NASA begins preparation to launch its Lucy mission in October: Here’s all you need to know

NASA is starting preparations to launch a new mission to the stars… or to the asteroids, to be exact.

The mission – named Lucy – will for the first time explore Trojan asteroids that share an orbit with the planet Jupiter and are leftovers of our early solar system. These small asteroids form two ‘swarms’ of asteroids, with some at the front and others behind Jupiter while it orbits the Sun. These orbits are grouped around Lagrange Places, which are stable points of gravitational equilibrium.

Artist's concept of Lucy spacecraft at Trojan asteroid. Image credit: NASA

Artist’s concept of Lucy spacecraft at Trojan asteroid. Image credit: NASA

“The Trojan Asteroids are leftovers from the early days of our solar system, effectively the fossils of planet formation,” said scientist Hal Levison.

Currently, the spacecraft is in a cleanroom in NASA’s Kennedy Space Center (KSC) in Florida, after arriving on Friday, 30 July. The spacecraft will be prepared, tested and fueled before it is launched.

Seven years in the making, this spacecraft will launch from Cape Canaveral Space Force Station. It has a 23-day launch period that begins from 16 October.

The spacecraft has been designed and built by Lockheed Martin Space at its facility in Littleton, Colorado.

“It takes a lot of coordination and careful planning to get this spacecraft to its launch site, and I’m very proud of the team who worked so tirelessly through a global pandemic to get us to this moment,” said Rich Lipe, Lucy program manager at Lockheed Martin.

About the mission

Lucy is the 13th mission in NASA’s Discovery Program. This program first began in 1992, and it gives NASA scientists and engineers the chance to form teams and develop interesting planetary research missions. They all aim to expand our understanding of the solar system.

Psyche is another asteroid mission, part of the Discovery program, that NASA is working on. A spacecraft will travel to 16 Psyche, which is a giant, metal-rich asteroid.

The mission gets its name from the 3.2-million-year-old ape fossil found in 1974, in Ethiopia. It was the first Australopithecus afarensis skeleton ever found, though only about 40 percent of the skeleton is complete. Lucy was a hominid and her bones show evidence of her being a bipedal locomotion, or having the ability to walk upright.

The Lucy spacecraft will be no more than 14 metres long. It has massive solar panels that will power the spaceship as it flies out to Jupiter’s orbit. Each panel is over seven metres in diameter. The much smaller spacecraft body will house all of the equipment, as well as the two-metre, high-strength antenna required for communication with Earth.

The official patch of the Lucy mission. Image credit: NASA

The official patch of the Lucy mission. Image credit: NASA

The spacecraft has a mission life of 12 years and during that time, it will travel to eight different asteroids — a Main Belt asteroid and seven Trojans.

The science objectives of the mission are as follow:

  • Surface Geology – Lucy will map the albedo, shape, crater spatial and size-frequency distributions, determine the nature of crustal structure and layering, and determine the relative ages of surface units.
  • Surface Color and Composition – Lucy will map the colour, composition and regolith properties of the surface of the Trojan asteroid and determine the distribution of minerals, ices, and organic species.
  • Interiors and Bulk Properties – Lucy will determine the masses and densities, and study sub-surface composition via excavation by craters, fractures, ejecta blankets and exposed bedding.
  • Satellites and Rings – Lucy will look for rings and satellites of the Trojan asteroids.

About the Trojan asteroids

These asteroids form two separate groups and exist both ahead of and behind Jupiter. They are divided into three groups – C-, P- and D-types.

According to NASA, the P- and D-type Trojans asteroids are similar to those found in the Kuiper Belt. The C-types are found mostly in the outer parts of the Main Belt of asteroids, between Mars and Jupiter.

This diagram illustrates Lucy's orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary, giving the trajectory its pretzel-like shape. After launch in October 2021, Lucy has two close Earth flybys before encountering its Trojan targets. In the L4 cloud Lucy will fly by (3548) Eurybates (white) and its satellite, (15094) Polymele (pink), (11351) Leucus (red), and (21900) Orus (red) from 2027-2028. After diving past Earth again Lucy will visit the L5 cloud and encounter the (617) Patroclus-Menoetius binary (pink) in 2033. As a bonus, in 2025 on the way to the L4, Lucy flies by a small Main Belt asteroid, (52246) Donaldjohanson (white), named for the discoverer of the Lucy fossil. After flying by the Patroclus-Menoetius binary in 2033, Lucy will continue cycling between the two Trojan clouds every six years. Credits: Southwest Research Institute

This diagram illustrates Lucy’s orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary. Credits: Southwest Research Institute

These asteroids have an abundance of dark carbon compounds and are probably rich in water and other volatile substances.

This mission will give us our first view of the Trojan asteroids that are thought to be ‘time capsules’ from the birth of our solar system, some four billion years ago. They are supposed to be ‘remnants of the primordial material that formed the outer planets.’

About Lucy’s instruments

Lucy has four instruments that will allow it to carry out remote-sensing science. They are:

  • L’Ralph is Lucy’s colour visible imager and an infrared imaging spectrometer.
  • LEISA will allow us to look for the absorption lines that serve as the fingerprints for different silicates, ices and organics that likely will be on the surface of the Trojan asteroids. MVIC will take color images of the Trojan asteroid targets, and help determine how active they are.
  • L’LORRI, the Long Range Reconnaissance Imager is the high spatial resolution visible imager. This camera will provide the most detailed images of the surface of the Trojans.
  • L’TES is the Thermal Emission Spectrometer. This infrared spectrometer will allow the Lucy team to learn much more about the properties of the Trojans such as their thermal inertia, how well the bodies retain heat, which teaches us about the composition and structure of the material on the surface of the asteroids.
  • Lucy’s High Gain Antenna to determine the masses of the targets using the Doppler shift of the radio signal. It will use its terminal tracking camera (T2CAM) to take wide-field images of the asteroids to better constrain the asteroids shapes.