Given the number of steps that need to be improved, a simple listing of suggestions would not be adequate to properly impart the whole mindset of decreasing the probability of component or procedural failure. Therefore, a systematic approach is taken in this document, where explanations are given under each of the major categories of design, construction, testing, administration, flight planning, launch preparations, pre-launch checklist, tracking / telemetry, and post-flight analysis.
The purpose for these exercises remains to be for gaining experience in working with cutting - edge GPS and communications technology, to gain insight into strategies for both the hardware and organization useful to the amateur radio community to better meet public emergency and routine volunteer communication needs, as well as to serve as a stimulus for interest in technology and teamwork with other hams and students at the University.
Use redundancy - separate telemetry channel from voice and digital contacts. This means that additional frequencies and bands will be used for packet contacts, cross - band repeater use and beacons. HF frequencies would be used for beacons, while it is li kely that a VHF - UHF crossband combination would be used for a repeater. Telemetry should be on the 2M VHF band, as this is the most common band for use by radio amateurs in the club.
All electronics should be chosen to be able to withstand testing that include severe temperature ranges that mimic conditions in the air: 60 C for high, - 40 for low.
A lightweight frame should be used to mount the different balloon electronic modules . This frame should be easily lifted out of the styrofoam box for testing and repairs. The frame material can also serve as a ground plane if metallic.If a composite material is used, it must be as light as possible. All modules should be mounted in lightweight boxes for strength and ease of assembly and troubleshooting. Aluminum boxes can be used if light enough, or else plastic boxes sprayed with RF protective coatings, such as EMI - RFI Shield from Electrosonic (stock # 10 - 4807, $9.09 / can).
Circuit boards should be coated to prevent moisture damage or shorting using an RTV, urethane or silicone - based cover such as Hysol PC28 Spray (urethane) (stock # PC28, $12.30 / can) from Electrosonic. All circuit boards will be shock mounted within the boxes, with rubber grommets around the bolts. Grommets are available at WES (Cardinal Electronics) in all sizes at moderate cost. Boxes can be purchased, made by us, or custom built (Empire Sheet Metal on Route 90 can do boxes - minumum charge $15.00 per order).
All electronics must be in as lightweight yet as strong a configuration as possible. This means that printed circuit boards should be made for custom designs. Copper - clad protoboards could also be used for non - surface mount components.
Should wire-wrap construction be used, all IC's must be soldered at the power and ground pins of their sockets to secure them in place. All crystals shall be directly soldered in place, with a rigid wire soldered over them from the ground plane to provide extra strength and additional noise immunity. TNC's and transmitters will be a small as possible, using single-board units and/or surface mount technology.
No wire will run from board to board using strictly soldered connections. All connecting wires will be at least 24 guage, stranded wire to prevent vibration breakage. Likewise, all wires will be soldered are also polarized for proper insertion. Power wires will be 22 guage, with redundant connections on the battery packs - ie, separate connections to each positive and negative point of 2 - 15 volt lithium batteries in parallel. Rubber grommets will be used for all access holes where 22 guage wire leaves packages.
Fuses will be used from each module to power. Power connectors will be in parallel, in order that each system is independent in its power supply. This means that only one module will shut down at a time if a fuse blows. A diagnostic routine can be programmed in to check whether any fuses have blown. Power supply voltage will also have to be monitored to further aid in troubleshooting and keeping track of payload power usage.
Voltage regulators should be heat sinked, with the sink bolted to the aluminum box for maximum heat dissipation in the enclosed space. This will also aid to heat the box in the cold high altitude air. Heat sink thermal joint compound such as Thermalcote (from Active Electronics) will be used on all metal - metal connections conducting heat.
A remote cut - down mechanism will be utilized and tested. There should be a way of remotely testing to see if it worked. The preferred method is to use nichrome, or "toaster" wire, that will cut the neck of the balloon when a potential is applied across it. This mechanism will be self - disabling after a predetermined time to prevent heating of the element once on the ground.
Separate command and telemetry channels will be used for the payload. Telemetry will consist of a steady stream of GPS positional data on a dedicated VHF 2M frequency, while telemetry will be transmitted either a separate frequency of its own or with the GPS data.
