Cool Jobs: Probing Pluto | Science News for Students

Cool Jobs: Probing Pluto

These scientists and engineers worked together to take New Horizons to the dwarf planet
Feb 16, 2017 — 7:10 am EST
New Horizons, Pluto

An illustration of what the New Horizons spacecraft would have looked like as it was flying past Pluto.

Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

This is one in a series on careers in science, technology, engineering and mathematics made possible with generous support from Arconic Foundation.

July 4, 2015, was supposed to be a routine day at the mission operations center for NASA’s New Horizons spacecraft. After a 9.5-year journey across the solar system, that craft was just 10 days away from flying past Pluto. It would take the first close-up photos of the dwarf planet.

Alice Bowman
Alice Bowman was the Mission Operations Manager, or “MOM,” of the New Horizons spacecraft.

Yet on this U.S. holiday — Independence Day — NASA’s New Horizons crew was suddenly called into work at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Md. A potential crisis had emerged: The spacecraft had fallen silent.

The scientists and engineers met up in the “situation room,” just outside the operations center. Among those in charge was Alice Bowman. She was the project’s “MOM,” or mission operations manager. It would be up to Bowman and her colleagues to find out what made the craft go mute — if they could.

In her off hours, Bowman dives into music. (An accomplished clarinetist and bass fiddle player, she’s partial to bluegrass.) Right now, however, she was all business.

Soft spoken and quietly confident, Bowman is NASA’s first female MOM. She’d had this role since 2002. That’s when she stepped up to shepherd the New Horizons spacecraft through its 4.8-billion-kilometer (3-billion-mile) trek to Pluto. Her team was charged with testing every command before it was radioed to the craft. This made sure that those instructions could be executed safely. It also ensured that every signal transmitted from New Horizons would be recorded back on Earth.

And at 1:55 p.m. East Coast time (ET) on this day, MOM’s baby had stopped broadcasting.

Bowman and her team had no idea if the spacecraft was still alive. They knew there was about a one in 10,000 chance that a piece of space debris had disabled the craft. New Horizons was now moving at 52,300 kilometers per hour (32,500 miles per hour). At that speed, colliding with even something as small as a grain of rice might prove fatal.

Pluto's heart
The New Horizons spacecraft sent back the best pictures ever taken of the Pluto, including this one, which revealed a giant heart-shaped feature on the dwarf planet.

And even if New Horizons was intact, there was no way to be sure that it still would be on July 14. That was when it was due to fly past Pluto. Its one and only shot at exploring the dwarf planet, close up, was a mere 10 days away.

Without a signal from the craft, troubleshooting “is like stabbing in the dark because you don’t have any information at all,” explains Bowman.

Space missions can be full of surprises. So the people charged with pulling off these novel endeavors have to be clever and ready for the unexpected. Here we meet some of those who worked under pressure to ensure that the New Horizons mission achieved its goal — turning Pluto from a distant, fuzzy point of light into a real landscape.

Enlisting some big ears

On that July 4, the team desperately searched for signs the spacecraft was still alive. “You need to let your team work though all the different scenarios and recreate on the ground what’s going on [with the spacecraft],” notes Bowman. “If you don’t fully understand the problem before you start trying to fix it, you can get yourself into deeper trouble.”

One possible explanation for its radio silence was that a glitch that forced New Horizons to switch to its backup computer. In that case, the spacecraft might still be broadcasting, just at a slightly different frequency. To test this idea, MOM and her team quickly contacted NASA’s Deep Space Network.  

That network consists of three large radio dishes (near Barstow, Calif.; Madrid, Spain and Canberra, Australia). These ears on the universe are charged with signaling and listening to spacecraft. The network’s new mission: Search for any broadcasts at the new frequency. Only the Canberra dish was at the right location to listen for it.

