1998-011A
The Communications and Broadcasting Engineering Test Satellite is a NASDA experimental satellite using a modified Toshiba ETS 6 bus; system integrator for COMETS was NEC. COMETS will act as a data relay satellite for ADEOS, OICETS and ETS-7, as well as test mobile communications technology. It will use Ka-band transmissions to support HDTV and digital broadcasting experiments and both Ka-band and mm-wave mobile communications.
COMETS was developed by NASDA and CRL/Tokyo. Launch drawings indicate the 4S fairing was used.
Launch was on 1998 Feb 21, but the orbit achieved was lower than planned. Initial planned transfer orbit was 250 x 35552 km x 28.5 deg, but NORAD tracked it in 247 x 1883 km x 30.0 deg. The second burn of the second stage cut off after only 44 seconds of the planned 3 min 12 sec burn when exhaust gases broke through the top of the engine nozzle due to a manufacturing flaw. Post-launch name was Kakehashi (`bridge' or `intermediary'). COMETS was tracked as object 25176 until Mar 23, then became object 25175.
COMETS had a Unified Propulsion Subsystem (UPS) with a 1700N apogee engine derived from LAPS. Unlike LAPS, UPS was an integral part of the COMETS satellite and included the RCS system which was separate on the earlier mission. After the failed launch, the UPS was used to raise the orbit of COMETS to 472 x 17715 km.
The IES engine was tested in early 1999 for a total of 14 hours.
| COMETS | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1998 Feb 21 | 0755 | Launch by H-II-5/LAPS | TNSC Y |
| T+1:37 SRB sep | |||
| 0759 | Fairing sep T+4:00 | ||
| 0801 | Stage 1 sep T+5:54 | ||
| 0801 | Stage 2 burn 1, 304s | ||
| 0806 | SECO-1 802s coast | ||
| 0818 | T+23:26 Stage 2 burn 2 | ||
| 0819 | cutoff at 44s | 106.51 247 x 1883 x 30.0 | |
| 0822s | COMETS sep | ||
| 1998 Mar 8 | 1745 | 106.45 248 x 1876 x 30.0 | |
| 1998 Mar 20 | 2210? | LAPS-1 | 397 x 2493 x 30.0 |
| 1998 May 6 | LAPS burn | ||
| 1998 May 8 | 132.32 435 x 4011 x 30.0 | ||
| 1998 May 26 | 201.25 463 x 9533 x 30.0 | ||
| 1998 Jun 1 | 319.20 472 x 17715 x 30.0 | ||
| 1999 Feb 26 | Ion engine test | ||
| 1999 Mar 8 | end of IES tests | ||
| 1999 Aug 6 | 318.91 479 x 17688 x 30.1 | ||
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