Apollo 15

Apollo 15 (July 26th 1971 - August 7th 1971) is a live mission of the Programme Apollo. It is the first mission utilizing the lunar Rover, traversing 27,9 kilometers. The rover was very practical like tool for exploration and to transport samples and the crew, before being finally abandoned on the Moon.

The mission Apollo 15 also inaugurated the “missions J” of the Programme Apollo, longer than the preceding ones, with for objective a thorough scientific exploitation. For this purpose, many instruments were embarked, inter alia a Spectromètre of gamma rays.

Equip and crew

The vessel Apollo 15 counted on its board three team members:

David R. Scott (Gemini 8, Apollo 9): commander;
Alfred Mr. Worden: pilot of the module of order;
James B. Irwin: pilot of the Lunar module.

They were all three graduates by the Université of Michigan. If one (or several) of the members would be unable to take part in the mission at the time of launching, a temporary crew had been designated and trained:

Dick Gordon: temporary commander;
Vance Brand : pilot of the temporary module of order;
Harrison Schmitt: pilot of the temporary lunar module.

A team specialized on the ground, dedicated to planning and the decisions concerning the mission, maintaining the communication with the vessel ( Capsule communicators or capcoms ) was made up of:

Joe Allen (STS-5, STS-51-A);
Bob Parker (STS-9, STS-35);
Karl Henize (STS-51-F).

All three took part later on in a flight in a Space shuttle. The direction of the flight was distributed to four teams, located by a color ( gold , maroon , black , white ), whose directors were:

Gerald Griffin ( gold TEAM );
Milton Windler ( maroon TEAM );
Glynn Lunney ( black TEAM );
Gene Kranz ( white TEAM ).

Preparation and objectives

The crew of Apollo 15 was the temporary crew of the mission Apollo 12. There was a strong complicity as well as a certain competition, these first being US Navy and the latter of the US Air Force.

Apollo 15 owed at the origin being a “mission H”, like Apollo 12, Apollo 13 and Apollo 14. But on September 2nd 1970, NASA announced the cancellation of Apollo 19 and the objectives planned for Apollo 15. In order to reduce the number of missions, Apollo 15 would be from now on a “mission J”, and would carry the lunar Rover.

One of the changes more the Nets in the drive of the crew consisted of the geological formation. It was not to be a question of military knowledge of bases taught at the time of the preceding missions: geology was an important objective of the mission. Scott and Irwin were involved with Lee Silver, geologist of Caltech, impassioned Précambrien, recommended by Harrison Schmitt as alternate to the lectures that NASA used hitherto. Inter alia things, Silver carried out work on the methods of dating of the rocks, based on the taking into account of the radioactive decay of the Uranium in Plomb.

Silver prepared the crew and the temporary crew with various situations, all the more realistic as the date of launching approached. The astronauts carried counterparts of their helmets or combinations, bags with back, used the walkie-talkie to communicate with a capcom , accompanied by a group of geologists not knowing the zone — in order to evaluate the precision of descriptions.

The decision of the site of lunar landing was made in September 1970. The initial selection was reduced: the rille of Rima Hadley or the crater Marius. Although its choice is not decisive, the opinion of the commander is always important. For Dave Scott, the choice was clear: Hadley, “ exploration At its finest ”.

The pilot of the module of order, Al Worden, undergone a different geological drive: he worked with the Egyptian Farouk El-Baz, flying over at low altitude a prepared ground, in order to locate the important objects and geographical elements there.

Course of the mission

Takeoff and placement in orbit

The crew awoke with 4:19 (local time). After rapids medical examinations, they had their breakfast with the temporary team and the capcoms . They threaded their combination and were brought on the site of launching, where they arrived at 6:45 (local time). Scott settled on the left, Worden in the medium and Irwin on the right of the module of order/service.

The launching of Apollo 15 took place on July 26th, 1971 with 13:34: 00 UTC of the Space center Kennedy, and was held without major event. The first stage (SIC) of Saturn V propelled the whole in upper atmosphere, then second stage (software firm) taken the relay.

Shortly after the separation of the first stage, the instruments on board this one returned the heart. That was connected to the propulsion of the second stage, striking full whip and burning the electronics components. That had never occurred before, and the incident was possible because of a reduction of the number of loads of retreat from 8 to 4. Discovered when the two stages were dangerously close, thus depriving of any correction, the following missions recovered the original number of loads of retreat. Third stage (S-IVB) placed the vessel in terrestrial orbit.

One of the port-holes of Apollo 15 deliberately let pass the rays Ultraviolet S, in order to carry out photographs in this frequency band of the Earth and the Moon. The crew will affaira itself as soon as it reaches the terrestrial orbit, and continued there throughout the mission. When the port-hole was not used, it was covered with a mask to limit the exposure of the crew.

