Editing Apollo 16 (section)

===Lunar surface===
[[File:Apollo 16 meeting.jpg|thumb|right|NASA officials conferring on whether to allow the Apollo 16 landing, April 20, 1972]]

The crew continued preparing for Lunar Module activation and undocking shortly after waking up to begin flight day five. The boom that extended the [[mass spectrometry|mass spectrometer]] in the SIM bay was stuck, semi-deployed. It was decided that Young and Duke would visually inspect the boom after undocking the LM from the CSM. They entered the LM for activation and checkout of the spacecraft's systems. Despite entering the LM 40 minutes ahead of schedule, they completed preparations only 10 minutes early due to numerous delays in the process.<ref name="fullsummary" /> With the preparations finished, they undocked 96 hours, 13 minutes, 31 seconds into the mission.<ref>{{cite web|title=Apollo 16: Day Five Part Two: Lunar Module Undocking and Descent Preparation; Revs 11 and 12|url=https://history.nasa.gov/ap16fj/14_Day5_Pt2.htm|work=Apollo 16 Flight Journal|archive-url=https://web.archive.org/web/20111021160435/http://history.nasa.gov/ap16fj/14_Day5_Pt2.htm|archive-date=October 21, 2011|url-status=dead|editor-first=David|editor-last=Woods|editor2-first=Tim|editor2-last=Brandt|publisher=[[NASA]]}}</ref><ref name="timeline">{{cite web |url=https://history.nasa.gov/SP-4029/Apollo_16i_Timeline.htm |title=Apollo 16 Timeline |publisher=[[NASA]] |access-date=October 8, 2019 |archive-date=December 31, 2020 |archive-url=https://web.archive.org/web/20201231213215/https://history.nasa.gov/SP-4029/Apollo_16i_Timeline.htm |url-status=live }}</ref>

For the rest of the two crafts' passes over the [[near side of the Moon]], Mattingly prepared to shift ''Casper'' to a higher, near-circular orbit, while Young and Duke prepared ''Orion'' for the descent to the lunar surface. At this point, during tests of the CSM's steerable rocket engine in preparation for the burn to modify the craft's orbit, Mattingly detected oscillations in the SPS engine's backup gimbal system. According to mission rules, under such circumstances, ''Orion'' was to re-dock with ''Casper'', in case Mission Control decided to abort the landing and use the Lunar Module's engines for the return trip to Earth. Instead, the two craft [[Orbital station-keeping|kept station]], maintaining positions close to each other. After several hours of analysis, mission controllers determined that the malfunction could be worked around, and Young and Duke could proceed with the landing.<ref name="overview" />

Powered descent to the lunar surface began about six hours behind schedule. Because of the delay, Young and Duke began their descent to the surface at an altitude higher than that of any previous mission, at {{convert|20.1|km|nmi|sp=us}}. After descending to an altitude of about {{convert|4000|m|ft|abbr=on|sp=us|order=flip}}, Young was able to view the landing site in its entirety. Throttle-down of the LM's landing engine occurred on time, and the spacecraft tilted forward to its landing orientation at an altitude of {{convert|2200|m|ft|abbr=on|sp=us|order=flip}}. The LM landed {{convert|270|m|ft|abbr=on|sp=us|order=flip}} north and {{convert|60|m|ft|abbr=on|sp=us|order=flip}} west of the planned landing site at 104 hours, 29 minutes, and 35 seconds into the mission, at 2:23:35 UTC on April 21 (8:23:35&nbsp;pm on April 20 in Houston).<ref name="fullsummary" /><ref name="landing">{{cite web|title=Landing at Descartes|date=December 9, 2015|url=http://www.hq.nasa.gov/alsj/a16/a16.landing.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=December 31, 2020|archive-url=https://web.archive.org/web/20201231213219/https://www.hq.nasa.gov/alsj/a16/a16.landing.html|url-status=live}}</ref> The availability of the [[Lunar Roving Vehicle]] rendered their distance from the targeted point trivial.<ref name="overview" />