Pluto scientists
At Johns Hopkins’ Applied Physics Laboratory, people cheered at the moment when New Horizons flew past Pluto on July 14, 2015. No one would know until hours later, however, whether the craft survived the flyby.
NASA/Bill Ingalls

At 3:11 p.m. ET, a signal from the spacecraft arrived at the mission operations center. The Canberra radio dish had found New Horizons. It was still alive!

But that didn’t end the tension. Indeed, the only sleep Bowman would get for the next two days were 15-minute catnaps on her office floor. (It took those days to make sure the craft could take new commands and transmit images.) But at least for now, MOM knew her spacecraft was safe and its mission to Pluto was still on track.

How this MOM got there

Growing up in Richmond, Va., Bowman had caught the space bug early. She had been fascinated by the Gemini rocket program. This NASA project paved the way for the Apollo missions, which ferried people to the moon.

On July 20, 1969, peeking through her fingers at the images on her family’s black-and-white television set, 8-year-old Bowman, her sister and mother watched astronaut Neil Armstrong land on the moon. “It was scary and neat at the same time,” she recalls.

In college, Bowman studied both chemistry and physics. After graduation, she helped develop anticancer drugs. She also developed solid-state sensors to help astronomers and the military detect infrared radiation — heat. But an interest in satellite operations ultimately brought her to Hopkins’ Applied Physics Laboratory as an engineer. Her first job there was as part of a military-sponsored project to map bright sources of infrared radiation in the sky. The program’s goal was to be able to track the path of possible incoming ballistic missiles.

From that project and others, Bowman learned the importance of teamwork. On New Horizons, she notes, “My calmness comes from the trust I have in all my teammates and the expertise, support and respect we share with and give each other.”

Some of her team had advanced degrees in physics or engineering. But Bowman says she never needed more than her four years of college: “Physics and chemistry was the foundation that enabled me to move into spaceflight operations.”

From puzzles to astronomy

Cathy Olkin was deputy project scientist for the New Horizons mission. As a child, she enjoyed math. Yet in third grade and again in middle school, her math teachers had labeled her as a slow learner or hard to teach. In fact, she was neither. Bored with the standard coursework, Olkin was trying to tackle math puzzles on her own instead of focusing on class. Fortunately, her parents had faith in the girl’s abilities. And two teachers would eventually nurture her love of puzzles. In the end, they turned her frustration into success.

Cathy Olkin
Cathy Olkin was the deputy project scientist for the New Horizons mission to Pluto.
NASA/Aubrey Gemignani

To prove that Olkin could do basic addition and subtraction, her father devised a game for her at the supermarket. If she could figure out how much change her family was due before the supermarket cashier did, she could keep the money. Olkin pocketed cash every time.

As a teen, astronomy was not the only science that intrigued her. Olkin’s interests jumped from rock hound to archaeologist to doctor.

In fact, years before Olkin analyzed the makeup of ice on Pluto, she was collecting rocks on Earth. In fifth grade, she became fascinated with her teacher’s rock tumbler, marveling at how it made the rocks shiny. Soon, she was asking her parents to stop on the side of highways, near construction sites, so she could pick up new rocks.

Around that time, one of her teachers gave Olkin a Petoskey stone. Such rocks are decorated with the hexagonal (six-sided) shape of fossilized coral that are native to her home state of Michigan. She still has that stone.

Although many of Olkin’s interests shifted over time, two always remained: her love of unusual math puzzles and a keen interest in taking things apart. Early on, these interests sometimes risked getting her in trouble. Such as when she dismantled her family’s rotary telephone (these were the days long before touch-tone and cell phones). Her father, a doctor, was on call. He had to have a working phone in case the hospital suddenly called him in on an emergency. (At her mother’s urging, Olkin quickly put the phone back together.)

Although Olkin had intended to follow in dad’s footsteps and become a physician, she chose to attend the Massachusetts Institute of Technology in Cambridge. The university is known for its engineering program. There, “I looked around and saw all these opportunities that I had never fully appreciated,” she says.

