Editing Apollo 17 (section)

=== Lunar surface ===

====First EVA====
[[File:Apollo 17 Cernan on moon.jpg|thumb|upright=1.3|right|Cernan on the lunar surface, December 13, 1972]]

During their approximately 75-hour stay{{sfn|Orloff 2004|loc=Statistical Tables: General Background}} on the lunar surface, Cernan and Schmitt performed three moonwalks ([[Extra-vehicular activity|EVAs]]). The astronauts deployed the LRV, then emplaced the ALSEP and the seismic explosive charges. They drove the rover to nine planned geological-survey stations to collect samples and make observations. Additionally, twelve short sampling stops were made at Schmitt's discretion while riding the rover, during which the astronauts used a handled scoop to get a sample, without dismounting.<ref name="geostations">{{cite web |url=https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/surface_opp/ |title=Apollo 17 Mission: Surface Operations Overview |publisher=Lunar and Planetary Institute |website=Universities Space Research Association |access-date=November 29, 2021 |archive-date=November 9, 2020 |archive-url=https://web.archive.org/web/20201109201434/https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/surface_opp/ |url-status=live }}</ref> During lunar-surface operations, Commander Cernan always drove the rover, while Lunar Module Pilot Schmitt was a passenger who assisted with navigation. This division of responsibilities between the two crew positions was 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|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 15 Lunar Surface Journal|access-date=January 6, 2022|archive-date=July 21, 2019|archive-url=https://web.archive.org/web/20190721143222/https://www.hq.nasa.gov/alsj/a15/a15.summary.html|url-status=live}}</ref>{{sfn|Riley, Woods, & Dolling 2012|p=165}}<ref name="reunion">{{cite web |url=https://www.space.com/apollo-astronauts-talk-risks-explorers-club-2019.html |title=The Risk of Apollo: Astronauts Swap Harrowing Tales from NASA's Moon Shots |last=Gohd |first=Chelsea |date=March 22, 2019 |website=[[Space.com]] |access-date=January 6, 2022 |archive-date=July 26, 2020 |archive-url=https://web.archive.org/web/20200726063901/https://www.space.com/apollo-astronauts-talk-risks-explorers-club-2019.html |url-status=live }}</ref>

The first lunar excursion began four hours after landing, at 6:54&nbsp;p.m. EST on December 11. After exiting through the hatch of the LM and descending the ladder to the footpad, Cernan took the first step on the lunar surface of the mission. Just before doing so, Cernan remarked, "I'm on the footpad. And, Houston, as I step off at the surface at Taurus–Littrow, we'd like to dedicate the first step of Apollo 17 to all those who made it possible."<ref name="firststeps">{{cite web|title=Down the Ladder|url=https://www.hq.nasa.gov/alsj/a17/a17.1ststep.html|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 17 Lunar Surface Journal|access-date=January 6, 2022|archive-date=July 21, 2019|archive-url=https://web.archive.org/web/20190721181802/https://www.hq.nasa.gov/alsj/a17/a17.1ststep.html|url-status=live}}</ref> After Cernan surveyed the exterior of the LM and commented on the immediate landing site, Schmitt joined Cernan on the surface.<ref name="firststeps"/> The first task was to offload the rover and other equipment from the LM. While working near the rover, Cernan caught his hammer under the right-rear fender extension, accidentally breaking it off. A similar incident occurred on Apollo 16 as John Young maneuvered around the rover. Although this was not a mission-critical issue, the loss of the part caused Cernan and Schmitt to be covered with dust stirred up when the rover was in motion.<ref name="brokenfender">{{cite web|title=ALSEP Off-load|url=http://www.hq.nasa.gov/alsj/a17/a17.alsepoff.html|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 17 Lunar Surface Journal|access-date=August 24, 2011|archive-date=August 16, 2015|archive-url=https://web.archive.org/web/20150816205258/http://www.hq.nasa.gov/alsj/a17/a17.alsepoff.html|url-status=live}}</ref> The crew made a short-lived fix using [[duct tape]] at the beginning of the second EVA, attaching a paper map to the damaged fender. Lunar dust stuck to the tape's surface, however, preventing it from adhering properly. Following deployment and testing the maneuverability of the rover, the crew deployed the ALSEP just west of the landing site. The ALSEP deployment took longer than had been planned, with the drilling of core holes presenting some difficulty, meaning the geological portion of the first EVA would need to be shortened, cancelling a planned visit to [[Emory (crater)|Emory crater]]. Instead, following the deployment of the ALSEP, Cernan and Schmitt drove to [[Steno-Apollo|Steno crater]], to the south of the landing site. The objective at Steno was to sample the subsurface material excavated by the impact that formed the crater. The astronauts gathered {{convert|14|kg|lbs}} of samples, took seven gravimeter measurements, and deployed two explosive packages. The explosive packages were later detonated remotely; the resulting explosions detected by geophones placed by the astronauts and also by seismometers left during previous missions.<ref>{{cite journal |last1=Brzostowski |first1=Matthew |last2=Brzostowski |first2=Adam |date=April 2009 |title=Archiving the Apollo active seismic data |url=http://tle.geoscienceworld.org/content/28/4/414.abstract |journal=[[Society of Exploration Geophysicists#Journals, books, and newsletters|The Leading Edge]] |location=Tulsa, OK |publisher=[[Society of Exploration Geophysicists]] |volume=28 |issue=4 |pages=414–416 |doi=10.1190/1.3112756 |bibcode=2009LeaEd..28..414B |issn=1070-485X |access-date=June 12, 2014 |archive-date=November 4, 2016 |archive-url=https://web.archive.org/web/20161104200304/http://tle.geoscienceworld.org/content/28/4/414.abstract |url-status=live }}</ref> The first EVA ended after seven hours and twelve minutes.<ref name=astronautix/> and the astronauts remained in the pressurized LM for the next 17 hours.{{sfn|Orloff & Harland 2006|p=516}}

