An epic 10-year, 3-billion-mile journey from Cape Canaveral to the rim of the solar system is almost halfway complete, and in 2015, NASA's New Horizons spacecraft will allow us to lay eyes directly on the mysterious, beloved Pluto for the first time.
"Every time that we go to a new kind of place, we find out stuff that just blows our minds," said planetary scientist Alan Stern of the Southwest Research Institute, leader of the New Horizons Mission.
When the spacecraft launched in 2006, NASA called it the beginning of "an unprecedented journey of exploration to the ninth planet in the solar system." Of course, after Pluto's official demotion from planet to dwarf planet, the mission can no longer claim to be exploring the final planet frontier. But regardless of the controversy, Pluto remains an intriguing object that astronomers and the public alike can't wait to learn more about.
And after conducting the first in-depth, close-up study of Pluto and its moon Charon, the unmanned spaceship will venture even further into the Kuiper Belt, a vast strip of icy objects that sit just outside of Neptune's orbit, roughly 50 astronomical units from the Sun.
"When Pluto was first discovered in 1930, it just looked like an oddball," Stern said. "We had the four rocky, terrestrial planets and the four big gas giants, and then we had this odd thing Pluto."
But with the discovery of the Kuiper Belt in the 1990s, scientists discovered that the small, icy orb was hardly unique. "We found out that there are a lot of Plutos," Stern said. "In fact, it's the dominant class of planets in the solar system. This transformed our view not only of the solar system, but also of the importance of sending a spacecraft to Pluto. We realized that we had never sent a spacecraft to the most common type of planet."
In 2001, a special committee from the National Academy of Sciences met to advise NASA on its 10-year goals for planetary exploration, and the group picked exploration of the Kuiper Belt, including Pluto and Charon, as its highest scientific priority.
Part of the motivation for exploring the Kuiper Belt was the recognition of just how little we know about this cold, dark region at the fringe of our solar system. Late last month, an astronomer from Queen's University in Belfast reported the existence of a red spot on the surface of Haumea, one of the largest and weirdest objects in the Kuiper Belt. Scientists guess the mysterious crimson streak is either evidence of a recent collision or a gas leak coming from Haumea's hot interior. Either way, it's the first time astronomers have observed this kind of surface detail on an object in the Kuiper Belt.
By sending a spacecraft to Pluto, we'll get much closer look. Stern expects that the most exciting result of our mission to the Kuiper Belt will be something that we can't possibly predict ahead of time. "No one expected Venus to be the poisonous hell that it is, or Mars to have the river valleys that it does," he said.
But launching an unmanned spacecraft on a 3-billion mile journey to a planet with a surface temperature of -387 degrees Fahrenheit is no easy task. Initially, the New Horizons engineers were also racing against the clock: By getting a gravity kick from Jupiter, the spacecraft could shave three years off its total mission time. But to get this slingshot boost, New Horizons had to launch right on time — being just a few days late could have extended the 10-year mission to more than 13 years.
"It was a horse race to make that launch," Stern said. Remarkably, everything went without a hitch, and in February 2007, New Horizons got the necessary push from our solar system's biggest planet, snapping a few beautiful pictures of the red giant along the way.
Currently, New Horizons is midway through its eight-year "interplanetary cruise" from Jupiter to Pluto. During most of this trek, the spacecraft is in hibernation mode, with all but the most critical electric equipment turned off to conserve energy. During these periods of "sleep," New Horizons is powered by a single radioisotope thermoelectric generator and uses less power than a pair of 100-watt household light bulbs.
Once a year for about 50 days, the spacecraft turns back on for a checkup and recalibration. So far, Stern says, NASA engineers have had to do very little in the way of trouble-shooting. "You know, it's amazing," he said. "Everything on the spacecraft works, and we're not using any backup systems. We've had some software glitches and put up some software patches, and there are some differences in the way we run it compared to how we expected to run it. But overall, we are right on course and right on schedule."
Once New Horizons reaches Pluto, she'll use her seven different scientific instruments to map the surface of the dwarf planet and characterize its unique atmosphere, which is thought to contain trace amounts of carbon monoxide and methane gases. All data collected by the spacecraft will get beamed back to Earth using a radio transmitter and an 83-inch diameter radio antenna.
"It will take months to get it all home, and I’m sure it will take years to digest it all," Stern said. "But we will likely have great pictures and other kinds of data sets even on the first day."
Of course, that first day isn't for another five and a half years — a long time to wait if you're one of the eager Plutophiles who wants to see your favorite dwarf restored to its former planet status.
For Stern, however, 2015 seems right around the corner. "I've already been waiting since 1989," he said, "so five and a half years sounds like we're almost there."
*Images: **1) Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute. 2) *NASA/JHU/APL. 3) The New Horizons mission bumper sticker/APL.
See Also:
- Dwarf Planet Rebranding Contest
- Pluto 2015: Journey to the Rim of the Solar System
- Underdog Planet: Why We Love Pluto
- Dwarf Planet Eris Proven to be More Massive than Pluto
- Pluto Probe's Jupiter Flyby Found Moon, Planetary Surprises
- 'New Horizons' Captures Stunning Images of Jupiter and Moons
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