SCIENCE
How Aluminium Brought Us The Best-Ever Images of Pluto
Aluminium designed cameras withstands the harshest conditions of deep space to deliver groundbreaking images of our solar systems most distant "dwarf planet"
November 23, 2015
NASA's New Horizons space probe, launched back in January 2006, made international headlines in July when it sent back the clearest images of Pluto mankind has ever seen.
The New Horizons probe is the first to ever travel so far out into our solar system, and the photos of Pluto it has sent back are sure to be a point of reference for decades to come. Traveling into such deep space presents unprecedented challenges, including both radiation and thermal fluctuations. How, then, did NASA build an onboard camera durable enough to survive these hazards and capture such breathtaking pictures?
Simple: by building it almost entirely out of aluminium.
Simple: by building it almost entirely out of aluminium.
Deep Space camera that captured the Pluto images by Google Images
One of three cameras built into New Horizons, "Ralph" is a Multispectral Visible Imaging Camera (MVIC) which captured the sepia-toned images of Pluto released in July. With three panchromatic (black and white) and four color imagers, the camera and Ralph's other component parts (including a short-wavelength infrared spectrometer and eight detectors) run on less wattage than a light bulb.
Building "Ralph" to survive in deep space, however, required NASA engineers to build the device out of a material that would suffer only minimal shrinkage in the frigid cold of deep space. By building the camera's key components out of aluminium, the team ensured they would shrink at the same rate. Engineer Lisa Hardaway, who led its development, explains:
Building "Ralph" to survive in deep space, however, required NASA engineers to build the device out of a material that would suffer only minimal shrinkage in the frigid cold of deep space. By building the camera's key components out of aluminium, the team ensured they would shrink at the same rate. Engineer Lisa Hardaway, who led its development, explains:
" We actually built the mirrors and the chassis out of aluminium so that as they shrink, they would shrink together, to maintain the same focal length. We could do a reasonable test on Earth and still expect the same quality image."
Lisa Hardaway
Engineer, Ball Aerospace
How did her team manage to transform dull aluminium into mirrors? By polishing it with diamonds.
In addition to drastic temperature changes in space, the engineering team behind "Ralph" successfully overcame a host of other challenges. Flying so far from the sun, New Horizons had to be able to capture Pluto using only the faint amount of light reflecting off one of its moons. To get the best results, the team built Ralph for the exact light conditions present on that side of Pluto other than that, the camera isn't adjustable.
To save space and energy on the craft, the "Ralph" team was asked to make the camera as light and as energy-efficient as possible. They responded to the challenge, building a camera that weighed less than 23 pounds and uses only seven watts of electricity. By building such a lightweight device, the team freed up valuable space for more fuel aboard New Horizons, adding years to the spacecraft's working life.
To save space and energy on the craft, the "Ralph" team was asked to make the camera as light and as energy-efficient as possible. They responded to the challenge, building a camera that weighed less than 23 pounds and uses only seven watts of electricity. By building such a lightweight device, the team freed up valuable space for more fuel aboard New Horizons, adding years to the spacecraft's working life.
Excited NASA team celebrating receiving the first Pluto images by Google Images
Now that it has brought Pluto to Earth, what's next for the New Horizons craft? With NASA's approval, the probe is set to push further out into the solar system and explore the Kuiper belt. With enough plutonium fuel to last into the late 2020s, New Horizons may have more incredible discoveries in store.