Launched in January, 2006, NASA’s New Horizons spacecraft finally reached its principal mission goal – Pluto – nine years later in 2015. After traveling billions of miles through black space, New Horizons flew around the colorful dwarf planet for three months and another 1.4 million miles. In the process, as it soared 7,800 miles above the body’s surface, the spacecraft – the first to visit Pluto – was close enough to send back some extraordinary images to Earth.
Ever since Soviet Russia launched its satellite Sputnik 1 into orbit around the Earth in 1957, scientists and dreamers have looked forward to a future where we can explore other planets. The vast distances, of course, present a huge barrier. For example, Pluto is anywhere between 4.67 and 2.66 billion miles from Earth, depending on the point in the orbital cycle.
The New Horizons mission is the initial part of NASA’s New Frontiers project which has so far cost some $700 million. New Frontiers currently has two other projects on the go. New Frontiers 2 is dubbed Juno and it involves a solar-powered spacecraft traveling to Jupiter. Juno’s purpose is to investigate the internal make-up and magnetic fields of the largest planet in the Solar System.
New Frontiers 3 is the OSIRIS-Rex project which plans to send a spacecraft into orbit around the asteroid 101955 Bennu. There is a chance that this asteroid may crash into the Earth towards the end of the 22nd century. So, understandably, NASA would like to know a little more about it. The craft was launched in September 2016 and is scheduled to reach 101955 Bennu in 2020. The plan is to actually land on the asteroid to take samples from its surface. Assuming this is successfully accomplished, the spacecraft should complete its journey back to Earth by 2023.
As well as these three missions currently taking place, a fourth is at the competitive-bidding stage. NASA has proposed six different possible missions for scientific study. These include a possible Moon landing to collect research samples, a probe to visit Saturn’s atmosphere and an unmanned landing on Venus. A competition winner for one of the missions will be announced in 2019, with a projected launch to take place in 2024.
But the strongest current focus for NASA has been the mission to Pluto. And, thanks to the spectacular images beamed back to Earth by New Horizons, the project has attracted much attention from the world’s media. This is hardly surprising, given that the mysteries of Pluto have exercised the human imagination for many years.
But, in fact, Pluto was only discovered as recently as 1930, although the existence of a ninth planet in the Solar System had been posited long before. Businessman and astronomer Percival Lowell had used some of his substantial wealth to set up the Lowell Observatory in Flagstaff, Arizona in 1894. In 1906, Lowell proposed to discover what he called Planet X. Sadly, Lowell died in 1916 before he could see his investment pay off.
Astronomer Clyde Tombaugh was working at the Flagstaff observatory in February 1930 when he discovered the ninth planet through the painstaking analysis of photographs. But there remained the question of giving it a more appropriate name than the somewhat austere Planet X. In a strange twist to the story, its name was actually suggested by an 11-year-old English schoolgirl, Venetia Burney. And there is no connection with the canine Disney character who by an unearthly coincidence happened to appear in the same year as the discovery of Pluto.
But, after more than 60 years as a planet, Pluto suffered the indignity of being downgraded to a mere object in 1992. It was found to be part of the Kuiper Belt, a swirling chaos of space debris. Some charts now started to show Neptune as the furthest planet from the Sun instead of Pluto, which was sometimes omitted altogether. Eventually, the highly respected International Astronomical Union designated Pluto as a dwarf planet.
So what else do we know about Pluto? Firstly, it is really quite small, with a width only about half that of the U.S. landmass. The dwarf planet’s complete orbit around the Sun takes about 248 Earth years. Consequently, one Pluto day equates to about six and a half days on our planet. Pluto has five moons, and the largest, Charon, is about half its size. Nevertheless, there is a lot more for us to discover about the dwarf planet.
Of course, the whole point of NASA’s New Frontiers project is to increase mankind’s knowledge about the Solar System. But once the New Horizons spacecraft had passed Jupiter, it was effectively put on standby. All but the most essential systems on the vessel were put into sleep mode. This was to conserve as much energy as possible for the groundbreaking work it would do when it reached Pluto.
Flying close to Jupiter actually assisted the New Horizons to speed on its way to Pluto. The spacecraft achieved this by utilizing what NASA terms a “slingshot maneuver.” This is when a craft takes advantage of a planet’s gravitational field to increase its velocity. The Jupiter flyby, albeit at some 1.4 million miles distance from the planet, increased New Horizons’ speed to 51,000 mph. Consequently, this slingshot move actually shaved an impressive five to six years off the journey time.
It was in December 2014 that the spacecraft made its final preparations for its flight past Jupiter. In a press release published the following year, Alan Stern, NASA’s principal investigator for New Horizons, spoke about the mission. He said, “Throughout the almost nine-year trip, flight controllers would ‘wake up’ New Horizons once every year to confirm the health of the spacecraft and perform any needed course corrections. It was brought out of its final hibernation period on December 6, 2014 to prepare for the Pluto encounter this summer.”
And so it came to pass, on July 1, 2015, NASA scientists were able to confirm that New Horizons was safely on its way to its rendezvous with Jupiter. This was after a detailed seven-week analysis of any possible obstacles in its planned flight path. With the spacecraft’s speed now at 30,800 mph, even something the size of a grain of rice in its way could have spelled catastrophe.
Then a fortnight later, on July 14, 2015, New Horizons finally began its historic close flight over Pluto’s surface, taking unique images as it passed the dwarf planet. One of the most intriguing phenomenons that New Horizon’s cameras captured were towering columns, hundreds of feet tall, which NASA evocatively described as “resembling giant knife blades of ice.”
In fact, the space agency’s experts were able to offer an explanation for these weird structures. Research scientist Jeffrey Moore, said, “When we realized that bladed terrain consists of tall deposits of methane ice, we asked ourselves why it forms all of these ridges, as opposed to just being big blobs of ice on the ground. It turns out that Pluto undergoes climate variation and sometimes, when Pluto is a little warmer, the methane ice begins to basically ‘evaporate’ away.”
Surprisingly, it turns out that we can see something that’s not too dissimilar on Earth, albeit much smaller in size. These dagger-like ice formations are called penitentes. But they are just a matter of a few feet tall as opposed to the giant structures sighted on Pluto. These earth-bound penitentes can be observed easily on the Chajnantor plain in Chile.
The New Horizons spacecraft successfully transmitted huge amounts of scientific data and images back to Earth. Images showed an extraordinary range of mountains near Pluto’s equator with soaring peaks reaching an altitude of 11,000 feet. And these mountains are young in geological terms, probably only arising about 100 million years ago. This has lead scientists to speculate that they may still be on the move.
But some of the most extraordinary images of Pluto captured by New Horizons were only released in early 2017. A series of 100 stills taken from the spacecraft has been turned into a short video. And the clip creates a stunning sequence of what it would be like to actually land on Pluto’s surface.
So now, thanks to NASA technology, we can visually experience piloting a spaceship into Pluto’s atmosphere and then landing it. But that is not all we have to be thankful to New Horizons for. The Pluto adventure is by no means the end of the spacecraft’s journey. Its mission into deep space continues with a course now set for an object in the Kuiper Belt. The plan is for New Horizon to encounter 2014 MU69 on New Year’s Day 2019 – watch the skies!