Space Sunday: “Godspeed, John Glenn”*

An unusual shot of John Glenn as he examines a celestial training device in preparation for his Mercury-Atlas orbital launch in February 1962. Credit: NASA

An unusual shot of John Glenn as he examines a celestial training device in preparation for his Mercury-Atlas orbital launch in February 1962. Credit: NASA

On December 8th, 2016, John Glenn, the first American astronaut to orbit the Earth, passed away at the age of 95.

A  U.S. Marine Corps pilot who served in both World War II and the Korean War, Glenn was actually the third American to fly into space after Alan Shepard and Gus Grissom, who both flew in 1961. However, for his 1962 flight, Glenn completed three orbits of the Earth aboard his Friendship 7 capsule before splashing down in the Atlantic Ocean, becoming the third man to circle the Earth in space. His death means that all of the Mercury 7 – astronauts  chosen to lead the fledging American space programme in 1959 – have now passed away.

Born in 1921 in Ohio, Glenn was commissioned in the US Marine Corps in 1943. After training, he served in the Pacific theatre of war, flying 59 fighter combat missions during World War II. In 1946, he returned to the far east, serving in Northern China and then Guam through until 1948, when he transferred to Texas as an instructor in advanced flight training. After further training, he served two tours of duty in the Korean War, flying a total of 149 combat missions. In 1954, he graduated from th U.S. Naval Test Pilot School, and in 1957 completed the first supersonic transcontinental flight, travelling from California to New York in 3 hours 23 minutes and 8.3 seconds.

Glenn preparing for his orbital flight, February, 1962. Credit: NASA

Glenn preparing for his orbital flight, February, 1962. Credit: NASA

He became involved in the US space programme before he was selected as a part of NASA’s first astronaut intake. As a serving Marine Corps officer, he was part of NASA research on re-entry vehicle shapes and participated in the Mercury capsule design.

even so, his acceptance into the astronaut corps was not assured: he was almost turned down on the grounds of age – he was approaching 40, the upper age limit for candidates, and he lacked the required science-based degree at the time. However, he fought hard for selection, and was accepted into the Space Task Group in 1959, where, in addition to astronaut training, he was involved in helping with both the Mercury and early Apollo cockpit layout and control functions.

He quickly became the unofficial spokesperson for the Mercury 7, having an easy way with the press – but he wasn’t necessarily popular within the group, setting himself somewhat aside from the rest through study and hard work. This became apparent when the choice for the first man to fly into space came down to a vote among the Seven themselves. Glenn came in third behind Alan Shephard and Gus Grissom, both of whom did fly before him despite a lot of behind-the-scenes lobbying by Glenn himself to get assigned to the first sub-orbital flight. have himself put on the first flight.

However, all this passed into history on February 20th, 1962, when Glenn lifted off atop his Mercury-Atlas 6 rocket, flying his Friendship 7 capsule on a 5 hour, 3-orbit flight round the Earth. And I do mean “fly”: during the flight, he was supposed to briefly take control of the Mercury capsule and manually fly it for 30 minutes before handing control back to the flight systems. However a malfunction in the automatic control system during his first orbit mean he had to take over control of the vehicle for the two remaining orbits.

His problems were then further compounded by telemetry suggesting his capsule’s heat shield had come loose, forcing him to manually fly the vehicle and keep the disposal retro-rocket pack (normally jettisoned prior to re-entry into Earth’s denser atmosphere) in place in case the straps from it were the only things keeping his heat shield in position. At the time, the frictional heat caused the rocket pack to burn up, with large chunks of flaming debris from it passing his window, prompting him to think his vehicle was burning up. “Fortunately it was the rocket pack,” he later wryly told a reporter, “Or I wouldn’t be answering these questions!”

His successful splashdown in the Atlantic meant Glenn became the fifth man to fly in space, and the third to orbit the Earth, after Russians Yuri Gagarin and Gherman Titov. Any upset he may have felt at being passed over for the first Mercury flight was swept aside as Glenn found himself fêted by the press and politicians alike; he later called the flight the “greatest day of his life”.

