Space Sunday: 50 years – last and first at the Moon

Apollo 17 lifts off from Launch Complex 39A, Kennedy Space Centre, December 7th, 1972. Credit: NASA
At 05:33 UTC on December 7th, 1972, the last of the Moon-bound Saturn V rockets thundered into the Florida skies from Kennedy Space Centre’s Launch Complex 39A At the start of the Apollo 17 mission.

Looking back at the Apollo era now, it is incredible to think that the entire project was conceived and – in terms of its lunar aspirations –  executed in just 13 years, with the missions to the land humans on the Moon all taking place within a span of just 42 months. It was originally initiated in early 1960 under the Eisenhower administration as a means for the US to expand its space capabilities by providing a vehicle system capable of being used in the construction of a space station and, eventually, of carrying humans to the Moon. But in 1961 the project was co-opted as the best means of achieving President Kennedy’s desire to see America “commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth”.

In doing so, Apollo set in motion the biggest single increase in NASA’s capabilities ever witnessed, giving rise to the facilities – such as the Merritt Island Launch Operations Centre with its massive VAB and two launch facilities at pad 39A and Pad 39B, and the sprawling mass of the Johnson Space Centre in Texas (often colloquially referred to as “Mission Control”) – people take for granted today as the most public elements of NASA’s infrastructure. Even so, by the time Apollo 11 landed on the Moon, the programme had already started towards closure: Apollo 20 had already been diverted for use in the Skylab project, while Apollo 18 and 19 would be cancelled early in 1971, leaving Apollo 17 as the last Apollo flight to the Moon.

The Apollo 17 crew: seated in the lunar rover replica is Gene Cernan, with Harrison Schmitt to the left behind him, and Ronald Evans to the right
The Apollo 17 crew, 1972: seated in the lunar rover replica is Gene Cernan (Commander), with Harrison Schmitt (Lunar Module pilot) to the left behind him, and Ronald Evans (Command Module pilot) to the right, and the Saturn V launch vehicle on the pad behind them. Credit: NASA

A “J-Class” mission, Apollo 17 was one of only three of the lunar flights designated as being for “extensive scientific investigation”, the missions up to and including Apollo 14 being focused primarily on the task of making precision lunar landings, with all science activities running secondary to that. It was also the only Apollo mission to the Moon to carry a full trained scientist in the form of geologist Harrison H. Schmitt.

Initially, Schmitt had been slated for Apollo 18, but when that mission was cancelled, there was a push from the science community to have him moved to Apollo 17 – a push resisted by mission commander Eugene Cernan, who (understandably) wanted to keep his original team of himself, Ronald Evans and Joe Engle. However, Cernan’s own leadership of the mission was seen as questionable by some at NASA after pilot error on his part caused during a training flight resulted in a helicopter crash; so when it became clear the choice was to replace Engle with Schmitt or have the who crew replaced, Cernan capitulated – and he and Schmitt went on to form a strong working relationship and friendship.

En-route to the Moon: Harrison Schmitt catches a cheeky-looking Eugene Cernan (l) and Ronald Evans (r). Credit: NASA

The only night-time launch for an Apollo lunar surface mission, Apollo 17 proceeded precisely on schedule despite a brief launch-pad delay. Planned as the longest of the Apollo missions at 12 days and 14 hours, it would also become the most successful of the three lunar science flights for Apollo, with the science work commencing whist en route to the Moon, with the crew carrying out observations of Earth and its weather patterns. Also carried aboard the Command Module were 5 additional crew members: pocket mice the crew unofficially named Fe, Fi, Fo, Fum and Phooey. Carried in their own self-contain life support unit, they were part of an experiment to investigate exposure to cosmic rays in interplanetary space, although the findings of the experiment were ultimately inconclusive.

This science work took a further turn when, as the CSM and LM combination approached the Moon, a panel on the side of the Service Module was jettisoned to expose the contents of the Scientific Instruments Module (SIM), a battery of lunar science packages Evans would monitor whilst his crewmates were on the Moon’s surface.

