Proposed second high altitude manned flight into the lower Van Allen radiation belt for radiological-biological studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. All follow-on Vostok missions cancelled in Spring 1964.
First spacewalk, with a two man crew of Colonel Pavel Belyayev and Lt. Colonel Aleksey Leonov. During Voskhod 2's second orbit, Leonov stepped from the vehicle and performed mankind's first "walk in space." After 10 min of extravehicular activity, he returned safely to the spacecraft through an inflatable airlock.
This mission was the original raison d'etre of the Voskhod series, with the original name 'Advance'. It almost ended in disaster when Leonov was unable to reenter the airlock due to stiffness of the inflated spacesuit. He had to bleed air from the suit in order to get into the airlock. After Leonov finally managed to get back into the spacecraft cabin, the primary hatch would not seal completely. The environmental control system compensated by flooding the cabin with oxygen, creating a serious fire hazard in a craft only qualified for sea level nitrogen-oxygen gas mixes (Cosmonaut Bondarenko had burned to death in a ground accident in such circumstances, preceding the Apollo 204 disaster by many years). On re-entry the primary retrorockets failed. A manually controlled retrofire was accomplished one orbit later (perhaps with the backup solid rocket retropack on the nose of spacecraft - which did not exist on Vostok). The service module failed to separate completely, leading to wild gyrations of the joined reentry sphere - service module before connecting wires burned through. Vostok 2 finally landed near Perm in the Ural mountains in heavy forest at 59:34 N 55:28 E on March 19, 1965 9:02 GMT. The crew spent the night in the woods, surrounded by wolves, before being located. Recovery crew had to chop down trees to clear a landing zone for helicopter recovery of the crew, who had to ski to the clearing from the spacecraft. Only some days later could the capsule itself be removed.