The primary objective of Apollo 9 was an Earth-orbital engineering test of the first crewed lunar module, or LM. Concurrent prime objectives included an overall checkout of launch vehicle and spacecraft systems, the crew, and procedures. This was done by performing an integrated series of flight tasks with the command module, or CM, the service module, or SM, the joined command and service module, or CSM, the LM and S-IVB stage while they were linked in launch or various docked configurations, and while they were flying separate orbital patterns. The LM was to be tested as a self-sufficient spacecraft, and was also to perform active rendezvous and docking maneuvers paralleling those scheduled for the following Apollo 10 lunar-orbit mission.
The flight plan’s top priority was the CSM and LM rendezvous and docking. This was performed twice – once while the LM was still attached to the S-IVB, and again when the LM was active. Further goals included internal crew transfer from the docked CSM to the LM; special tests of the LM’s support systems; crew procedures; and tests of flight equipment and the extravehicular activity, or EVA, mobility unit. The crew also configured the LM to support a two-hour EVA, and simulated an LM crew rescue, which was the only planned EVA from the LM before an actual lunar landing.
The LM descent and ascent engines fired on orbital change patterns to simulate a lunar-orbit rendezvous and backup abort procedures. The CSM service propulsion system, or SPS, fired five times, including a simulation of an active rendezvous to rescue an LM that had become inactivate.
After separation of the CSM from the SLA in Earth orbit and jettison of the SLA’s LM protective panels, the CSM was to transpose position and dock with the exposed LM. The docked modules were to separate and the spacecraft was to adjust its orbit 2,000 feet away from the S-IVB stage. The S-IVB engine was then to restart twice, placing the stage in an Earth-escape trajectory and into solar orbit. This would simulate a translunar injection of the stage for Apollo 10 and subsequent lunar missions. Other objectives included the multi-spectral photographic experiment for subsequent crewed spacecraft.
All prime mission objectives were met. All major spacecraft systems were successfully demonstrated. The few off-nominal conditions that developed did not affect achievement of the major goals.
Apollo 9 launched from Cape Kennedy on March 3, 1969, into a nominal 117 by 119-mile Earth orbit with Commander James McDivitt, Command Module Pilot David Scott and Lunar Module Pilot Russell Schweickart aboard.
On the first day, and after orbit injection of the combined S-IVB stage and its SLA-LM-CSM payload, venting of the S-IVB propellant tanks changed the orbit to 123 by 127 miles. The CSM separated and the SLA panel walls jettisoned, transposing the CSM to 180 degrees toward the LM atop the S-IVB. The CSM docked with the LM in the second orbit. The linked modules ejected from the S-IVB, and the thrust placed the CSM-LM a safe distance away for a 62-second restart of the S-IVB, which raised the apogee to 1,895 miles. To achieve a hyperbolic orbit for the planned escape trajectory, the S-IVB restarted a second time for four minutes, two seconds. It resulted in a less than desired maximum velocity increase and was off nominal by about 11 percent. While this did not affect the Apollo 9 flight, a lunar mission might have been aborted. Before the third S-IVB burn, the CSM SPS fired for five seconds, placing the CSM in an orbit of 125 by 145 miles. The firing improved orbital lifetime, checked the capability of the guidance and navigation system to control the burn, and performed a hard check of the LM’s ability to withstand thrust acceleration and vibration.
The second SPS firing for one minute, five seconds occurred on March 4. It changed Apollo 9’s orbit to 123 by 213 miles and tested the structural dynamics of the docked CSM-LM under loads about those of a lunar mission. A third SPS firing the same day for four minutes, 42 seconds, changed the orbit to 126 by 313 miles. The fourth burn, which lasted for 28.2 seconds, was an out-of-plane change.
On Flight Day 3, McDivitt and Schweickart put on spacesuits and transferred to the LM through the tunnel connection to perform a systems checkout. This included a 367-second firing of the LM descent engine to simulate the throttle pattern to be used during a lunar landing mission. McDivitt controlled the final 59 seconds, varying the thrust from 10 to 40 percent and shutting it off manually. This was the first crewed throttling of an engine in space and increased the spacecraft’s orbit to 130 by 300 miles. After nine hours, McDivitt and Schweickart transferred back to the CSM with Scott. Then, the SPS fired for the fifth time as the final shaping maneuver prior to the rendezvous exercises to be performed two days later. The firing placed Apollo 9 into an orbit of 142 by 149 miles.
