Zond (L1E)

Kosmos 382 (L1E)

The two L1E satellites were test missions for the L1 and Blok-D systems for lunar missions in high elliptical earth orbit.

The payload stack consisted of a reduced L1 type spacecraft attached to a heavily instrumented Blok-D upper stage. The L1 spacecraft did not have a heat shield for reentry and remained intentionally attached to the upper stage. The Blok-D stage was fitted with cameras in the tanks to monitor the fuel and oxidizer behaviour in weightlessness and during acceleration.

The first L1E mission did not reach orbit due to a failure of the Proton launch vehicle.

The second one was successfully orbited and named Kosmos 382. Over the course of 5 days, the Blok-D was ignited three times to raise the initial ~190 km × ~300 km × 51.6° orbit to a final 2577 km × 5082 km × 55.87° orbit to simulate the lunar orbit insertion burn, the lunar orbit circularization burn and the descent burn to bring the LK lunar lander just over the surface.