"Wipe your feet." -- a note left by the builders of Salyut 4 for its first crew. Soyuz 17 was a month-long mission to the Salyut 4 space station. Several experiments were performed, including tracking ships from orbit and contacting mission control through satellites in higher orbits. It was the highest Russian docking at the time at 350 km; this orbit was used to reduce by half the amount of propellant required for Salyut. The crew also made observations of the Sun using the station's telescope.