====Second EVA====
[[File:Ap17 strolling.ogv|thumb|Astronauts Cernan and Schmitt singing "I Was Strolling on the Moon One Day" to the words and tune of the 1884 song "[[The Fountain in the Park|While Strolling Through the Park One Day]]"]]
On December 12, awakened by a recording of "[[Ride of the Valkyries]]" played from Mission Control,<ref name="valkyries">{{cite web|url=https://www.hq.nasa.gov/alsj/a17/a17.eva2wake.html|title=EVA-2 Wake-up|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 17 Lunar Surface Journal|date=May 20, 2014|access-date=January 7, 2022|archive-date=July 21, 2019|archive-url=https://web.archive.org/web/20190721171500/https://www.hq.nasa.gov/alsj/a17/a17.eva2wake.html|url-status=live}}</ref> Cernan and Schmitt began their second lunar excursion. The first order of business was to provide the rover's fender a better fix. Overnight, the [[flight controller]]s devised a procedure communicated by John Young: taping together four stiff paper maps<ref name="valkyries"/> to form a "replacement fender extension" and then clamping it onto the fender.<ref name="transcript">{{cite web |url=https://www.hq.nasa.gov/alsj/a17/AS17_TEC.PDF |archive-url=https://ghostarchive.org/archive/20221009/https://www.hq.nasa.gov/alsj/a17/AS17_TEC.PDF |archive-date=2022-10-09 |url-status=live |title=Apollo 17 Technical Air-to-Ground Voice Transcription |publisher=NASA |date=December 1972|page=977}}</ref> The astronauts carried out the new fix which did its job without failing until near the end of the third excursion.{{sfn|Chaikin 1995|p=542}}{{sfn|Swift 2021|pp=1043–1045, 1085}} Cernan and Schmitt then departed for station 2—[[Nansen-Apollo (crater)|Nansen Crater]], at the foot of the South Massif. When they arrived, their range from the ''Challenger'' was 7.6 kilometers (4.7 miles, 25,029 feet<ref name="eva table">{{cite web |url=https://history.nasa.gov/SP-4029/Apollo_18-30_Extravehicular_Activity.htm |title=Extravehicular Activity |publisher=NASA |access-date=January 6, 2022 |archive-date=November 18, 2004 |archive-url=https://web.archive.org/web/20041118103553/https://history.nasa.gov/SP-4029/Apollo_18-30_Extravehicular_Activity.htm |url-status=live }}</ref>). This remains the furthest distance any spacefarers have ever traveled away from the safety of a pressurizable spacecraft while on a planetary body,{{sfn|Swift 2021|pp=1053–1058}} and also during an EVA of any type.{{efn|Apart from the Apollo program's moonwalks (and a unique trio of deep-space EVAs conducted during the program's J-missions), all other spacewalks have been conducted in Low-Earth orbit, of which almost all have involved a safety tether keeping the spacefarer attached to the spacecraft by a short distance. The exceptions occurred in 1984 and 1994, when a series of seven EVAs involved untethered activity using the [[Manned Maneuvering Unit]] (MMU) and the [[Simplified Aid For EVA Rescue]] Unit (SAFER). Among this latter group, the greatest distance traveled away from a spacecraft during orbital flight was approximately 100 meters (320 feet), achieved by [[Bruce McCandless II|Bruce McCandless]] on [[STS-41-B]] during the first test of the MMU.<ref>{{cite web |last=Chaikin |first=Andrew |title=Untethered |date=October 2014 |publisher=Air and Space Magazine |url=https://www.airspacemag.com/space/untethered-180952792/ |access-date=January 6, 2022 |archive-date=December 14, 2021 |archive-url=https://web.archive.org/web/20211214000747/https://www.airspacemag.com/space/untethered-180952792/ |url-status=live }}</ref>}} The astronauts were at the extremity of their "walkback limit", a safety constraint meant to ensure that they could walk back to the LM if the rover failed. They began a return trip, traveling northeast in the rover.{{sfn|Chaikin 1995|pp=527–530}}

