followed the first moments of the flight. Six minutes after liftoff, at a speed of about , Young and Duke reached lunar orbit. Young and Duke successfully rendezvoused and re-docked with Mattingly in the CSM. To minimize the transfer of lunar dust from the LM cabin into the CSM, Young and Duke cleaned the cabin before opening the hatch separating the two spacecraft. After opening the hatch and reuniting with Mattingly, the crew transferred the samples Young and Duke had collected on the surface into the CSM for transfer to Earth. After transfers were completed, the crew would sleep before jettisoning the empty lunar module ascent stage the next day, when it was to be crashed intentionally into the lunar surface in order to calibrate the seismometer Young and Duke had left on the surface. The next day, after final checks were completed, the expended LM ascent stage was jettisoned. Likely because of a failure by the crew to activate a certain switch in the LM before sealing it off, it tumbled after separation. NASA could not control it, and it did not execute the rocket burn necessary for the craft's intentional de-orbit. The ascent stage eventually crashed into the lunar surface nearly a year after the mission. The crew's next task, after jettisoning the lunar module ascent stage, was to release a subsatellite into lunar orbit from the CSM's scientific instrument bay. The burn to alter the CSM's orbit to that desired for the subsatellite had been cancelled; as a result, the subsatellite lasted just over a month in orbit, far less than its anticipated one year. Just under five hours after the subsatellite release, on the CSM's 65th orbit around the Moon, its service propulsion system main engine was reignited to propel the craft on a trajectory that would return it to Earth. The SPS engine performed the burn flawlessly despite the malfunction that had delayed their landing several days previously. During the return to Earth, Mattingly performed an 83-minute EVA to retrieve film cassettes from the cameras in the SIM bay, with assistance from Duke who remained at the command module's hatch. At approximately from Earth, it was the second "deep space" EVA in history, performed at great distance from any planetary body. , it remains one of only three such EVAs, all performed during Apollo's J-missions under similar circumstances. During the EVA, Mattingly set up a