The latest Satellite Situation Report contains the following entries : 8197 75-082A KIKU 1 (ETS 1) JPN 105.9 47.0 1102 975 2.1 8352 75-082B N-1 R/B JPN 105.9 47.0 1099 972 1.7 10674 78-018A UME 2 (ISS-B) JPN 107.2 69.4 1220 974 1.9 10675 78-018B N-1 R/B JPN 107.1 69.4 1216 973 1.7 I think NORAD has switched the payload and the rocket in both cases. 78- 18 B is really the payload Ume 2, and 75- 82 B is really the payload Kiku 1. Ume 2 has a twin sister which was launched in 1976, called Ume 1. In 'Solar Terrestrial Environmental Research in Japan' of 1981, I found an article about the Ume-satellites. Ume 2 was an identical copy of Ume 1. It was launched because Ume 1 failed after a few months in orbit. Ume 2 (also called Ionospheric Sounding Satellite - ISS b) is a small cylindrical satellite about 0.7 meters high and 0.8 meters in diameter. It has 4 huge booms. Two of 36.8 m, two of 11.4 m (from tip-to-tip). The pairs are diametrically located with respect to the cylinder axis. The satellite was originally spin stabilized with a nominal spin rate of 13.6 rpm (i.e. 4.41 seconds). Guess what the initial flash periods of 78-18 B (as reported in the PPAS archive of the Belgian Working Group Satellites) were ? Name Date Time (UT) Obs FP Remarks ------------------------------------------------------------------- 78- 18 B 78-03-28 19:35.7 PW 40 2.20 F'fF'f 78- 18 B 78-04-06 19:51.7 PW 50 2.196 F'fF'f 78- 18 B 78-07-23 21:13.4 BD 44.1 20 2.21 F'F'F'Mffff 78- 18 B 78-08-18 23:05:58 BD 20 2.21 78- 18 B 78-08-24 20:46:38 BD 60 1.11 78- 18 B 78-08-24 22:04:30 BD 40 1.11 78- 18 B 78-08-28 20:46:38 BD 66.5 60 1.108 dp, F'F'Mffff 78- 18 B 78-08-28 22:36:52 BD 20 2.22 78- 18 B 78-09-03 21:36 LA 10 2.18 78- 18 B 78-09-03 21:37 KDL 45 2.24 78- 18 B 78-09-04 20:48 KDL 15 2.22 78- 18 B 78-09-04 20:50.4 PW 50 2.264 F'fF'f 78- 18 B 78-10-11 04:39 VB 52 2.224 F'F' 78- 18 B 78-12-05 18:01.0 PW 75 2.244 F'fF'f 78- 18 B 78-12-06 17:16.0 PW 2.241 F'fF'f 78- 18 B 79-03-24 20:21:17 BD 10 2.24 78- 18 B 79-04-27 21:26.5 PW 40 2.41 78- 18 B 79-06-25 00:51:47 BK 20 1.12 78- 18 B 79-07-17 21:35:31 BD 44.7 20 2.23 78- 18 B 80-08-14 21:40:44 BD 45.9 20 2.29 78- 18 B 82-12-20 18:36:30 HK 31.2 0.1 13 2.40 mag +6.3-inv 78- 18 B 83-01-16 04:36 HK 1.4 20 2.360 mag +5.3-inv ISS-b worked for 2-3 years (haven't found exact information). The flash periods reported initially are just too close to the spin rate to be coincidence. Also, look at what PW reports : F'fF'f (i.e. a bright specular flash, followed by a fainter specular one, etc...) That is exactly what you would expect from a set-up with 4 booms, 2 big ones and 2 small ones. 76- 19 A (Ume 1) is identical in appearance (to 78- 18 B) : specular flashes with a low and almost constant period. What about the rockets ? The late German observer Horst Koehnke observed 76-19 B 20 times between 1976 and 1980. It was steady 5 times, slowly var 13 times and twice seen flashing (once with 3.48 and once with 2.20). The latter two observations are possibly occasions where HK was observing 76-19A. Average mag over all these passes was 7.85. HK observed 78-18 A 3 times, once steady and twice slowly var. Average mag was 8.6. And Mike McCants has 'a couple of observations of 78 18A at intrinsic magnitude 7'. The N-1 third stage is pretty faint and usually not flashing. The correct identification of 78- 18 B as Ume 2 has been a well known fact for a long time in the Belgian Working Group Satellites, thanks to the late Horst Koehnke. That NORAD has possible also switched A and B in the 75- 82 launch is something new. One of those two objects (75- 82 A and 75- 82 B) is identical with ETS-I (Engineering Test Satellite) , also called Kiku 1. On p. 981 of Astronautica Acta, vol. 7, there is an interesting picture of ETS-I. It looks remarkably similar to Ume 2, i.e. it has four long booms and is covered with solar cells. The main body is a 26-hedron with about 80 cm diameter. It was also spin-stabilized, unfortunately I haven't been able to find the nominal spin rate of this satellite. The list of observations (as reported in the PPAS of the BWGS) contains several indications that 75- 82 B is the payload and not the rocket ! 