Goals: This spacecraft was designed to go into a highly elliptical orbit around Earth so mission planners could develop trajectory-measurement techniques that could be employed on future lunar-orbiter missions.

Accomplishments: Plans for an orbit that would have been 250,000 km from Earth at its furthest were dashed by the premature cutoff of the upper-stage rocket. But even with an orbit measuring 60,710 by 260 km, it is likely that Soviet engineers gathered much of the data they sought.