Two hours 50 minutes and 2,6 seconds after launching, stage S-IVB was re-ignited and burned during 5 minutes and 49 seconds, bringing the vessel of 7.809 m/s to 10.827 m/s to reach an altitude of 310,0 km.

Injection translunaire

The crew was to prepare the vessel with the lunar landing, while placing the Lunar module slew-round with the module of order. To carry out that, it was necessary to separate the CSM from third stage (S-IVB), to move it, carry out a rotation with 180° then to fasten itself, for finally detaching the lunar module of the third stage.

The operation was carried out in approximately half an hour. The third stage consumed the fuel remainder to place itself on a trajectory which would make it be crushed on the the Moon with 3°39' S, 7°35' W.

At the time of the first part of this operation, the indicator “ SPS Thrust ” of the control panel ignited, indicating that the valves of the engine propelling the module of service ( Service Propulsion System ) were open — thus that the engine was ignited, which was not the case. By safety, the crew used the circuit breakers controlling the valvules to close them.

After some time of diagnosis, the reason of the incident was allotted to a Court-circuit in the switch of the engine Delta-V, which controlled the opening of the valves of the SPS.

One of the reasons of the success of Apollo 15 is probably the redundancy of the critical systems — concerning the SPS, there were two independent systems of valves. The short-circuit affected only one of both, which still made it possible to ignite the engine.

Control on the ground halfway cancelled finally the first correction ( first midcourse correction , MCC-1). That indicated that the remaining tasks were secondary, like placing the vessel in passive thermal control ( Passive Thermal Control , PTC, or “barbecue mode”) to ensure a fair distribution of heat. Approximately 15 hours after launching, the crew extinguished the lights of the cockpit and prepared to sleep.

The second day of the mission Apollo 15 was centered on the second correction halfway and a preliminary examination of the lunar module, called “ Falcon ”. The crew lit the SPS during 0,7 second on order of control on the ground, before the correction envisaged, in order to locate the place of the short-circuit. The diagnosis was confirmed, and one found after the flight a piece of wire, length 1,4 mm, carrying out a false-contact in the switch. This correction was effective, adding 1,62 m/s at the speed of the vessel, and the two following corrections were cancelled.

After having eliminated the air from the lunar module, then to have repressurisé it, the crew passed the hopper since the module of control then placed itself in the LM. Scott and Irwin checked the instruments to make sure that there was no change since launching, as well as the communication systems and of measurement. They noticed that one of the dials had broken, sending pieces of glass in the cockpit. Although not very awkward, for safety reasons, that had to be corrected. After having passed by again the hopper, the crew ate and lay down in the module of control.

The third day was articulated around the Phosphène S felt by the crew, of the visual flashes which intrigued the doctors of NASA since the flight Apollo 11. Some astronauts had already complained some, even when they closed the eyes. Irwin explained why it had undergone this phenomenon during its sleep. They tested by fixing a direction, by covering the eyes, by closing the port-holes, describing the position, the color and the duration as of these flashes . One allots them today to interactions without danger between the eye and the cosmic rays, very energy.

Entry in lunar orbit

The crew returned one second time in the Falcon , which they emptied of his air and cleaned, activating a pump to eliminate the fragments of glass. During this period, the vessel passed the point to which the field of gravity of the Moon becomes stronger than that of the Earth.

After one day calm, they discovered a water escape. In weightlessness, it was presented just as a broad ball. Although the vessel is electrically insulated and hermetic, if it had suddenly burst in droplets, that could have inconvenienced the crew. The escape came from a bad screwing of a part of the pump to Chlore, used to clean drinking water used by the crew by killing the Bactérie S and Champignon S which could develop to with it. The problem could easily be corrected.

The fourth day of the mission, fourth correction halfway (actually the second actually carried out), during 0,91 second, addition 1,65 m/s at the speed of the vessel. The astronauts threaded their combination for the separation of the door of the scientific module of instrumentation ( Science Instruments Modulates , SIM), which was done by an explosive cord, with the risk to depressurize the vessel. It was possible that then the crew turns over on Earth without these combinations. Separation was carried out without incident.

Then, they dealt with the operation of injection in lunar orbit ( Lunar Orbit Insertion , LAW), since the “hidden” face of the Moon, without possible contact with the Earth. They lit the SPS to be placed in elliptic orbit. The communication with the Earth ( Loss off Signal , LOS) was lost 78 hours 23 minutes and 31 seconds after launching, and preceded 8 minutes the beginning of the procedure LAW. Like the whole of the LAW carried out at the time of the Apollo program, this one was perfect, the SPS burned during 6 minutes and 38 seconds, placing the vessel in an elliptic orbit 313 km × 109,3 km.