On Flight Day 4, McDivitt and Schweickart re-entered the LM. Because of nausea, Schweickart’s scheduled two-hour EVA to simulate external transfer rescue techniques was canceled. Instead, he climbed out of the LM porch for a 37.5 minute EVA, testing the EVA mobility unit, including the portable life support system backpack.
On Flight Day 5, with McDivitt and Schweickart again aboard the LM, it separated from Scott’s CSM. The LM descent engine fired once for 24.9 seconds to place the spacecraft into a 137 by 167 mile orbit. If fired again for 24.4 seconds to circularize the orbit about 154 by 160 miles, some 12 miles higher than the CMS. Four hours later, horizontally 113 miles away from the CSM, the LM descent stage jettisoned for a first-time firing in space of the ascent stage engine. It lowered the LM orbit by 11 miles and placed it 75 miles behind and 10 miles below the CSM, leaving it able to commence a rendezvous. Six hours later, the CSM and LM redocked. The LM ascent stage jettisoned and was commanded to fire its engine to fuel depletion.
Although postponed by one revolution on Flight Day 6, a sixth firing of the CSM SPS lowered the orbit to 121 by 138 miles. On the seventh day, the crew performed Earth landmark tracking over the U.S. and the South Atlantic. On the eighth day, a seventh burn of the SPS altered the orbit of Apollo 9 to 113 by 288 miles. No major mission activities were scheduled for the ninth day.
Two telecasts were made to Earth from Apollo 9. The first, on March 5, lasted for almost seven minutes. The second telecast on the following day lasted about 13 minutes, and only showed interior views of the LM. Photographs taken as part of the multi-spectral terrain photographic experiment were successful.
On March 13, the tenth day, re-entry was extended by one revolution because of heavy seas in the primary recovery area. Six hundred miles into its 152nd revolution, Apollo 9 splashed down at 23.25 degrees north, 68 degrees west. The crew was within three miles and in full view of their recovery ship, about 341 miles north of Puerto Rico. The flight totaled 241 hours, 53 seconds – 10 seconds longer than planned. The S-IVB stage reached heliocentric orbit and the LM ascent stage reached Earth orbit. The LM descent stage decayed March 22.
The Apollo 10 mission encompassed all aspects of an actual crewed lunar landing, except the landing. It was the first flight of a complete, crewed Apollo spacecraft to operate around the moon. Objectives included a scheduled eight-hour lunar orbit of the separated lunar module, or LM, and descent to about nine miles off the moon’s surface before ascending for rendezvous and docking with the command and service module, or CSM, in about a 70-mile circular lunar orbit. Pertinent data to be gathered in this landing rehearsal dealt with the lunar potential, or gravitational effect, to refine the Earth-based crewed spaceflight network tracking techniques, and to check out LM programmed trajectories and radar, and lunar flight control systems. Twelve television transmissions to Earth were planned. All mission objectives were achieved.
Apollo 10 launched from Cape Kennedy on May 18, 1969, into a nominal 115-mile circular Earth-parking orbit at an inclination of 32.5 degrees. One-and-a-half orbits later, translunar injection occurred. The S-IVB fired to increase velocity from 25,593 to 36,651 feet per second on a free-return trajectory. Twenty-five minutes later, the CSM separated for transposition and docking with the LM, similar to the maneuver performed on Apollo 9. The orbital vehicle was comprised of the S-IVB stage, and its payload of the CSM, the LM and spacecraft-lunar module adapter, or SLA, shroud. The Apollo 10 crew members were Commander Thomas Stafford, Command Module Pilot John Young and Lunar Module Pilot Eugene Cernan.
The first live color TV transmissions to Earth began three hours after launch when Apollo 10 was 3,570 miles from Earth and concluded when the spacecraft was 9,428 miles away. The transmission showed the docking process and the interior of the CSM. About four hours after launch, Apollo 10 separated from the S-IVB sage, which was followed by another telecast from 14,625 miles out. A third TV transmission of pictures of Earth was made from 24,183 miles out, and a fourth telecast of the Earth was made from 140,000 miles.
