By Published: June 1, 2015

Illustration of NASA's New Horizons spacecraft approaching Pluto

NASA’s New Horizons spacecraft is about to become humanity’s first emissary to Pluto. Alan Stern has the insider view.

It’s been a while.

In 2006 Western Union scrapped its telegram service, Twitter was born and a tiny but mighty spacecraft roared away from the Florida coast on a journey of more than 3 billion miles to Pluto and beyond.

Dubbed “The Fastest Spacecraft Ever Launched,” New Horizons reached supersonic speed in 28 seconds, easily escaped Earth’s gravity well and plowed toward Jupiter at 36,000 miles per hour.

PlutoNew Horizons infographic detailing the journey to Pluto.

The spacecraft, about the size of a baby grand piano, would cover half a billion miles in a lickety-split 13 months, intersecting Jupiter’s orbit at a moment when its gravity would slingshot New Horizons forward, accelerating it to 41,000 miles per hour.

Even at these spectacular speeds, New Horizons would need nine years to reach Pluto, the most distant of the traditional planets in Earth’s solar system.

Now the epic journey has reached its final countdown. On July 14 the spacecraft is expected to come closer to Pluto than any Earth emissary has, flying within 7,000 miles of its surface before shooting into the unexplored region known as the Kuiper Belt.

Alan Stern

Alan Stern is chief mission scientist.

“We are going to the frontier of the solar system,” says Alan Stern (PhDAstro’89), chief scientist of the NASA-sponsored mission. “It’s like exploring the Wild West. We will be seeing a new class of planets, and what we are most looking forward to is being surprised.”

In January New Horizon’s imagers and spectrometers began a salvo of operations that will intensify upon approach, focusing on Pluto and its five known moons.

The only one of the craft’s seven major scientific instruments to operate continuously since launch was built at CU-Boulder — by students. The Student Dust Counter (SDC) measures the miniscule building blocks of planets, providing new data on how plants form. It is the first student-built instrument ever to fly on a NASA interplanetary mission.

Together New Horizons’ instruments will provide the most detailed picture ever of a tiny planet that continues to inspire affection despite its hotly debated 2006 demotion to dwarf planet-status.

Scientists are keenly interested in the composition of Pluto’s icy surface and its tenuous atmosphere, which may at times have clouds and winds and appears to experience seasonal changes, including snow, as the planet moves nearer and farther from the sun.

“We really have little sense of what Pluto looks like,” says CU-Boulder planetary scientist Fran Bagenal, a member of the New Horizons science team. “Even with the Hubble Space Telescope, it just looks like a fuzzy blob. But with New Horizons we will get our first detailed glimpse of the surface. We will see whether there are craters, or volcanoes, or frost, or tectonic cracks — or something totally unexpected.”

The first serious plans for a NASA Pluto mission were hatched in May 1989, when Stern, then a CU graduate student, and Bagenal dined in Baltimore with about 10 other scientists, a group that became known as the “Pluto Underground.” The movement gained steam after NASA’s Voyager 2 explored Neptune later that year and sent back breathtaking images of the blue giant’s wondrous rings and moons.

Still, it took more than 15 years before Congress agreed, in 2002, to fund New Horizons.

“We picked ourselves up off the floor six different times and never quit,” says Stern, a former top NASA scientist and now a research executive with the nonprofit Southwest Research Institute (SwRI) in Boulder. “In the end what really sold the mission to NASA was the discovery of the Kuiper Belt in 1992. After we found there was a third zone to our solar system, everyone realized the real importance of Pluto as a new class of planet.”

Scientists are revved up about the Kuiper Belt, which includes the 1,500-mile-wide Pluto (smaller than Earth’s moon) and spans more than a billion miles past Neptune’s orbit. The region is believed to harbor some 70,000 objects more than 60 miles in diameter and billions of comets, each containing material created during our solar system’s formation 4.5 billion years ago.

New Horizons spacecraft launch

The New Horizons spacecraft started its 3-billion-mile trip to Pluto in 2006. It’s almost there. 

Stern, 57, has been involved in 26 different space missions, beginning with suborbital rocket payloads during his CU-Boulder days. He served as administrator of NASA’s Science Mission Directorate in 2007, the same year he was named one of Time magazine’s “100 Most Influential People in the World.” Prior to that, in 1994, he started the Boulder office of the San Antonio-headquartered SwRI, growing it from two to nearly 100 people, including some of the best space science researchers in the world.

A New Orleans native raised in Texas, Stern has flown in F-18 Hornet jets to search for asteroids from the stratosphere, consulted for space entrepreneur Richard Branson’s company, Virgin Galactic, and founded the Golden Spike Company with former NASA Johnson Space Center director Gerry Griffin; their goal is to provide the first commercial space transportation services to the moon.

“I never wanted to be a fireman or policeman as a kid,” says Stern. “All I remember ever wanting to be was a space explorer.”

He was influential in making CU’s Student Dust Counter — a thin plastic film resting on a honeycombed aluminum structure mounted on the outside of the spacecraft — part of the Pluto mission. The instrument assesses each microscopic dust particle that strikes the detector, allowing inference of the mass and possible origin of each.

A revolving cast of more than 20 CU-Boulder undergraduate and graduate students began designing and building it in 2002, according to Professor Mihaly Horanyi of the Laboratory for Atmospheric and Space Physics and chief scientist for the SDC. It was finished in 2005 as New Horizons was being readied for launch. In July, Horanyi says, former team members plan to return to Boulder to share the moment of encounter.

New Horizons’ Colorado connections run deep. Of more than 30 SwRI researchers who helped design its instruments, serve on the science team or are responsible for payload operations, 12 are CU-Boulder alumni.

Lockheed Martin Space Systems of Littleton built the 224-foot Atlas V launch rocket, the only system powerful enough to boost New Horizons to the solar system’s outer planets, as well as its plutonium-powered thermoelectric generator. And Ball Aerospace & Technologies Corp. of Boulder built one of the seven core instruments, named Ralph (after character Ralph Kramden of the 1950s sitcom The Honeymooners); it will help scientists map the surface of Pluto and its moons and assess their compositions.

Johns Hopkins University’s Applied Physics Laboratory designed, built and operates the spacecraft.

Hoping NASA will fund New Horizons for an extended mission after the Pluto encounter, astronomers have used Hubble to identify two Kuiper Belt objects in reach, each measuring about 40 miles across.

As it travels through space, New Horizons bears mementos, including some of astronomer Clyde Tombaugh’s ashes. He discovered Pluto in 1930.

How will it end for New Horizons? It might not, ever.

Astronomers believe that in about 5 billion years, the sun will swell like a balloon and vaporize the inner planets, including Earth. But New Horizons, its fuel spent, will continue cruising through space in a frozen state at about 35,000 miles per hour: Once set in motion, an object in the vacuum of space keeps on trekking.

“Nothing in space will age it or change it substantially,” says Stern. “Think about it: The Earth will be gone, and New Horizons will survive. Pretty amazing.”

Render by Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI); Photography courtesy Southwest Research Institute (portrait); NASA (launch)