The essence of the first hour in lunar orbit consisted in carrying out descriptions of the ground and formations observable on the ground. Geological training of the crew — and in particular of Worden — allowed them a faithful description. They also carried out many photographs, benefitting from their strongly tilted orbit, far from the equatorial plan where the preceding modules were placed.

Lunar landing

The procedure of descent ( Descent Orbit Insertion, DOI) was still carried out behind the Moon, at the time of the second orbit. They thus placed in eccentric orbit 108,9 km × 17,6 km, the point low being located at the top of their site of lunar landing (Rima Hadley). The presence of Mascon S on the way was supposed, but unknown. The control center on the ground had predicted that the following day, them periselene would have fallen to stabilize to approximately 16,1 km — estimate which appeared too optimistic.

The team was awaked 18 minutes earlier than envisaged, when it appeared that their orbit had been modified: 108,8 km × 14,1 km. One thus needed that they carry out an operation quickly, which they did by igniting the engine of the module of control ( Reaction Control System , RCS) during 20 seconds, gaining 0,94 m/s. That replaça their periselene to approximately 17,8 km.

At the time of the eleventh orbit, Scott and Irwin were placed in the Falcon , activating its instruments and checking its operation, to prepare separation. They reflect up to date the computer of guidance on the LEM and carried out telemetric aimings on the ground to define the recorded position of the site of lunar landing.

Separation was to occur at the end of this eleventh orbit, but a cable badly placed delayed this operation. After Worden carried out the corrections, separation was carried out without problem. The only effect of this delay was a delayed lunar landing and the need for an update of the markings out of the ground.

104 hours, 30 minutes and 12 seconds after launching, the engine of descent of the Falcon ignited. Burning to 10% of its capacities during the 26 first second — so that the computer of guidance can adapt the push in order to place the LEM on an adequate trajectory — passing then to full power. Irwin confirmed that the system of abandonment of guidance ( Abort Guidance System , AGS) and the principal system of navigation ( Primary Guidance and Navigation System , PGNS) agreed on their altitude and their speed of descent. Three minutes later, the computer carried out a rotation of the vessel, so that the Radar can analyze surface. Still three minutes afterwards, they were to 9000 m of surface.

On Earth, the learned flight director that the data of follow-up indicated a lunar landing to 900 m in the south of the site envisaged. Although he initially preferred not of it to inform the crew, the capcom ED Mitchell pushed it to do it. Scott, this time during, tried to see surface since its port-hole, trying in vain to see Rille. According to simulations, it was possible that it is not visible. After nine minutes and 10 seconds of propulsion, the trip computer of the LEM launched the Program 64 and the lunar module was rectified, so that the crew could see the ground. Using the manual measurements carried out by Irwin and itself, Scott found the place of lunar landing envisaged by the computer and could possibly take the manual control of navigation to correct the final trajectory. It did it 18 times, moving the module of 338 meters in the direction of the orbit and of 409 meters in north.

Irwin recovered the altitude and the speed of descent. To 120 m, the computer started the Program 66 intended to prepare the lunar landing itself, and giving all controls in manual mode. Passed 37 m, Scott noticed that it raised dust — arriving between 18 and 15 m, the external sight was entirely darkened by this dust. Irwin announced whereas the light of contact had ignited, indicating that one of the “legs” of the Falcon had touched the ground. Scott cut the engine immediately, for fear a conduit does not strike surface, which could damage it or make there return of dust and would compromise their return voyage. Their speed of descent at this time was estimated at 2 m/s, that is to say twice as much as at the time of the preceding missions. Scott informed control on the ground:

“ Okay, Houston. The Falcon is one the Lime pit At Hadley. ”

The lunar module was leaning of 10° towards the back-left, that is to say 5° in lower part of the acceptable maximum. It was posed on the edge of the crater, damaging the turbine of its engine. They were to 600 m in north and 175 m in the west of the site envisaged, which, thanks to the lunar Rover, would not pose large problems.

Observations and operations on the Moon

Since the module of order

During the three days of exploration on the surface by Scott and Irwin, Worden dealt with the observations since its vessel in orbit. Apollo 15 was the first mission to carry a unit of instruments (SIM), of which a panoramic camera, a Spectromètre of gamma rays, a telemetric camera, an altimeter Laser, a spectrometer alpha, a spectrometer X and a Mass spectrometer. Worden was to handle the obturators and the lenses and to check the instruments. At the time of the return voyage, it will carry out a Sortie extravéhiculaire to recover the cassettes of the cameras.

