Editing Apollo 15 (section)

== Hardware ==

=== Spacecraft ===
[[File:Apollo 15 SIM bay.jpg|thumb|upright|left|alt=Area of spacecraft with lunar sensors|Apollo 15 SM SIM bay]]
Apollo 15 used command and service module CSM-112, which was given the [[call sign]] ''Endeavour'', named after [[HMS Endeavour|HMS ''Endeavour'']], and Lunar Module LM-10, call sign ''Falcon'', named after the [[United States Air Force Academy]] mascot. Scott explained the choice of the name ''Endeavour'' on the grounds that its captain, [[James Cook]], had commanded the first purely scientific sea voyage, and Apollo 15 was the first lunar landing mission on which there was a heavy emphasis on science.{{sfn|Lindsay|pp=301–302}} Apollo 15 took with it a small piece of wood from Cook's ship,<ref>{{cite news|last=Scurr|first=Ruth|title='Endeavour' by Peter Moore review – the ship that changed the world|date=August 25, 2018|access-date=January 5, 2019|url=https://www.theguardian.com/books/2018/aug/25/endeavour-ship-captain-cook-peter-moore|newspaper=[[The Guardian]]|archive-url=https://web.archive.org/web/20190106010649/https://www.theguardian.com/books/2018/aug/25/endeavour-ship-captain-cook-peter-moore|archive-date=January 6, 2019|url-status=live|df=mdy-all}}</ref> while ''Falcon'' carried two falcon feathers to the Moon{{sfn|Irwin|p=85}} in recognition of the crew's service in the Air Force.<ref group=ALSJ name=hammer /> Also part of the spacecraft were a [[Launch Escape System]] and a Spacecraft-Lunar Module Adapter, numbered SLA-19.<ref name = "hardware">{{cite web|title=Apollo/Skylab ASTP and Shuttle Orbiter Major End Items|date=March 1978|url=https://s3.documentcloud.org/documents/6473665/Apollo-Skylab-ASTP-and-Shuttle-Orbiter-Major-End.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://s3.documentcloud.org/documents/6473665/Apollo-Skylab-ASTP-and-Shuttle-Orbiter-Major-End.pdf |archive-date=2022-10-09 |url-status=live|publisher=[[NASA]]|page=6}}</ref>

Technicians at the [[Kennedy Space Center]] had some problems with the instruments in the service module's scientific instrument module ([[scientific instrument module|SIM]]) bay. Some instruments were late in arriving, and principal investigators or representatives of NASA contractors sought further testing or to make small changes. Mechanical problems came from the fact the instruments were designed to operate in space, but had to be tested on the surface of the Earth. As such, things like the 7.5&nbsp;m (24&nbsp;ft) booms for the [[Mass spectrometry|mass]] and [[gamma ray spectrometer]]s could be tested only using equipment that tried to mimic the space environment,<ref>{{cite book |last=Compton |first=William D. |url=https://history.nasa.gov/SP-4214/contents.html |title=Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions |year=1989 |chapter=The Lunar Rover and New Experiments|chapter-url=https://www.hq.nasa.gov/office/pao/History/SP-4214/ch13-3.html|id=SP-4214|publisher=U.S. Government Printing Office |location=Washington, D.C. |oclc=1045558568}}</ref> and, in space, the mass spectrometer boom several times did not fully retract.{{sfn|Mission Report|p=171}}<ref name = "moon mountain">{{cite book |last=Compton |first=William D. |url=https://history.nasa.gov/SP-4214/contents.html |title=Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions |year=1989 |chapter=To The Mountains of the Moon|chapter-url=https://www.hq.nasa.gov/office/pao/History/SP-4214/ch13-4.html|id=SP-4214|publisher=U.S. Government Printing Office |location=Washington, D.C. |oclc=1045558568}}</ref>

On the Lunar Module, the [[fuel]] and [[oxidizer]] tanks were enlarged on both the descent and ascent stages, and the [[Rocket engine nozzle|engine bell]] on the descent stage was extended. Batteries and [[solar cell]]s were added for increased electrical power. In all this increased the weight of the Lunar Module to {{convert|36000|lb|kg|abbr=off}}, {{convert|4000|lb|kg}} heavier than previous models.<ref name=presskit />