The launch trajectory had been so satisfactory that only one of four midcourse corrections was needed. This was accomplished 26.5 hours into the flight. About 76 hours into the mission, lunar-orbit insertion occurred with the firing of the service propulsion system, or SPS. A second firing of the engine 4.5 hours later circularized the lunar orbit of Apollo 10 at approximately 69 miles, which was followed by the first color TV pictures to Earth of the moon’s surface.
Stafford and Cernan entered the LM and prepared for the undocking maneuver that occurred on the 12th revolution, a little more than 98 hours into the flight. At about 100 hours, on May 22, the vehicles separated and briefly flew a station-keeping lunar orbit of 66.7 by 71.5 miles. To achieve a simulation of the future Apollo 11 landing, the LM descent engine fired for 27.4 seconds, with 10 percent thrust for the first 15 seconds and 40 percent thrust for the rest. This brought the LM to a new orbit of 9.7 by 70.5 miles.
The LM flew over Landing Site 2 in the Sea of Tranquility. During this run, the LM landing radar was tested for altitude functioning, providing both “high gate” and “low gate” data. Following a 7.5-second firing of the LM reaction control system, or RCS, thrusters, the descent engine fired in two bursts for 40.1 seconds – at 10 percent and at full throttle – placing the LM into an orbit of 13.7 by 219 miles. On the 14th revolution, it reached a pericynthion of 12.7 miles and was “staged.” The descent stage jettisoned on a second attempt and an uncontrollable gyration of the ascent stage occurred. It was later attributed to an error in a flight-plan checklist, causing an incorrect switch position.
The ascent engine fired for 15 seconds, lowering the LM apocythion to 53.8 miles, 230 miles behind and below the CSM. The RCS thrusters fired for 27.3 seconds when the LM was 16.9 miles below the CSM and 170.4 miles behind, yielding an orbit of 54.5 by 48.1 miles. To prepare for the terminal phase of rendezvous, the RCS fired again, resulting in an orbit of 17.2 by 81.7 miles.
Stafford sighted the CSM’s running lights at about 48 miles. The 15-second terminal phase initiation firing reduced velocity as the LM entered an intercept trajectory and the two vehicles achieved station-keeping of the 16th lunar revolution. With Young in the CSM taking on an active rendezvous role, the vehicles were re-docked on May 23, slightly more than 106 hours into the mission. The LM ascent stage jettisoned and its engine fired to depletion.
The rest of the time in lunar orbit was spent on landmark tracking and photography. On the 31st orbit, the SPS restarted. Apollo 10 was on the back side of the moon when it was injected into a trans-Earth trajectory.
After a midcourse correction, and command and service module separation, Apollo 10 re-entered Earth’s atmosphere May 26. The module splashed down 165 degrees west, and 5 degrees, 8 minutes south in the Pacific Ocean. It’s landing was within television range of its primary recovery ship, the USS Princeton. Apollo 10 completed a flight of 192 hours, three minutes, 23 seconds – one minute, 24 seconds longer than planned. The Apollo 10 S-IVB third stage and LM ascent stage went into solar orbits. The LM descent stage went into a selenocentric orbit.
Apollo 11 Mission Overview
“The Eagle has landed…”
The primary objective of Apollo 11 was to complete a national goal set by President John F. Kennedy on May 25, 1961: perform a crewed lunar landing and return to Earth.
Additional flight objectives included scientific exploration by the lunar module, or LM, crew; deployment of a television camera to transmit signals to Earth; and deployment of a solar wind composition experiment, seismic experiment package and a Laser Ranging Retroreflector. During the exploration, the two astronauts were to gather samples of lunar-surface materials for return to Earth. They also were to extensively photograph the lunar terrain, the deployed scientific equipment, the LM spacecraft, and each other, both with still and motion picture cameras. This was to be the last Apollo mission to fly a “free-return” trajectory, which would enable a return to Earth with no engine firing, providing a ready abort of the mission at any time prior to lunar orbit insertion.