“I was more interested in building things than being a doctor,” Olkin says. “So I switched.”

She went on to earn a master’s degree in aerospace engineering from Stanford University in California. After that, Olkin found work on spacecraft navigation at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Planning a path through space for missions like the Saturn-bound Cassini spacecraft fascinated her.

But not quite enough. She went back to school for a PhD in planetary science. While there, she examined the atmosphere of Triton, Neptune’s largest moon. The thin atmosphere of such a distant moon isn’t normally visible, so Olkin and her colleagues relied on a well-known trick to probe it. They used the light of a background star. As that star’s light filters through, it reveals the chemicals in the atmosphere’s gasses.

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Pluto haze
About 20 layers of haze appear in this photo of Pluto and its atmosphere. The haze was imaged using the RALPH Multispectral Visible Imaging Camera on the New Horizons spacecraft.

On to Pluto

Olkin tried to study Pluto’s atmosphere the same way. Alas, no background star happened to pass behind the dwarf planet during her studies.

Then, in 2004, after taking a break from research to care for her two young children, she joined the Southwest Research Institute in Boulder, Colo. This research center was designing the New Horizons Pluto probe. Olkin’s diverse experience — in designing instruments, planning orbital navigation and planetary science — paid off.  So did her drive to excel.

Blue haze Pluto
New Horizons’ Ralph system used infrared light to capture this blue ring depicting haze around Pluto. That haze appears to be a photochemical smog created when sunlight drives reactions between methane and other molecules.

She began working on a New Horizons instrument called Ralph. This telescope makes images of objects in both visible light and longer, infrared wavelengths. Before long, Olkin started taking on more assignments. “When people do good work, people ask them to do more,” she notes. “I never actually imagined that I would be doing all the different things [on the mission] that I am doing now.”

By 2015, Olkin had spent 8 years as part of a three-person team that turned the wish list of scientists working with the spacecraft’s seven instruments into a coordinated plan to spy on Pluto as closely and deeply as possible. They decided which observations to make and in what order so that they could get the most data possible during the brief flyby.

Olkin also helped figure out at what distance the craft should fly past Pluto. Get too close and the images would lack the global view that scientists wanted. Stay too far back and the images would lack detail. Her team even helped choose which side of Pluto to fly past. They chose the “face” that was known to be brightest in carbon-dioxide ice. It seemed easiest to image. Its rocky makeup also seemed likely to be the most interesting.

“It was dumb luck that [that face] had this large, heart-shaped glacier,” says Olkin. However, she notes that her team had always suspected that side of Pluto would prove intriguing.

Hands-on science

Mark Holdridge was manager of the mission’s encounter with Pluto. Like Olkin, he began tinkering at an early age. He grew up in rural Highland, Md. His father, an electrical engineer, had tried to interest the boy in that line of work. But “I needed something more visual,” Holdridge says. He found it next door — in his neighbor’s tool shed. It had been converted from an old barnyard. The boy became a frequent and welcome visitor, learning to use the drill press and other tools to work on his own projects.

Mark Holdridge
Long before Mark Holdridge worked on NASA missions, he tinkered in his neighbor’s tool shed.
Matthew Stoss

A workbench his father bought him one Christmas — made from a long door and four legs — became his muse for building, woodworking and general tinkering. Working on his own, without supervision, “I was lucky I didn’t burn the house down,” he now says.

In college and graduate school, Holdridge pursued aerospace engineering. Still, he found himself more drawn to the space side of things. And harkening back to those tinkering days, he found he preferred working on things that were “more hands on.” He says, “I think that’s probably why I do flight operations.” Why? These do not involve theory so much as working with concrete objects.

In the late 1990s, Holdridge managed operations for NASA’s first mission to orbit an asteroid. There had been friction between managers and engineers on this mission, known as NEAR. (NEAR stands for Near Earth Asteroid Rendezvous.) But Holdridge ultimately got the groups to trust each other.

