New horizons it is about to reach a very rare space, but do not expect the NASA spacecraft to rest on considerable laurels.
On Saturday night (April 17), New Horizons will arrive 50 astronomical units (AU) from the sun, a distance traveled by only four other operational probes in the history of spaceflight. (An AU is the average Earth-Sun distance – about 93 million miles or 150 million kilometers.)
The landmark is an opportunity to celebrate and appreciate the epic mission of New Horizons, which gave humanity its first close look Pluto in July 2015 and followed with a flyby of Arrokoth, an even more distant world, three and a half years later.
Destination Pluto: NASA’s New Horizons mission in pictures
“When I stop everyone in our days of planning and managing, analyzing data and budgets and all that stuff, stop and think about what we’ve accomplished as a team, it’s really inspiring,” the lead researcher said. of New Horizons, Alan Stern told Space.com. “Sometimes I want to pinch myself.”
But there are plenty of reasons to look both forward and backward, because New Horizons is far from over. Although it has been around for 15 years, the probe remains in perfect health, Stern said, and could continue to study its exotic surroundings for many years to come.
“We have the energy and fuel to continue until the late 2030s,” said Stern, who is based at Southwest Research Institute in Boulder, Colorado. “So we’re about halfway through this mission, in terms of what’s possible from an engineering standpoint.”
New Horizons is powered by a thermoelectric radioisotope generator (RTG), which produces electricity from the heat emitted by the radioactive decay of plutonium-238. The RTGs also powered most of NASA’s other deep space probes, including the four that crossed the 50 AU threshold before New Horizons – Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2.
Pioneer 10 and 11 ceased operations years ago, but the two Voyagers stay active today, more than 40 years after its launch. Both are exploring interstellar space: Voyager 1 is currently about 152 AU from Earth, and Voyager 2 is about 127 AU from us.
A very long journey
The New Horizons journey began three decades ago and is full of twists and turns. Stern and his colleagues began developing a Pluto project in the late 1980s, but the $ 720 million mission did not get official approval until the early 2000s. (For more on the sinuous history of the mission, read the 2018 book of Stern and planetary scientist David Grinspoon, “Pursuing new horizons. “)
New Horizons was launched in January 2006, with the task of performing Pluto’s first flyby. The distant dwarf planet had been mysterious since Clyde Tombaugh discovered it in 1930, appearing only as a blur even in NASA’s best photographs. Hubble Space Telescope could gather.
New Horizons brought its long-awaited flight on July 14, 2015, increasing to a distance of 12,550 km from the cold surface of Pluto. The observations made by the probe during this close encounter turned Pluto from that fuzzy spot into a real place – and Amazingly diverse and interesting place to this, with towering mountains of ice-water, bizarre “paddle land” and a gigantic plain of nitrogen-ice that forms a lobe of a famous “heart” now.
After flying, New Horizons continued to collect data about its surroundings, the ring of cold bodies, at a great distance, beyond the orbit of Neptune, known as Kuiper belt. The probe studied its local environment, observed a series of objects in the Kuiper Belt (KBO) from a distance and, on January 1, 2019, performed the second close flyby, this time with a small KBO.
During the New Year’s Day meeting, New Horizons magnified just 3,040 km from Arrokoth, which is about 1 billion miles (1.6 billion km) beyond Pluto’s orbit. The return of this close encounter, the centerpiece of the probe’s extensive mission, was perhaps even more surprising than Pluto’s data: Arrokoth, 22 miles (36 km) wide, looks like a flattened, reddish snowman with two distinct lobes.
New Horizons observations show that Arrokoth is a clean and primordial object, a planetary block that has remained from the early days of the solar system. And his two lobes were probably distinct objects once, which came together in an easy fusion, mission team members said.
“Both of our main goals have proven to be wonderful scientific countries – beyond the wildest expectations in either case,” Stern said.
Related: Flyby New Horizons’ Arrokoth in pictures
Looking for the number three flyby target
The New Horizons team has already begun searching for another KBO along the spacecraft’s path, using photos captured by powerful instruments such as the Hawaii Subaru Telescope. Stern pointed out that a third struggle is long, given how thin the Kuiper belt is, but he and his colleagues are doing everything they can to increase their chances.
For example, mission team members JJ Kavelaars and Wes Patrick recently began applying machine learning techniques to KBO hunting to study, both remotely and up close.
When the duo “resumed search data from 2020 with their new software tools, not only did it run 100 times faster, but it introduced dozens of new KBOs that human searchers had not found in search images!” Stern wrote in a mission update last month. “We will take advantage of this important new tool again this year, and next year and beyond.”
Even if no suitable flight target appears, New Horizons will have a lot to do in the coming months and years. The probe has already looked at nearly 30 KBOs so far, Stern said, and will study for another three months if everything goes according to plan.
The May campaign will be “another brick in the wall of building a statistically relevant collection of KBOs that we have studied in ways you can only do by being in the Kuiper Belt or by close force. , either because of the different angles at which we see things, “Stern said.” We’re building this database. It’s a legacy. “
New Horizons will do other work. It will continue to gather data about Uranus and Neptune, for example, and still characterizes its environment in the Kuiper Belt, a land that very few wells have explored to date. And as long as it stays healthy and NASA continues to approve the mission’s expansion, New Horizons will teach scientists about the realms beyond the Kuiper Belt, whose outer edge is believed to be about 70 AU from sun.
New Horizons will reach that limit by the end of 2020, Stern said. The spacecraft will likely reach about 100 AU by the end of its power in the late 2030s, consolidating its place in the history of exploration.
“We said we would build a spaceship that could fly over the solar system and explore new worlds,” Stern said. “And I did that and we still do that. But when I say the words – it sounds like science fiction, but I’m not.”
Mike Wall is the author of “There“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for extraterrestrial life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.