America’s exposed Science Instruments Module (SIM) imaged from the Lunar Module Challenger. Credit: NASA
These experiments comprised a lunar sounder designed to map the interior geology of the Moon to a depth of 1.3 km; an infra-red scanning radiometer intended to obtain a temperature  map of the Moon’s surface to assist in understanding structural differences in the lunar crust; and a far-ultraviolet spectrometer to obtain data on the composition, density, and constituency of the lunar atmosphere and detect far-UV radiation emitted by the Sun that had been reflected off the lunar surface. Also in the SIM bay were a pair of cameras for imaging the Moon and a laser altimeter.

twenty-four hours after entering orbit around the Moon, Schmitt and Cernan boarded the Lunar Module Challenger, departing the Command Module America on December 11th, 1972 to touch down within the Taurus-Littrow valley at 19:54:58 UTC that day. The landing marked the start of some 75 hours on the lunar surface. During this time, Cernan and Schmitt carried out 3 EVAs, two of them making use of the third Lunar Rover vehicle to the carried to the Moon.

Challenger orients itself ready to start its descent to the lunar surface, as captured by Ronald Evans aboard America. Credit: NASA

The rover was deployed during the first EVA, with Cernan managing to repeat an error made by John Young on Apollo 16, accidentally ripping off one of the dust guards over the rover’s wheels such that both he and Schmitt would be showered in lunar “fines” (dust) kicked up by the wheel when the rover was in motion despite efforts to make repairs under Young’s supervision. In addition, this EVA also saw the two men deploy the surface experiments designed to be used within the vicinity of the Lunar Module.

The second EVA, on December 12th set a series of records for lunar surface operations: the furthest distance travelled from the LM (7.6 km), the longest distance travelled in a single EVA overall, the most time spent of the surface of the Moon in a single EVA (7 hours, 37 minutes) and the largest haul of samples from a single EVA to that point – 34 Kg. Along the way they visited several sites – Nansen Crater, at the foot of the South Massif; Shorty crater, and Camelot crater,

This EVA would go down in history for other reasons as well. At Shorty Crater, Schmitt came across orange soil, never before seen on the Moon. Initially it was thought he’d come across a volcanic vent in the lunar crust, but subsequent analysis of the material’s tiny volcanic beads revealed it has been formed some 3.5 billion years ago during the Moon’s volcanic period, and was exposed when a small asteroid slammed into the Moon to form Shorty a mere 20 million years ago.

Between Nansen and Shorty, the crew also stopped at a then-unnamed crater where Schmitt stumbled and fell in an awkward pirouette. While the fall left him uninjured, it prompted duty CapCom Robert Parker to quip to the crew that the Houston Ballet had called, requesting Schmitt audition for them on his return to Earth (in 2019, the crater was officially named Ballet Crater in honour of Schmitt’s tumble). Also during the EVA, both men (led by Schmitt) offered their own take on the popular song I Was Strolling in the Park One Day, which more than anything else revealed the bond that had grown between them.

The final Apollo era lunar EVA began at 22:35 UTC on December 13th, 1972, carrying out surveys of three “stations”: the North Massif and the Sculptured Hills; a house-sized boulder Cernan dubbed “Tracy’s Rock” after his daughter; and Van Serg crater. Whilst short in distance that the second EVA, this one set a further new record for samples collected – 66 Kg, including the 8 Kg sample designated 70215, a small part of which is now displayed at the Smithsonian Institution as one of the few samples of lunar rock the general public can touch.

At the end of the EVA, Schmitt and Cernan unveiled a plaque mounted on the side of the Lunar Module’s descent stage, commemorating both their own time on the Moon and the Apollo mission as a whole. Schmitt then climbed back into the LM, leaving Cernan as The Last Man On the Moon, expressing some of his thoughts thus:

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 … 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.

– Eugene Cernan, December 13th, 1972

A composite image of Harrison Schmitt alongside of “Tracy Rock”, taken by Eugene Cernan. Credit: NASA

Cernan and Schmitt successfully lifted off from the lunar surface in the ascent stage of the LM on December 14th, 1972 at 22:54 UTC. Following a 7-minute ascent, they entered lunar orbit and coasted to a rendezvous with America, where Evans had been busy with his own work. Following docking and transfer, Challenger was jettisoned at 04:51 UTC on December 15th, 1972, to be successful de-orbited to crash on the Moon’s surface where seismometers left by several Apollo mission recorded the impact.

While en route back to Earth, Evans completed one of only three “deep space” EVAs so far performed, and the last EVA of the Apollo missions to the Moon. At 296,000 km from Earth, he departed the Command Module, watched over by Harrison Schmitt, and retrieved the film cassettes from the cameras in the SIM on the Service Module.

