Chasing New Horizons: Inside Humankind's First Mission to Pluto

by Alan Stern

To stay in touch, New Horizons depends, as do all long-distance spacecraft, on a largely unknown and unsung marvel of planetary exploration: NASA’s Deep Space Network. This trio of giant radio-dish complexes in Goldstone, California; Madrid, Spain; and Canberra, Australia, seamlessly hands off communication duties between one another as the Earth rotates on its axis every twenty-four hours. The three stations are spread around the world so that no matter where an object is in deep space, at any time at least one of the antenna complexes can point in its direction.

There is a phrase from World War I describing warfare as “months of boredom punctuated by moments of terror.” The same applies to long spacecraft missions.

Finally, sure of their find, on March 13, 1930, which was both the 149th anniversary of the discovery of Uranus and what would have been Percival Lowell’s 75th birthday, they announced their discovery. In no time at all, the sensational news spread around the world. The New York Times ran the banner headline: NINTH PLANET FOUND AT EDGE OF SOLAR SYSTEM: FIRST FOUND IN 84 YEARS, and the story was run by countless other papers and radio broadcasts.

Pluto takes 248 years to make it just once around the Sun.

Pluto turned out to be only about 1/400th the mass of Earth. Rather than being another giant like Neptune, it was a tinier planet than any previously discovered.

In 1950 Kuiper had proposed that the process of accretion (the building of larger objects from smaller ones), which originally formed the Earth and other planets, should have left behind a huge number of “planetesimals,” or small building blocks of planets, out beyond the outermost of giant planets, Neptune.

Beginning in 1992, planetary scientists began to find KBOs—and thus Pluto’s cohort!

The RTG and the plutonium dioxide then met for testing at DOE’s Idaho National Lab, a fortified defense lab replete with tanks, barbed wire, control towers, and heavily armed guards who follow visitors everywhere, even to the bathroom. Once the RTG was tested, it was shipped to Florida in a manner befitting a spy story. DOE and NASA sent it cross-country to Cape Kennedy in a covert but heavily armed convoy; in fact, DOE sent multiple convoys to the Cape—all but one containing decoy RTGs—to make it even harder for anyone trying to sabotage or pilfer the plutonium.

Someone brought me over to that bonfire and told me what was up. The Atlas team had a tradition of burning all the now-obsolete emergency contingency procedures books after a successful launch. The team gave me the honor of throwing the last of them into the flames, which I did—with gusto! That Atlas team bonfire was the coolest post-launch tradition I’d seen in a long while.