From: Richard Eddings firstname.lastname@example.org
Past Deliverables: Brian: Complete a short list of materials Complete frame design Price & determine availability of materialFor the material selection, the rover was broken into four separate subsystems: Wheels, legs, Body structure and electronics enclosure. The material choices are as follows:
|Subsystem||Density||Yield Strength||Thermal Conductivity|
|Cast Aluminum Alloy 355.0 TS||2.71||172||180|
|Wrought Aluminum Alloy 7075||2.8||503||180|
|Thermoplastic Carbon Nylon 6/6 (30% fiber)||1.37||241||N/A|
|Thermoset Graphite Epoxy (48% fiber)||1.48||140||N/A|
|Thermoplastic Glass PPS (30% fiber)||1.56||138||N/A|
|Thermoplastic Carbon PPS (30% fiber)||1.56||186||N/A|
Also, preliminary drawings were made on the structure and electronics enclosure.
Richard: Continue thermal revisions Begin preparations for construction Assist in structural revisions The thermal revisions are now 1 week behind schedule, but should be completed on schedule. The drive motors and steering motors for the prototype are ready to be ordered, pending availability of funds. Tim: Complete communications system design Complete research on obstacle detection Complete block diagram of sensor systemCamera information has not been received. Preliminary selections have been made for the communications system. Currently, the light stripping detection system from used by the JPL Pathfinder rover is what we are considering for obstacle detection.
This afternoon after I talked with Mark, I talked to Motorola and they said that they would not be able to increase the data rate on the radio modem. I had been looking at that and saw that it would require a complete rework of the modems design (i.e. the bandwidth would have to be changed on the radio and the logic board would have to be faster). I then called JPL and dicussed the matter with them and they said that they were limited to that data rate because of the mission specs. I then found some info on the Deep Space Network (DSN) and found that it is not set up to handle large bandwidths, like that of a video signal.
So, as for the design of the comm. system on the rover. I will design it around the Motorola Radio Packet Modem using it as the means by which images are transmitted. As the design continues a video transmitter can easily be added to the system if power and mass allow. I have choosen to do it this way for now because the obstacle detection system is going to require a great deal of time to design. However, I do feel that having a video transmitter would be a really big plus but until more details are known about the lander earth link this design will allow us to complete the mission.
James: Complete listing of possible computers Complete power calculations A short list of CPU possibilities has been constructed. A preliminary power mode chart has been started. It will outline the power requirements for various modes of operation. Next: Future Deliverables: Richard: Continue thermal revisions Continue preparations for construction Begin ordering of prototype parts Brian: Complete stress calculations Order material for prototype Compose a weight list for all components Tim: Complete block diagram of sensor system Begin detailed design of sensor system James: Complete operational modes requirements Complete power flow diagrams
Mass: 7 kg
Power: 30 W