There was also drama aboard the spacecraft. Its main thruster failed to fire in late December 1998. That left the craft in danger of never reaching the asteroid it was supposed to orbit (named 433 Eros). A successful firing 11 days later brought the craft back on track. It not only orbited the space rock for an entire Earth year but also landed on it. That was a bonus — something the craft had not even been designed to do.

NEAR’s success jump-started Holdridge’s career. It also paved the way for his work with New Horizons. But there’s a world of difference between managing a visit to a near-Earth asteroid versus an object on the edge of the solar system.

“Deep space is unforgiving,” he notes. Adding to the challenges was the 9-hour-long delay in round-trip communication between Earth and a very distant spacecraft.

“Whenever we were going to do a maneuver, I was always preparing for the worst and hoping for the best,” he recalls. “My fear,” Holdridge says, “was that there was going to be some huge unknown error.”

And then there are the anxieties, he adds. After working on something important for 15 years, he says you realize “you’ve got only one chance to get it right. “

But his team did get it right. After traveling nearly a decade (some 300 million seconds) to the solar system’s fringes, New Horizons arrived at Pluto right on time. Well, almost. New Horizons actually arrived 1 minute, 28 seconds earlier than planned.

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New Horizons women teammembers
Women accounted for roughly one in four of the workers on NASA’s New Horizon’s mission to Pluto. Coralie Jackman is seen kneeling second from right. Cathy Olkin is standing, eighth from left; Alice Bowman stands on the end at right.

Learning on the job

Holdridge, Bowman and Olkin held many jobs before joining New Horizons. Not Coralie Jackman. One of the youngest members of the team, she joined just out of college, more than five years ago. As an optical navigations specialist, this engineer helped make sure the craft stays on course.

She works at KinetX Aerospace in Simi Valley, Calif. Until a year before the flyby, the spacecraft was too far away from the dwarf planet to image the body in sufficient detail. Pluto scientists needed other ways to monitor their target. So for her first three years on the job, Jackman used computers to model the exact location of the center of the Pluto system (which includes one large moon and four far smaller ones in addition to Pluto).

Friends on other engineering projects would typically see results within months of starting. Jackman would have to wait years. By the spring of 2015, the craft began recording images of the dwarf planet that were sharper than those taken by the Hubble Space Telescope. Nearly every day, an image of Pluto would arrive that was sharper than one from the day before. What had been a faint point of light was turning into a world sculpted by ice.

These pictures proved critical for refining the distance between the craft and Pluto. They helped determine if and when New Horizon’s thrusters would need to be fired to keep the spacecraft on course.

What steered her to this career?

Until she entered high school outside Chicago, Ill., Jackman had wanted to become an archaeologist. But in 2004 she was captivated by an image taken by the upgraded Hubble Space Telescope. Called the Hubble Ultra Deep Field, this photo provided the sharpest and most distant view of galaxies in the universe. They revealed what the cosmos looked like only a few hundred million years after its birth.

Coralie Jackman
Coralie Jackman, one of the youngest members of the New Horizons mission.
Courtesy of Susan Mumm/University of Illinois at Urbana-Champaign

“Just seeing the photograph really got me interested in space,” she says. “I kind of dove right in.”

As a teen, Jackman threw annual star parties. She’d set up telescopes at her school to observe the heavens. “I wanted to share what I loved,” she says. A high school teacher also encouraged her to apply for an internship at Chicago’s Adler Planetarium, the nation’s oldest. And she succeeded. For two summers she tracked comets and asteroids at the Yerkes Observatory, two hours away in Williams Bay, Wisc.

By college, Jackman knew she wanted to work on a space mission. But she also knew she did not want to spend 10 years in school, studying to get a PhD. The teen figured that becoming an engineer was a faster route to joining a space mission. She focused on spacecraft navigation, she recalls, “because it straddles the line between engineering and science.”

When she later applied for a job at KinetX, her prospective boss reviewed all that she’d done since high school. He told the young woman that it looked like she’d been training her whole life to be a navigator. In fact, she says, “I had just followed what I thought was interesting.” Now, while continuing to work at KinetX, she’s earning a master’s degree in aerospace engineering.

NOTE: Story corrected for an initial error in the reported speed of New Horizons when it went quiet.

Power Words

(more about Power Words)

atmosphere     The envelope of gases surrounding Earth or another planet.

ballistic missile     A missile whose flight path cannot be altered after it has burned up its fuel.

broadcast     To cast — or send out — something over a relatively large distance.

carbon dioxide (or CO2)     A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter (including fossil fuels like oil or gas) is burned. Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

Cassini     A space probe sent by NASA to explore the planet Saturn. Cassini was launched from Earth in 1997. It reached Saturn in late 2004. The craft included a variety of instruments meant to study Saturn’s moons, rings, magnetic field and atmosphere.

chemical     A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.

chemistry     The field of science that deals with the composition, structure and properties of substances and how they interact with one another. Chemists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances. (about compounds) The term is used to refer to the recipe of a compound, the way it’s produced or some of its properties. People who work in this field are known as chemists.

colleague     Someone who works with another; a co-worker or team member.

comet     A celestial object consisting of a nucleus of ice and dust. When a comet passes near the sun, gas and dust vaporize off the comet’s surface, creating its trailing “tail.”

concrete     To be solid and real.

cosmos     (adj. cosmic) A term that refers to the universe and everything within it.

debris     Scattered fragments, typically of trash or of something that has been destroyed. Space debris, for instance, includes the wreckage of defunct satellites and spacecraft.

dwarf planet     One of the solar system’s small celestial objects. Like a true planet, it orbits the sun. However, dwarf planets are too small to qualify as true planets. Prime examples of these objects: Pluto and Ceres.

electrical engineer     An engineer who designs, builds or analyzes electrical equipment.

engineer     A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

frequency     The number of times a specified periodic phenomenon occurs within a specified time interval. (In physics) The number of wavelengths that occurs over a particular interval of time.

galaxy    A massive group of stars bound together by gravity. Galaxies, which each typically include between 10 million and 100 trillion stars, also include clouds of gas, dust and the remnants of exploded stars.

glacier     A slow-moving river of ice hundreds or thousands of meters deep. Glaciers are found in mountain valleys and also form parts of ice sheets.

graduate school     A university program that offers advanced degrees, such as a Master’s or PhD degree. It’s called graduate school because it is started only after someone has already graduated from college (usually with a four-year degree).

high school     A designation for grades nine through twelve in the U.S. system of compulsory public education. High-school graduates may apply to colleges for further, advanced education.

internship     A training program where students learn advanced professional skills by working alongside experts. People who participate in these training programs are called interns. Some intern in medicine, others in the sciences, journalism or business.

maneuver     To put something in a desired or necessary position by using one or more skilled movements or procedures.

master’s degree     A university graduate degree for advanced study, usually requiring a year or two of work, for people who have already graduated from college.

middle school     A designation for grades six through eight in the U.S. educational system. It comes immediately prior to high school. Some school systems break their age groups slightly different, including sixth grade as part of elementary school and then referring to grades seven and eight as “junior” high school.

model     A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes.

moon     The natural satellite of any planet.

NASA     Short for the National Aeronautics and Space Administration. Created in 1958, this U.S. agency has become a leader in space research and in stimulating public interest in space exploration. It was through NASA that the United States sent people into orbit and ultimately to the moon. It has also sent research craft to study planets and other celestial objects in our solar system.