An HF beacon will be used for propagation testing and locating should VHF and UHF transmitters fail.
Ideally, each package will have either its own power supply, or have redundant, heavy duty connections to a parallel package of two batteries.
All soldering will be tested by putting pressure on the connections after they have cooled. Likewise, each connection will be tested / inspected for continuity and cold solder joints.
Antennas will be secured in place with silicone sealant in such a way that if stress is put on the antenna (ie, on landing) the antenna will be able to bend without breaking the feed cable. Feed cables will be coax that is securely soldered, with the entire connection protected with heat shrink tubing.
All plug and soldered wire connections will be protected with heat shrink tubing to prevent vibration from weakening the solder connections.
Wire runs will be kept to a minimum to avoid crosstalk and resistance.
Sensors will be calibrated using U of M equipment - humidity, temperature, pressure, etc. Environmental chambers can be found in the faculty of Agriculture, and Botany or Chemistry departments in the Faculty of Science.
The philosophy used in testing will be to ensure that the payload will survive the effects of vibration, landing shock, extreme temperatures and moisture. The intention is to be able to retrieve the payload in order that it be used again for future flights, demonstrations, field exercises and fox hunts.
As each portion of the payload is completed, it will undergo a burn - in time to ensure functionality. This should last at least two days.
After burn - in , there will be shock and vibration testing of each component. The component must survive a cushioned landing from a height that allows the styrofoam covering it to achieve terminal velocity, ie. a speed of at least 25 ft/sec. Obviously, expensive components will get extra padding so that it is the connections that are put under stress, and not the integrity of the part itself. Vibration testing will take place by imitating the effect of a rough takeoff and landing. During the test phase, all details of the repairs that take place and the reasons for failure will be noted. Once these tests are finished, the unit will be tested for a further 2 days (at least) or preferably at least a week. These tests will be in the form of fox hunts, running the device while driving around the city, bench burn - in, etc.
Ensure all parties taking part in the launch have complete information. If Environment Canada is participating in the launch, they will have to know which days we are looking at to launch, as they will have to have equipment ready and set up beforehand. Transport Canada and Air Traffic Control (ATC) will need prior notices, in order that NOTAMs be issued in advance of the flight. Waivers will also have to be obtained for the flight. Media outlets need at least a week notice if they are to cover the event.
It is very important that all launch clearances be gained before flight. This means that Transport Canada must be contacted at least 1 month before the expected day. A helpful person in the department is the Civil Aviation Inspector, Air Navigation System Requirements, Aerodrom Standards & Certification. If launching in conjunction with Environment Canada, they may handle this aspect of the flight.
The reason for the contact with Transport is so that a waiver can be obtained to do the launch in controlled airspace (ie., the air above Canada!). It is also necessary to get the proper contacts set up with those that are in air traffic control. Also, minimum parameters will be set up for the launch, for example, visibility must be 5 miles up to 10,000 feet, and winds less than 15 knots on the ground.
A new callsign has been approved by Industry Canada for future UMARS experimental activities. This will remove confusion while people are trying to log into the balloon TNC in the future. The new callsign is VE4UMX and will be used to identify the actual experimental payload being used. Net control stations, data reporting stations, etc. will use VE4UM, while VE4UMR will be for use exclusively on the repeater.
Consider the objectives of each flight, and look for winds that will send the payload in the proper direction. For example, if it is a long search - and - recover mission that is desired, it may be preferable to launch in Saskatchewan or Western Manitoba.
No portions of the payload will be flown any less than two days testing time before flight, preferably a week. This allows for burn - in time on electronics and testing all possible parameters for communication - related functions.
Wind trends will be monitored for a week before launch. This includes both surface and upper air winds. This will serve as a base indicator of whether the launch will be likely to go ahead on the expected date.
Winds must be guaged to ensure that they will not be excessive on launch day. Likewise, it is important that they allow the payload to land beyond a safe distance of city limits - for example, at least 20 miles out for a safety factor. Maximum launch speed will be 10 km/hour, in order that the balloon can be walked to the launch site. This will allow a Raven balloon to be used for maximum altitude, and thus the best data results can be obtained. Launching in a lower wind will also reduce jostling of the payload. Upper air winds must not be more that 40 knots, otherwise we run the risk of blowing into the U.S., Lake Winnipeg, or thick bush in Northwestern Ontario. Estimates can be obtained from Environment Canada, through the launch contacts, or the Flight Service Centre.
