Page "Apollo 16" Paragraph 39

Eight minutes before departing the lunar surface, capsule communicator ( CAPCOM ) James Irwin notified Young and Duke from mission control that they were go for liftoff.

Two minutes before launch, they activated the " Master Arm " switch and then the " Abort Stage " button, after which they awaited ignition of Orion ’ s ascent stage engine.

When the ascent stage ignited, small explosive charges severed the ascent stage from the descent stage and cables connecting the two were severed by a guillotine-like mechanism.

Six minutes after liftoff, at a speed of about, Young and Duke reached lunar orbit.

Young and Duke, in the LM, successfully rendezvoused and re-docked with Ken Mattingly, who had remained in orbit to perform observations while his fellow crewmembers explored the surface, in the Command / Service Module.

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.