After landing, Young and Duke began powering down some of the LM's systems to conserve battery power. Upon completing their initial procedures, the pair configured ''Orion'' for their three-day stay on the lunar surface, removed their space suits and took initial geological observations of the immediate landing site. They then settled down for their first meal on the surface. After eating, they configured the cabin for sleep.<ref>{{cite web|title=Post-Landing Activities|url=http://www.hq.nasa.gov/alsj/a16/a16.postland.html|date=July 21, 2015|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=December 31, 2020|archive-url=https://web.archive.org/web/20201231213248/https://www.hq.nasa.gov/alsj/a16/a16.postland.html|url-status=live}}</ref><ref>{{cite web|title=Window Geology|url=http://www.hq.nasa.gov/alsj/a16/a16.window.html|date=May 29, 2012|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=December 31, 2020|archive-url=https://web.archive.org/web/20201231213220/https://www.hq.nasa.gov/alsj/a16/a16.window.html|url-status=live}}</ref> The landing delay caused by the malfunction in the CSM's main engine necessitated significant modifications to the mission schedule. Apollo 16 would spend one less day in lunar orbit after surface exploration had been completed to afford the crew ample margins in the event of further problems. In order to improve Young's and Duke's sleep schedule, the third and final moonwalk of the mission was trimmed from seven hours to five.<ref name="fullsummary" />

==== First moonwalk ====
After waking up on April 21, Young and Duke ate breakfast and began preparations for the first extravehicular activity (EVA), or moonwalk.<ref>{{cite web|title=Wake-up for EVA-1|date=November 22, 2009|url=http://www.hq.nasa.gov/alsj/a16/a16.eva1wake.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=December 31, 2020|archive-url=https://web.archive.org/web/20201231213246/https://www.hq.nasa.gov/alsj/a16/a16.eva1wake.html|url-status=live}}</ref><ref>{{cite web|title=Preparations for EVA-1|date=September 22, 2014|url=http://www.hq.nasa.gov/alsj/a16/a16.eva1prep.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=February 1, 2022|archive-url=https://web.archive.org/web/20220201050321/https://www.hq.nasa.gov/alsj/a16/a16.eva1prep.html|url-status=live}}</ref> After the pair donned and pressurized their space suits and depressurized the Lunar Module cabin, Young climbed out onto the "porch" of the LM, a small platform above the ladder. Duke handed Young a jettison bag full of trash to dispose of on the surface.<ref name="briar">{{cite web|title=Back in the Briar Patch|url=http://www.hq.nasa.gov/alsj/a16/a16.eva1prelim.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|date=December 7, 2012|access-date=September 23, 2021|archive-date=December 31, 2020|archive-url=https://web.archive.org/web/20201231213221/https://www.hq.nasa.gov/alsj/a16/a16.eva1prelim.html|url-status=live}}</ref> Young then lowered the equipment transfer bag (ETB), containing equipment for use during the EVA, to the surface. Young descended the ladder and, upon setting foot on the lunar surface, became the ninth human to walk on the Moon.<ref name="fullsummary" /> Upon stepping onto the surface, Young expressed his sentiments about being there: "There you are: Mysterious and unknown Descartes. Highland plains. Apollo 16 is gonna change your image. I'm sure glad they got ol' [[Brer Rabbit]], here, back in the briar patch where he belongs."<ref name="briar" /> Duke soon descended the ladder and joined Young on the surface, becoming the tenth person to walk on the Moon. Duke was then aged 36; no younger human has ever walked on the lunar surface. Duke expressed his excitement, stating to CAPCOM Anthony England: "Fantastic! Oh, that first foot on the lunar surface is super, Tony!"<ref name="briar" /> The pair's first task of the moonwalk was to offload the Lunar Roving Vehicle, the Far Ultraviolet Camera/Spectrograph,<ref>{{cite web|title=Experiment Operations During Apollo EVAs |url=http://ares.jsc.nasa.gov/HumanExplore/Exploration/EXlibrary/docs/ApolloCat/Part1/UVC.htm |work=[[Astromaterials Research and Exploration Science Directorate]] |publisher=[[NASA]] |url-status=dead |archive-url=https://web.archive.org/web/20130220145727/http://ares.jsc.nasa.gov/HumanExplore/Exploration/EXLibrary/docs/ApolloCat/Part1/UVC.htm |archive-date=February 20, 2013 }}</ref> and other equipment. This was done without problems. On first driving the lunar rover, Young discovered that the rear steering was not working. He alerted Mission Control to the problem before setting up the television camera, after which Duke erected the United States [[Lunar Flag Assembly|flag]]. During lunar surface operations, Commander Young always drove the rover, while Lunar Module Pilot Duke assisted with navigation; this was a division of responsibilities used consistently throughout Apollo's J missions.<ref name="cdrdriver">{{cite web|url=https://www.hq.nasa.gov/alsj/a15/a15.summary.html|title=Apollo 15 Mission Summary: Mountains of the Moon|date=November 6, 2012|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 15 Lunar Surface Journal|access-date=March 2, 2020|archive-date=February 20, 2022|archive-url=https://web.archive.org/web/20220220212002/https://www.hq.nasa.gov/alsj/a15/a15.summary.html|url-status=live}}</ref><ref name="Haynes">{{cite book |title=Lunar Rover: Owner's Workshop Manual |last1=Riley |first1=Christopher |last2=Woods |first2=David |last3=Dolling |first3=Philip |date=December 2012 |publisher=[[Haynes Manual|Haynes]] |isbn=978-0-85733-267-7 |page=165}}</ref>