Neptune     The furthest planet from the sun in our solar system. It is the fourth largest planet in the solar system.

network     A group of interconnected people or things.

observatory     (in astronomy) The building or structure (such as a satellite) that houses one or more telescopes.

optical     An adjective that refers to light or vision.

orbit     The curved path of a celestial object or spacecraft around a star, planet or moon. One complete circuit around a celestial body.

PhD     (also known as a doctorate) A type of advanced degree offered by universities — typically after five or six years of study — for work that creates new knowledge. People qualify to begin this type of graduate study only after having first completed a college degree (a program that typically takes four years of study).

physics     The scientific study of the nature and properties of matter and energy. Classical physics is an explanation of the nature and properties of matter and energy that relies on descriptions such as Newton’s laws of motion. Quantum physics, a field of study that emerged later, is a more accurate way of explaining the motions and behavior of matter. A scientist who works in that field is known as a physicist.

planet     A celestial object that orbits a star, is big enough for gravity to have squashed it into a roundish ball and it must have cleared other objects out of the way in its orbital neighborhood. To accomplish the third feat, it must be big enough to pull neighboring objects into the planet itself or to sling-shot them around the planet and off into outer space. Astronomers of the International Astronomical Union (IAU) created this three-part scientific definition of a planet in August 2006 to determine Pluto’s status. Based on that definition, IAU ruled that Pluto did not qualify. The solar system now includes eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

planetary science     The science of planets other than Earth.

Pluto     A dwarf planet that is located in the Kuiper Belt, just beyond Neptune. Pluto is the tenth largest object orbiting the sun.

pressure     Force applied uniformly over a surface, measured as force per unit of area.

propulsion     The act or process of driving something forward, using a force. For instance, jet engines are one type of propulsion for keeping airplanes aloft.

radiation     (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.

radio     To send and receive radio waves; or the device that receives these transmissions.

rocket     Something propelled into the air or through space, sometimes as a weapon of war. A rocket usually is lofted by the release of exhaust gases as some fuel burns. (v.) Something that flings into space at high speed as if fueled by combustion.

satellite     A moon orbiting a planet or a vehicle or other manufactured object that orbits some celestial body in space.

Saturn     The sixth planet out from the sun in our solar system. One of the four gas giants, this planet takes 10.7 hours to rotate (completing a day) and 29 Earth years to complete one orbit of the sun. It has at least 53 known moons and 9 more candidates awaiting confirmation. But what most distinguishes this planet is the broad and flat plane of seven rings that orbit it.

scenario     An imagined situation of how events or conditions might play out.

solar system     The eight major planets and their moons in orbit around the sun, together with smaller bodies in the form of dwarf planets, asteroids, meteoroids and comets.

star     The basic building block from which galaxies are made. Stars develop when gravity compacts clouds of gas. When they become dense enough to sustain nuclear-fusion reactions, stars will emit light and sometimes other forms of electromagnetic radiation. The sun is our closest star.

technology     The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

telescope     Usually a light-collecting instrument that makes distant objects appear nearer through the use of lenses or a combination of curved mirrors and lenses. Some, however, collect radio emissions (energy from a different portion of the electromagnetic spectrum) through a network of antennas.

theory     (in science) A description of some aspect of the natural world based on extensive observations, tests and reason. A theory can also be a way of organizing a broad body of knowledge that applies in a broad range of circumstances to explain what will happen. Unlike the common definition of theory, a theory in science is not just a hunch. Ideas or conclusions that are based on a theory — and not yet on firm data or observations — are referred to as theoretical . Scientists who use mathematics and/or existing data to project what might happen in new situations are known as theorists.

thruster     An engine that pushes or drives with force by expelling a jet of fluid, gas or stream of particles.

universe     The entire cosmos: All things that exist throughout space and time. It has been expanding since its formation during an event known as the Big Bang, some 13.8 billion years ago (give or take a few hundred million years).

wavelength     The distance between one peak and the next in a series of waves, or the distance between one trough and the next. Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light. Longer-wavelength radiation includes infrared light, microwaves and radio waves.


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