S71-41836 (2 Aug. 1971) --- Scientist-astronaut Joseph P. Allen, left, directs the attention of astronaut Richard F. Gordon Jr., to an occurrence out of view at right in the Mission Control Center's (MCC) Mission Operations Control Room (MOCR), while Dr. Donald K. (Deke) Slayton, on right with back to camera, views activity of Apollo 15 on a large screen at the front of the MOCR. Astronauts David R. Scott and James B. Irwin are seen on the screen performing tasks of the mission's third extravehicular activity (EVA), on Aug. 2, 1971. Dr. Slayton is director of Flight Crew Operations, NASA-MSC; Gordon is Apollo 15 backup commander; and Dr. Allen is an Apollo 15 spacecraft communicator.