The Telemetry, Tracking, and Command (TT&C) subsystem is responsible for Spartnik’s hardware, software, and the ground station. Table I shows a summary of the satellite’s onboard software and computer hardware, and also the ground station.
Table 1
| Onboard Computer Software
|
- Most of software code will be written at SJSU
- SJSU written interrupt driven Operating System (OS)
- We will also be using a customized version of AX.25 and PACSAT for data transition.
- Maximum of 8 users are able to log on at any given time.
- Number of pictures to be taken on each pass is TBD due to power levels.
|
| Onboard Computer Hardware |
- Intel 80C188EC 20 MHz, 8-bit microprocessor (386 Intel chip)
- 256K ROM, 756K RAM (MAIN Memory)
- 6 Megs of RAMDISK (Secondary Storage)
- 2 Analog to Digital Converters
- 128 analog sensors
- Error Detection and Correction (EDAC) circuit
- 2 internal UARTS or Serial Communication Ports
- SDLC chip used for Rx/Tx communications with S/C
- Motherboard is being made by UCS
|
| Ground Station |
- Custom Windows Application (running NT)
- 2 meter uplink and 70 centimeter downlink
- YAESU transceiver
- DSP2232 Terminal Node Controller
- Ground Station computer is a Pentium based PC.
- All OD and AD code will be processed at the ground station
- Upload at 9600 baud and download at speeds up to 57.6 K baud rate
- Will be able to track and keep the transceiver tuned on passes by using INSTANTRACK and Kansas City Tracker software and hardware.
- We will be using cross-yagi antenna for the ground station.
- Ground station location is in Engr. 236
|
System Status: May 2001
Work on the computer hardware, software, and ground station continues. The File System Module and the PATSAT protocol are complete, and we are awaiting the arrival of Spartnik's computer to SJSU from University of Santa Cruz. The ground station is now able to communicate in both JA and JD modes (Analog & Digital: 2m uplink, 70cm downlink). The tracking is being done with the aid of a Kansas City Tracker and work is continuing to bring the Kansas City Tuner on Line. Work also continues to enable full-duplex digital communication.
System Status: December 2000
The work on the computer hardware, software, and ground station continues. The ground station is currently operational in the JA (Analog: 2m uplink, 70cm downlink) mode with work continuing to enable the JD (Digital: 2m uplink, 70cm downlink) mode of our ground station. The tracking is being done with the aid of a Kansas City Tracker and the ground-station is scheduled to be fully operational by the start of the Spring ’01 semester.
System Status: July 2000
Some of our spartnik members attended a HAM communications Field Day up in the Santa Cruz Mountains the last weekend of June. This was a very good learning experience, which can now be used in TT& C and on the MGS.
Computer Hardware:
We are looking for volunteers to design the charge controller and the power distribution ciruit in the shortest amount of time. Current status: We are currently trying to obtain the hardware specifications from Steve Peterson from UCSC.
Computer Software:
PACSAT is still being tested and debugged and the AX25 is still being updated.
Ground Station:
The Summer team is in the process of re-calibrating the "Cross-Yaggi" antenna for the ground station. The only thing left is to align the Cross-Yaggi's with true north. The Azimuth Elevation Controller is up and working. Special thanks to Jeff Long for letting us use his SWR meter and dummy load till we can acquire them for TT&C.
System Status: February 2000
February was a productive month for TT&C. Thus far, the communications aspect of TT&C had remained a mystery for the Spartnik team. On February 16, 2000 we gave a Spartnik presentation to the West Valley Amateur Radio Association, and acquired volunteers to help with the HAM communication aspect of Spartnik.
We are also collaborating with Mr. Walter Miller from NASA-AMES Research Center. He is advising our team with his expertise of communication system compliance with aerospace industry standards, as well as, antenna configuration. Thanks to both contacts, we are making tremendous advancement in TT&C and Spartnik communication.
Computer Hardware:
WenRui Mui, a senior Electrical Engineering student, has volunteered to design the charge controller and the power distribution circuit. He will be completing the project in conjunction with his senior project. Current status: He is obtaining the hardware specifications from Steve Petersen from UCSC.
Computer Software:
PACSAT is under testing and debugging and the AX25 is being updated.
Ground Station
We have received pre-owned furniture for the ground station, acquired by hard working Spartnik members. Special thanks goes to Dan Coyle, the US. Air Force, and Lockheed Martin Technical Operations for donating the furniture. The ground station is being modified to retain state of the art standards.
System Status: December 1999
The computer subsystems and the Ground Station have been merged into a single subsystem, Telemetry Tracking and Command (TT&C).
Computer Hardware:
Currently we are designing and manufacturing a power distribution circuit and a charge controller. We are looking forward to the Electrical Engineering students at San Jose State on the spartnik team to accomplish both tasks. Both designs have become senior projects for EE students.
Computer Software:
Keiko has been working hard to update our AX25 from version 2.0 to 2.2. Various debugging software have been used, such as Visual C++. At this time, AX25 is at the testing stage, as the PACSAT software. Two new programmers joined the team, Robbie Singh and Tim Michaels. Both of them will be writing the Camera Module software for Spartnik.
Ground Station:
We
have put our GPS antenna up on the roof successfully and are now looking forward to haveing someone recalibrate the . Cross Yaggi. antenna for the ground station. The Azimuth Elevation Controller is up and working. Now we need to make some more purchases for miscallaneous equipment.
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