[[File:Ap16 rover.ogv|thumb|left|Young driving the LRV during the "Grand Prix"]]
The day's next task was to deploy the ALSEP; while they were parking the lunar rover, on which the TV camera was mounted, to observe the deployment, the rear steering began functioning. After ALSEP deployment, they collected samples in the vicinity. About four hours after the beginning of EVA-1, they mounted the lunar rover and drove to the first geologic stop, Plum Crater, a {{convert|36|m|ft|abbr=on|adj=mid|-wide|order=flip}} crater on the rim of [[Flag (crater)|Flag Crater]], about {{convert|240|m|ft|abbr=on|sp=us}} across. There, at a distance of {{convert|1.4|km|mi|abbr=on|sp=us}} from the LM, they sampled material in the vicinity, which scientists believed had penetrated through the upper regolith layer to the underlying [[Cayley (crater)|Cayley Formation]]. It was there that Duke retrieved, at the request of Mission Control, the largest rock returned by an Apollo mission, a [[breccia]] nicknamed [[Big Muley]] after mission geology principal investigator [[William R. Muehlberger]].<ref name="honeysuckle">{{cite web |url=http://www.honeysucklecreek.net/msfn_missions/Apollo_16_mission/hl_apollo16.html |title=Apollo 16 |last=Lindsay |first=Hamish |publisher=[[Honeysuckle Creek Tracking Station]] |type=Essay |access-date=November 27, 2011 |archive-date=December 31, 2020 |archive-url=https://web.archive.org/web/20201231213249/https://www.honeysucklecreek.net/msfn_missions/Apollo_16_mission/hl_apollo16.html |url-status=live }}</ref><ref>{{cite web|title=Station 1 at Plum Crater|date=April 7, 2018|url=https://www.hq.nasa.gov/alsj/a16/a16.sta1.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|archive-date=February 25, 2021|archive-url=https://web.archive.org/web/20210225171542/https://www.hq.nasa.gov/alsj/a16/a16.sta1.html|url-status=live}}</ref> The next stop of the day was Buster Crater, a small crater located north of the larger [[Spook (crater)|Spook Crater]], about {{convert|1.6|km|mi|abbr=on}} from the LM. There, Duke took pictures of Stone Mountain and South Ray Crater, while Young deployed the LPM.<ref>{{cite web|title=Station 2 at Buster Crater|date=July 18, 2011|url=http://next.nasa.gov/alsj/a16/a16.sta2.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111025113946/http://next.nasa.gov/alsj/a16/a16.sta2.html|archive-date=October 25, 2011}}</ref> By this point, scientists were beginning to reconsider their pre-mission hypothesis that Descartes had been the setting of ancient volcanic activity, as the two astronauts had yet to find any volcanic material. Following their stop at Buster, Young did a "Grand Prix" demonstration drive of the lunar rover, which Duke filmed with a [[16 mm film|16 mm]] movie camera. This had been attempted on Apollo 15, but the camera had malfunctioned.<ref>{{cite web|title=Grand Prix|url=http://next.nasa.gov/alsj/a16/a16.trvlm1.html|date=January 17, 2020|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111026114051/http://next.nasa.gov/alsj/a16/a16.trvlm1.html|archive-date=October 26, 2011}}</ref> After completing more tasks at the ALSEP, they returned to the LM to close out the moonwalk. They reentered the LM 7{{nbsp}}hours, 6{{nbsp}}minutes, and 56 seconds after the start of the EVA. Once inside, they pressurized the LM cabin, went through a half-hour debriefing with scientists in Mission Control, and configured the cabin for the sleep period.<ref name="honeysuckle" /><ref>{{cite web|title=EVA-1 Closeout|url=http://next.nasa.gov/alsj/a16/a16.clsout1.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111024214907/http://next.nasa.gov/alsj/a16/a16.clsout1.html|archive-date=October 24, 2011}}</ref><ref>{{cite web|title=Debrief and Goodnight|url=http://next.nasa.gov/alsj/a16/a16.debrief1.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111021105620/http://next.nasa.gov/alsj/a16/a16.debrief1.html|archive-date=October 21, 2011|date=June 18, 2011}}</ref>