Apollo 11 launched from Cape Kennedy on July 16, 1969, carrying Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module Pilot Edwin “Buzz” Aldrin into an initial Earth-orbit of 114 by 116 miles. An estimated 530 million people watched Armstrong’s televised image and heard his voice describe the event as he took “…one small step for a man, one giant leap for mankind” on July 20, 1969.Two hours, 44 minutes and one-and-a-half revolutions after launch, the S-IVB stage reignited for a second burn of five minutes, 48 seconds, placing Apollo 11 into a translunar orbit. The command and service module, or CSM, Columbia separated from the stage, which included the spacecraft-lunar module adapter, or SLA, containing the lunar module, or LM, Eagle. After transposition and jettisoning of the SLA panels on the S-IVB stage, the CSM docked with the LM. The S-IVB stage separated and injected into heliocentric orbit four hours, 40 minutes into the flight.
The first color TV transmission to Earth from Apollo 11 occurred during the translunar coast of the CSM/LM. Later, on July 17, a three-second burn of the SPS was made to perform the second of four scheduled midcourse corrections programmed for the flight. The launch had been so successful that the other three were not needed.
On July 18, Armstrong and Aldrin put on their spacesuits and climbed through the docking tunnel from Columbia to Eagle to check out the LM, and to make the second TV transmission.
On July 19, after Apollo 11 had flown behind the moon out of contact with Earth, came the first lunar orbit insertion maneuver. At about 75 hours, 50 minutes into the flight, a retrograde firing of the SPS for 357.5 seconds placed the spacecraft into an initial, elliptical-lunar orbit of 69 by 190 miles. Later, a second burn of the SPS for 17 seconds placed the docked vehicles into a lunar orbit of 62 by 70.5 miles, which was calculated to change the orbit of the CSM piloted by Collins. The change happened because of lunar-gravity perturbations to the nominal 69 miles required for subsequent LM rendezvous and docking after completion of the lunar landing. Before this second SPS firing, another TV transmission was made, this time from the surface of the moon.
On July 20, Armstrong and Aldrin entered the LM again, made a final check, and at 100 hours, 12 minutes into the flight, the Eagle undocked and separated from Columbia for visual inspection. At 101 hours, 36 minutes, when the LM was behind the moon on its 13th orbit, the LM descent engine fired for 30 seconds to provide retrograde thrust and commence descent orbit insertion, changing to an orbit of 9 by 67 miles, on a trajectory that was virtually identical to that flown by Apollo 10. At 102 hours, 33 minutes, after Columbia and Eagle had reappeared from behind the moon and when the LM was about 300 miles uprange, powered descent initiation was performed with the descent engine firing for 756.3 seconds. After eight minutes, the LM was at “high gate” about 26,000 feet above the surface and about five miles from the landing site.
The descent engine continued to provide braking thrust until about 102 hours, 45 minutes into the mission. Partially piloted manually by Armstrong, the Eagle landed in the Sea of Tranquility in Site 2 at 0 degrees, 41 minutes, 15 seconds north latitude and 23 degrees, 26 minutes east longitude. This was about four miles downrange from the predicted touchdown point and occurred almost one-and-a-half minutes earlier than scheduled. It included a powered descent that ran a mere nominal 40 seconds longer than preflight planning due to translation maneuvers to avoid a crater during the final phase of landing. Attached to the descent stage was a commemorative plaque signed by President Richard M. Nixon and the three astronauts.
The flight plan called for the first EVA to begin after a four-hour rest period, but it was advanced to begin as soon as possible. Nonetheless, it was almost four hours later that Armstrong emerged from the Eagle and deployed the TV camera for the transmission of the event to Earth. At about 109 hours, 42 minutes after launch, Armstrong stepped onto the moon. About 20 minutes later, Aldrin followed him. The camera was then positioned on a tripod about 30 feet from the LM. Half an hour later, President Nixon spoke by telephone link with the astronauts.
Commemorative medallions bearing the names of the three Apollo 1 astronauts who lost their lives in a launch pad fire, and two cosmonauts who also died in accidents, were left on the moon’s surface. A one-and-a-half inch silicon disk, containing micro miniaturized goodwill messages from 73 countries, and the names of congressional and NASA leaders, also stayed behind.