75- 82 B 76-03-19 19 HB 4.35 different max The different max probably refers to the set-up with two different sets of antennae. 75- 82 B 76-03-20 20 HB 4.35 different max 75- 82 B 76-03-28 19 HB 8.72 different max 75- 82 B 76-08-07 22 HB 2.2 different max The reporting of a double and a half period fit in perfectly with the four antennae set-up. 75- 82 B 76-08-08 21 HB 8.85 different max 75- 82 B 76-08-15 21 HB 4.45 different max 75- 82 B 76-10-07 04 RE 10 4.25 75- 82 B 76-11-01 18 HB 4.25 different max 75- 82 B 77-03-13 19 HB 9.0 75- 82 B 77-08-01 21 LA 9.21 sf 75- 82 B 77-08-04 22 HB 9.2 sm 75- 82 B 77-08-05 22 HB 4.6 sm 75- 82 B 81-10-01 20:21:36 BK 57 2.681 I know that ETS-1 was functional until April 1980 at the least, which may be reflected in the very limited change of the spin period during the time after launch. Furthermore, the initial flash period lies very close to the initial spin period of Ume, probably not a coincidence. Though the case is less strong than for Ume 2, just based on analogy, I think it's safe to say that NORAD screwed up also with the 75- 82 launch. It would be interesting to have recent observations of 75- 82 B and 75- 82 A. If NORAD hasn't switched them by now, I would be willing to bet a lot of money on it that 75- 82 A will be faint and steady, and 75- 82 B will be flashing with a flash period well below 10 s. There are two other N-1 launches that left the rocket body in orbit : 82- 87 and 80-18. The PPAS contains only one observation each for 82-87 A and B : 82- 87 A 82-10-15 19:44 BD 30.9 10 3.09 82- 87 B 91-04-09 21:02:14 PN S Admittedly not much data to work with, but I would bet that NORAD has the 82-87 launch correct, i.e. the 82- 87 A is the payload Kiku 4 (#13492) and the B-object really is the N-1 rocket body. We have no PPAS data on 80-18. The payload is in geostationary orbit, the rocket body is in a highly eccentric orbit with perigee 256 km and apogee at 16952 km, inclination 24.5. Here NORAD was helped by the different orbits of payload and rocket. Who observes 82- 87 A, B and 75- 82 A, B and reports their observations on SeeSat-L ? Here are the most recent elements from oig : 1 08352U 75082B 96002.94668676 -.00000104 +00000-0 +28315-4 0 08553 2 08352 046.9934 207.9504 0085607 319.0134 040.4297 13.60033282009530 1 08197U 75082A 96003.00943577 -.00000116 +00000-0 +12503-4 0 04566 2 08197 046.9916 228.7152 0086596 297.0940 062.1097 13.59262142009328 1 13492U 82087A 96004.10947235 -.00000114 00000-0 33643-5 0 4484 2 13492 44.6199 254.8201 0010123 171.9698 188.1282 13.70308565666853 1 13493U 82087B 96003.13487234 -.00000070 +00000-0 +58779-4 0 06815 2 13493 044.6278 018.0250 0175200 307.3866 051.1097 13.43867287654903 Thanks to all observers who contributed their measurements (mentioned in this message) to the Photometric Periods of Artificial Satellites database : BD Bram Dorreman, Achel, Belgium BK Bertus Kroon, the Netherlands HB Hermann Boehnhardt, Garching, Germany HK Horst Koehnke, Stade/Elbe, Germany KDL Kris Delcourte, Belgium LA Georges Lauwers, Belgium MM Mike McCants, Austin, Texas PN Pierre Neirinck, Dunkerque, France PW Patrick Wils, St-Katelijne-Waver, Belgium RE Russell Eberst, Edinburgh, UK VB Isi Vandenbrouck, Mechelen, Belgium Cheers, Bart De Pontieu <bdp@mpe.mpe-garching.mpg.de>