At station 3, Schmitt fell to the ground while working, looking so awkward that Parker jokingly told him that NASA's switchboard had lit up seeking Schmitt's services for Houston's ballet group, and the site of station 3 was in 2019 renamed Ballet Crater.{{sfn|Swift 2021|pp=1062–1063}} Cernan took a sample at Station 3 that was to be maintained in vacuum until better analytical techniques became available, joking with the CAPCOM, Parker, about placing a note inside. The container remained unopened until 2022.<ref name="transcript"/><ref>{{cite web|last=Wamsley|first=Laurel|title=NASA is just now opening a vacuum-sealed sample it took from the moon 50 years ago|publisher=[[National Public Radio]]|access-date=March 11, 2022|url=https://www.npr.org/2022/03/08/1085241811/nasa-moon-samples-apollo-artemis|date=March 8, 2022|archive-date=March 11, 2022|archive-url=https://web.archive.org/web/20220311021647/https://www.npr.org/2022/03/08/1085241811/nasa-moon-samples-apollo-artemis|url-status=live}}</ref>

Stopping at station 4—[[Shorty (crater)|Shorty crater]]—the astronauts discovered orange soil, which proved to be very small beads of volcanic glass formed over 3.5 billion years ago.{{sfn|Cortright 2019|p=276}} This discovery caused great excitement among the scientists at Mission Control, who felt that the astronauts may have discovered a volcanic vent. However, post-mission sample analysis revealed that Shorty is not a volcanic vent, but rather an impact crater. Analysis also found the orange soil to be a remnant of a [[lava fountain]]. This lava fountain sprayed molten lava high into the lunar sky in the Moon's early days, some 3.5 billion years ago and long before Shorty's creation. The orange volcanic beads were droplets of molten lava from the fountain that solidified and were buried by lava deposits until exposed by the impact that formed Shorty, less than 20 million years ago.{{sfn|Chaikin 1995|pp=527–530}}

The final stop before returning to the LM was [[Camelot (crater)|Camelot crater]]; throughout the sojourn, the astronauts collected {{convert|34|kg|lbs}} of samples, took another seven gravimeter measurements, and deployed three more explosive packages.<ref name=astronautix/> Concluding the EVA at seven hours and thirty-seven minutes, Cernan and Schmitt had completed the longest-duration EVA in history to-date, traveling further away from a spacecraft and covering more ground on a planetary body during a single EVA than any other spacefarers.<ref name="eva table"/> The improvised fender had remained intact throughout, causing the president of the "Auto Body Association of America" to award them honorary lifetime membership.{{sfn|Swift 2021|pp=1070–1071}}

