The crew is completing a 197-day mission.
Sperm was among the hundreds of things SpaceX sent to the International Space Station.
SpaceX is launching a Falcon 9 rocket that will carry tons of scientific supplies to the International Space Station aboard a Dragon spacecraft.
"We've had space junk falling out of the sky on a regular basis."
Three more astronauts have arrived at the International Space Station.
The rogue space station is expected to crash to Earth in the next few months.
Italian astronaut Paolo Nespoli shared a timelapse of the storms over his home country.
China's space agency lost control of the spacecraft in 2016, five years after the unmanned station was launched.
Russia is testing dust samples from the International Space Station, believing they contain extraterrestrial lifeforms.
An official said authorities would attempt to provide "early warning for possible collision with objects."
Putin is trying to revive Russia's space program, which is beset by problems after years of post-Soviet neglect.
The crewmen, from Russia, America and Germany, have landed their capsule in Kazakhstan after almost six months in orbit
"I have definite personal knowledge of the odors existing inside her anodized aluminum hull," retired Astronaut Clayton C. Anderson writes