If Apollo 15 had flown as an H mission, it would have been with CSM-111 and LM-9. That CSM was used by the [[Apollo–Soyuz Test Project]] in 1975,<ref group=ALSJ name=postseva>{{cite web |title=Stand-Up EVA |url=https://www.hq.nasa.gov/alsj/a15/a15.postseva.html |year=1996 |editor-last=Jones |editor-first=Eric M. |work=Apollo 15 Lunar Surface Journal |publisher=NASA |access-date=September 9, 2018 |archive-url=https://web.archive.org/web/20161012014119/http://www.hq.nasa.gov/alsj/a15/a15.postseva.html |archive-date=October 12, 2016 |url-status=live |df=mdy-all }}</ref> but the lunar module went unused and is now at the [[Kennedy Space Center Visitor Complex]].<ref>{{cite web|title=Location of Apollo Lunar Modules|publisher=Smithsonian Air and Space Museum|url=https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/spacecraft/location/lm.cfm|access-date=September 9, 2018|archive-url=https://web.archive.org/web/20180909222118/https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/spacecraft/location/lm.cfm|archive-date=September 9, 2018|url-status=live|df=mdy-all}}</ref> ''Endeavour'' is on display at the [[National Museum of the United States Air Force]] at [[Wright-Patterson Air Force Base]] in [[Dayton, Ohio]],<ref>{{cite web|title=Apollo 15 Command Module|publisher=[[National Museum of the United States Air Force]]|url=https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/197685/apollo-15-command-module/|date=April 4, 2016|access-date=December 23, 2018|archive-url=https://web.archive.org/web/20180828134559/https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/197685/apollo-15-command-module/|archive-date=August 28, 2018|url-status=live|df=mdy-all}}</ref><ref>{{cite web|url=https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/spacecraft/location/cm.cfm|title=Location of Apollo Command Modules|publisher=Smithsonian National Air and Space Museum|access-date=August 27, 2019|archive-date=June 1, 2021|archive-url=https://web.archive.org/web/20210601052353/https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/spacecraft/location/cm.cfm|url-status=dead}}</ref> following its transfer of ownership from NASA to the [[Smithsonian]] in December 1974.<ref name = "hardware" />

=== Launch vehicle ===
The [[Saturn V]] that launched Apollo 15 was designated SA-510, the tenth flight-ready model of the rocket. As the payload of the rocket was greater, changes were made to the rocket and to its launch trajectory. It was launched in a more southerly direction (80–100 degrees [[azimuth]]) than previous missions, and the Earth [[parking orbit]] was lowered to {{convert|166|km|nmi||abbr=off|sp=us}}. These two changes meant {{convert|1100|lb|kg}} more could be launched. The [[propellant]] reserves were reduced and the number of retrorockets on the [[S-IC]] first stage (used to separate the spent first stage from the [[S-II]] second stage) reduced from eight to four. The four outboard engines of the S-IC would be burned longer and the center engine would also burn longer. Changes were also made to the S-II to dampen [[pogo oscillation]]s.<ref name=presskit/>

Once all major systems were installed in the Saturn{{nbsp}}V, it was moved from the [[Vehicle Assembly Building]] to the launch site, [[Launch Complex 39]]A. During late June and early July 1971, the rocket and Launch Umbilical Tower (LUT) were struck by [[lightning]] at least four times. There was no damage to the vehicle, and only minor damage to ground support equipment.{{sfn|Mission Report|p=162}}

=== Space suits ===
The Apollo 15 astronauts wore redesigned [[space suit]]s. On all previous Apollo flights, including the non-lunar flights, the commander and lunar module pilot had worn suits with the life support, liquid cooling, and communications connections in two parallel rows of three. On Apollo 15, the new suits, dubbed the "[[Apollo/Skylab A7L#A7LB Spacesuit (Apollo, Skylab and ASTP)|A7LB]]", had the connectors situated in triangular pairs. This new arrangement, along with the relocation of the entry zipper (which went in an up-down motion on the old suits), to run diagonally from the right shoulder to the left hip, aided in suiting and unsuiting in the cramped confines of the spacecraft. It also allowed for a new waist joint, letting the astronauts bend completely over, and sit on the rover. Upgraded backpacks allowed for longer-duration moonwalks.<ref name = "presskit" /> As in all missions from and after Apollo 13, the commander's suit bore a red stripe on the helmet, arms and legs.<ref group=ALSJ name="suit">{{cite web |url=https://www.hq.nasa.gov/alsj/alsj-CDRStripes.html |title=Commander's stripes |year=1996 |editor-last=Jones |editor-first=Eric M. |work=Apollo 15 Lunar Surface Journal |publisher=NASA |access-date=February 25, 2019 }}</ref>

Worden wore a suit similar to those worn by the Apollo 14 astronauts, but modified to interface with Apollo 15's equipment. Gear needed only for lunar surface EVAs, such as the liquid cooling garment, was not included with Worden's suit, as the only EVA he was expected to do was one to retrieve film cartridges from the SIM bay on the flight home.<ref name=presskit/>