The majority of its observations related to the “hidden” face of the Moon, which had not been observed in detail: the panoramic stereotypes allow a space resolution of one meter surface. It there had 1.529 stereotypes of this type, occupying 2 km of film, that is to say 25 kg. In particular, Worden could locate with the Sextant the Falcon once posed, measurement which was of an main interest during the later planning of the mission.

An experiment of very an other type consisted in measuring the dielectric Constante lunar surface. For that, a radio signal was sent towards the Moon, was reflected by its surface then received by an observatory on Earth. One then tries to measure the Angle of Brewster, to which the considered signal is weakest, and depends directly on this constant.

The scientists were particularly interested by the rocks having high concentrations in Samarium, Uranium, Thorium, Potassium and Phosphore. They had given them the Acronyme “KREEP” (K Rare earth elements P the mission revealed a concentration of these rocks in Mare Imbrium, Mare Ingenii and in particular Aitken, which is rarer elsewhere. The observations consolidate the idea that the meteoritic impact at the origin of Imbrium Pond excavated rocks KREEP and projected them on surface.

One of the objectives of the observation related to the crater Aristarchus: in 1963, Jim Greenacre saw a reddish gleam in this area, which confirmed four other people, of which the director of then of the Observatoire Lowell. Apollo 15 was the first live mission to fly over the site. Worden did not see any phenomenon &mdash initially; whereas the Moon was lit by reflected light by the Earth.

Passing to the top of the area of Littrow, Worden noticed “small irregular cones”, which constituted one of the objects of study of Apollo 17. It appeared that they were not craters of impact.

During the third day, Worden noticed problems concerning the mass spectrometer: located on a retractable cane, instruments stated regularly that it could not be returned, and Worden was to activate the switch of many times before the operation does not succeed. At the time of its EVA to the return, it inspected it and observed that the steering bars of the cane were almost across this one. After fuller analyzes, he noticed that these problems occurred primarily when the cane was in the shade of the vessel — that was taken into account and brought modifications on the instruments of Apollo 16 and Apollo 17.

After 146 hours of flight, Worden positioned the vessel to be able to take photographs of the area in the direction opposed to the Sun, to observe the Gegenschein and the Lumière zodiacale. Among the other not-lunar objectives, it was to take photographs of the solar Couronne.

From surface

Once the Lunar module posed, before venturing in the outside, Scott and Irwin was to sleep, and both recognized that they could not hold the seven hours of exit without rest. Nevertheless, insistent Scott to have an outline of the places before carrying out the mission: he argued before launching with the control center, which had granted an excursion of recognition and a platform for objective téléphoto to him 500 mm, the so massive first carried on the Moon. Two hours after the lunar landing, they depressurized the LEM, then dismounted the cover and the mechanism of stowing. Scott was held then upright and observed with the outside while passing its head by the opening thus formed. Its first task was to take a stereo panorama of the landscape with a lens of 60 mm, to photograph points of interest with the téléphoto and to carry out a panorama color with the lens of 60 Misters.

The first observations Radar since the Earth seemed to reveal that the surface of the area was covered with balls, making impossible the use of the lunar Rover. Scott did not observe any more broad stone than a score of centimetres. Thirty minutes after being left, Scott returned, closed again the cover and the two astronauts repressurisèrent the Falcon .

At the time of the sleep of the astronauts, the control center worried about a slow pressure decrease in the oxygen reserves of the lunar module. To preserve energy during the night, this last reduced the frequency of emission of the telemetric data, which made impossible a remote diagnosis. Not wishing to awake the crew, they preferred to wait until this one finished to rest. The flight director Peter Frank decided all the same to shorten their one hour sleep in order to restore the normal frequency of the telemetric emissions, which revealed that the valve of the eliminator of urines ( Urine Transfer Device ) was opened, even when its valve was closed: on the whole, 3,6 of 43 kg oxygen had been lost. Scott and Irwin will register in their report/ratio which the team on the ground should have prevented them as soon as the escape was detected.

First EVA

The astronauts prepared with their first “official” Sortie extravéhiculaire, EVA-1. They prepared the Falcon and their combinations for this operation. Four hours after their alarm clock, they accepted the agreement of the control center to depressurize the LEM. Scott, the seventh man to then pose the foot on the Moon, known as:

“ Ace I stand out young stag in the wonders off the unknown At Hadley, I leaves off realize there' natural S.A. fundamental truth to our. Man must explores. And this is exploration At its greatest. ”

After having inspected the LEM, Scott detached the packages of equipment ( Modularised Equipment Stowage Assembly , MESA) and brought the camera, the sachets of samples, the batteries, the filters air and all the necessary one to their operations. Approximately seven minutes after Scott, Irwin touched surface. Its first task was to collect samples quickly. Scott placed the camera on a tripod, and showed at the control center the deployment lunar Rover.

