Ground Station Design

The station that you will design to support your school's contact with the Shuttle or MIR will depend on the type of contact you will be making. Early in the process, up until the time you have been notified that your group has been selected, you will not know which type of contact you will be making. Therefore, develop working plans for both types of stations early. Once you have been selected, you can then finalize the plans for the type of station you will really need.
Since you do not know beforehand what the format of your contact will be, you should read and understand both the telebridge and the direct contact station material below. When your school is scheduled for a contact, you should then focus on the station type required for your primary contact opportunity. If you are scheduled for a direct contact, you will need to focus on a direct contact station. However, since contingency flight timeline adjustments or a need to use a backup pass could require the use of the telebridge instead of your direct contact station, you will need to have a plan to convert your station to support one. Therefore, you will need to fully understand the engineering details and operations procedures for both types of contacts.
If your school is selected for a telebridge contact as the primary opportunity, you do not need to worry about a direct contact station. Your primary and any backup opportunity will remain a telebridge contact.

CONTACT-TYPE SPECIFIC STATION DESIGN GUIDELINES

Direct Contact Station

Telebridge Contact Station

Incorporating NASA TV or Amateur ATV
Many groups have inquired about the possibility of setting up a satellite (TVRO) dish and receiving the NASA Select video directly. They have requested that NASA provide the live video of the crewmember at the SAREX radio during the contact, so that the stidents can see as well as talk to the crew.
Adding TVRO to view the direct NTV downlink from the Satellite increases the complexity and your team's workload. Additionally, NASA will not provide this video on a request. "Downlink Video" is a premium resource and the majority of the TV pictures sent down from the shuttle are being used for scientific and engineering purposes directly in support of the Shuttle's main mission. If the downlink video happens to be of a crewmember operating SAREX, it is purely by chance. And if it were to be provided, your students and group will be very confused by the timing of things. The NASA Select video is sent from the orbiter, to the Tracking and Data Relay Satellites (TDRSS) and then down to earth, where it is processed and then sent back up to the satellite that carries it to the networks and other subscribers. All of these hops introduce time delays into the signal, so that by the time it is received by a satellite dish viewer, it is about 5 to 7 seconds behind what is actually going on.
SAREX contacts, on the other hand, take place in "real-time" or "in the present", since it is direct from your station to the Shuttle. The result is very confusing if the students try to watch the crewmember while talking him and the video of the crewmember is still showing the what was happening with the last student. The confusion that will occur will result in hesitations and delays on the part of the students that will waste precious time. To overcome this, everyone will be forced to ignore the video and concentrate on the radio contact. This would waste the precious TV downlink time as well as interfere with the amateur radio focus of the event. Therefore, using NASA Select video as a part of your station is not possible, nor is it practical.
Lastly, AMSAT has received several requests and inquiries regarding the reception of ATV onboard the shuttle. Previous groups have wanted to work in sending live television to the crew. The ATV mode of SAREX existed only in configurations D and E. Due to space, weight, and power requirements, along with the complexity of the package and marginal results achived, these configurations are no longer flown and have been deleted from SAREX.

Configuration Control and Management
A very important aspect of your station is the management of its configuration. This means keeping accurate, detailed records of the equipment and components, along with all the settings and interconnections necessary to make the system work as designed. It is highly recommended that you place one person in charge of making sure that this information is recorded and verified as accurate. When the system is designed and checked out, write down all your settings and make detailed drawings of how everything is hooked up. This person becomes the configuration manager, and is responsible for keeping these records and for verifying on contact day, that everything is in place and properly set up.
Once you have achieved a working system, and have recorded its configuration, including software parameters on the orbit and tracking software, the configuration manager sets this information aside as your baseline design. Any and all changes to this baseline design must be verified to and approved by the SAREX Lead (group coordinator) and the Configuration Manager. This prevents anyone from slipping in any last minute changes that have not been tested and approved by the team.
Make it a rule that no changes will be introduced to the system less than 48 hours before your scheduled contact. By that time, it is usually too late to be coming up with anything new. If your team is putting together a new design to improve upon the existing set up, and they cannot complete the checkout and integration into the baseline by 48 hours before the contact, it should be dropped from consideration.

Redundancy
For all important and critical systems onboard, the Shuttle always has a spare. This is called redundancy. Some systems, such as life support and the navigation units, are so critical that three complete systems are carried (triple redundancy). For your station, whether its for a telebridge or a direct contact, you are strongly advised to design in as full a measure of redundancy as possible. Have all backup components ready at your operating positions and have them set up so that they can be brought into use with little or no delay. Identify all critical components and have spares on hand. A second transceiver, power amp, preamp, and power supplies are advised. o A second tracking computer system should be running the same tracking program and a clock, keeping time in UTC, should be right next to the primary tracking computer. The Tracking Officer should be able to disable the primary computer's control of the rotors and take manual control if necessary. The YAESU G5400B control box provides manual control ability. Its not necessary nor desirable to have both computers interfaced to the rotors. The second computer provides a means of determining the antenna pointing angles for manual control of the rotors.
Some redundant station components can be built into your design so that they are powered up and ready to be brought in-line to replace a failed component through throwing a coaxial switch or a toggle switch. Radios, power amps, preamps, antennas, and power supplies are amenable to this type of backup provision. These are called "hot spares", as they are already "hot" with power and ready to go on a moment's notice.
During your system testing and checkout, make sure you test and verify all of your backup equipment as well. Develop contingency plans to switch to the backup system in the event of an unexpected and sudden failure of your primary station. Practice this "fallback" routine until all of your contact team members are comfortable with it. Should something unexpected happen, and Murphy's Law says it will pick the worst possible moment to do so, there will be a lot of things going on, and your radio operators will need to be able to make the switch effortlessly and without appearing disorganized. You should also be aware that all of this will be going on with TV cameras and reporters watching, so practice enough so that you can at least appear calm!

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