==== Second moonwalk ====
[[File:Young and Rover on the Descartes - GPN-2000-001133.jpg|thumb|upright=1.3|right|The view from the side of Stone Mountain, which Duke described as "spectacular"<ref name=station4/>]]

Waking up three and a half minutes earlier than planned, they discussed the day's timeline of events with Houston.<ref>{{cite web|title=EVA-2 Wake-up|url=http://next.nasa.gov/alsj/a16/a16.eva2wake.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111017000524/http://next.nasa.gov/alsj/a16/a16.eva2wake.html|archive-date=October 17, 2011|date=January 15, 2006}}</ref><ref>{{cite web|title=Preparations for EVA-2|url=http://next.nasa.gov/alsj/a16/a16.eva2prep.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111021105700/http://next.nasa.gov/alsj/a16/a16.eva2prep.html|archive-date=October 21, 2011|date=May 9, 2010}}</ref> The second lunar excursion's primary objective was to visit Stone Mountain to climb up the slope of about 20 degrees to reach a cluster of five craters known as "[[Cinco (crater)|Cinco craters]]". They drove there in the LRV, traveling {{convert|3.8|km|mi|abbr=on|sp=us}} from the LM. At {{convert|152|m|ft|abbr=on|sp=us}} above the valley floor, the pair were at the highest elevation above the LM of any Apollo mission. They marveled at the view (including South Ray) from the side of Stone Mountain, which Duke described as "spectacular",<ref name=station4>{{cite web|title=Geology Station 4 at the Stone Mountain Cincos|url=http://next.nasa.gov/alsj/a16/a16.sta4.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111025050902/http://next.nasa.gov/alsj/a16/a16.sta4.html|archive-date=October 25, 2011|date=July 19, 2011}}</ref> then gathered samples in the vicinity.<ref name=honeysuckle/> After spending 54 minutes on the slope, they climbed aboard the lunar rover en route to the day's second stop, dubbed Station 5, a crater {{convert|20|m|ft|abbr=on}} across. There, they hoped to find Descartes material that had not been contaminated by ejecta from South Ray Crater, a large crater south of the landing site. The samples they collected there, despite still uncertain origin, are according to geologist Wilhelms, "a reasonable bet to be Descartes".<ref name=honeysuckle/>

The next stop, Station 6, was a {{convert|10|m|ft|abbr=on|adj=mid|-wide|sp=us}} blocky crater, where the astronauts believed they could sample the Cayley Formation as evidenced by the firmer soil found there. Bypassing station seven to save time, they arrived at Station 8 on the lower flank of Stone Mountain, where they sampled material on a ray from South Ray crater for about an hour. There, they collected black and white breccias and smaller, [[crystal]]line rocks rich in [[plagioclase]]. At Station 9, an area known as the "Vacant Lot",<ref>{{cite web|title=Geology Station 9|url=https://www.hq.nasa.gov/alsj/a16/a16.sta9.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|access-date=September 23, 2021|date=May 1, 2018|archive-date=June 8, 2021|archive-url=https://web.archive.org/web/20210608152734/https://www.hq.nasa.gov/alsj/a16/a16.sta9.html|url-status=live}}</ref> which was believed to be free of ejecta from South Ray, they spent about 40 minutes gathering samples. Twenty-five minutes after departing the Vacant Lot, they arrived at the final stop of the day, halfway between the ALSEP site and the LM. There, they dug a double core and conducted several [[penetrometer]] tests along a line stretching {{convert|50|m|ft|abbr=on}} east of the ALSEP. At the request of Young and Duke, the moonwalk was extended by ten minutes. After returning to the LM to wrap up the second lunar excursion, they climbed back inside the landing craft's cabin, sealing and pressurizing the interior after 7{{nbsp}}hours, 23 minutes, and 26 seconds of EVA time, breaking a record that had been set on Apollo 15.<ref name="honeysuckle" /><ref>{{cite web|title=EVA-2 Closeout|url=http://next.nasa.gov/alsj/a16/a16.clsout2.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111026042001/http://next.nasa.gov/alsj/a16/a16.clsout2.html|archive-date=October 26, 2011|date=July 28, 2011}}</ref> After eating a meal and proceeding with a debriefing on the day's activities with Mission Control, they reconfigured the LM cabin and prepared for the sleep period.<ref>{{cite web|title=Post-EVA-2 Activities and Goodnight|url=http://next.nasa.gov/alsj/a16/a16.eva2post.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20120425231519/http://next.nasa.gov/alsj/a16/a16.eva2post.html|archive-date=April 25, 2012|date=September 25, 2011}}</ref>

