Donnerstag, 5. November 2015 - 17:45 Uhr

Raumfahrt - New Horizons Raumsonde nimmt Kurs auf 2014 MU69 im Kuiper-Gürtel



New Horizons has sped past the Pluto system and is now on its way to its next target in the Kuiper Belt, 2014 MU69. Image Credit: NASA/JHUAPL/SwRI
After having completed its successful encounter with Pluto and its moons last July, the New Horizons spacecraft is now setting its sights on its next target much farther out in the Kuiper Belt: a tiny rocky world called 2014 MU69, which is less than 30 miles in diameter and orbits nearly 1 billion miles past Pluto, in the far outer reaches of the Solar System.
According to a report today by the Associated Press, New Horizons fired its thrusters for the first in a series of course-correction changes this afternoon. Four such maneuvers will be needed altogether over the next two weeks. Flight controllers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., sent commands to the spacecraft in advance for the course change.
2014 MU69, also known as Potential Target 1 (PT1), was first spotted by the Hubble Space Telescope in 2014 and was chosen from a group of candidates as being the best target since it will take less fuel to get there. While much smaller than Pluto, about 1 percent the size and one-ten-thousandth the mass, it is thought to be 10 times larger and 1,000 times more massive than an average comet. The mission team hopes to get closer than the distance that the spacecraft came to during the flyby of Pluto.
Diagram of the path of New Horizons towards its next target, a Kupier Belt object called 2014 MU69 (nicknamed “PT1” for “Potential Target 1”). Image Credit: NASA/JHUAPL/SwRI/Alex Parker
2014 MU69 represents the kind of rocky objects left over from the early formation of the Solar System. They are similar to main belt asteroids but are colder and better preserved, remaining virtually unchanged over billions of years. This provides scientists with a unique opportunity to study such ancient, primordial relics of our Solar System’s birth. It was recommended by the 2003 National Academy of Sciences’ Planetary Decadal Survey (“New Frontiers in the Solar System”) that this first mission to the Kuiper Belt should include flybys of both Pluto and other KBOs in order to maximize the science return.
According to New Horizons Principal Investigator Alan Stern: “2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by. Moreover, this KBO costs less fuel to reach (than other candidate targets), leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen.”
New Horizons is scheduled to arrive at 2014 MU69 on Jan. 1, 2019. The rocky object will then be the furthest world ever seen up close in our Solar System.
Image from the Hubble Space Telescope of 2014 MU69, which was discovered on June 26, 2014. The object’s movement is circles as it crosses a field of background stars. Image Credit: NASA
“Although this flyby probably won’t be as dramatic as the exploration of Pluto we just completed,” according to Stern, “it will be a record-setter for the most distant exploration of an object ever made.”
“There’s so much that we can learn from close-up spacecraft observations that we’ll never learn from Earth, as the Pluto flyby demonstrated so spectacularly,” said New Horizons science team member John Spencer, of the Southwest Research Institute (SwRI) in Boulder, Colo. “The detailed images and other data that New Horizons could obtain from a KBO flyby will revolutionize our understanding of the Kuiper Belt and KBOs.”
The Kuiper Belt was named after Gerard Kuiper, who first theorized its existence. Over 1,000 KBOs have been identified so far, including Pluto, but many more are also expected to be discovered.
New Horizons has sent back an incredible amount of data from the Pluto system, including stunning images and science discoveries which will revolutionize our understanding of this small world. As reported previously on AmericaSpace, the first science results have now been published in the journal Science and were the cover story for the Oct. 16, 2015, issue.
The first images of Pluto’s tiny moon Kerberos were also just released today, completing the “family portrait” of Pluto’s five known moons. Kerberos appears to be smaller and more reflective than scientists had expected.
“Once again, the Pluto system has surprised us,” said New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Our predictions were nearly spot-on for the other small moons, but not for Kerberos,” added New Horizons co-investigator Mark Showalter, of the SETI Institute in Mountain View, Calif.
The moon has a double-lobed shape, with the larger lobe approximately 5 miles (8 kilometers) across and the smaller lobe approximately 3 miles (5 kilometers) across. The reflectivity suggests that Kerberos is coated with water ice, similar to the other small Plutonian moons.
The first 3-D images of Pluto’s surface have also now been released; the images now make global stereo mapping of Pluto’s surface possible, and require red/blue stereo glasses to view.