Glenn, left, became close friends with John F. Kennedy (centre) and Robert Kennedy,entering US politics in 1964 at Robert Kennedy's prompting. In this photograph, Glenn and Kennedy are seen with the second man to orbit the Earth, Russian cosmonaut Gherman Titov, who orbited the Earth 17 times in August 1961. Credit: NASA / Asif A. Siddiqi

Glenn, left, became close friends with John F. Kennedy (centre) and Robert Kennedy,entering US politics in 1964 at Robert Kennedy’s prompting. In this photograph, Glenn and Kennedy are seen with the second man to orbit the Earth, Russian cosmonaut Gherman Titov, who circled the Earth 17 times in August 1961, and who to this day remains the youngest person to fly in space at the time of his flight; he was just 26 years old. Credit: NASA / Asif A. Siddiqi

In 1964, Glenn retired from NASA, still a commissioned officer in the US Marine Corps (from which he retired in 1965 with the rank of colonel). His interest turned to politics, having been solidly befriended by John and Robert the Kennedy – that latter of whom persuaded him to run for office. After two unsuccessful attempts, he was elected to the US Senate representing his home state of Ohio in 1974, and remained so through until 1999. In 1984 he sought nomination as the Democratic Party’s candidate for the US Presidential election that year, losing out to Walter Mondale – who in turn lost to Republican Ronald Reagan in the election.

In 1998, shortly before retiring from the Senate, Glenn returned to orbit aboard the space shuttle Discovery during mission STS-95. He was 77 at the time, making him the oldest person to fly in space – a record he still holds.

The Mercury 7 - NASA's first astronauts. Standing (l-r): Alan B. Shephard Jr. (1st US astronaut to fly in space); Walter B. Schirra Jr; John Glenn (first US astronaut to orbit the Earth). Seated (l-r): Virgil I Grissom (2nd US astronaut in space); M. Scott Carpenter; Donald Slayton and L. Gordon Cooper Jr. Credit: NASA

The Mercury 7 – NASA’s first astronauts. Standing (l-r): Alan B. Shephard Jr. (1st US astronaut to fly in space); Walter B. Schirra Jr; John Glenn (first US astronaut to orbit the Earth). Seated (l-r): Virgil I Grissom (2nd US astronaut in space); M. Scott Carpenter; Donald Slayton and L. Gordon Cooper Jr. Credit: NASA

Ostensibly, the flight was to assist research into how space flight affects people of different ages, focusing on things like heart function, immune system changes and  / or protein turnover or vestibular functions may change / be impaired. However, as Glenn failed to meet two of the criteria required for the test subject, critics pounced on his selection as being more about the man than the mission. Writing in his memoirs, Glen claimed he had no idea NASA were willing to let him fly at the time the announcement was made, and went on to voice disappointment that NASA never followed up on his flight with further missions involving people in his age group.

Throughout his life, Glenn remained both an advocate of space flight and also something of a critic. In the 1960s he spoke against women being admitted into the astronaut corps – although at the time, a NASA stipulation that astronauts must be drawn from the ranks of test pilots pretty much excluded women anyway. While in 2001 he was an out spoken opponent of the first “Space tourist” flight to the International Space Station, which was completed by multi-millionaire Dennis Tito.

The STS-95 Discovery crew in a pose reminiscent of some of the Mercury 7 publicity shots. (l-r): Stephen K. Robinson; Pedro Duque (ESA); Curtis L. Brown Jr. (Mission Commander); Chiaki Mukai (NASDA); Senator John Glenn; Steven W. Lindsey (Shuttle Pilot) and Scott F. Parazynski. Credit: NASA

The STS-95 Discovery crew in a pose reminiscent of some of the Mercury 7 publicity shots. (l-r): Stephen K. Robinson; Pedro Duque (ESA); Curtis L. Brown Jr. (Mission Commander); Chiaki Mukai (NASDA); Senator John Glenn; Steven W. Lindsey (Shuttle Pilot) and Scott F. Parazynski. Credit: NASA

Glenn was taken ill at the start of December 2016, and was hospitalised at the James Cancer Hospital, Columbus, Ohio, where his condition was said to be “grave”. At the time of writing, his cause of death remains undisclosed. He is survived by his wife of 73 years, Annie, and their children, and grandchildren. He will be interred at the Arlington National Cemetery.

*”Godspeed, John Glenn”, the words spoken by Capsule Communicator and Fellow Mercury 7 astronaut Scott Carpenter to John Glenn just before the final 10-second countdown for his flight commenced, on February 20th, 1962. They were used again around the world on December 8th, 2016, to mark Glenn’s passing.

Quick Robot Mission Round-up

Mars Science Laboratory

NASA’s Curiosity rover is in a “photo and environment monitoring” mode while a further drill mechanism issue is investigated. The rover had been due to use the drill to gather samples from its sixteenth target rock on December 1st, when it detected a fault and halted the operation without extending the robot arm to the target rock.