Given the nature of the terrain in this district, fox hunters and trackers must be prepared for bush and water travel. Appropriate bush gear, canoes and/or powerboats will be needed on the expedition should the payload land in such and area. Canoes will be necessary if there are portages through numerous lakes.
A month prior to launch, alert the Amateur Radio community that there will be a launch on a certain date, with a scrub date also given in the message. Repeat the message 2 weeks before, then during the week up to launch with any updates to payload, timing, etc. Arrange to have interested people act as chasers. Have a chaser coordinator (preferably the person who will work in the club room on launch day) arrange to have all chasers at a central location 1 1/2 hours before launch for deployment. Deployment will depend on the wind information obtained from Environment Canada. Launch will not take place until chasers are in place.
This is pre-tested by weighing down the entire cord length with 5X the lift of the balloon, to take into account any wind effects. The tether will be firmly tied to a strength point at the bottom of the payload, such as the bottom of a nylon mesh screen. The end held to the ground will be tied onto a loop - type handle so that it does not cause too much pressure on the holder's hand. The suggested cord for this use is 40 lb. test fishing line, such as that used on the parachute.
Tests will be done at this point on all portions of the payload - ie, a packet contact will be tried, cross - band repeater strength and sensitivity will be tested, and telemetry tested (everything but the cut - down mechanism - this can be tested for continuity with a diode - protected A/D converter). It is suggested that the restraining cord be cut when all tests are complete and all systems have passed. Cutting the cord will prevent tangling.
One club member will remain at the launch site with the Environment Canada team to serve as a redundant tracking location in the event that positional contact is lost with the UMARS payload of the balloon. They will plot the location and altitude of the balloon as it progresses. It would also be of advantage to get a copy of their software if possible, in that it could be used as an additional backup with the 150 foot tower at the UMARS club location should the Environment Canada station lose the radiosonde signal. A scanner set up for 403 MHZ can be used for reception. Likewise, if we can get a copy of the tracking software, it would be useful to practice with the system by borrowing a radiosonde from Environment Canada to ensure the system works before flight.
At least 1 hour before launch, there will be an experienced member in the club room, running the tracking net. They will place chase teams before launch, and direct them as the balloon progresses. There will be at least one additional assistant in the club room to plot the balloon and chase team progress on a large-scale aeronautical wall map. The head of the club tracking location will also be the contact person with Area Air Traffic Control, giving bearing, distance and altitude of the balloon from the airport. Should the UMARS balloon equipment fail to give precise positional data, the member with the Environment Canada tracking location will then provide the positional reports to Air Traffic Control (ATC).
The members at the UMARS club will switch from the VHF roof antenna to the repeater antenna once the chase teams are out of range of the UMARS repeater. The repeater will then be run from a temporary 2 M vertical on the roof. Using the UMARS 150 - foot tower will enable trackers to maintain contact with the balloon for a considerably longer distance. In order to maintain contact, a preamplifier can be used on the input, and a 100 - watt linear amplifier on the output. Net control will then continue on the MRS repeater system, and cellular telephones if the need arose.
Should the winds before flight suggest a possible landing in a remote location, provisions should be made for renting an aircraft for use during the flight. Aircraft are available at Winnipeg Flying Club, often on short notice, for charter at about $110.00 per hour. This will enable a tracker to follow the balloon on its decent, and determine if it is still functional on landing. One likely possibility is to call up the CASA people, and ask if they would like to use our balloon flight as a search and rescue exercise. Tracking a transmitter would be like looking for an ELT, while the GPS would be like looking for one of the new types of ELT's expected to be approved for use in the near future. This way, we could also get a UMARS member in the air as additional tracking redundancy.
If possible, get the telemetry data from Environment Canada in order that it can serve as a comparision to our data. All data collected should be compiled in a spreadsheet, in order to get pertinent stats: