NASA’S NEW HORIZONS PROBE IS HEADED TO PLUTO AND THE KUIPER BELT

One of the most amazing things to me, a 51 year old amateur space nut, is that the missions NASA has launched to the planets over the last 40 years have been conducted largely under the radar of press coverage and interest by the American people. This state of affairs will probably be looked on 500 years from now by historians with some measure of astonishment. They will marvel at the fact that mankind’s initial attempts to explore their solar system neighborhood would have been met with a collective yawn by a media that routinely reports every pimple that breaks out on Brittany Spear’s face but can’t find the time or effort to describe the wondrous, almost magical efforts to answer questions that have been asked by humanity since our ancestors were loping effortlessly across the African savannah.

Who are we? Why are we here? Are we alone?

In a very real sense, NASA’s New Horizon’s mission to Pluto and the Kuiper Belt beyond will close the first chapter in our quest to solve some of the most fundamental mysteries of the universe. And the fact that this effort has been given such short shrift by our celebrity-obsessed, trivia reporting media reveals much about our manic efforts to remain ignorant about matters so sublime in their implications for adding to the encyclopedia of human understanding that one could actually question the collective sanity of the human race if not for the fact that there are plenty of examples already.

On January 11, 2006, NASA will launch the New Horizons spacecraft toward an expected rendezvous with Pluto in 2015. While there has been much discussion among scientists in the last year or so about whether or not Pluto is a planet, the mission will conclude mankind’s initial effort to photograph and study all nine bodies we have studied and believed to be planetary bodies for 75 years. Recent evidence suggests that there are other icy, rocky bodies even bey0nd Pluto which will probably continue to call into question Pluto’s nomenclature. If so, the value of going to Pluto will be to study an entirely new class of objects in the solar system, a not insignificant goal in and of itself. One interesting note is that last year, the international astronomical body in charge of classifying objects was ready to yank Pluto’s designation as a planet until tens of thousands of school children wrote letters asking them not to. Just goes to show that even scientists can’t resist the importuning of a child.

Pluto is weird. It’s very small – less than 1/5 the size of Earth – with gravity that’s 2 1/2 times less than on our moon. Speaking of moons, Pluto’s satellite Charon is half the size of it’s mother planet! The two bodies do a strange gravitational dance around each other that scientists are still scratching their heads trying to figure out.

Pluto’s orbit is highly irregular. It careens around the solar system like a drunken sailor, passing inside the orbit of Neptune (thus for a time making Neptune the most distant planet) as well as orbiting in the opposite direction than the rest of the planets.

What makes going to Pluto so exciting is that what we know about that impossibly cold, icy world could be written on a postcard. Even the Hubble Telescope can only resolve Pluto into a barely discernible circular smudge. And one of the weirdest of planetary catastrophes may inhibit our observations – the collapse of Pluto’s atmosphere.

Evidently, the farther Pluto gets from the sun and the colder it gets, atmospheric physicists believe that the mass of the atmosphere will completely freeze and become too heavy to remain above the planet. It will thus drift to the surface of the planet or “collapse” thus not only obscuring the surface from our efforts to photograph it but probably make efforts to measure the atmosphere itself problematic:

Pluto has been racing away from the sun since its closest approach in 1989 and scientists do not know how much time remains before Pluto’s atmosphere collapses. Once that happens its atmosphere is not expected to re-emerge for about 200 years.

“Some people think its 20 years off and some people think its five years off,” said Stern. “No one really knows when Pluto’s atmosphere will snow out and collapse.”

As frigid Pluto grows even colder as it travels further from the sun, scientists believe that more and more of its surface will be cloaked in nitrogen-based snow, accelerating the freezing process that causes the atmosphere to collapse. Stern said the New Horizons team cannot be sure that there will still be an atmosphere to study until less than a year from encounter.

Another aspect of this mission that will set it apart from other planetary missions is speed. The Galileo mission to Jupiter took nearly 4 years of space travel, taking a gigantic elliptical path toward the planet after being launched from earth. And the Cassini probe took more than 6 years to reach Saturn after being launched from earth, going around the sun twice (and getting 2 gravity assists from Venus) before swinging by earth for another gravity assist, on the way to Jupiter for another boost until finally settling into an orbit around Saturn.

Because of its relatively small size – about as big as a grand piano – Horizons will be rocketed toward Pluto using a multi stage booster:

[T]he New Horizons spacecraft, which is about the size of a grand piano, will be lifted into orbit atop a Lockheed Martin Atlas 5 rocket equipped with five solid-rocket boosters, a Centaur upper stage and a special STAR 48B solid propellant-fueled third stage that will propel the spacecraft out of low Earth orbit and toward its destination.

About a year after launch, assuming the spacecraft gets off in time for the gravity assist, New Horizons would encounter Jupiter, snapping pictures, making measurements and picking up speed as it slingshots past the gas giant on an eight-year cruise.

How fast will the probe be going? Faster than any spacecraft that has ever left earth:

When launched on its Atlas V rocket in January, New Horizons will be the fastest spacecraft ever to leave Earth, and that speed is crucial. New Horizons will cross the orbit of the moon in just 9 hours-something that took Apollo spacecraft over three days to accomplish after their launch to a speed of 25,000 miles per hour.

New Horizons will then journey to Jupiter for a gravitational slingshot to further speed the journey to Pluto. Whereas the two most recent missions NASA sent to Jupiter-Galileo and Cassini-took 6 and 4 years, respectively, the much faster New Horizons spacecraft will make its trip to Jupiter in just 13 months.

Four billion miles is a long way to go to snap a few pictures and take some measurements. That’s why once the probe swings within 10,000 kilometers of Pluto it will continue on into the mysterious Kuiper Belt where scientists think we will find leftover elements dating to the very beginning of the solar system. The potential gold mine of scientific information is so rich that the National Academy of Scientists put a mission to the Kuiper Belt as the number one priority for exploration this decade.

Outside of our missions to Mars, public interest in planetary probes of this sort is confined to a few fans like me and the scientific community. What does it say about our culture and perhaps even the state of our educational system that this is so? Is it so difficult to inculcate a sense of wonder and curiosity at the universe in our children that they can grow up oblivious to the stupendous achievement inherent in hurling a spacecraft 4 billion miles into the void and having it arrive on target in order to give us a glimpse of eternity?

Perhaps future generations will have more reverence for the efforts of the scientists and engineers who for nearly half a century have enriched our knowledge of the cosmos almost beyond measure with their single minded determination to explore space. Their achievements will be noted as long as humans are writing history.

And the hell of it is, we are a poorer species collectively by virtually ignoring their accomplishments,