Scott had the honor of the first control, at the time which it carried out some turns of the LEM. The rover could turn the nose gear wheels and back, but Scott announced that only the back direction functioned — moreover, the combination made the sitting position uncomfortable. This put aside, the astronauts charged the rover with the adequate equipment. They however were limited outdistances some by the remaining quantity of oxygen in their backpacks ( Portable Life Support Systems , PLSS). At the time of this EVA-1, they went until the base of Hadley Delta, via the rille. Their primary goal was the crater St George, followed crater Elbow, this last being more close to the astronauts. They also benefitted from this exit to define the exact position of their lunar landing, starting from the navigation system embarked on the rover.

The control center announced the cancellation of the study of the Flow crater, for reasons of time. The two astronauts thus went up in the rover, passing by Elbow to turn over to the LEM. To approximately 125 m of a crater named Rhysling, Scott located a piece of Basalte — not being able to resign itself to give up it, it stopped Rover. This stop not being envisaged, it claimed at the control center that its belt had been detached — it went down from the rover, rua towards the stone, took photographs and a sample and turned over to the rover. During this time, Irwin tried to distract the control center by describing the craters neighborhood. This entourloupe was located only after the end of the mission, when the samples were analyzed.

Of return to the Falcon , Scott and Irwin deployed the parcelling of experiments ( Apollo Lunar Surface Experiment Package , ALSEP). Scott was to bore holes in the ground and to place there probes while Irwin prepared the remainder of the equipment, which included/understood a seismograph, a magnetometer, a spectrometer intended for the solar wind, a detector of ions, an experiment with cold cathode, a detector of lunar dust and the experiment of heat flow. Irwin added to that a telemetric laser ( Lunar Laser Ranging Experiment , LRRR) and an analyzer of Solar wind. All that was connected by cables to a central processing unit which drew its energy from a thermoelectric generator.

Drilling posed problem with Scott: the first 40 cm were easy, then the operation required efforts &mdash more and more; after 1,6 m (half of what was envisaged) it could not go any more further. With the agreement of the control center, it passed to the following hole. The forest, damaged, could be withdrawn only by the assistance of another tool, which delayed it more. The second hole did not exceed 1 Mr.

The control center ordered the end of the operations for the day. They spent 6 hours and half on the Moon, and a failure of the combination of Irwin having deprived it of water during all this time, it was found dehydrated.

Second EVA

The objective of the second Sortie extravéhiculaire was again Hadley Delta, that the crew joined by a more direct road. Rolling to 9 km/h, they reached this point quickly. The first stop of the day, Station 4 , was cancelled so that they have time to finish drilling fallen through the day before with the Dune crater. After being itself delayed in Spur to check their position, they traversed the 3 km who separated them from the Station 5 . Scott found there the site relatively uninteresting, and decided to stop 3 more km of St George. They arrived then at the Station 6 .

They took a sample of a young crater of one meter, in the middle of older of 3 meters, then carried out other taking away around Rover. The essence made up of breach S, but they also found porphyritic Basalte. Scott went down in a crater 12 m, the largest neighborhood. The control center required of them to dig to study the nature of the ground and to take a deeper sample. Irwin dug and Scott took photographs and a taking away.

Turning over to the rover, they joined a large rock, broad of approximately 3 m, located at 200 m on a slope of 10° with 15°. To even traverse short distances on this slope required much time, and one of the astronauts was to supervise the rover to make sure that it did not slip. Scott could thus confirm what Irwin had noticed earlier: this rock had green colors, which proved to be related to the presence of magnesium oxide. From return on the rover, they went to the Spur crater, broad 100 m and deep of 20 Mr. On the edge of this one, they found small fragments including one presenting a white vein. Irwin thought of having found another mineral yellow-green, but Scott noticed that the reflection of the light on their visor — gilded — distorted the vision of the colors.

At this point in time they saw what was going to become the lunar sample most famous of all the Programme Apollo: sample #15445 , baptized by the media “ Genesis Rock'n'roll ”. It was at first sight about a simple partially crystallized rock, but a more attentive eye revealed than this rock consisted of almost pure Plagioclase: Anorthosite. One first of all thought of having found a piece of the paramount crust of the Moon, but of the later analyzes could date this sample with 4,1 ± 0,1 billion years, which is much younger than the Moon itself and goes back to one period when its crust was already solid — it was nevertheless about a very old rock, probably going up with the higher Imbrien. The rock, under the name of " sample 15415" , was brought back on Earth. Its weight is given with 269,4g (http://curator.jsc.nasa.gov/lunar/lsc/15415.pdf). Time starting to miss, they decided to collect the most possible fragments in the area. They also took 78 samples of the Régolithe.