==== Third moonwalk ====
[[File:JSC2007e045382.jpg|thumb|upright=1.8|left|John Young adjusting the LRV's antenna near Shadow Rock]]

Flight day seven was their third and final day on the lunar surface, returning to orbit to rejoin Mattingly in the CSM following the day's moonwalk. During the third and final lunar excursion, they were to explore [[North Ray (crater)|North Ray]] crater, the largest of any of the craters any Apollo expedition had visited. After exiting ''Orion'', the pair drove to North Ray crater. The drive was smoother than that of the previous day, as the craters were shallower and boulders were less abundant north of the immediate landing site. After passing [[Palmetto (crater)|Palmetto]] crater, boulders gradually became larger and more abundant as they approached North Ray in the lunar rover. Upon arriving at the rim of North Ray crater, they were {{convert|4.4|km|mi|abbr=on|sp=us}} away from the LM. After their arrival, the duo took photographs of the {{convert|1|km|mi|abbr=on|sp=us}} wide and {{convert|230|m|ft|abbr=on|sp=us}} deep crater. They visited a large boulder, taller than a four-story building, which became known as 'House Rock'. Samples obtained from this boulder delivered the final blow to the pre-mission volcanic hypothesis, proving it incorrect. House Rock had numerous bullet hole-like marks where [[micrometeoroid]]s from space had impacted the rock.<ref name = "honeysuckle" />

About 1{{nbsp}}hour and 22 minutes after arriving at the North Ray crater, they departed for Station 13, a large boulder field about {{convert|0.5|km|mi|abbr=on|sp=us}} from North Ray. On the way, they set a lunar speed record, traveling at an estimated {{convert|17.1|km/h|mph|sp=us}} downhill. They arrived at a {{convert|3|m|ft|abbr=on|sp=us}} high boulder, which they called "Shadow Rock". Here, they sampled permanently shadowed soil. During this time, Mattingly was preparing the CSM in anticipation of their return approximately six hours later. After three hours and six minutes, they returned to the LM, where they completed several experiments and unloaded the rover. A short distance from the LM, Duke placed a photograph of his family and an Air Force commemorative medallion on the surface.<ref name="honeysuckle" /> Young drove the rover to a point about {{convert|90|m|ft|abbr=on|sp=us}} east of the LM, known as the 'VIP site,' so its television camera, controlled remotely by Mission Control, could observe Apollo 16's liftoff from the Moon. They then reentered the LM after a 5-hour and 40-minute final excursion.<ref>{{cite web|title=VIP Site|url=http://next.nasa.gov/alsj/a16/a16.vip.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20111026075705/http://next.nasa.gov/alsj/a16/a16.vip.html|archive-date=October 26, 2011|date=August 9, 2011}}</ref> After pressurizing the LM cabin, the crew began preparing to return to lunar orbit.<ref>{{cite web|title=Post-EVA-3 Activities|url=http://next.nasa.gov/alsj/a16/a16.eva3post.html|publisher=[[NASA]]|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 16 Lunar Surface Journal|url-status=dead|archive-url=https://web.archive.org/web/20120425231532/http://next.nasa.gov/alsj/a16/a16.eva3post.html|archive-date=April 25, 2012|date=November 23, 2008}}</ref>