(Okay, we'll try to stop saying Benjamin.) For the results, Kayak looked at both domestic and international round-trip flights in economy class; evaluating search dates between July 1, 2016 and June 30, 2017 for travel dates in that same period. Of course, What are the cheapest days to fly? is a complicated question.
A Russian Soyuz capsule usually takes at least two days to rendezvous with the ISS, because of the carefully timed dance of manoeuvres that must take place for a spaceship to safely meet the orbiting laboratory. Using a new launch process, three astronauts have now made the trip in just under 6 hours.
There are 24 hours in a day, therefore the ISS revolves around the Earth approximately 16 times per day. The number varies very slightly because it is based upon orbital altitude. When the ISS is closer to the Earth, it orbits more quickly and when the ISS is farther from the Earth, it orbits more slowly.