Vostok 5 was a joint mission with Vostok 6. During launch the upper stage of the rocket malfunctioned and placed Vostok 5 into a slightly lower but safe orbit. Lasting nearly 5 days, this mission stands to this day as the record for the longest solo human spaceflight. The flight was supposed to last 8 days, but an expansion of Earth's atmosphere from solar flare activity caused the orbit to decay quicker than previous missions and the flight was ended early.