dna@dsd.UUCP (03/15/84)
Posted: Wed Mar 14, 1984 1:38 PM PST Msg: FGIE-1739-8125 From: HPRICE To: amsat Subj: UO-11 commanding I wanted to mention the folks involved in the LA UO-11 command effort. We have been attempting to command on the 1.2 GHz uplink, unfortunately without success. Phil Karn has been feeding us orbital predictions with frequencies corrected for doppler (there is a lot of doppler at 1.2GHz). Phil has some new data that shows that the element set he has been predicting from may have been off far enough that we wouldn't have stood a chance of getting in, even with our blast at the sky method. On some of the passes, we picked a spot in the sky through which the s/c should pass and didn't move the antenna array, assuming that even if we were wrong on the time, the s/c ground track should have been close. We have been using the station of N6CA, Chip Angle. He's been running 160 watts into a 340 element array, for about 60kw eirp. Wally, WA6JPR and Skip, WB6YMH have provided other equipment and support. Henry Radio Inc., thru Jack, WA6VGS loaned us equipment, including an FM source for 27-30 MHz. LA attempts will resume, after the element set problem is sorted out. We haven't given up hope. Keep listening, Harold, NK6K. Posted: Wed Mar 14, 1984 4:14 PM PST Msg: EGIE-1740-1232 From: PKARN To: msweeting CC: amsat Subj: Re: UOB Elements Roger, Neville, John Browning, W6SP, has agreed to check a few contacts back at the USAF command center in Sunnyvale and see what he can find. Yesterday, after coming to the realization that the elements were suspect, I spent quite a bit of time on the phone trying to resolve the issue without much luck, probably because I don't know the right questions to ask. I'm sure John can help. My primary contact for elements, the MIT Lincoln Labs Millstone Hill (MH) radar site in central Massachusetts, does only deep space tracking (period > 225 minutes) with their 1295 mhz radar. While I developed good contacts there when they helped us immeasurably after the AO-10 launch, they aren't much help for UO-B; all they can do is repeat other (i.e., NORAD) elements if they've come in on the teletype machine. I also called "direct to the source", i.e., NORAD at Cheyenne Mountain in Colorado, and asked for recent elements; I got the same set I had previously gotten from MH. I then asked for all known objects associated with the same launch, and there were only three (Landsat, UoSAT, launcher). Of these, the launcher is clearly identifiable, since it is in a 500 x 700 elliptical orbit due to the post-separation depletion burns. Here's some predicted AOS times for KA9Q from a collection of element sets. As I mentioned before, the big jump in time for UO-11 occurred between NASA sets #2 & #3, while Landsat predictions have changed less than 2 minutes in 9 days. UO-11, set 2 (epoch on day 62): 00:24:58 UO-11, set 13 (epoch on day 73): 00:11:49 Landsat, set 5 (epoch on day 64): 00:24:03 Landsat, set MH 3-14-84 (epoch on day 73): 00:25:48.5 I don't know what they could be tracking as "UoSAT". Is there a possibility that the clamp band or other debris (a bolt cutter, say) broke off the launcher at separation? If they are tracking something associated with the launch, it would most likely be a lightweight object with relatively high drag/mass ratio to have moved ahead in time by so much. FYI, here's the Landsat set I received yesterday. Until we get something more reliable for UO-11, maybe you're just as well off trying these? Satellite: landsat-dp Catalog number: 14780 Epoch time: 84073.64226640 Tue Mar 13 15:24:51.817 1984 UTC Element set: MH 3-13-84 Inclination: 98.2540 deg RA of node: 136.0650 deg Eccentricity: 0.0011736 Arg of perigee: 240.0130 deg Mean anomaly: 120.0140 deg Mean motion: 14.60568742 rev/day Decay rate: 0 rev/day^2 (none given) Epoch rev: 134 Semi major axis: 7066.558 km Anom period: 98.591731 min Apogee: 712.419 km Perigee: 695.832 km Good luck & 73, Phil