1970-062A
The second Philco-built Skynet 1 was launched on 1970 Aug 19. The Star 17A apogee motor failed; telemetry and tracking vanished half way through the apogee motor burn. Launch operations were by NASA until stage 3 sep, then control was transferred to AFSCF who commanded the ABM burn.
Satellite mass 129 kg BOL, 243 full consistent with 114 kg prop. Star 17A has mass 112 kg prop 12 kg inert with Impulse 319.5 kNs; Seff = 286.7s = 2.812 km/s; so dV = 2.812 ln ( minitial/mfinal ) = 2.812 ln (243 / 129 ); for full burn, = 1.781 km/s. GTO apogee vel = 1.596 km/s at 28.0 deg; GEO vel = 3.075 km/s at 0 deg. So dV required is 1.827 km/s at 24 deg, within 3 percent of estimate. Now if the AKM failed halfway through burn, mass final = 186 kg, so dV = 0.752 km/s. Scaling components, final vel is 2.142 km/s at 12 deg for an estimated orbit of 7300 x 36000 km x 12 deg, if no extra impulse provided after the explosion. Of course this is very approximate. Another solution gives 10100 x 38300 x 18 deg.
| Skynet 1B | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1970 Aug 19 | 1211:00 | Launch by Delta | CK LC17A |
| T+0:39 SRM 1-3 burnout | |||
| 1212 | SRM sep (T+1:10) | ||
| 1214 | Thor MECO (T+3:38) | ||
| 1214 | Delta burn T+3:45 | ||
| Thor sep T+3:45 | |||
| 1214 | Fairing sep (T+3:49) | ||
| 1220 | Delta SECO, coast (T+9:53) | -1200? x 400? x 29? | |
| 1233 | Delta sep (T+22:53) | ||
| 1234 | Star 37 burn (T+23:06) | ||
| 1234 | Star 37 cutoff (T+23:46) | ||
| 1235 | Star 37 sep (T+25:30) | ||
| 636.5 270 x 36041 x 28.04 (RAE) | |||
| 664 254 x 37523 x 25.94 (TR1022) | |||
| 664 254 x 37523 x 26.02 (MOR P) | |||
| 1700? | Apo 1 101E | ||
| 1970 Aug 20 | 0400? | Apo 2 68W | |
| 1530? | Apo 3 125E | ||
| 1970 Aug 21 | 0230? | Apo 4 40W | |
| 1330? | Apo 5 150E | ||
| 1970 Aug 22 | 0030 | Apo 6 10W | |
| 1130? | Apo 7 180E | ||
| 1970 Aug 22 | 1140? | Star 17A AKM, failed (7th apogee) | |
| 7300? x 36000? x 12? (guess) | |||
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