Apollo Expeditions to the Moon|
FIRST MANNED FLIGHT OF THE LMThe Apollo 9 mission was to be the first manned flight in the lunar module, and the whole purpose of the mission was to qualify, in flight, that portion of the overall spacecraft system. Further, we wanted to show that the lunar module, in combination with the command and service modules, could perform its assigned tasks in weightless flight. It wasn't necessary to go to the Moon for this work, so the Apollo 9 mission took place in Earth orbit. The conditions were the same, insofar as those qualifying tests were concerned, and we had the further advantage of a more comfortable situation in case any problems developed.
It was planned to fly a ten-day mission, approximating in time a complete trip to the Moon, a lunar landing, stay and ascent, and then return to the Earth. We had developed a mission profile that would put astronauts into the lunar module on three separate occasions during the flight, first of all to check a lot of procedures and other items, and second to do multiple activations and deactivations of the lunar module. This mission was the only one in which the LM was powered up and down more than once; it was done here with the intent of discovering anything that might go wrong, and to refine the procedures worked out in simulations.
The lunar module might well be called the first true spacecraft, since it was designed for flight only in the environment of space. Folded and stowed as it was in the nose of the Saturn V, its frail body caused some concern about its ability to stand up to the stress of a Saturn launch. Some of the earlier Saturn launches had shown what was called a pogo oscillation, named after the pogo-stick phenomenon. We wanted to make certain that the LM would be able to take that longitudinal acceleration and shock. We also wanted to make sure the mechanisms for extending its landing legs and pads would not be jammed by unusual loads in flight, and that the adapter between the LM and the rest of the spacecraft could take those loads.
Other objectives of the mission included checking propulsion system operation in both the docked and undocked conditions, to complete a rendezvous between the LM and the command module, with the LM being the active partner during the maneuver, and to demonstrate extravehicular activity from both spacecraft in order to evaluate the case or difficulty of that kind of task, and to check out the handholds, handrails, and localized illumination that had been developed for EVA.
The crew for Apollo 9 was commanded by James A. McDivitt. David R. Scott was the command pilot and Russell L. Schweickart was lunar module pilot. There was an initial three-day delay, not because of any equipment failure but because one of the crew had a cold. Liftoff occurred on March 3, 1969, at 11 AM The normal launch phase followed, and then the S-IVB stage was ignited to place the spacecraft in a nearly circular Earth orbit of about 102 by 104 nautical miles. That orbit was the arena for what was to follow. In a routine manner, the combined command and service modules were separated from the rest of the spacecraft, turned in space, and docked with the lunar module. About one hour later, the docked spacecraft were ejected from the S-IVB, using the ejection mechanism for the first time. From this point on, many of the events were done for the first time.
About two hours after the ejection, the crew fired the service propulsion system for the first time on that mission, in a burst that lasted five seconds. It was the first of several such firings planned to check the service module propulsion system and the resulting maneuvering capability of the docked and undocked spacecraft. That task also completed the list of work for the first day in orbit. It may seem as if there was very little for the astronauts to do on that first day, but it must be realized that much time is spent checking and rechecking onboard systems, the communications and telemetering links to the ground stations, the receipt of data, and all the myriad tasks that confront astronauts in space.
On the second day in Earth orbit, the crew of Apollo 9 also spent much time in systems checks. They fired the service propulsion system three times, each time with about a two-hour interval between firings. Two of the firings were long, lasting almost two and almost five minutes; the third was a shorter burst of less than a half-minute.