The R-7 was also known by its GURVO designation 8K71, as well as the T-3, M-104, and Type A. The R-7 modified for the PS-2 satellite launch was designated 8k71PS. Unlike Sputnik 1, Sputnik 2 was not designed to detach from the R-7 sustainer core, since Sputnik 1's core stage had demonstrated an acceptable orbital lifespan. This allowed the core's Tral D telemetry system to be used to transmit data, but would lead to speculation that Sputnik 2 had failed to separate. After Sputnik 2 reached orbit, the interior temperature rapidly climbed to over , and Laika survived for only a few hours instead of the planned ten days.