Satgen 129 Mars, Jupiter and AO13 By GM4IHJ 15th Sept 91 MARS An interesting Japanese mission offers some excellent parallels for DJ3ZC's suggested Amsat Phase3d flight Mars probe. Both would probably use the economic Mars Hohmann transfer orbit window - leaving earth orbit Dec 96 , arrive Mars Sept 97. Details proposed by Japanese ISAS are - 250Kg plus Martian orbit injection fuel. Payload 40Kg . Name Planet B. Purpose to orbit Mars at 150 to 34000km altitude examining interaction of Solar Wind on Martian atmosphere. One very interesting suggestion they make is that only single axis spin stabilised earth pointing for communications,is required because this will also provide adequate solar illumination. Cost to be 50 million pounds sterling plus another 25 million for the solid fuel M-V rocket. If any JA readers get to know Planet B's downlink ( and that of 1995 JA Lunar mission ), will they please publish them on packet because a lot of Radio Amateurs are getting interested in long range tracking. JUPITER We now know from IARU ( not Amsat), that SARA the French Jupiter Listening satellite has been declared an intruder in the Radio Amateur 2m band. This decision was apparently taken when Amsat sat builders assembled in Marburg earlier this year to discuss Phase 3D. I believe this was a bad mistake. What has happened to Amsats declared policy of cooperation with other space groups. Doubtless there are some reasons, but I seriously question whether they outweigh the dreadful " Get Lost " message we now seem to be giving to all other Space groups. Please do not tell me that Radio Amateurs are uninterested in SARA. On August 30th last we had Amsat NA Hq plagiarising my satgen126 bulletin word for word, then putting it back onto worldwide packet as their own bulletin. I suggest this positively illustrates how interesting they think SARA is. Noting that their action caused hopeless duplication when other stations in US and Europe followed Amsat NA's example and put even more duplicate copies onto the BBS. Do the people who made that wrong decision at Marburg realise that I can lose my license if I listen to or report a "non amateur accredited" signal , even if it is on the Amateur Bands. Thank you very much chaps for the boob of the century, the many radio amateurs interested in Radio Astronomy , as attested by the weight in my mail box since I wrote the RSGB Space Radio Hanbook , are appalled by your short sighted ignorance. Is this " I want to be alone" , the new Amsat policy ? AO13 Perigee was down to 771kms on 29 August 91, While this indicates a slight reduction in the steepness of AO13's Kamikaze dive, it is not as yet very reassuring. The present descent rate of 1.2km/day will even if it decreases considerably , bring AO13 down to the point where though its dash to earth has ceased, its low altitude susceptibility to drag will prevent it recovering and reattaining a safe altitude. Please also note that some micro software has problems with high eccentricity orbits, and the original W3IWI iteration loop may fail if AO13's eccentricity gets much higher. Binary substitution is a much safer way to do this calculation , so ask for it in future Phase 3 software. 73 de GM4IHJ @ GB7SAN POSITIVELY NO DUPES PLEASE.