Page 26 - EngineerIt January 2021

SPACE TECHNOLOGY

are incorporated into young planetary
systems. This will help them understand
how common planetary systems like ours
are throughout the cosmos.
Multiple mission partners are beginning
construction on various hardware and
software components for SPHEREx. The
telescope that will collect near-infrared light
will be built by Ball Aerospace in Boulder,
Colorado. The infrared cameras that
capture the light will be built by JPL and
Caltech (which manages JPL for NASA).
JPL will also build the sun shields that will
keep the telescope and cameras cool,
while Ball will build the spacecraft bus,
which houses such subsystems as the
power supply and communications
equipment. The software that will manage
reality. Usually, the review is done in-person, but with COVID-19 safety the mission data and make it accessible to scientists
precautions in place, the team had to adjust their presentation to a new format. around the world is being built at IPAC, a science and
"It felt like we were producing a movie," said Beth Fabinsky, data centre for astrophysics and planetary science at
SPHEREx's deputy project manager at JPL. "There was just a lot of Caltech. Critical ground support hardware for testing
thought put into the production value, like making sure the animations we the instruments will be built by the Korea Astronomy
wanted to show would work over limited bandwidth." and Space Science Institute (KASI), a science partner
on the mission in Daejeon, South Korea.
THREE KEY QUESTIONS The SPHEREx team is scheduled to spend 29
Inflation months building the mission components before entering
The SPHEREx science team has three overarching goals. The first is to look for the next mission phase, when those components will
evidence of something that might have happened less than a billionth of a be brought together, tested and launched. n
billionth of a second after the big bang. In that split second, space itself may
have rapidly expanded in a process scientists call inflation. Such sudden Watch video here: https://youtu.be/KHQINJoW6jc
ballooning would have influenced the distribution of matter in the cosmos, and
evidence of that influence would still be around today. With SPHEREx,
scientists will map the position of billions of galaxies across the universe The spectro-photometer for the History of the
relative to one another, looking for statistical patterns caused by inflation. The Universe, Epoch of Reionisation and Ices Explorer
patterns could help scientists understand the physics that drove the expansion. (SPHEREx) mission is a planned two-year mission
One way to test the theory of inflation is to measure the imprint of funded at $242 million (not including launch costs).
inflationary ripples on the large-scale structure (LSS) of galaxies. SPHEREx SPHEREx will survey the sky in optical as well as near-
will probe the statistical distribution of inflationary ripples by measuring the infrared light which, though not visible to the human
large-scale 3D distribution of galaxies. It will achieve this by measuring eye, serves as a powerful tool for answering cosmic
galaxy redshifts over a large cosmological volume at low redshifts. questions. Astronomers will use the mission to gather
data on more than 300 million galaxies, as well as
History of galaxy formation more than 100 million stars in our own Milky Way.
The second goal is to study the history of galaxy formation, starting with the SPHEREx will survey hundreds of millions of
first stars to ignite after the big bang and extending to present-day galaxies. galaxies near and far, some so distant their light has
SPHEREx will do this by studying the faint glow created by all the galaxies in taken 10 billion years to reach Earth. In the Milky
the universe. The glow, which is the reason the night sky is not perfectly dark, Way, the mission will search for water and organic
varies through space because galaxies cluster together. By making maps in molecules - essentials for life, as we know it, in
many colours, SPHEREx scientists can work out how the light was produced stellar nurseries, regions where stars are born from
over time and start to uncover how the first galaxies initially formed stars. gas and dust, as well as disks around stars where new
planets could be forming.
Building blocks of life on Earth Every six months, SPHEREx will survey the entire
Thirdly, scientists will use the SPHEREx map to look for water ice and frozen sky using technologies adapted from Earth satellites
organic molecules - the building blocks of life on Earth - around newly and interplanetary spacecraft. The mission will
forming stars in our galaxy. Water ice gloms onto dust grains in cold, dense create a map of the entire sky in 96 different colour
gas clouds throughout the galaxy. Young stars form inside these clouds, bands, far exceeding the colour resolution of
and planets form from disks of leftover material around those stars. Ices in previous all-sky maps. It also will identify targets for
these disks could seed planets with water and other organic molecules. In more detailed study by future missions, such as
fact, the water in Earth's oceans most likely began as interstellar ice. NASA's James Webb Space Telescope and Wide Field
Scientists want to know how frequently life-sustaining materials like water Infrared Survey Telescope. n

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