“Chasing New Horizons” Gets to the Heart of Mysterious Pluto

By Douglas Messier
Managing Editor

Chasing New Horizons: Insider the Epic First Mission to Pluto
by Alan Stern and David Grinspoon
Picador, 2018
hardcover, 320 pp., illus.
ISBN 978-1-250-09896-2
US$28.00

As America celebrated Independence Day on July 4, 2015, many members of the Johns Hopkins University Applied Physics Laboratory (APL) team that had guiding NASA’s New Horizons spacecraft toward the first ever exploration of Pluto took a little time off to relax before their lives became very busy.

After a 9.5-year long journey, the spacecraft was only 10 days out from its closest approach to the mysterious dwarf planet. All the secrets Pluto had kept hidden for 85 years since Clyde Tombaugh discovered in 1930 were about to be revealed.

And then the unthinkable happened. Controllers suddenly lost contact with the spacecraft as they were loading the final software needed to guide it through week-long flyby sequence set to begin in only three days. When communications were restored, controllers discovered to its horror that the program and all the supporting files they had spent months uploading had been wiped from the spacecraft’s computer.

Working around the clock — many in summer clothes and flip flops they had worn to barbecues and other holiday events, team members managed to reload all the software with four hours to spare. The subsequent flyby went precisely as planned, returning a bountiful harvest of data about Pluto and its five moons that will keep scientists busy for many years to come.

The successful mission is the subject of an excellent new book, Chasing New Horizons: Inside the Epic First Mission to Pluto, written by the mission’s principal investigator, Alan Stern, and science journalist David Grinspoon. The book provides a fly-on-the-wall, insider’s account of what turned out to be a decades-long effort to explore that distant and mysterious world.

NASA had originally planned to flyby Pluto in 1986 as part of the grand tour of the outer Solar System conducted by the Voyager 1 and Voyager 2 spacecraft. However, the space agency decided to send Voyager 1 on a close flyby of Saturn’s cloud shrouded moon, Titan. The required trajectory sent the spacecraft out the plane of the ecliptic and precluded a flyby of Pluto. Voyager 2 went on to fly by Uranus and Neptune on a trajectory that also made exploring Pluto impossible.

It was in 1988 that Stern, while still in graduate school, began pondering how to send a dedicated mission to explore the distant, mysterious world. In the years that followed, he would gather a group of like-minded scientists to advocate for NASA to launch a mission.

It would take nearly 18 years before New Horizons was launched from Cape Canaveral in January 2006. That period would be filled with reversals, changing priorities and budgets, and two mission cancelations.

I found this section of the book really fascinating. It’s one thing to see the spectacular images beamed back by NASA’s missions to Pluto, Mars, Ceres and other distant worlds. But, Stern and Grinspoon provide an interesting account of exactly how NASA goes about choosing these missions and how one gets built.

The story features a David vs. Goliath battle between the venerable Jet Propulsion Laboratory (JPL), which is NASA’s premiere center for planetary missions, and Johns Hopkins APL, a smaller player with no experience in outer planetary missions before New Horizons.

Both laboratories wooed Stern with offers to become the principal investigator for proposals they would submit to NASA. However, JPL planned to submit multiple proposals to the space agency, meaning Stern might not have the pick of the center’s best talent and might lose to another of the center’s teams. APL committed to submitting one proposal and backing it with all the resources it could muster.

Stern gambled on APL – and won. On Nov. 29, 2001, Stern got the phone call from NASA that they had gotten the nod. Thirteen years of effort had paid off.

But, in a case of beware what you wish for, APL had a comparatively short period of time – just over four years — to design, build and launch a complex spacecraft. And the team had a budget adjusted for inflation much lower than what NASA had allocated for the Voyager missions decades earlier.

The authors do a good job of recounting how APL designed, built and operated New Horizons in ways that saved weight, power, money and time. They used heritage instruments and systems – which had been proven on previous space missions – where they could.

New Horizons would spend most of its 9.5-year journey to Pluto in hibernation with most of its systems turned off. This move conserved the limited power of its nuclear generator for the encountered with Pluto and reduced the size of the mission control team during most of the flight.

In order to save weight, power and money, the spacecraft’s communications systems transmitted at 10-times-lower bit rates at Pluto than Voyager 2 had when it flew past Neptune in 1989. It would take APL more than a year to get all the data back from New Horizons following the Pluto flyby.

There were additional political battles to fight. Stern was gob smacked when in February 2002, President George W. Bush’s proposed budget for NASA zeroed out the New Horizons mission because of cost overruns.

It was unbelievable. NASA had approved the mission less than three months earlier, and APL didn’t even have a formal contract yet. How could they have overspent money NASA hadn’t even allocated?

Although the money was restored, the cancellation reflected a lack of support for and confidence in the mission at NASA Headquarters. There was even an effort to install JPL, which had lost the mission to Stern and his team, as the mission’s manager for NASA.

In the end, a neutral party — NASA’s Marshall Space Flight Center in Alabama — was selected to manage the mission. This proved to be a god sent. A brash young Marshall engineer named Todd May helped to get the New Horizons mission on track and proved instrumental to its success.

Finally, on Jan. 19, 2006, New Horizons blasted off aboard an Atlas V booster from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. After nearly two decades of effort, the spacecraft was on its way to explore Pluto.

The book sags a bit after New Horizons is sent on its way. There are chapters describing what the team was doing during the 9.5 year voyage to Pluto, which included a gravity-assist flyby of Jupiter.

Reading this section, I felt like a little kid on a long car trip to Disney World. Are we there yet? How much longer ’til we get there? When will we get to Orlando? There just wasn’t that much drama until the Fourth of July anomaly.

The images New Horizons beamed back once it arrived at Pluto startled planetary scientists and laymen alike. It looks like someone had assembled the world from spare parts left over from other planets. Terrain with a reddish hue brushed up against a massive frozen region shaped like a heart. Other parts of the planet were covered in shades of yellow and blue.

“Ground fogs, high-altitude hazes, possible clouds, canyons, towering mountains, faults, polar ice caps, apparent dune fields, suspected ice volcanoes, evidence for free-flowing (and even standing) liquids in the past, and more. The little red planet perched 3 billion miles away in the Kuiper Belt packed more punch than any other known small world explored, and indeed more punch than many much larger worlds,” the authors wrote in an appendix describing the mission’s top 10 scientific discoveries.

New Horizons also sent back the first close-up pictures of Pluto’s large moon, Charon, and four smaller satellites – Hydra, Mix, Styx and Kerberos. Scientists found evidents that Charon might once have had a large, interior ocean beneath its surface.

I finished the book wishing New Horizons and the authors had lingered longer at Pluto. The appendix with the mission’s top discoveries is nice, but I would really have liked to learn more about this bizarre little world.

Perhaps that will be the subject of a sequel. In the meantime, this volume is an excellent contribution to the library of planetary exploration books that tells the story of Stern and others who lived the mission. It is well worth a read.

  • There are serious discussions already underway about returning to Pluto with an orbiter.