Lunar Module Descent..Lunar LandingThe lunar module will be manned and checked out for undocking and subsequent landing on the lunar surface at Apollo site 2. Undocking will take place at 100:09:50 GET prior to the MSFN acquisition of signal. A readially downward service module RCS burn of 2.5 fps will place the CSM on an equiperiod orbit with a maximum separation of 2.2 nm one half revolution after the separation maneuver. At this point, on lunar farside, the descent orbit insertion burn (DOI) will be made with the lunar module descent engine firing retrograde 74.2 fps at 101:38:48GET. The burn will start at 10 percent throttle for 15 seconds and the remainder at 40 percent throttle.The DO1 maneuver lowers LM pericynthion to 50,000 feet at a point about 14 degrees uprange of landing site 2.A three-phase powered descent initiation (PDI) maneuver begins at pericynthion at 102:53:13 GET using the LM descent engine to brake the vehicle out of the descent transfer orbit. The guidance- controlled PDI maneuver starts about 260 nm prior to touchdown, and is in retrograde attitude to reduce velocity to essentially zero at the time vertical descent begins. Spacecraft attitudes range from windows down at the start of PDI, to windows up as the spacecraft reaches 45,000 feet above the lunar surface and LM landing radar data can be integrated by the LM guidance computer. The braking phase ends at about 7,000 feet above the surface and the spacecraft is rotated to an upright windows-forward attitude. The start of the approach phase is called high gate, and the start of the landing phase at 500 feet is called low gate.Both the approach phase and landing phase allow pilot take-over from guidance control as well as visual evaluation of the landing site. The final vertical descent to touchdown begins at about 150 feet when all forward velocity is nulled out. Vertical descent rate will be three fps. Touchdown will take place at 102:47:ll GET.
July 20, 1969I wake up feeling refreshed and have a quick breakfast. The eastern horizon is just starting to show a bit of light as I hit the road. I arrive at the control center without any memory of passing through League City and Webster, small towns along the way. In an instant, it seems, I am pulling my '67 Cougar into my parking space on the north side of the building, just as I have done hundreds of times before....The mission operations control room door is heavy, and entering the room, I again realize how small it really is considering the magnitude of operations that take place in it. My eyes have difficulty adjusting to the heavy gray-blue gloom cast by the world map and the dimmed lights over the Trench. I listen to the ambient voice level of the room. It is always the first indication of what is going on. Today it is quiet. Lunney's team is busy closing out its shift, and a lot of messages are being read by the CapCom.I glance at the TV of the flight plan to the right of the room. The astronauts are awake and well into post-sleep activities. Many of my White Team controllers are on the console and already starting handover. Jerry Bostick, chief of the Flight Dynamics Branch, is standing behind the Trench, listening to his controllers. He is tall, thin, wears a coat, and has allowed his black hair to grow long; he used to have a crew cut like mine. He is in the process oftaking a pulse check on his people. Bostick is like some permanent fixture in the MCC; I wonder if he ever sleeps because he is always there, standing behind his controllers, head cocked, coaching his people.The coat rack is overly full. It swings like a pendulum and it threatens to tip over as I hang up my sport coat. The trip to the flight director console is like walking through a minefield, dodging books, lunches, and the spaghetti of headset cords. The room smells of cigarettes, with an overlay of pizza, stale sandwiches, full wastebaskets, and coffee that has burned onto the hot plates. The smell has never changed since we opened the control center four years ago.A bouquet of roses glows red against the gray wall ofthe Mission Control room. The bouquet always arrives as we near launch day for the Apollo missions. The accompanying card simply states "from an admirer." Initially they came from Dallas, subsequently from various Canadian cities, and then the eastern United States. The sender became known among the controllers simply as the "flower lady." For us they were a tangible link with someone who represented the hopes and good wishes of the millions who cheered us on as we pushed deeper into space. We would not know the name of this anonymous supporter until the end of the Apollo mission, when we received, for the first time, a card signed with only the sender's first name, Cindy. It became almost a talisman; the launch flight director always wanted to know that the flowers had arrived--and they always had every time. We placed the flowers in a vase on a small table to the right and beneath the operation room's ten-by-ten-foot TV screen. This was in the area where we normally congregated to celebrate a successful mission. We knew that the TV cameras would pick up the roses sitting there in the background, thus showing our appreciation to the unknown well-wisher.
