Near Space Ventures, Inc.
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NOTE: Suggestions for improvement and corrections
to facts in this document are encouraged. ========================= PAGE ONE. ========================= Launch date: YYYY-MO-DA ie 2006-02-21 ------------------------ Launch time: HH:MM:SS ie 09:00:00 Use Zulu or whatever. If you intend to use the the GPS log that the program generates to load a GPS, use ZULU, otherwise, it doesn't matter much. ------------------------ Callsign: Your callsign ie KCOMIC-11 The '-11' is an APRS convention. An '11' means 'balloon' ------------------------ Lat: Latitude in degrees.decimal-degrees For our primary KC launch site try: 39.204657 ------------------------ Lon: Longitude in degrees.decimal-degrees For our primary KC launch site try: 94.38786 ------------------------ Elevation: The elevation above mean sealevel of the launch site: For our primary KC launch site try: 900 ------------------------ ascent rate: The estimated ascent rate of the spacecraft in FPM Ususally somewhere between 600 and 1200. This factor is a primary determinate in the flight. Slower ascents mean longer flights. This is affected by the 'free lift' you measure when you fill the balloon. The more free-lift you have, the faster the ascent rate. Tables exist for this function but I haven't found them to be helpful. Ususally, 1000 fpm is optimum. It really depends on how you design the mission (slower assent rates = longer mission times and downrange distances.) ------------------------- Decent rate: This is a function of the weight of the spacecraft vs the area of the parachute. It's usually 1000-1200 fpm at 1000ft agl. It has _some_ impact on landing site but not anywhere near as much as ascent rate. The parachute is not effective till about 20,000 ft so the 'drift' is determined by mostly by winds aloft at and below 10,000. Usually use 1200 here. ------------------------- Burst Altitude: Where the balloon bursts (or is released). This is the other primary determinate of landing site. If you use the 'cutdown device' at 60,000 ft in the summer, you'll get a longer flight. In the winter, you'll get a shorter flight if you cutdown early. This is because, IN GENERAL, the winds move east over 60,000 ft during winter, but in the summer they move west. If you 'cutdown' before 60000 ft in the summer, the west winds won't have pushed the balloon back toward the launch site. Anyway typical flights are between 90,000 and 105000 -------------------------- Wx station: The weather station idenitifier nearest your launch site. Click on 'station list' to get lists of stations by state. For the KC launch site we use either MCI or TOP Later in the process the program interfaces to NOAA to get winds, temps and pressures aloft. It uses this data to tell NOAA what data to use. -------------------------- Now you need to click a button for GFS model. GFS is a model that NOAA uses on it's 'READY' site to provide forcasts for winds aloft. There's 0-84 hr, 0-180 hr and 192-384 hr forecasts. The closer the model, the more accurate the forecast. The '0' model is actual measurements. You can use those models to try to predict landing sites upto a week or so away but they don't get accurate till about a day or two before launch. Even then, if you have a front moving through, the predictions will change in 6hr period. IN GENERAL, we've found that predictions made on the morning of the launch get you within 10-12 miles. To test with, click the 0-84 button. --------------------------- Once you've filled the form in, click the 'SUBMIT' button. ============================= PAGE 2 ============================= Forecast period: This is a pulldown menu with the forcast periods for whichever GFS model you choose on page 1. Pick the time and day that you plan to launch. Keep in mind that the times are ZULU so they'll be 6 hours ahead of Central Time. This data is pulled from the NOAA READY forecast site. --------------------------- ACCESS CODE: This is a 'security image' from the NOAA website. You need to enter it as you see it. ---------------------------- If everything is right, click 'GET PROFILE'. If you get a page that says "ERROR" and nothing else, whatever you typed in ACCESS CODE did not match the security image. Try again. ============================= PAGE 3 ============================= FINALLY!!! You should see these links: Raw text of ARL READY report. TNC formatted GPS track log. Download TNC formatted GPS track log. Download XML GPS track file. Plot Track on Google Maps. Click on "Plot Track on Google Maps" Another window will pop up with a very usable mission map that you can traverse, get satellite views, hybrid street/photo views. If you click on the Landing Balloon Marker, you can get driving directions from the launch site. The landing site has 'range rings' on it. Mouse over the "altitude" markers and get the radio horizon, speed and course. =========================== NOTES =========================== The program stores a cookie on your browser and will keep the last data you entered. So everytime you go to that site, it will fill in the first page with the last projection you entered. This is a great 'what-if' tool. On launch morning, run a couple of projections for different burst altitudes, print the maps and give them to all the chase teams. |