During the flight, Cosmonauts Anatoly Filipchenko and Nikolai Rukavishnikov tested the androgynous docking system to be used for the ASTP mission by retracting and extending a simulated 20 kg American docking ring. The crew also tested modified environmental systems, new solar panels and improved control systems, as well as a new radar docking system. air pressure was reduced from 760 mm to 540 mm and oxygen raised from 20% to 40% to test reducing the planned transfer time to Apollo from two to one hour. On 7 December 1974, the docking ring was jettisoned with explosive bolts to test emergency measures if the capture latches got stuck during the ASTP flight.