=== Lunar Roving Vehicle ===
[[File:Apollo 15 Lunar Rover and Irwin.jpg|thumb|upright=1.49|right|alt=Astronaut works on the Moon at the lunar rover|Irwin with the [[Lunar Roving Vehicle]] on the Moon. [[Mons Hadley]] is in the background.]]
{{main|Lunar Roving Vehicle}}

A vehicle that could operate on the surface of the Moon had been considered by NASA since the early 1960s. An early version was called MOLAB, which had a closed cabin and would have massed about {{convert|6000|lb}}; some scaled-down prototypes were tested in Arizona. As it became clear NASA would not soon establish a lunar base, such a large vehicle seemed unnecessary. Still, a rover would enhance the J missions, which were to concentrate on science, though its mass was limited to about {{convert|500|lb}} and it was not then clear that so light a vehicle could be useful. NASA did not decide to proceed with a rover until May 1969, as [[Apollo 10]], the dress rehearsal for the Moon landing, made its way home from lunar orbit. [[Boeing]] received the contract for three rovers on a [[cost-plus contract|cost-plus basis]]; overruns (especially in the navigation system) meant the three vehicles eventually cost a total of $40&nbsp;million. These cost overruns gained considerable media attention at a time of greater public weariness with the space program, when NASA's budget was being cut.<ref name=summaryalsj group=ALSJ/>

The Lunar Roving Vehicle could be folded into a space 5&nbsp;ft by 20 in (1.5 m by 0.5 m). Unloaded, it weighed 460&nbsp;lb (209&nbsp;kg) and when carrying two astronauts and their equipment, 1500&nbsp;lb (700&nbsp;kg). Each wheel was independently driven by a {{frac|1|4}} [[horsepower]] (200 W) electric motor. Although it could be driven by either astronaut, the commander always drove. Travelling at speeds up to 6{{nbsp}}to 8{{nbsp}}mph (10{{nbsp}}to 12{{nbsp}}km/h),<ref name=summaryalsj group=ALSJ/> astronauts for the first time could travel far afield from their lander and still have enough time to do some scientific experiments.<ref name=presskit>{{cite web |url=https://history.nasa.gov/alsj/a15/A15_PressKit.pdf|archive-url=https://web.archive.org/web/20090327000948/https://mira.hq.nasa.gov/history/ws/hdmshrc/all/main/DDD/17978.PDF |url-status=live |archive-date=March 27, 2009 | title=Apollo 15 Press Kit |date=July 15, 1971 |publisher=NASA |location=Washington, D.C. |id=Release No: 71-119K |access-date=January 6, 2019}}</ref> The Apollo 15 rover bore a plaque, reading: "Man's First Wheels on the Moon, Delivered by Falcon, July 30, 1971".<ref>{{cite web |url=https://www.hq.nasa.gov/alsj/a15/AS15-88-11862HR.jpg |title=Apollo 15 Map and Image Library |last=Jones |first=Eric M. |date=November 23, 2016 |website=Apollo Lunar Surface Journal}}</ref> During pre-launch testing, the LRV was given additional bracing, lest it collapse if someone sat on it under Earth conditions.{{sfn|Compton|p=230}}

=== Particles and Fields Subsatellite ===
[[File:Apollo 15 Subsatellite.jpg|thumb|right|alt=Illustration of satellite being deployed from a space vehicle|Artist's conception of subsatellite deployment]]

The Apollo 15 Particles and Fields Subsatellite (PFS-1) was a small satellite released into lunar orbit from the SIM bay just before the mission left orbit to return to Earth. Its main objectives were to study the plasma, particle, and magnetic field environment of the Moon and map the lunar gravity field. Specifically, it measured plasma and energetic particle intensities and vector magnetic fields, and facilitated tracking of the satellite velocity to high precision. A basic requirement was that the satellite acquire fields and particle data everywhere on the orbit around the Moon.<ref name=presskit/> As well as measuring magnetic fields, the satellite contained sensors to study the Moon's [[Mass concentration (astronomy)|mass concentrations]], or mascons.{{sfn|Mission Report|pp=37–39}} The satellite orbited the Moon and returned data from August 4, 1971, until January 1973, when, following multiple failures of the subsatellite's electronics, ground support was terminated. It is believed to have crashed into the Moon sometime thereafter.<ref>{{cite web|title=Apollo 15 Subsatellite|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-063D|publisher=[[NASA]] Space Science Data Coordinated Archive |access-date=December 21, 2018}}</ref>