NASA Selects SwRI Mission To Jupiter’s Trojan Asteroids

Lucy, an SwRI mission proposal to study primitive asteroids orbiting near Jupiter, has been selected for development under NASA’s Discovery Program. Image Credit: Southwest Research Institute

January 4, 2017 – NASA has selected a Southwest Research Institute mission to study primitive asteroids orbiting near Jupiter that could give insights into the origins of the solar system. The mission, known as Lucy, will proceed to mission formulation, with the goal of launching in October 2021.

Lucy, a robotic spacecraft, is slated to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.

Southwest Research Institute is leading NASA’s Lucy mission, which will launch in 2021 for the first reconnaissance of the Trojans, a population of primitive asteroids orbiting in tandem with Jupiter. In this artist’s concept (not to scale), the Lucy spacecraft is flying by Eurybates, one of the six diverse and scientifically important Trojans to be studied. Image Credit: SwRI

“This is a unique opportunity,” said Dr. Harold F. Levison, principal investigator of the Lucy mission from the Southwest Research Institute in Boulder, Colorado. “Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins.”

Lucy will use a proven Lockheed Martin spacecraft and remote-sensing instrument suite to study the geology, surface composition, and bulk physical properties of these bodies at close range. The payload includes three complementary imaging and mapping instruments, including a color imaging and infrared mapping spectrometer from NASA’s Goddard Space Flight Center (GSFC), a high-resolution visible imager from the Johns Hopkins University Applied Physics Laboratory, and a thermal infrared spectrometer from Arizona State University. In addition, Lucy will perform radio science investigations using its telecommunications system to determine the masses and densities of the Trojan targets.

The spacecraft will build on the success of NASA’s New Horizons mission to Pluto and the Kuiper Belt (also led by SwRI), using newer versions of the RALPH and LORRI science instruments that helped enable the mission’s achievements. Several members of the Lucy team are veterans of the New Horizons Mission. Lucy will also draw on the heritage of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team. Dr. Catherine Olkin, a manager in SwRI’s Space Science and Engineering Division, is the mission’s principal investigator. In addition to SwRI, team members include Goddard Space Flight Center and Lockheed Martin.

Lucy was selected as part of NASA’s Discovery Program, a class of missions that are relatively low-cost, with their development capped at about $450 million. The Discovery Program is managed for NASA’s Planetary Science Division by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama. The missions are designed and led by a principal investigator, who assembles a team of scientists and engineers, to address key science questions about the solar system.

In addition to Lucy, another asteroid mission was selected by NASA today. The Psyche mission will explore a giant metal asteroid in the main asteroid belt known as 16 Pysche. This asteroid measures about 130 miles (210 kilometers) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be comprised mostly of metallic iron and nickel, similar to Earth’s core. Scientists wonder whether Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.

The mission, led by Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe, will help scientists understand how planets and other bodies separated into their layers – including cores, mantles and crusts – early in their histories.

Psyche is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025.

In addition to selecting the Lucy and Psyche missions for formulation, the agency will extend funding for the Near Earth Object Camera (NEOCam) project for an additional year. The NEOCam space telescope is designed to survey regions of space closest to Earth’s orbit, where potentially hazardous asteroids may be found.

“These are true missions of discovery that integrate into NASA’s larger strategy of investigating how the solar system formed and evolved,” said NASA’s Planetary Science Director Jim Green. “We’ve explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun. Lucy will observe primitive remnants from farther out in the solar system, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold.”

NASA’s Discovery Program requested proposals for spaceflight investigations in November 2014. A panel of NASA and other scientists reviewed the 27 submissions and selected five for additional development in September 2015.

The Discovery Program portfolio includes 12 prior selections such as the MESSENGER mission to study Mercury and the InSight Mars lander, scheduled to launch in May 2018.

NASA’s other missions to asteroids began with the NEAR orbiter of asteroid Eros, which arrived in 2000, and continues with Dawn, which orbited Vesta and now is in an extended mission phase at Ceres. The OSIRIS-REx mission, which launched on September 8, 2016, is speeding toward a 2018 rendezvous with asteroid Bennu, and will deliver a sample back to Earth in 2023. Each mission focuses on a different aspect of asteroid science to give scientists the broader picture of solar system formation and evolution.