New Horizons is a long, long, long way from home.
Fifteen years after launching from Earth at a record speed and six years since it became the first spacecraft to fly PlutoNASA’s New Horizons is about to reach a kilometer that only four other robotic probes in history have surpassed.
Saturday (April 17) at 20:42 EDT (0042 GMT April 18), The new horizons will reach 50 AU (astronomical units) from the sun – or 50 times the distance between the Earth and the sun. That is 7.5 billion kilometers (4.65 billion miles). At 50 AU, it will take more than 6.5 hours for the signals sent from New Horizons to reach Earth, and that as we travel at the speed of light.
Destination Pluto: NASA’s New Horizons mission in pictures
“I’m just thinking about its enormity,” Alan Stern said. New horizons the lead investigator at the Southwest Research Institute in Boulder, Colorado, said in an interview with collectSPACE.com. “It hasn’t been done in a generation, since Voyagers have traveled these distances and we’re the only spacecraft in the outer heliosphere and the Kuiper Belt.”
Get out there
New Horizons is the fifth farthest spacecraft from Earth.
Pioneer 10, which was launched in 1972 and was the first probe to pass through the asteroid belt and flew from Jupiter, reached 50 AU on September 22, 1990. Today, it is about 129 AU from Earth.
His sister ship, Pioneer 11, reached 50 AU a year later, in 1991. It was launched in 1973 and, in addition to flying by Jupiter, was the first to make direct observations of Saturn. It is now about 105 AU from Earth.
NASA has launched Travel 1 on 5 September 1977, 16 days after the twins, Travel 2. Voyager 1 studied Jupiter and Saturn, while Voyager 2 also encountered Uranus and Neptune. Voyager 1 today is 152 AU from Earth. Voyager 2 is at 127 AU. While Pioneer 10 and Pioneer 11 ceased operations years ago, both Voyagers remain active today.
Pioneers and travelers they are so far away today that none of them is the closest probe to New Horizons. NASA’s Juno spacecraft, orbiting Jupiter, is now closer.
“In the very distant future, we will be so far away from everyone else that we will be closer to travelers and pioneers, but we will never get past them, because three of the four go faster than us,” Stern said. “Right now, we’re almost 100 AU from Voyager 1.”
To highlight how far Voyager 1 traveled, NASA pointed the probe’s camera back at the inner solar system in 1990, when it was about 40.11 AU from Earth. The resulting mosaic image, now known as the “Family Portrait”, captured six planets – Venus, Earth, Jupiter, Saturn, Neptune and Uranus – as just a few pixels of light each.
At 50 AU from the sun, New Horizons could not do the same.
“Mathematics tells us that our room would burn out because we would be facing the sun,” Stern said, noting that even at such a great distance, the sun remains too bright for its long-range reconnaissance imager, which was calibrated for the dimly lit encounter with Pluto. “So we don’t want to do that until we cross the Kuiper Belt in years to come.”
Instead, Stern and his team headed for New Horizons to Voyager 1, marking the first time a Kuiper Belt spacecraft photographed the location of an even more distant spacecraft now traveling through interstellar space.
“Of course, I didn’t see Voyager 1 because it’s too weak, but I imagined the star field,” Stern told collectSPACE. “We looked with the camera at the location of the farthest spacecraft and took a picture of that stellar field from our position in the Kuiper Belt. For me it’s just awful, even if it’s just a picture of stars. . “
“It simply came to our notice then Voyager’s pioneering mission, in addition to marking what we do, “he said.
Voyager at 40:40 photos from NASA’s “Grand Tour” epic mission
Over the hill
More than just a round number stage, reaching 50 AU means that everything New Horizons does exceeds the projected lifespan.
“One of the first things you do when designing a spacecraft is set requirements, and one thing we had to set was the maximum distance we designed the spacecraft to operate,” Stern said. “Now, always build on the margins so you can do better, but we had to have a number, so if we crossed that goal line, we could declare victory – that the spacecraft has met its design goals.” .
“That target line was 50 AU,” Stern said.
New Horizons flew near Pluto, returning the first close look at the world and its months, in July 2015, when the spacecraft was at 39.2 AU from the sun. Then, on New Year’s Day 2019, New Horizons made the farthest flight in history (so far), capturing the first close-up observations of a small object in the Kuiper Belt (“Arrokoth”) at a distance of 43.4 AU from the sun.
“We’re still getting data back from that flyby,” Stern said. “Meanwhile, as we fly over the Kuiper Belt, we do three other things: study the heliosphere, plasma, dust, and gas; we study other Kuiper Belt objects, we know they have more than 30 that we have observed in ways that you cannot take from Earth or from any other spaceship; and we use the Hawaii Subaru telescope, which is one of the largest telescopes in the world, to find new objects in the Kuiper Belt to study and hoping you find a flying target, because we still have fuel in the tank and we are able to do more a flyby. “
The hope is to find another target before New Horizons runs out of power. Although it draws its electricity from a nuclear battery (a radioisotope thermoelectric generator, or RTG), its plutonium supply generates 33 watts less each decade. By the end of the 2030s, when New Horizons will be at or near 100 AU from the sun, the power may be too low to operate.
Even if New Horizons does not reach 100 AU, Stern is impressed by how far the mission has gone and even more by how much he has managed to achieve his team.
“When the Voyagers flew, their crew was 450 people. New Horizons does this on about 50 belly buttons, so about 10 times smaller,” he said.
“When I think about what our team has achieved in these 15 years with a single spacecraft and without reserve, going there to study Pluto for the first time, the Kuiper Belt for the first time and now pass the 50 AU mark where it was designed to be at its maximum distance, it seems to me only science fiction “, said Stern. “I have to pinch that this group of people managed to do this, it’s much bigger than life.”
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