Once thought to be a relatively inactive world, being so bitterly cold and far from the Sun, Pluto has been shown to be more geologically active than anticipated, with mountains of solid water ice, canyons, unusual pits, and large, slowly moving glaciers of nitrogen, methane, and carbon monoxide ices. The thin nitrogen atmosphere also glows blue when seen backlit by the Sun, not too different from what we see on Earth.
“The New Horizons mission completes our initial reconnaissance of the Solar System, giving humanity our first look at this fascinating world and its system of moons,” said Jim Green, director of planetary science at NASA Headquarters in Washington. “New Horizons is not only writing the textbook on the Pluto system, it’s serving to inspire current and future generations to keep exploring – to keep searching for what’s beyond the next hill.”
New Horizons is currently 3.1 billion miles (5 billion kilometers) from Earth. Data from the flyby will continue to be sent back to Earth for about another year.
New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Ala. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.
Quelle: AS
Update: 5.11.2015
NASA’s New Horizons Completes Record-Setting Kuiper Belt Targeting Maneuvers
NASA’s New Horizons spacecraft has successfully performed the last in a series of four targeting maneuvers that set it on course for a potential January 2019 encounter with 2014 MU69. This ancient body in the Kuiper Belt is more than a billion miles beyond Pluto; New Horizons will explore it if NASA approves an extended mission.
Getting the data: Following the last in a series of four maneuvers targeting NASA's New Horizons spacecraft toward Kuiper Belt object 2014 MU69, flight controller George Lawrence monitors spacecraft data as it streams into the New Horizons Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory on Nov. 4, 2015.
The four propulsive maneuvers were the most distant trajectory corrections ever performed by any spacecraft. The fourth maneuver, programmed into the spacecraft’s computers and executed with New Horizons’ hydrazine-fueled thrusters, started at approximately 1:15 p.m. EST on Wednesday, Nov. 4, and lasted just under 20 minutes. Spacecraft operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, began receiving data through NASA’s Deep Space Network just before 7 p.m. EST on Wednesday indicating the final targeting maneuver went as planned.
The maneuvers didn’t speed or slow the spacecraft as much as they “pushed” New Horizons sideways, giving it a 57 meter per second (128 mile per hour) nudge toward the Kuiper Belt object (KBO). That’s enough to allow New Horizons to intercept MU69 in just over three years. 
"This is another milestone in the life of an already successful mission that's returning exciting new data every day," said Curt Niebur, New Horizons program scientist at NASA Headquarters in Washington. "These course adjustments preserve the option of studying an even more distant object in the future, as New Horizons continues its remarkable journey."
Path to a KBO: Projected route of NASA’s New Horizons spacecraft toward 2014 MU69, which orbits in the Kuiper Belt about 1 billion miles beyond Pluto. Planets are shown in their positions on Jan. 1, 2019, when New Horizons is projected to reach the small Kuiper Belt object. NASA must approve an extended mission for New Horizons to study the ancient KBO.
The New Horizons team will submit a formal proposal to NASA for the extended mission to 2014 MU69 in early 2016. The science team hopes to explore even closer to MU69 than New Horizons came to Pluto on July 14, which was approximately 7,750 miles (12,500 kilometers).
“New Horizons is healthy and now on course to make the first exploration of a building block of small planets like Pluto, and we’re excited to propose its exploration to NASA,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI), Boulder, Colorado.
The KBO targeting maneuvers were the mission’s largest and longest, and carried out in a succession faster than any sequence of previous New Horizons engine burns. They were also accurate, performing almost exactly as they were designed and setting New Horizons on the course mission designers predicted. “The performance of each maneuver was spot on,” said APL’s Gabe Rogers, New Horizons spacecraft systems engineer and guidance and control lead.  
The first three maneuvers were carried out on Oct. 22, 25 and 28. At the time of the Nov. 4 maneuver, New Horizons, speeding toward deeper space at more than 32,000 miles per hour, was approximately 84 million miles (135 million kilometers) beyond Pluto and nearly 3.2 billion miles (about 5.1 billion kilometers) from Earth. The spacecraft is currently 895 million miles (1.44 billion kilometers) from MU69. All systems remain healthy and the spacecraft continues to transmit data stored on its digital recorders from its flight through the Pluto system in July. 
Quelle: NASA

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