They turned over then to the Falcon , still recovering some samples. The capcom Joe Allen alerted them that they remained to them ten minutes. The camera of Irwin was discharged, Scott took over with its apparatus. Of return to the LEM, Scott tried once again drillings. Irwin recovered some deeper samples around the ALSEP. Like the previous day, drillings were difficult, and Scott only managed to gain a few centimetres, hardly exceeding a meter. The analysis made after the end of the mission revealed, moreover, that drilling was badly made, the holes being too close. A penetrometer evaluated the resistance of the reg. Scott bored a new hole to take a very deep sample, it arrived to 2,4 m with a forest finer. Not wanting to waste time the day following to withdraw this carrot, it tried to withdraw it immediately. He managed to raise it of 20 cm.

The last task of the day consisted in drawing up the flag of the the United States. They left the Falcon during 7 hours and 12 minutes.

Third EVA

At the time of the night, the control center decided the cancellation of the crossing in north, benefitting from time thus saved to withdraw the coring of the day before. Beginning their third exit extravéhiculaire, the two astronauts took photographs of themselves beside the flag, then went to the ALSEP to withdraw forgotten carrot the day before. After a long effort, they managed to extract it.

The analysis of the sample revealed that the density and the concentration varied enormously. On the 2,4 m length, one counted more than fifty distinct layers, thickness variable and ranging between 0,5 and 21 cm. An interesting point related to the deepest layers, isolated from the cosmic rays. The camera of the rover had problems: any attempt to assemble it or descend it made it hang ineluctably towards the ground. After having carried out a film of the control of the rover, having intended to the engineers, they prepared with the main objective of this last exit: Hadley.

They arrived at a crater of 15 m close to their objective, Scarp. Scott stopped the rover, recovered samples and took a panorama of the places, then set out again in the rille. They recovered some samples of the ground, Irwin carried out some panoramas, Scott took a photograph with the téléphoto 500 mm of the part far away from the rille. They sought layers in the walls of this one to determine if the casting of Lave which had filled Palus Putredinis were single, or if it were about a slow and repeated process.

Scott recovered a piece of rough basalt of the 9,5 kg, largest which was brought back on Earth by the mission, baptized “ Great Scott ”. They went to the last point of the mission, Station 10 . At the time of remaining time, they photographed a crater of 60 Mr. Scott had then, once turned over to the lunar module:

“In my left Hand, I have a Plume; in my right hand, a hammer. And I suppose that one of the reasons for which we are here today is due to a gentleman named Galileo, a long time ago, who made a relatively important discovery concerning the objects which fall into the fields from gravity. And we thought that there would be better place to confirm its lucky finds only on the Moon. And thus we thought of testing that for you here. The feather seems to be, in an adapted way, a feather of Faucon for our Falcon . And I will release both here who, fortunately, will reach the ground at the same time. ”

What functioned. Scott then led the rover to 90 m of the LEM so that this last can observe their departure. It there placed small a Bible and deposited to approximately 6 m the plate of the mission, bearing the names of the 14 astronauts who lost the life at the time of the space conquest, beside which it posed a small statuette, entitled “ Fallen Astronaut ”. The rover was abandoned with its plate, representing two faces of the Earth, the names and signatures of the astronauts of Apollo 15 and the message:

“ MANS FIRST WHEELS ONE THE MOON, DELIVERED BY FALCON, 1971-07-30”

They left the Falcon during 4 hours and 50 minutes.

Return to the Endeavor

The Falcon took off 171 hours 37 minutes and 16 seconds after the launching of the mission. It placed in lunar orbit 77,8 km × 16,7 km. It was not in the same orbital plan as the module of order controlled by Worden, it carried out a new lighting of its engine to correct its trajectory.

When they approached, the Falcon being behind the Endeavor , this last slows down when they were to approximately 40 m one of the other, so that their distance remained constant. The crew benefitted from it to carry out many photographs. Finally, the lunar module was fastened, consequently finishing its role in the mission.

After the opening of the châpe, they transferred the samples from rocks collected to surface. Scott and Irwin depressurized their combinations in order to disencumber them with possible of dust which recovered them. They transferred films, food, the tanks of urine and a system of purification ( Oxygen Purge System , OPS) — this last was to be useful in the event of urgency if a problem occurred in EVA or in the LEM. Worden will use it at the time of its own EVA, later in the mission.

Once these finished transfers, the crew placed in the module of order and sealed the door separating them from the LEM to prepare his final separation by explosion. Some difficulties arose during the depressurization of the hopper separating the two apparatuses. The crew supposed an escape, inspected the door without finding &mdash of it; the depressurization finally possible and was carried out an orbit that envisaged later.

