Polyus

 1987-U01

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The first launch of the Energiya booster carried a 100 tonne spacecraft, 17F19DM Skif-DM, which was a prototype of the Polyus (pole) station. Skif-DM was built around a TKS-type FSB (Funktsional'no-sluzhebnovo blok, Operations/service Unit), No. 162, with an enormous payload section carrying a mockup prototype laser weapon.

The Polyus was 37.57 m long and 4.1m in diameter, with a planned in orbit mass of 88 tonnes. It may have included a set of subsatellites which were to have been used for a missile defense sensor technology experiment, similar to the US Delta 181 mission,  although these may have been cancelled prior to launch.

Launch was at 2130 Moscow Time. Energia No. 6SL launch mass was 2365 tonnes. The Blok A strapons carried 1240t fuel, Blok Ts carried 710t fuel, Blok A dry was 250t, Blok Ts was 86t, leaving 80t for the payload.

After separation of Skif-DM from Energiya, Skif began a planned 180 degree rotation. The rotation should have been stopped at 180 degrees but was not; the DKS engines fired at apogee while Skif completed two whole revolutiions in pitch. The engines should have changed the orbit by 87 m/s to a 155 x 280 km orbit; a second burn at 1830 UTC would have circularized the orbit at 280 x 280 km x 64.6 deg.

Skif-DM
Date	Time	Event	Orbit
1987 May 15	1730:01	Launch by Energiya 6SL	KB
		T-14.4s Blok Ts MES
		T-3.2s Blok A (1-4) MES
		Zenit strapons sep
	1733	T+3:32 GO (fairing) sep, 2 sections, 90 km
	1737	T+7:36 Energiya core to low thrust
	T+7:39 Energiya engines cutoff
	1737	T+7:40 Energiya/Skif-DM sep at 110 km	-15 x 155 x 64.61
	1738	T+8:32 Skif-DM orientation mvr begins
	1739	T+9:25 DO (Donnovo obtekatel') sep
	1739	T+9:28 BB Side fairings sep (2?), SBV exhaust cover sep
	1739:29	T+9:28 Polyus ODU burn, 384s 87m/s
	1745	T+15:25 Apogee 155 km; DKS burn fires in wrong direction
	1822	T+52:07 Polyus impact in Pacific