====Third EVA==== 
[[File:AS17-140-21493+AS17-140-21497.jpg|thumb|upright=1.5|Composite image of Harrison Schmitt working next to [[Tracy's Rock]] during EVA-3]]
The third moonwalk, the last of the Apollo program, began at 5:25&nbsp;p.m. EST on December 13. Cernan and Schmitt rode the rover northeast of the landing site, exploring the base of the North Massif and the Sculptured Hills. Stopping at station 6, they examined a house-sized split boulder dubbed [[Tracy's Rock]] (or Split Rock), after Cernan's daughter. The ninth and final planned station was conducted at [[Van Serg (crater)|Van Serg crater]]. The crew collected {{convert|66|kg|lbs}} of lunar samples and took another nine gravimeter measurements.<ref name=astronautix/> Schmitt had seen a fine-grained rock, unusual for that vicinity, earlier in the mission and had stood it on its edge; before closing out the EVA, he went and got it. Subsequently, designated Sample 70215, it was, at {{convert|17.7|lb}}, the largest rock brought back by Apollo 17. A small piece of it is on exhibit at the [[Smithsonian Institution]], one of the few rocks from the Moon that the public may touch.<ref>{{cite journal|last=Craddock|first=Bob|title=In the Museum: The Rock|date=March 2002|journal=[[Air & Space/Smithsonian]]|url=https://www.airspacemag.com/space/in-the-museum-the-rock-28431174/|access-date=December 4, 2021|archive-date=December 4, 2021|archive-url=https://web.archive.org/web/20211204210836/https://www.airspacemag.com/space/in-the-museum-the-rock-28431174/|url-status=live}}</ref> Schmitt also collected a sample, designated as [[Troctolite 76535|Sample 76535]], at geology station 6 near the base of the North Massif; the sample, a [[troctolite]], was later identified as the oldest known "unshocked" lunar rock, meaning it has not been damaged by high-impact geological events. Scientists have therefore used Sample 76535 in [[Thermochronology|thermochronological]] studies to determine if the Moon formed a metallic [[Planetary core|core]] or, as study results suggest, a [[Dynamo theory|core dynamo]].<ref>{{cite journal|last=Garrick-Bethell|first=Ian|display-authors=etal |title=Early Lunar Magnetism|journal=Science|date=January 2009|volume=323|pages=356–359|doi=10.1126/science.1166804|pmid=19150839|bibcode=2009Sci...323..356G|issue=5912|s2cid=23227936}}</ref><ref>{{cite web |title=Lunar Sample 76535 |url=https://www.lpi.usra.edu/lunar/samples/atlas/detail/?mission=Apollo%2017&sample=76535 |publisher=Lunar and Planetary Institute |access-date=December 13, 2021 |archive-date=June 25, 2021 |archive-url=https://web.archive.org/web/20210625061132/https://www.lpi.usra.edu/lunar/samples/atlas/detail/?mission=Apollo%2017&sample=76535 |url-status=live }}</ref>

Before concluding the moonwalk, the crew collected a [[breccia]] rock, dedicating it to the nations of Earth, 70 of which were represented by students touring the U.S. and present in [[Christopher C. Kraft Jr. Mission Control Center#Houston (1965–present)|Mission Control Center]] in [[Houston|Houston, Texas]], at the time. Portions of this sample, known as the Friendship Rock, were subsequently distributed to the nations represented by the students. A plaque located on the LM, commemorating the achievements made during the Apollo program, was then unveiled. Before reentering the LM for the final time, Cernan remarked,<ref name=astronautix/>{{sfn|Chaikin 1995|p=543}}

{{blockquote|text= ...{{nbsp}}I'm on the surface; and, as I take man's last step from the surface, back home for some time to come – but we believe not too long into the future – I'd like to just [say] what I believe history will record. That America's challenge of today has forged man's destiny of tomorrow. And, as we leave the Moon at Taurus–Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind. "Godspeed the crew of Apollo 17."<ref name=alsjeva3>{{cite web|title=EVA-3 Close-out|url=http://www.hq.nasa.gov/alsj/a17/a17.clsout3.html|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 17 Lunar Surface Journal|access-date=August 22, 2011| archive-url= https://web.archive.org/web/20110718153102/http://www.hq.nasa.gov/alsj/a17/a17.clsout3.html| archive-date=July 18, 2011| url-status= live}}</ref>}}

Cernan then followed Schmitt into the LM; the final lunar excursion had a duration of seven hours and fifteen minutes.<ref name=astronautix/> Following closing of the LM hatch and repressurization of the LM cabin, Cernan and Schmitt removed their spacesuits and reconfigured the cabin for a final rest period on the lunar surface. As they did following each of the previous two EVAs, Cernan and Schmitt discussed their geological observations from the day's excursion with mission control while preparing to rest.<ref>{{cite web|title=Post-EVA-3 Activities|url=https://www.hq.nasa.gov/alsj/a17/a17.eva3post.html|publisher=NASA|editor-first=Eric M.|editor-last=Jones|editor2-first=Ken|editor2-last=Glover|work=Apollo 17 Lunar Surface Journal|access-date=December 11, 2021|archive-date=December 13, 2021|archive-url=https://web.archive.org/web/20211213180515/https://www.hq.nasa.gov/alsj/a17/a17.eva3post.html|url-status=live}}</ref>