Satgen73 DOVE WORLDWIDE MESSENGER by GM4IHJ 21 August 90 The Dove satellite downlink on 145.825 MHz FM , is presently sending ASCII digital packet telemetry. This is likely to suffer regular interuptions for several weeks, as the Dove controllers switch off the downlink, so that Dove can hear and accept their uplink of the software Dove needs for its next phase of operation. Once this software is loaded, Dove will begin its LAP1 program. Language Arts Project 1, is planned to run for about 1 year. Students between 8 and 18 years old, will be asked to forward tapes of their personal voice recordings of peace messages. Messages should be not longer than 40 words, and should be non political and non religious. Individual schools should forward the 10 best messages to their nominated message centre. Presently only Project Dove c/o R C Ensign, Amsat Science Education Adviser, 412 N Military, Dearborn , MI 48124 USA, has been nominated. Dove will rebroadcast these Voice messages and will also send its standard telemetry data and Amsat voice bulletins, by computer generated voice. Initial announcements by the Dove Voice synthesizer are planned, in English, Portuguese, Spanish and Russian. Other languages will follow. It is anticipated that digital packet telemetry may also be broadcast at times, as is done full time at the moment. EXPERIMENT 1 SPINNING in the SUN. Dove telemetry frames Hex 26 to Hex 2B report electric current produced by Dove's solar panels. All 6 sides of Dove have solar panels. The top panel is +Z hex 2B and the bottom is -Z hex 2A. Two opposite sides are +X hex 27 and -X hex 26, with the other pair of opposite sides being +Y hex 29 and -Y hex 28. As Dove spins it sends succesive frames of telemetry whose arrival you can time. At a typical moment recently Dove sent 26:06 27:1A 28:02 29:15 2A:06 2B:7D Less than a minute later it sent 26:02 27:1A 28:18 29:01 2A:04 2B:69 Even if you do not bother to use the full formulas to translate these readings to amps it is clear that the +Z face of the satellite is getting almost all the sunlight, whilst the side panels are getting very little . If you want to make more exact comparisons , be aware that INSOLATION = useful amount of sunlight falling on each satellite face is proportional to the Sine of the angle between the face of that plane and a line drawn from the Sun to the satellite. EXPERIMENT 2 INFRA RED DETECTOR. This is reported in telemetry frame box 0E and it has a very easy decode formula . Simply translate the hex in this box to ordinary numbers and multiply by one. Compare the way Infra red readings change as opposed to the way the sunlight on the panels changes. What are the likely sources of Infra red seen by Dove ? Infra red comes strongly from even moderately warm objects. So objects do not need to be visibly hot in order to give out infra red. The IR sensor is on Dove's +Z top face. To better understand the above experiments students should know that a bar magnet aboard Dove interacts with the Earth's magnetic field and flips it head over heels twice per orbit, and in addition the satellite is spun about its Z axis by having the elements of its turnstile aerial painted black on one face and white on the other. With the help of solar photons,which hit black and give one push as they are absorbed,or, hit white,and give one push,then another as they are reflected off again. 73 de John GM4IHJ@GB7MAC