Apollo 17
Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon or traveled beyond low Earth orbit. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, while Command Module Pilot Ronald Evans orbited above. Schmitt was the only professional geologist to land on the Moon; he was selected in place of Joe Engle, as NASA had been under pressure to send a scientist to the Moon. The mission's heavy emphasis on science meant the inclusion of a number of new experiments, including a biological experiment containing five mice that was carried in the command module.
Mission type
Crewed lunar landing (J)
- CSM: 1972-096A
- LM: 1972-096C
- CSM: 6300
- LM: 6307
12 days, 13 hours, 51 minutes, 59 seconds
- Apollo CSM-114
- Apollo LM-12
- CSM: North American Rockwell[1]
- LM: Grumman
48,609 kilograms (107,165 lb)[2]
5,500 kilograms (12,120 lb)[3]
3
- CSM: America
- LM: Challenger
1 in cislunar space
3 on the lunar surface
1 hour, 5 minutes, 44 seconds
(Spacewalk to retrieve film cassettes)
December 7, 1972, 05:33:00 UTC (12:33 a.m. EST)[4]
Saturn V SA-512
December 19, 1972, 19:54:58 UTC[5]
South Pacific Ocean
17°53′S 166°07′W / 17.88°S 166.11°W
December 10, 1972, 19:53:55 UTC[5]
December 16, 1972, 23:35:09 UTC[5]
75
December 11, 1972, 19:54:58 UTC[5]
December 14, 1972, 22:54:37 UTC[5]
115 kilograms (254 lb)
3
- 22 hours, 3 minutes, 57 seconds
- First: 7 hours, 11 minutes, 53 seconds
- Second: 7 hours, 36 minutes, 56 seconds
- Third: 7 hours, 15 minutes, 8 seconds
35.7 kilometers (22.2 mi)
Mission planners had two primary goals in deciding on the landing site: to sample lunar highland material older than that at Mare Imbrium and to investigate the possibility of relatively recent volcanic activity. They therefore selected Taurus–Littrow, where formations that had been viewed and pictured from orbit were thought to be volcanic in nature. Since all three crew members had backed up previous Apollo lunar missions, they were familiar with the Apollo spacecraft and had more time for geology training.
Launched at 12:33 a.m. Eastern Standard Time (EST) on December 7, 1972, following the only launch-pad delay in the course of the whole Apollo program that was caused by a hardware problem, Apollo 17 was a "J-type" mission that included three days on the lunar surface, expanded scientific capability, and the use of the third Lunar Roving Vehicle (LRV). Cernan and Schmitt landed in the Taurus–Littrow valley, completed three moonwalks, took lunar samples and deployed scientific instruments. Orange soil was discovered at Shorty crater; it proved to be volcanic in origin, although from early in the Moon's history. Evans remained in lunar orbit in the command and service module (CSM), taking scientific measurements and photographs. The spacecraft returned to Earth on December 19.
The mission broke several records for crewed spaceflight, including the longest crewed lunar landing mission (12 days, 14 hours),[7] greatest distance from a spacecraft during an extravehicular activity of any type (7.6 kilometers or 4.7 miles), longest total duration of lunar-surface extravehicular activities (22 hours, 4 minutes),[8] largest lunar-sample return (approximately 115 kg or 254 lb), longest time in lunar orbit (6 days, 4 hours),[7] and greatest number of lunar orbits (75).[9]
Planning and training
Scheduling and landing site selection
Prior to the cancellation of Apollo 18 through 20, Apollo 17 was slated to launch in September 1971 as part of NASA's tentative launch schedule set forth in 1969.[4] The in-flight abort of Apollo 13 and the resulting modifications to the Apollo spacecraft delayed subsequent missions.[37] Following the cancellation of Apollo 20 in early 1970, NASA decided there would be no more than two Apollo missions per year.[38] Part of the reason Apollo 17 was scheduled for December 1972 was to make it fall after the presidential election in November, ensuring that if there was a disaster, it would have no effect on President Richard Nixon's re-election campaign.[39] Nixon had been deeply concerned about the Apollo 13 astronauts, and, fearing another mission in crisis as he ran for re-election, initially decided to omit the funds for Apollo 17 from the budget; he was persuaded to accept a December 1972 date for the mission.[40]
Like Apollo 15 and 16, Apollo 17 was slated to be a "J-mission", an Apollo mission type that featured lunar surface stays of three days, higher scientific capability, and the usage of the Lunar Roving Vehicle. Since Apollo 17 was to be the final lunar landing of the Apollo program, high-priority landing sites that had not been visited previously were given consideration for potential exploration. Some sites were rejected at earlier stages. For instance, a landing in the crater Copernicus was rejected because Apollo 12 had already obtained samples from that impact, and three other Apollo expeditions had already visited the vicinity of Mare Imbrium, near the rim of which Copernicus is located. The lunar highlands near the crater Tycho were rejected because of the rough terrain that the astronauts would encounter there. A site on the lunar far side in the crater Tsiolkovskiy was rejected due to technical considerations and the operational costs of maintaining communication with Earth during surface operations. Lastly, a landing in a region southwest of Mare Crisium was rejected on the grounds that a Soviet spacecraft could easily access the site and retrieve samples; Luna 20 ultimately did so shortly after the Apollo 17 site selection was made.[41] Schmitt advocated for a landing on the far side of the Moon until told by Director of Flight Operations Christopher C. Kraft that it would not happen as NASA lacked the funds for the necessary communications satellites.[42]