Nasa announced its plans for two new asteroid missions on Wednesday (4 January), known as Lucy and Psyche, which it hopes to launch in 2021 and 2023, respectively.
The space agency will explore the early solar system instead of launching a new mission focused on Venusian volcanoes.
"Lucy will visit a target-rich environment of Jupiter's mysterious Trojan asteroids, while Psyche will study a unique asteroid that's never been listed before," Thomas Zurbuchen, associate administrator for Nasa's Science Mission Directorate in Washington, said in a statement.
"This is what Discovery Programme missions are all about — boldly going to places we've never been to enable groundbreaking science."
Lucy is slated to launch first in 2021 and will visit unexplored areas of "Trojan" asteroids clustered at the L4 and L5 points of Jupiter's orbit around the Sun, Ars Technica reported. The mission is expected to stop at a small mail belt asteroid in 2025 before making five flybys of Trojan steroids from 2027 to 2033.
The second project, Psyche, will launch in 2023 and aims to send a spacecraft to 16 Psyche, an asteroid in the belt between Mars and Jupiter.
16 Psyche has a diameter of 210km (130m) and is one of the largest objects in the asteroid belt. Unlike most other asteroids, 16 Psyche is believed to comprise of metallic iron and nickel, much like Earth's core, Nasa said.
"This is an opportunity to explore a new type of world — not one of rick or ice, but of metal," Psyche Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe said. "16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space."
Lucy and Psyche were part of five proposed missions that Nasa looked into. According to Ars Technica, two other missions hoped to study Venus' atmosphere and surface and a third would build an instrument that would identify asteroids that might strike Earth one day. The final asteroid project, called NEOCam, will continue to receive funding until further consideration, Nasa announced.
Jim Green, Nasa's chief planetary scientist, said in a video announcing the winning missions that Lucy and Psyche will allow the space agency to study relics of the early solar system. "These missions will help us learn about the infancy of our solar system, a period just 10 million years after the birth of our Sun," Green said.
Nasa noted that these Discovery Programme missions are "relatively low-cost" with development capped at around $450m (£365m).