OCT. 13, 2021 – With the Lucy spacecraft now fully integrated with its Atlas V rocket, NASA is ready to begin a 12-year mission to explore the Trojan asteroids. The Lucy mission is currently targeting an early morning launch on October 16, 2021, at 5:34 a.m. EDT from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida. As of October 13, 2021, the 45th Weather Squadron has predicted a 90% probability of acceptable weather conditions during the launch period on October 16th.
For its ride to orbit, Lucy will launch on board an Atlas V 401 launch vehicle. Notably, this launch will be the penultimate flight of a 400-series Atlas V, with only one final launch remaining—the JPSS-2 mission, flying from California on an identical 401 configuration—before the 400-series’ retirement.
Should the mission require additional launch opportunities, the Lucy mission will have hour-long opportunities every morning within a launch window that spans 23 days, starting on October 16 and lasting through November 7, 2021. Due to Lucy’s unique trajectory, if it misses this window, it only has one more attempt with a near-identical window next year before the mission must be called off.
As part of its primary mission, Lucy will explore one main-belt asteroid and seven Trojan asteroids, a record-breaking number of asteroid flybys. The Trojan asteroids are two groups of asteroids located at Jupiter’s Lagrange points—regions of space where gravitational forces between Jupiter and the Sun balance out to create stable points leading and trailing Jupiter’s orbit. Lucy will be the first mission to explore the Trojans, which have been trapped in the 4th and 5th Lagrange points since the early formation of the solar system, therefore making them extremely valuable to the scientific community.
Lucy will first complete two gravity assists off of Earth in October 2022 and December 2024, which will put the spacecraft on a course to encounter 52246 Donaldjohanson, its first target, at the main Asteroid Belt on April 20, 2025. This will be followed by a flyby of 3548 Eurybates, Lucy’s first Trojan, over two years later on August 12, 2027.
Onboard the spacecraft, Lucy features a number of scientific instruments to explore and study the asteroids, namely the Lucy LOng Range Reconnaissance Imager (L’LORRI), L’Ralph, and the Lucy Thermal Emission Spectrometer (L’TES). These instruments all find direct heritage to earlier NASA missions—L’LORRI and L’Ralph are derived from the similarly named instruments onboard the New Horizons probe, and L’TES from a long lineage dating back to the instrument on the ill-fated Mars Observer (and afterward the successful Mars Global Surveyor). For Lucy’s primary imaging camera, L’LORRI is the highest resolution camera on board and will provide detailed black and white imagery of the target asteroids.
Tasked with finding organic compounds on the surface of the asteroids, the L’Ralph instrument is responsible for scanning their surface composition using a number of different instruments: a color visible imager and an infrared spectrometer. To understand the thermal properties of Lucy’s targets, L’TES will be used to detect infrared radiation off of these asteroids. Data gathered from L’TES will also help scientists determine the amount of dust or rock present on the asteroids.
For power throughout the mission, Lucy will be utilizing two 7-meter (~24 ft.) wide circular solar panels, making it the most distant use of solar panels on a spacecraft to date.
Whether it may be through up-close high-resolution imagery or detailed surface scans of the Trojans, with the launch of NASA’s Lucy mission just days away, the spacecraft will soon be en route to potentially unlocking some of the greatest mysteries about the formation of the early Solar System, and perhaps Earth itself.