Project SunbYte II Integration Tests in Texas!
Team SunbYte have just returned home from an exciting trip to Palestine, Texas (US) for an integration event, where they worked alongside NASA engineers in order to get permission to launch their experiment in New Mexico on 4th September 2018.
The experiment was integrated onto the launch vehicle gondola and a thermal vacuum test was conducted along with other experiments. The thermal vacuum test aims to identify any issues with the hardware in terms of structural strength, material selection and mechanical movement. During the test both yaw and pitch movement (yaw, nose left or right about an axis running up and down; pitch, nose up or down about an axis running from side to side) were demonstrated at 5mbar pressure and -20C -- +40C temp. When the temperature was at -40C, the yaw function no longer responded whilst the pitch motor showed limited and delayed response. This indicated that the system operates fine at low pressures but requires warmer conditions. The lack of response by the yaw suggests the pitch motor was better insulated, which ended up being the case. Active heating could be used in conjunction with temperature gauge feedback which would ensure the motors remained warm during cold conditions without overheating during hot conditions.
A large area of the metallic base was exposed which led to high heat losses when the pressure was high enough for convection thermodynamic transfer. It was suggested that insulation be added to prevent heat loss.
A downlink test was also carried out, however an issue with the HASP launch vehicle hardware hindered efforts to demonstrate downlink. A spare TTL converter was installed which meant downlink communication was established. One area which required further investigation was the use of GP10 to USB serial communication. This method of communication is used between the three main on-board computers, all three are Raspberry Pi’s model 3B+. The science Pi and the tracking Pi both connect to the network Pi using this communication technique. The network Pi receives this data and combines them into a string along with the GPS signal and the Arduino data logger readings. This is then encoded in base64 and sent to the ground. The unreliability of this method is now being investigated by the team due to a lack of secure connection between the on-board computer - this is mission critical.
The team will now focus on addressing thermodynamic improvements which will take place in Sheffield. Work on the software is continuing in Hong Kong with the gimbal being used to test a new version of the code. SunbYte will travel to Fort Sumner, New Mexico, USA on Saturday 25th August and are scheduled to launch on 4th September.
Watch this space for updates on how the team get on, you can also see live updates on their Facebook page.
SSI: Thank you for the support and funding provide by the Department of ACSE, Aerospace, Faculty of Engineering, IET, the Alumni Fund and the School of Mathematics and Statistics.