After the death of the three Cosmonaut S of Soyuz 11, less than one month before the launching of Apollo 15, because of a valve of open repressurization during the separation of the module of service and the orbital module, the procedure was modified to limit the risks of such an incident. For Apollo 15, the crew should carry his combinations. After being itself separate lunar module, the CSM ignited its engine RCS to increase the distance more separating them. On its side, the Falcon directed its engine of kind to be crushed on surface. Because of the delay, it would not touch the site envisaged, but 26°12' NR, 0°6' E, to approximately 90 km of the site of lunar landing.

The crew was to rest, but the delay pushed them to carry out the checks of use initially. Enter others, they were to turn over in the SIM which had been decontaminated for the appointment in orbit. Before sleeping, Deke Slayton proposed to them to take a Somnifère, which the astronauts refused. The medical team on the ground worried about the electrocardiogram S about Scott and Irwin, which presented a rate/rhythm bigémellaire. They allotted that to a deficiency in Potassium, related on the Stress and the lack of sleep. Irwin died in 1991 of a Heart attack.

Finally, three hours and half after the hour designed to sleep, and two hours after they had the order to do it, they began their period from sleep at the time of their 54e orbit of the Moon. Scott had remained waked up 23 hours, Irwin and Worden 21 hours.

Return to earth

Injection transterrestre

Apollo 15 spent its last day orbits about it before the injection transterrestre ( Trans-Earth Injection , TEI), the last push of the SPS which would place them on the trajectory of return. The control center modified the plan of vol. deeply the laser altimeter returned the heart and was declared causes lost. The crew used the lens téléphoto 250 mm instead of the objective 80 mm, and accepted the order to carry out a maximum of photographs, to use the remaining film. Among their objectives the photography of the Terminateur was, separating the day from the night on Earth. The three astronauts on board affairèrent themselves of their better, taking turns to receive the instructions of the control center. Finally, one asked them to activate the panoramic camera and to let it turn, his role being in addition filled.

When Apollo 15 reappeared of behind the Moon at the time of its 73e orbit, that is to say two revolutions before the TEI, the crew was to prepare to release it of a Satellite and the starting of the engine which would bring back them on Earth. Like the main part of the components of the CSM and LEM, the SPS was made up many redundant elements. The satellite was to measure the gravitational field of the the Moon and to study the Magnétosphère lunar and terrestrial. It was hexagonal, relatively small (79 cm × 36 cm), weighing 35.6 kg and propelled by the solar energy recovered the day by panels photovoltaic and stored for the night by battery S Ag Cd. It had three canes which were spread after releasing it, a length of approximately 1,5 m each one.

Before releasing the satellite, the crew carried out a correction of their orbit, intended to leave the satellite longer on the spot. They thus passed from their orbit 121,1 × 96,7 km to a broader orbit of 140,8 × 100,6 km in 3 seconds. Released since this new position, the satellite was to be able to survive one year. Beginning to them 74e and last orbit from the Moon, the crew placed the vessel at correct altitude and released the satellite at the time envisaged while making jump two pyrotechnical nuts and by separating it by a system from springs, to get a light rotation movement to him.

Apollo 15 disappeared for last once behind the Moon, and began the injection by activating its SPS during 2 minutes and 21 seconds, gaining 930 m/s. The crew continued his photographs and placed the vessel in PTC.

At the time of the eleventh day of the mission in the esapce, Worden carried out a Sortie extravéhiculaire — the first carried out by the pilot of the module of order since that of Scott for Apollo 9. The vessel left the lunar sphere of influence 238 hours 14 minutes and 51 seconds after launching. After having extinguished and arrangehaving arranged the equipment of the SIM, they decontaminated the RCS, located beside this one and whose accidental lighting would be dangerous for Worden. Devices, placed on the control panel, made sure that an inattentive foot did not activate a switch inadvertently.

After having checked and put their combination, and having depressurized the vessel, they ouvrèrent the châpe and installed a camera there to film Worden at the time of this operation. This last removed the vessel from two bags of waste and moved using magnetic handles until the SIM. It recovered the cassettes of the instruments, while checking them to identify the cause of the various dysfunctions observed during the mission.

A score of minutes after being left, Worden returned in the module of order, whose door was closed again and locked. The SIM was placed of kind so that the spectrometer of x-rays points in direction of Cygnus X-1 and Scorpius X-1.

The next day, the crew still carried out some experiments with their Phosphène S, preparing the list of the instruments which could help them to study the phenomenon best, which will be used to the engineers for the design as dedicated tools embarked starting from Apollo 16. A press conference was taken place, the capcoms transmitting the questions of the journalists to the astronauts. Following this one, a sixth correction of trajectory was finally considered to be useless and cancelled. The crew started his last period of sleep.

