Trimethyl Aluminum (TMA) canister was a payload flown in a sounding rocket mission. The release of TMA at a particular altitude take place during flight which produces chemiluminescence on reaction with atomic oxygen, and the tracking of the same is done. This is employed for the estimation of wind propagation at upper atmosphere.
TMA, which is a liquid contained inside the canister in sounding rocket is subjected to external thermal environments during the prelaunch and flight phase. TMA is pressurized by Argon gas held in a separate compartment. Due to external aerodynamic heating during flight, temperature of Argon and TMA increases which result in pressure rise. It has to be ensured that temperature of TMA is within its boiling temperature at the time of release, which need to be estimated.
Thermal environment during pre-launch phase is due to solar heating. Solar heating is considered during prelaunch phase. During ascent phase of the vehicle, it is subjected to aerothermal environment due to friction with air and its compression. Heating during flight is estimated based on engineering method. Thermal response analysis is carried out based on an integrated model developed for TMA payload. Computed TMA temperature was within its boiling point of 126°C. Maximum estimated temperature of Argon at TMA release altitude of 100 km is 51°C. In flight TMA dispensing mechanism functioned as expected and performed its scientific objective. Maximum computed pressure rise of Argon is also computed and was compared with that measured in flight. It shows fairly good agreement with computation thus validating the methodology for heat flux estimation and thermal response analysis.