Pelletier lives in Quebec City. His job is to plot a course for NASA's New Horizons space probe, currently en route to Pluto. After a voyage that's taken nine years, and covered almost seven billion kilometres, the probe is scheduled to make its closest approach to Pluto on July 14.
Pelletier worked for NASA for 10 years. Then he joined KinetX, a private company looking to get a foothold outside the U.S. He moved his family back to his hometown, and has continued to explore space from there.
The company's current mission — navigating NASA's New Horizons — is going further into space than any manmade craft has ever been. Pelletier is in the driver's seat, but drawing the map as he goes.
He spoke to Quebec AM on Friday about his work.
Pelletier and his team have to plot the probe's trajectory through space.
The territory is uncharted, so navigating is a constantly evolving process. New Horizons sends back data daily, which allows the navigators to determine its position and predict where it should go.
But Pelletier says when the spacecraft turns to take pictures, there are constantly forces pushing it around — forces the team has to measure and account for in targeting New Horizons' course.
Unlocking the mysteries of the solar system
NASA launched New Horizons in 2006, with the aim of capturing the first close-up images of Pluto.
The dwarf planet is part of the Kuiper Belt, an asteroid belt at the very edge of the solar system. Pluto's position could allow scientists to better understand the beginnings of the system.
They also want to know more about the dwarf planet's moons and its atmosphere.
New Horizons has already offered scientists first-ever glimpses of Pluto from a distance. On Tuesday, July 14 at around 8 a.m. ET, the probe will make its closest approach, coming within 12,500 kilometers of Pluto — within the orbit of the planet's largest moon, Charon.
Pelletier says the trajectory won't bring the spacecraft too close to the surface.
"At that point you may see very cool surface features, but you miss a lot of the big picture. We need to make sure we can observe Charon and the other moons," he says.
Don't blink or you'll miss it
Between now and July 14, Pelletier's team has one key element that still needs to be determined.
Scientists currently have a two-dimensional portrait of Pluto. What's left to figure out is the radius distance of Pluto from the sun — the depth of its position in the solar system.
It's a dimension that's never been observed from Earth and can only come from a side view. That will only be available in the last week before New Horizons passes closest to Pluto. When the team has that view, that sequence of observations will be uploaded to the spacecraft and the order given for the exact time the probe should take its pictures.
Then, the navigators' work will be done. They'll be at mission control at Johns Hopkins University in Maryland, waiting for those images to be beamed home.
With the sheer quantity of data that has to be uploaded, the team isn't always conscious of just how groundbreaking their work is. But Pelletier says they take a moment every day to step back.
"We always have a daily tag-up with the whole team… and they always show us the Pluto-of-the-day picture and every day it gets bigger and more interesting and at those moments we say, 'Oh wow. This is really cool. This is why I do this job.'"Suggest a correction