Sea landing

With their alarm clock, the astronauts extinguished the SIM, brought back the cane of the spectrometer of x-rays and made safe the equipment. Just as the remainder of the module of service, it will burn at the time of the atmospheric re-entry.

They carried out then the last correction of trajectory (MCC-7) by using during 21 S the RCS, slowing down of 1,7 m/s. Their last task was then to separate from the module of service and to direct the vessel correctly. They activated the module radio operator VHF for the communication which would follow the re-entry. For separation, a series of pyrotechnical systems, started by a button then relayed automatically was to break the bonds between the two vessels. Then, a timed release activated the RCS to move away the module from order, and the electric cables either were disconnected or crossed by small explosive loads. The last bonds were eliminated by a kind of small Guillotine. Lastly, a system of springs gave an impulse to the module of service.

While entering the atmosphere, they accelerated up to 6 G (59 m/s ²), before decreasing. To 7.300 m, the top of the module released while exploding a set of temporary parachutes, which stabilized and slows down the apparatus of 500 km/h to 280 km/h. Lastly, a score of seconds later, the three final parachutes were spread. The team which brought back the apparatus after the sea landing reported that only two of the three parachutes had functioned.

The point of sea landing is approximately, to 530 km in the north of Honolulu (Hawaii) and 9,8 km of the ship dedicated to the repatriation of the capsule, WORN the Okinawa .

The loss of a parachute did not block the operation of the capsule, this one being supernumerary. The men frogs of WORN the Okinawa found the astronauts in a handle of minutes, which they took along on lifeboats to the bridge of the ship. Apollo 15 was the first mission at the conclusion which the crew was not put in Forty in the event of infection by micro-organisms of lunar origin — preceding missions having confirmed the absence of any form of life on the Moon. It was taken along to the base of Hickam to in Hawaii, from where a plane brought them to the air base of Ellington with Houston.

The module of order is exposed to the National Museum off the United States Air Force, with Dayton, Ohio.

Detailed data

Parameters of mission

Apollo Mission 15 (AS-510)

Module of order CM-112 “ Endeavor ”
Module of service SM-112
Lunar module LM-10 “ Falcon ”
lunar Rover: LRV-1

Launching on July 26th, 1971 with 13:34: 00 UTC of the Launch Complex 39-A (LC-39A) of the Space center Kennedy by Saturn V
Lunar landing on July 30th, 1971 with 22:16: 29 UTC on Rima Hadley (26° 7 ' 55,99" NR 3° 38 ' 1,90" E)
Takeoff on August 2nd, 1971 with 171:37: 16 GET.
Sea landing on August 7th, 1971 with 20:45: 53 UTC (26°13 ′ NR, 158°13 ′ W)

Lasted total on the Moon: 66. 54 min 53,9 S (new record)

Parameters of flight

Apollo Vessel 15 (46 782 kg)

Module of order/service (30 354 kg)

Module of order 5840 kg
Module of service 24.514 kg

Lunar module (16 428 kg)

Parameters of terrestrial orbit

Perigee: 169.5 km
Apogee: 171.3 km
Slope: 29.679°
Period: 87.84 min
Revolutions: 3

Lunar orbits : 74

Lunar module

Detachment on June 30th 1971 with 18:13: 16 UTC
Fastening on August 2nd, 1971 with 19:10: 25 UTC

Exits extravéhiculaires

Scott (July 31st 1971 of 00:16: 49 UTC with 00:49: 56 UTC)
Scott and Irwin (EVA July 1st, 31st and th 1971 of 13:12: 17 UTC with 19:45: 59 UTC)
Scott and Irwin (EVA August 2nd, 1st and th 1971 of 11:48: 48 UTC with 19:01: 02 UTC)
Scott and Irwin (EVA August 3rd, 2nd and th 1971 of 08:52: 14 UTC with 13:42: 04 UTC)
Worden (EVA August 4th, 5th and th 1971 of 15:31: 12 with 16:10: 19 UTC)

Badge of the mission

The badge of the circular mission, , presents Oiseau X stylized Bleu S, Blanc S and Rouge S, flying over Rima Hadley. They are immediately followed from two Cratère S forming the Roman numerals “XV”. The unit is girdled of red and white, where one can read “APOLLO 15” as well as the name of the astronauts. The badge carries a blue liseret.

The original idea of the drawing of the badge is due to the fashion designer Emilio Pucci, which suggested the reason with the three birds. The crew modified the original colors (blue and Vert) to approach those of the American flag.

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