During the EVA, in which they both ranged up to 300 feet from the Eagle, Aldrin deployed the Early Apollo Scientific Experiments Package, or EASEP, experiments, and Armstrong and Aldrin gathered and verbally reported on the lunar surface samples. After Aldrin had spent one hour, 33 minutes on the surface, he re-entered the LM, followed 41 minutes later by Armstrong. The entire EVA phase lasted more than two-and-a-half hours, ending at 111 hours, 39 minutes into the mission.
Armstrong and Aldrin spent 21 hours, 36 minutes on the moon’s surface. After a rest period that included seven hours of sleep, the ascent stage engine fired at 124 hours, 22 minutes. It was shut down 435 seconds later when the Eagle reached an initial orbit of 11 by 55 miles above the moon, and when Columbia was on its 25th revolution. As the ascent stage reached apolune at 125 hours, 19 minutes, the reaction control system, or RCS, fired so as to nearly circularize the Eagle orbit at about 56 miles, some 13 miles below and slightly behind Columbia. Subsequent firings of the LM RCS changed the orbit to 57 by 72 miles. Docking with Columbia occurred on the CSM’s 27th revolution at 128 hours, three minutes into the mission. Armstrong and Aldrin returned to the CSM with Collins. Four hours later, the LM jettisoned and remained in lunar orbit.
Trans-Earth injection of the CSM began July 21 as the SPS fired for two-and-a-half minutes when Columbia was behind the moon in its 59th hour of lunar orbit. Following this, the astronauts slept for about 10 hours. An 11.2 second firing of the SPS accomplished the only midcourse correction required on the return flight. The correction was made July 22 at about 150 hours, 30 minutes into the mission. Two more television transmissions were made during the trans-Earth coast.
Re-entry procedures were initiated July 24, 44 hours after leaving lunar orbit. The SM separated from the CM, which was re-oriented to a heat-shield-forward position. Parachute deployment occurred at 195 hours, 13 minutes. After a flight of 195 hours, 18 minutes, 35 seconds – about 36 minutes longer than planned – Apollo 11 splashed down in the Pacific Ocean, 13 miles from the recovery ship USS Hornet. Because of bad weather in the target area, the landing point was changed by about 250 miles. Apollo 11 landed 13 degrees, 19 minutes north latitude and 169 degrees, nine minutes west longitude July 24, 1969.
Neil Armstrong, Commander
Edwin E. Aldrin Jr., Lunar Module Pilot
Michael Collins, Command Module Pilot
James A. Lovell, Commander
Fred W. Haise Jr., Lunar Module Pilot
William A. Anders, Command Module Pilot
11/21/68 – LM-5 integrated systems test
12/6/68 – CSM-107 integrated systems test
12/13/68 – LM-5 acceptance test
1/8/69 – LM-5 ascent stage delivered to Kennedy
1/12/69 – LM-5 descent stage delivered to Kennedy
1/18/69 – S-IVB ondock at Kennedy
1/23/69 – CSM ondock at Kennedy
1/29/69 – command and service module mated
2/6/69 – S-II ondock at Kennedy
2/20/69 – S-IC ondock at Kennedy
2/17/69 – combined CSM-107 systems tests
2/27/69 – S-IU ondock at Kennedy
3/24/69 – CSM-107 altitude testing
4/14/69 – rollover of CSM from the Operations and Checkout Building to the Vehicle Assembly Building
4/22/69 – integrated systems test
5/5/69 – CSM electrical mate to Saturn V
5/20/69 – rollout to Launch Pad 39A
6/1/69 – flight readiness test
6/26/69 – Countdown Demonstration Test
July 16, 1969; 9:32 a.m. EDT
Launch Pad 39A
High Bay 1
Mobile Launcher Platform-1
Firing Room 1
Altitude: 118.65 miles
Inclination: 32.521 degrees
Orbits: 30 revolutions
Duration: eight days, three hours, 18 min, 35 seconds
Distance: 953,054 miles
Lunar Location: Sea of Tranquility
Lunar Coordinates: .71 degrees north, 23.63 degrees east
July 24, 1969; 12:50 p.m. EDT
Recovery Ship: USS Hornet
QuBits 19 November 2016
Courtesy of NASA