The cause of the problem is unknown, and engineers are investigating using Curiosity’s twin here on Earth. However, it appears the drill feed mechanism which extends the drill bit from the rover’s turret of instruments so it can cut into rock, failed to operate correctly. Since February 2015, the drill has been subject to a number of issues, mostly related to the percussive action of the mechanism, which allows it to both cut and hammer its way into a rock.  So much so, that this operation had also been intended to use a new method of gathering rock samples with the drill which does not require the percussive action.

While the project team are confident they can resolve the problem, it was decided to discontinue driving operations while the fault is being diagnosed, lest jolts or vibrations caused by the rover’s forward motion over the ground interfered with accurate analysis of the drill mechanism’s status.

 Juno

NASA’s Juno mission made a third science pass over Jupiter’s cloud tops at 17:04 UTC on Sunday, December 11th. At the point of closest approach (perijove), the spacecraft was just  4,150 km (2,580 mi) above the upper clouds of the Jovian atmosphere and travelling at 206,400 km/h (129,000 mph) – or 57.8 km (36.1 mi) per second – relative to the planet.

The four Galilean moons of Jupiter as images by Juno on July 5th, 2016

The four Galilean moons of Jupiter as images by Juno on July 5th, 2016

Seven out of the vehicle’s science instruments were active for the flyby, marking the first time Juno’s full science capability was available to look deep inside Jupiter’s interior structure with the aid of the planet’s massive gravity field. The only instrument not available  – and not required – for the flyby – was the Jovian Infrared Auroral Mapper (JIRAM). This is currently powered down while its software is in the process of being upgraded.

Following the flyby, the vehicle remains in its elongated 53.5 day orbit around Jupiter while engineers continue to examine an issue with a set of fuel pressurisation valves in the spacecraft’s rocket motor. It had been hoped that the motor could have been fired on the last close flyby of Jupiter in October to swing the vehicle into its 14-day, primary mission orbit. However, until such time as mission engineers are reasonably confident the valve issue has been resolved, the craft will remain in its extended orbit, which should not adversely affect the majority of the science mission.

Cassini

On November 28th, I wrote about NASA’s Cassini mission to Saturn, which was about to enter its penultimate phase as the spacecraft was due to start the first of a series of “ring grazing” missions, designed to bring it gradually closer to the outermost of Saturn’s most active ring, the F-ring, until in March and April 2017, it will be passing through the outer reaches of that ring, some 140,180km (87,612.5 mi) from the centre of Saturn.

Now occupying a polar orbit around the gas giant, Cassini swept through the ring system on December 4th, 2016, passing directly through a very faint ring created by the moons Janus and Epimetheus, some 11,000 km (6875 mi) further out from Saturn than the F-ring. The imaging systems on-board the orbiter were turned off for this first pass – although they did capture images before the fly through – but they will be active during future passages through the rings, ready to capture details of them and some of the tiny moons which shepherd them, as we’ve never seen them before.

In 2014, Cassini captured this image of what might be a new moon forming in Saturn’s rings. The new moon, if it is one, is only about 1 km in diameter. Credit: NASA/JPL / Space Science Institute

In 2014, Cassini captured this image of what might be a new moon forming in Saturn’s rings. The new moon, if it is one, is only about 1 km in diameter. Credit: NASA/JPL / Space Science Institute

The mission is itself responsible for the discovery of seven of those moons: Methone, Pallene and Polydeuces, which were all imaged in 2004), together with Daphnis, Anthe, Aegaeon and the still unnamed, S/2009 S 1, which were imaged between 2005 and 2009.

These discoveries brought the total number of confirmed moons orbiting Saturn to 62, of which 9 have yet to be named.  However, in 2014, Cassini imaged what appeared to be a brand new moon in the process of being formed at the outer edge of one of Saturn’s rings.

Commenting on the first “ring grazing” orbit, Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory said, “It’s taken years of planning, but now that we’re finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits. This is a remarkable time in what’s already been a thrilling journey.”

These flights will conclude in late April 2017, when the spacecraft will make a close pass around Saturn’s largest moon, Titan. This will swing the vehicle onto its final series of 22 orbits of Saturn, passing through the gap between the planet and its rings.

As I’ve previously noted, the Cassini mission is due to come to an end in late September 2017, when the vehicle, its manoeuvring propellants likely expended, will enter the upper reached of Saturn’s atmosphere and burn up.

 

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