July 10, 2015 – After a nine-year journey of 3 billion miles, a piano-sized, power-packed NASA spacecraft has an upcoming date with history that some University of Colorado Boulder students, faculty and alumni wouldn’t miss for the world. Tuesday, July 14, is the day the New Horizons spacecraft will whip by Pluto and become the first ever spacecraft to visit perhaps the dwarf planet.
A team of CU-Boulder students designed, built and tested the Student Dust Counter (SDC) for the mission to measure dust particles along the way — remnants of collisions between solar system bodies — making it the first student built and operated instrument ever to fly on a NASA planetary mission.
“We have waited a long time for this,” said CU-Boulder physics Professor Mihaly Horanyi of the Laboratory for Atmospheric and Space Physics (LASP) and a New Horizons co-investigator.
The SDC is the only one of the seven instruments aboard New Horizons that has been collecting data since launch. From 2002 to 2005 Horanyi shepherded a revolving group of about 20 students as they developed the dust counter, which is helping researchers learn more about the origin and evolution of our solar system and the formation of planets from dusty disks around other stars.
Doctoral student Jamey Szalay, one of two students currently on the SDC science team, came to CU-Boulder in 2010 when New Horizons was screaming nearly a million miles a day between the orbits of Saturn and Uranus.
“I’m thrilled to be a be a part of this mission,” Szalay said. “Since launch we have been flying through the disk of the solar system, learning about its structure and how planets push dust around.”
The dust counter is a thin plastic film resting on a honeycombed aluminum structure the size of a cake pan mounted on the spacecraft’s exterior. A small electronic box inside the spacecraft functions as the instrument’s “brain” to assess each individual dust particle that strikes the detector. The tiny dust grains hitting the dust counter create unique electrical signals, allowing the students to infer the mass of each particle.
“This mission will complete the first reconnaissance of our solar system and will reshape our understanding of the region where Pluto resides,” said CU-Boulder doctoral student Marcus Piquette, a member of the SDC science team.
CU-Boulder Professor Fran Bagenal, a mission co-investigator, leads the New Horizons Particles and Plasma Team. Bagenal was a member of the original “Pluto Underground” — a small, dogged band of planetary scientists who began lobbying NASA in 1989 for a Pluto mission. The Pluto Underground also included then-CU-Boulder doctoral student Alan Stern, who now leads the New Horizons mission from the Southwest Research Institute’s Planetary Science Directorate in Boulder.
Bagenal, a faculty member in the Department of Astrophysical and Planetary Sciences and LASP affiliate, said the interactions of the solar wind with Pluto’s tenuous atmosphere, which is leaking into space, is of high interest.
“It’s clear that when Pluto’s orbit takes it closer to the sun, like it is today, the atmosphere is escaping like crazy,” she said.
Scientists don’t yet know what happens to Pluto’s atmosphere when the dwarf planet moves further from the sun, since a single solar orbit takes 248 years.
Bagenal and her colleagues also want to learn more about why Pluto and some other objects in the Kuiper Belt — a region spanning more than a billion miles past Neptune’s orbit and believed to harbor thousands of moon-sized objects and billions of comets — seem to have a reddish hue.
“It could be that energetic solar particles and cosmic rays are causing chemical reactions on the planet’s surface, turning the methane ice on Pluto’s surface to a reddish-brown gunk,” she said.
The CU-Boulder scientists and students involved in New Horizons are at Johns Hopkins University’s Applied Physics Laboratory (APL) in Baltimore for the Pluto encounter. APL designed, built and operates the mission and manages it for NASA.
In addition to the dust counter, the New Horizons instrument suite includes two cameras, two imaging spectrometers and two particle spectrometers to gather data on the surfaces, atmospheres and temperatures of Pluto, its five moons and several Kuiper Belt objects.
“We really have little sense of what Pluto looks like,” said Bagenal. “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. I think we are in for a good ride, and it’s going to be lots of fun.”
“The flyby also is an emotional capstone for all the students who worked on SDC,” said Horanyi. “They have moved on to have families and kids and busy lives, but I know that all of them will closely follow the encounter, and remember their contributions with tremendous pride. The encounter is a landmark event along the way to explore the outskirts of the solar system, even beyond Pluto, for possibly decades to come.”
Stern, who earned his doctorate from CU-Boulder’s astrophysical and planetary sciences department in 1989, advises Pluto fans to cinch it up for July 14, which is Bastille Day in France. “That is the day we will storm the gates of the Kuiper Belt,” he said.