NASA's Jet Propulsion Lab in Pasadena provides 'window' on the universe
By Amanda Jermyn

I recently had an opportunity to visit NASA’s Jet Propulsion Laboratory (JPL), while on a visit to my youngest child, a student at the California Institute of Technology (Caltech) in Pasadena. What began in the 1930’s with a bunch of Caltech students testing rockets they’d built from cheap engine parts has blossomed into NASA’s chief center for the construction and operation of robotic planetary spacecraft.

In 1957, with the Soviet Union’s launch of Sputnik, the first artificial earth orbit spacecraft, the space race was on, spurring the formation of NASA by the USA in 1958. Though it is now a part of NASA, the Jet Propulsion Laboratory predates it by 22 years, and its early work consisted of building rockets and missiles for the military. Now, federally funded but operated by Caltech, it is at the cutting edge of spacecraft technology.

Arriving at the JPL campus at the foot of the San Gabriel Mountains one is immediately aware that this is a secure area, with government issued ID required, as well as prearranged sign-up for an authorized tour. Set on 177 acres, with about 6,000 employees, the Jet Propulsion Laboratory is a unique scientific community with its own police force, complete with NASA insignia and “rover crossing” street signs. Beneath shade umbrellas at an outdoor café employees sip coffee and talk science.

One of the highlights of the tour was a visit to a glassed-in observation deck overlooking a vast “cleanroom” where spacecraft are constructed. With more stringent requirements than a surgeon’s operating room, cleanroom workers go through a rigorous cleansing process involving shoe cleaning and an air shower to remove as much dirt, shed hair, dead skin cells and other detritus as possible. Then, depending on the level of cleanliness required for the current project, they don either a “bunny suit” which covers the whole body or a gown, cap and shoe covers. Automated particle counters constantly monitor the number of microscopic particles in the cleanroom air to make sure that these meet certain requirements. Extraordinary measures are taken to minimize contaminants because the spacecraft being constructed need to operate effectively and reliably in space. If they encounter problems, help is not exactly around the corner. For spacecraft with life-seeking probes, it is particularly important to avoid contaminants from Earth that could be mistaken for signs of extraterrestrial life, and we do not want to contaminate the celestial objects we explore with terrestrial life forms.

Workers in the cleanroom also wear metal wires to ground them so they don’t transmit damaging electrostatic shocks to the sensitive equipment. When not in use, this equipment is further protected by foil covers to prevent shock. For testing the equipment, there is also a cage-like section of the cleanroom that is shielded from stray radio waves that could confound the tests.
The cleanroom we visited is the one where the Mars rover Curiosity was built before its launch in November 2011. JPL also has a full size replica of Curiosity on display, along with a video documenting the “Seven minutes of terror” involved in its successful landing on Mars in August, 2013. On the model of Curiosity I noticed a palette of colors, and discovered that this is used to test the accuracy of the colors of the digital photos taken by the rover. It is important for the colors to be accurate as these help identify the substances analyzed by the rover’s soil-sampling equipment.

Because it would take too long (14 minutes) for instructions from Earth to reach the rover, the spacecraft has a primitive “brain” for navigation, with two built-in eyes providing accurate depth perception. Instead of the solar panels used in previous spacecraft, Curiosity is powered by nuclear batteries so it can last longer and is not dependent on access to the sun, as this can be a problem in dust storms and during the Martian night.

Perhaps most thrilling was my visit to the mission control room where the various spacecraft are tracked. This is the room seen in TV coverage of Curiosity’s successful landing, with jubilant employees and banks of monitors in the background. It is the control center for NASA’s Deep Space Network, the world’s largest and most sensitive scientific telecommunication system. This consists of an international array of giant radio antennas that supports interplanetary spacecraft missions and a few that orbit Earth. These antennas are positioned in California, Spain and Australia, providing constant communication as our planet rotates. Mission control is our major link to exploration beyond our home planet, our window on new images and discoveries that help us understand our universe. As I left the Jet Propulsion Lab I wondered what new ventures its creative minds have in store for us and what new frontiers it has yet to explore.