How a small piece of glass makes our boldest space missions possible

Cameras built into space orbiters and probes take photographs of nearby celestial bodies in stunning detail. These images, taken in extreme conditions millions of miles from Earth, show us the geographical features of planets, moons, and comets.

But these photos might not exist without a specialty glass lens. Radiation — the constant stream of subatomic particles being emitted from the sun and other planetary bodies — can destroy a camera’s lens. The particles break down the lens’s chemical structure, darkening it over time. Camera systems on orbiters and probes must be protected from this solarization process as they travel to their final destination.

Radiation-resistant glass, doped with cerium oxide, stops solarization and allows these camera systems to capture clear images of planets, moons, and comets. This specialty glass is used in many unmanned space missions currently underway, and it’s aiding scientific discoveries while bringing us close-ups of far-off planets than we’ve never seen before.

Rosetta: Rosetta and its lander, Philae, arrived at comet 67P/Churyumov-Gerasimenko in 2014. Its primary mission was to orbit and photograph the comet and find clues to how the solar system formed, but it also spent time observing how comets change as they orbit the sun due to fluctuating radiation levels. Radiation-resistant glass guarded Rosetta’s on-board cameras and allowed the probe to observe evidence of escaping gases and steam as increased solar radiation heated up the comet’s nucleus, giving scientists more clues into the comet’s makeup.

New Horizons: The New Horizons probe took photos and collected data during a six-month reconnaissance flyby of Pluto and its largest moon, Charon, before tumbling farther into the Kuiper Belt. SCHOTT’s radiation-resistant glass shielded the on-board camera systems from constant radiation during the orbiter’s nine-year journey to Pluto. That protection was critically important because New Horizons was tasked with mapping the planet’s surface during a July 2015 close-up. New Horizons completed this scientific mission and sent high-resolution photos of Pluto’s geological features back to NASA researchers.

Juno: JunoCam, the onboard camera of the Juno probe circling Jupiter, has returned stunning photographs of the solar system’s most massive planet. Protecting JunoCam is radiation-resistant glass, which guards the camera’s sensitive lens against radiation from Jupiter’s powerful magnetic field. The protective glass ensures JunoCam can cleanly photograph the planet’s poles during the mission’s repeated flybys. These images provide NASA scientists with important context about Jupiter’s atmosphere and auroras in conjunction with data from Juno’s other scientific instruments.

OSIRIS-REx: NASA’s OSIRIS-REx orbiter will arrive at Bennu, a comet classified as a Potentially Hazardous Asteroid, in 2018. As the explorer orbits Bennu, it will photograph and analyze the asteroid’s topography and features to find an ideal site for sample collection. Once OSIRIS-REx determines a suitable sample location, it will extend an arm and collect rocks and dust from the comet’s surface for analysis back on Earth. Radiation-resistant glasses will shield OSIRIS-REx’s camera systems as the orbiter travels around the sun, ensuring the cameras accurately detail Bennu’s jagged surface before pinpointing a suitable collection site.

Europa: Though NASA’s Europa mission doesn’t have a launch date yet, we know its mission: Discover if Europa, Jupiter’s smallest Galilean moon, has a liquid water ocean and the ingredients for life. Jupiter’s extreme radiation again poses a challenge for the spacecraft’s equipment, so multiple flybys of Europa will be required to collect the data NASA needs. The Europa Imaging System, protected by SCHOTT-made radiation-resistant glass, will take detailed images of the moon’s geography that will assist scientists in determining if Europa has favorable conditions for life.

Why this glass is mission critical

NASA’s Ranger 7 was the first spacecraft to take pictures in space, giving us an unprecedented view of the moon. Since that 1964 mission, satellites, probes, rovers, and manned missions have beamed photos of the cosmos back to Earth, much to humanity’s delight.

One might forget these photos are vital to each space mission. Together with the data collected by astronauts, rovers, and orbiters, the images allow scientists to map neighboring planets, moons, and comets. A small piece of radiation-resistant glass stops solarization of these camera lenses, even after years of radiation exposure from the sun and other celestial bodies, ensuring photographs are clear.

Because of this glass, cameras can offer a close-up of a planet’s topography and monitor weather patterns on faraway moons. Without these images, our knowledge of many of Earth’s closest planetary neighbors would be incomplete.

May 31, 2017


David Schimmel
Advanced Optics
SCHOTT North America, Inc.