improve our flight checklists
  • Improve knowledge of ground crews in GPS usage
  • Experiment with payload harnesses to reduce payload spin during flight
  • Perform ground-based analysis of cameras and camera configurations and settings and add results to pre-flight checklist
  • Add an upward facing camera to the payload to record balloon burst
  • Replace hand warmers with Arduino-based heating system to reduce moisture in the camera container
  • Add a Tracksoar tracker to provide SPOT Tracker backup and deliver real-time position and altitude data
  • Consolidate power supplies in the payload box
  • Obtain a second helium tank to ensure sufficient gas supply on launch

Flight Computers
The three Arduino-based flight computers consisted of the following:

  • GPS tracking system that measured latitude, longitude, altitude, UTC time and external temperature. All data was recorded to an SD card. The sensors included a U-Blox NEO-6M GPS and a LM61 temperature sensor.
  • Inertial Measurement Unit (IMU) that measured atmospheric pressure, internal temperature, altitude, local time, roll, pitch and heading. All data was recorded to an SD card. The sensors included an Adafruit 9-DOF IMU breakout card (containing a gyroscope, accelerometer and magnetic compass) and a BMP180 barometer.
  • Flight Termination Unit (FTU) that consisted of a radio receiver and a DTMS decoder that heats a nichrome wire to sever the balloon from the payload when receiving a pre-specified code from a ground-based radio transmitter (Baofeng FM transceiver with Arrow Yagi antenna).

Flight Video
A video of the flight can be found on YouTube using this link:
https://www.youtube.com/watch?v=xPVfD7lnE9I

Flight Data
Tracking data and charts from the flight computer data are included below.

Actual Flight Path vs. Predicted Flight Path

Predicted_Actual

Altitude and External Temperature Data from GPS Tracking System

GPS_Temp_Plot

Heading Data from the IMU

Heading

Roll Data from the IMU
Roll

Pitch Data from the IMU

Pitch

Atmospheric Pressure Data from the IMU

Pressure

Internal Temperature Data from the IMU

Internal_Temp