[Music]
The Lucy spacecraft will be taking a journey
where no other spacecraft has gone before: The Trojan asteroids.
The Trojans are two groups of asteroids that lead and trail Jupiter
in its orbit around the sun –
and they’ve been trapped in these stable locations
for over four billion years.
Lucy will have a suite of scientific instruments for collecting data
as it flies by the asteroids.
L’LORRI is a long range reconnaissance imager.
It’s often referred to as Lucy’s eagle eyes
since it has the highest spatial resolution of all of Lucy’s cameras.
This black-and-white camera is actually a type of telescope,
the same kind as the Hubble Space Telescope.
L’LORRI was built to produce clear images of the Trojans’ craters,
which will be a challenge since the Trojan asteroids
are extremely dark.
L’LORRI will be able to see 75-yard-wide craters
from over 600 miles away.
That’s like standing at one end of a football field
and being able to see a fly at the other end!
The instrument’s simple design does not use optical filters
and includes no moving parts,
reducing the risk of part failure during the mission.
L’LORRI will also search the Trojans for evidence of any rings
and new satellites.
The instrument's ability to see faint targets from far away
also makes it perfect for optical navigation.
L’LORRI will help Lucy navigate to a point in space,
and then a terminal tracking camera aboard the spacecraft,
known as T2Cam, will help the instruments
accurately point toward the targets.
L’TES is Lucy’s thermal emission spectrometer
which detects far infrared radiation emitted by the asteroids
due to how they are heated up by sunlight.
L’TES detects this radiation using a small telescope
to focus the incoming energy onto a detector –
similar to the way a remote thermometer works.
So, L’TES is not taking images, but rather,
temperature measurements at various points on the asteroid.
This data will be combined so that scientists can get an
understanding of its surface properties.
L’TES will examine the properties of the regolith on the surface
by measuring thermal inertia, which is the measure of how slowly
the asteroid heats up from sunlight and then releases that heat.
By taking the temperature readings
at different parts of the asteroid,
the Lucy science team can measure the thermal inertia
and figure out how much dust, sand or rock
is present on the asteroid’s surface.
That data will tell us a lot about how the asteroid was formed,
providing insight into the history of our solar system.
Lucy’s L’Ralph instrument will search the Trojans
for organics, ices, and hydrated minerals, and will help determine
the surface compositions of the asteroids.
L’Ralph is actually two instruments in one
and together they will measure and analyze
the spectra of light absorbed and reflected by the asteroid.
The first is a color visible imager -
the Multi-spectral Visible Imaging Camera or MVIC.
It takes visible light color images of the Trojan asteroids.
The second is an infrared imaging spectrometer known as LEISA -
the Linear Etalon Imaging Spectral Array -
which collects infrared spectra of the asteroids.
Like L’LORRI, L’Ralph does not have a focusing mechanism.
Instead, it is designed to stay in focus
despite the extreme temperature differences in space
by being made almost entirely from a single block of aluminum.
Using one material throughout the instrument means that
if a part expands or contracts,
the other parts will expand or contract at the same rate,
helping to keep L’Ralph in focus.
Even the mirrors are made of aluminum
finely polished with diamond dust.
Due to the massive size of the images L’Ralph will be taking,
the instrument will have around 256 gigabits of onboard memory.
And while the L’Ralph instrument aboard Lucy does require
substantially more power than its predecessors on other spacecraft,
it still will not use more energy than your average ceiling fan.
In addition to these three main science instruments,
other experiments aboard the spacecraft will help fulfill the mission.
Lucy will use its High Gain Antenna to communicate with Earth
for an additional radio science experiment
to determine the masses of the asteroid targets.
Lucy will also be able to use its two terminal tracking cameras,
or T2CAM, to track the asteroids during the flybys,
keep them in the field of view, and to take wide-field images
so that we can better determine their shapes,
and perhaps discover new asteroids nearby.
As you can see, the Lucy spacecraft has a large suite of tools
to study the Trojan asteroids, which will help us better understand
the formation of our solar system.