America re-entered Earth’s atmosphere and splashed down safely in the Pacific Ocean at 19:25 UTC, December 19th, 1972 just 6.4 km from the recovery ship USS Ticonderoga. The splashdown brought the Apollo lunar missions to a close. However, 5 more missions would fly under the Apollo banner: the four Skylab missions between 1973 and 1974 (which included the final flight of an Apollo Saturn V rocket), and the lS half of the Apollo-Soyuz Test Project (ASTP) in 1975.

Apollo 17 marked the last time Cernan flew into space, and the first and last times Schmitt and Evans did likewise. In 1976, Cernan departed NASA for the private sector, but maintained strong views on the direction of the US space programme, being highly critical of the Obama administration’s cancellation of the Constellation Programme and NASA’s move to rely on private sector resources. He passed away in January 2017, and is the subject of an obituary in these pages,

Ronald Evans remained at NASA until March 1977, performing key roles in both the ASTP mission and in the development of the space shuttle system. He passed away in 1990 after suffering a heart attack in his sleep. Harrison Schmitt was the first of the three to depart NASA, doing so in 1975 to pursue his political aspirations as a Republican Senator for New Mexico (1976-82). He became chair of the NASA advisory council in 2005  but then abruptly resigned 2008, clashing with NASA on the subject of climate change – of which he is a fervent denier (going so far as to state in 2013 that rising CO2 levels in the atmosphere are “good” because they allow us “to grow more crops”). He has also aligned himself with extremist conspiracy theorists such as Alex Jones.

Artemis 1 Comes Home

While it was not planned this way, fate determined that the 50th anniversary of Apollo17 landing on the Moon would be shared with the return to Earth of the first of NASA’s next generation of crew-carrying, lunar orbit capable vehicles, the Orion Multi-Purpose Crew Vehicle (MPCV).

I’ve covered the 26-day mission of Artemis 1 over the last few editions of Space Sunday. In many respects, it is the “reverse book-end” of Apollo 17; while the latter brought America’s first forays to the Moon to an end, Artemis 1 opens the door to a far more ambitious, international, and potentially far-reaching return to the Moon.

Perhaps the most iconic image of the Artemis 1 mission. Captured on December 5th, 2022 as the vehicle swings around the Moon, it shows the crescent Earth in the distance, the shadow of the Moon partially covering it. Credit: NASA

The mission, launched on November 16th, 2022, sent the Orion vehicle on a wide, slow cruise out to the Moon, which it transited past on November 21st, to enter a distant retrograde orbit (DRO), where it remained until December 5th, when a second close pass by the Moon allowed it to fire its main engine and start its way back to Earth.

The extended nature of the mission was to allow the systems on Orion to be thoroughly checked out over the duration of a typical mission duration, and to gather data on how well the vehicle protects the crew from radiation in the interplanetary medium – and the likely impact of exposure to the likes of cosmic radiation on humans who will spend 20-30+ days away from the protection of Earth’s magnetic fields.

December 11, 2022: Artemis 1 approaches Earth ahead of the Orion capsule separating from the Service Module. Credit: NASA

Approaching Earth on December 11th, 2022, the Orion capsule separated from is its European-built Service Module at 17:00 UTC, immediately performing a “skip” re-entry. This saw the capsule descend to around 60 km above the Earth before rising once more to 90 km to start its “full” re-entry. This “skip” manoeuvre allowed the vehicle to shave off its huge velocity – 40,000 km/h – in stages, both reducing  the over G-load the vehicle would face in a single go whilst also offering a greater flexibility in selecting a  splashdown location should there be an issue with the primary.

Splashdown came at 17:40 UTC bringing to an end a test flight covering a total distance of 2.3 million km. Prior to striking the water, the last of the vehicle’s velocity was reduced through the use of no fewer than 11 parachutes, opened in groups during its descent through the denser atmosphere.

Splashdown! 17:40 UTC, December 11th, 2022: the flight of Artemis 1 concludes as the Orion capsule splashes down safely off the coast of California. Credit: NASA / US Navy

While the mission will be subject to an extensive post-flight analysis, the general consensus is that SLS rocket and the Orion vehicle passed the test with more-or-less flying colours, helping to ensure things remain on course for the crewed mission of Artemis 2, due to take place in May 2024 over 10 days, head of the first planned lunar landing for Artemis 3, currently planned for launch in 2025.