From:Ronnie Baccus RBACCUS@ACS.TAMU.EDU
Progress Report - Texas A&M University
This week was spent finalizing design calculations on three primary mechanisms on the vehicle: ramp deployment mechanism, solar panel deployment and pointing mechanism, and rover quick-release mechanism. The individual performance characteristics of each mechanism have been determined and we are in the process of selecting components from vendor catalogs that will meet these requirements. The details of each mechanism will be available soon (power required, weight, etc.)
A detailed dynamic analysis of the current structural configuration was also done this week. This included a free vibration modal analysis to verify that the natural frequencies of the spacecraft are above the 30 Hz rms input from the Delta-II to prevent dynamic coupling between the booster and the lander during the launch phase. A random vibration analysis was also perfromed that verified that the rms stress values in every structural element were less than the stresses determined from the quasi-static load cases. The random loads applied by the Delta-II were taken from power spectral density data listed in the Delta-II payload planners guide and Griffin's Space Vehicle Design.
We have also been working with the landing gear team at Lamar to iron out the details of attachment so that there are no stowage conflicts within the Delta-II shroud. Analysis has shown that two radiator panels can be mounted to the top of the spacecraft (66 cm by 25 cm each). There is some concern that this could cause solar visibility problems for the O2 plant.
Next week will be spent finalizing these details and beginning the design report. The week after spring break will be spent finishing the design report by March 22.