Monday, July 13, 2015

On the Aptly-Named New Horizons Mission to Pluto

You gotta have a badass mission patch
Tomorrow, for a very brief few minutes, a probe that was launched from earth nine years ago will fly by Pluto at 31,000 miles per hour, coming within 8000 miles of the former planet. It will record images and data all along the approach and departure, and then return this data across a 3 billion mile chasm of space at a data rate of about 1 kilobit per second. For a year after the momentary close approach we will continue to receive information about the only major body in our solar system we have never seen in any detail before.

The science is not that remarkable.

New Horizons was designed in 2001 and constructed between 2003 and its launch in January of 2006. The technology that was used was mature at the time - in a probe like this one, only robust, well-understood and highly reliable systems can be used - essentially 20 years old at the time of the flyby.

The instrument package consists of:

LORRI - The Long Range Reconnaissance Imager - a high resolution camera with a 1024x1024 CCD and a resolution of approximately 1 arc-second.

SWAP - Solar Wind At Pluto -  one of the two instruments comprising New Horizons‍ '​ Plasma and high-energy particle spectrometer suite (PAM), SWAP measures particles up to 6.5KeV

PEPSSI - Pluto Energetic Particle Spectrometer Science Investigation - the other component of the PAM, PEPSSI measures higher energy particles than SWAP

Alice - An ultraviolet imaging spectrometer, Alice will help analyze Pluto's atmospheric composition

Ralph - Another camera, Ralph includes both a multispectral (color) visible light imager and a near-infrared imaging spectrometer

SDC - The Student Dust Counter - this instrument has been operating all throughout the mission, measuring the interplanetary dust levels. It will provide the first measurements of dust in the Kuiper Belt ever. This instrument was built by students at the University of Colorado Boulder.

REX - The Radio Science Experiment - a transmitter that will use New Horizon's communication systems to send a signal through the atmosphere of Pluto and Charon, to be received and analyzed by radio telescopes on earth.

The engineering is incredible.

The orbital dynamics are impressive. A mission travelling 3 billion miles over 9 years with a very precise gravitational boost from Jupiter, aimed at a point not just in space, but in time - a very specific point in three-space that will, at that precise moment, also be occupied by Pluto. The margin for error is so small it's difficult to even calculate. You'll hear repeatedly that that New Horizons is the fastest space probe ever launched - that's only partially true. It is the spacecraft with the fastest launch - it left earth orbit at 37,000 miles per hour and passed the lunar orbit in 9 hours. But the fastest spacecraft is Voyager 1, now leaving the confines of our solar system at 17 Kilometers per second.

The meaning is profound.

This is real science. We'll be learning things we didn't know, not just about Pluto and its moons, but then about the region outside Pluto's orbit, the Kuiper Belt. This is a region populated by icy chunks of the original primordial 'stuff' that formed the solar system five billion years ago. This is the material that drifts around in vast reaches of interstellar space until some gravitational perturbation starts pulling it all into a disc. This is our best chance to understand our own actual creation story. But it is so much more than that.

Set aside whether Pluto is a planet, a dwarf planet or something else altogether. This is the last completely unexplored, unobserved body in our solar system. And beyond that lies more, much more, of the great unknown. For all their bloodthirsty brutality, humans have always, from the very beginning, been driven by a need to know. What's over the next ridge, whats across the ocean, what's at the edge of the solar system. It is the one thing that makes our species noble, and special. It is the one thing that truly does unite us. Curiosity, the willingness to take great risks to learn, and the ability to make that knowledge meaningful and useful.

And tomorrow we're going to Pluto.


  1. Leah Crane ‏@DownhereonEarth 44s44 seconds ago

    If Pluto was 2 light-years farther away, it would take 2 more years for light from there to reach us. #LazyPlutoFacts
    This is why I get all my news from twitter now.