NASA has revealed details about two latest missions – Lucy and Psyche – it intends to launch in 2021 and 2023 to find answers to some of the questions about our Solar System when it was young.
Lucy will be investigating Jupiter Trojan asteroids while Psyche will be carrying out investigation of the 16 Psyche, which is an asteroid found in 1852 by Italian astronomer Annibale de Gasparis.
Lucy is the first ever mission to the Jupiter Trojan asteroids. Astronomers believe that these asteroids hold vital clues to deciphering the history of the Solar System. Due to an unusual and fortuitous orbital configuration, Lucy, which has been selected for further development as part of NASA’s Discovery Program, will perform an exhaustive landmark investigation that visits six of these primitive asteroids, covering both the L4 and L5 swarms, all the known taxonomic types, and a nearly equal mass binary. It will use a suite of high-heritage remote sensing instruments to map the geology, surface color and composition, thermal and other physical properties of its targets at close range – all this within constraints of the Discovery Program. Thus, Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins.
Through its unique tour, Lucy will provide crucial input to four of the ten Priority Questions for Planetary Science as expressed by the Decadal Survey in 2013 (DS13):
- What were the initial stages, conditions and processes of Solar System formation …?
- How did the giant planets … accrete, and is there evidence that they migrated to new orbital positions?
- What governed the accretion …, and what roles did bombardment by large projectiles play?
- What were the sources of primordial organic matter?
Lucy’s primary science objectives:
- Surface composition. Lucy will map the color, composition and regolith properties of the surface and determine the distribution of minerals, ices and organics species.
- Surface geology. Lucy will map albedo, shape, crater spatial and size distributions, determine the nature of crustal structure and layering, and determine the relative ages of surface units.
- Interior and bulk properties. Lucy will determine the masses and densities, and study subsurface composition via crater windows, fractures, ejecta blankets, and exposed bedding.
- Satellite and ring search. Lucy will determine the number, size-frequency distribution and location of km-scale satellites and dense rings.
The Psyche spacecraft is targeted to launch in October 2023 and travel to the asteroid using solar-electric (low-thrust) propulsion, arriving in 2030, follwing an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025. After a six-year cruise, the mission plan calls for 20 months spent in orbit around the asteroid, mapping it and studying its properties.
What gives 16 Psyche great scientific interest is that it is made of metal. It appears to be the exposed nickel-iron core of a protoplanet, one of the building blocks of the Sun’s planetary system. At 16 Psyche scientists will explore, for the first time ever, a world made not of rock or ice, but of metal.
The asteroid is most likely a survivor of violent hit-and-run collisions, common when the solar system was forming. Thus 16 Psyche may be able to tell us how Earth’s core and the cores of the other terrestrial planets came to be.
The science goals of the Psyche Mission are to understand these building blocks of planet formation and to explore first-hand a wholly new and unexplored type of world. The mission team seeks to determine whether Psyche really is a protoplanetary core, how old it is, whether it formed in similar ways to the Earth’s core, and what its surface is like. The spacecraft’s instrument payload includes magnetometers, multispectral imagers, a gamma ray and neutron spectrometer, and a radio-science experiment.