One special keynote address at Sensors Expo ‘19 featured Allison Barto, a senior program manager at Ball Aerospace who dazzled listeners with the story of the building of NASA's James Webb Space Telescope.
The Webb telescope is set to launch into space in 2021 to explore the depths of the universe. It will allow a look back, potentially, 13 billion years in time to the creation of the first galaxies.
Barto described to a room full of seasoned engineers how the 22-foot wide mirror in the reflector-type telescope will be the largest and most powerful space telescope ever built. It includes a tennis-court sized sunshield that will unfold once outside of Earth’s orbit.
She explained that years of testing in sub-zero labs have been needed to make sure temperature changes and the violent rocking of the launch don’t damage the mirror or lead to blurred images. That mirror is made up of 18 different sections, each weighing 500 pounds, which will be positioned and focused in space without the assistance of astronauts.
The material used to make the mirrors is beryllium, a silvery white metal that was mined in Utah. It took five years to compress the material and shape it properly to allow the mirror to focus. Beryllium was chosen because of its resistance to warping in the cold conditions of space.
After her talk, Barto was surrounded by engineers, nearly all men, who were obviously impressed by the mirror testing process and the complex nanometer-size electronics involved. She revealed that some of the electrical testing components had to be soldered by hand instead of by machine after technicians were specially trained to do the work.
In all, her role in the work on the Webb project has lasted 17 years. “I love it,” she said of the work, her eyes glistening. The audience listened adoringly like groupies at a rock concert.
Some of the slides Barto used to describe her work were pictures of galaxies taken by the Hubble telescope, now 29 years old. Without Hubble, scientists might not have confirmed many concepts we now accept about the universe, including the existence of black holes at the centers of galaxies.
When Galileo first used a telescope 400 years ago, he rocked the worlds of science and religion by proving Earth was not the center of the universe, she reminded the audience. With modern telescopes, science will be able to look at far more of the electromagnetic spectrum beyond visible light, including UV, infrared, gamma ray and x-ray.
The idea of placing telescopes outside Earth’s distorting atmosphere emerged in the 1940s. In 1946, theoretical physicist and astronomer Lyman Spitzer created a drawing showing an astronaut in a spacewalking suit assembling the panels of an enormous telescope in space. In reality, astronauts have seldom assembled satellites in space, a notable exception being the repairs made to the Hubble Space Telescope. Instead, most satellites unpack and configure themselves under command of ground controllers.
Space telescope technology has made discoveries possible that many doubted would ever be revealed. Engineers had to invent 10 new technologies just to test the components used in creating the Webb telescope.
“Never say never to a scientist or engineer,” Bartow said.