NASA has just announced two new missions to explore asteroids in our solar system, but these missions, set to launch in the 2020s, come with a cost. Choosing to move forward with this pair of asteroid missions means other big projects, like further exploring Venus, are now on the back burner.
NASA has been intent on funding missions to study and explore asteroids for a while now. In 2015, the Dawn mission got to Ceres, the largest floating rock in the asteroid belt. That was followed up by OSIRIS-REx, the mission to bring a little chunk of an asteroid back to Earth.
Now NASA is following up with two more asteroid-centric projects, Lucy and Psyche. Lucy will be headed to explore the Trojan asteroids that whirl around Jupiter. Meanwhile, Psyche is going to be the first spacecraft to go to a metal asteroid, 16 Psyche, an iron-rich body some scientists believe could actually be the core of what was once a small planet.
Focusing on asteroids makes a lot of sense from NASA's perspective. Asteroids are incredibly appealing science-wise because they're like enormous time capsules and could hold information about where the universe comes from. Paired with the relatively low cost of asteroid-focused missions, of course NASA is on an asteroid kick.
However, NASA's funding is notoriously tight and dependent on which way political winds are blowing, as we've noted before, and choosing to pursue one set of interests always comes at the cost of funding research on other things.
In this case, focusing on asteroids means other expeditions have to be set aside.
Of the five project proposals that made it to Discovery's semi-finals, three were about asteroids and two were about Venus, but the Venus projects were not selected because the pitches didn't score high enough when it came to looking at the cost, the risk and the scientific objectives to make either one worthwhile.
Still, planetary scientist Mark Marley told Popular Science he was shocked that neither of the Venus missions got selected. "If we're trying to understand atmospheres on exoplanets, we really need to understand as much as we can about our own Venus. It's very hard to get exoplanet data, and it's always lower quality than what you can get in the solar system," he told the magazine.
Venus is a big draw to a lot of planetary scientists like Marley because the planet has a thick atmosphere surrounding it. Further exploration of Venus represents one of the best chances we have of learning about how atmosphere really works. NASA hasn't paid attention to Venus in a while. The federal space agency last sent a probe there decades ago, in the 1970s, but it looks like more probing will just have to wait.
NASA's official stance is that the asteroid projects just make more sense from the standpoint of risk, cost and potential scientific reward. “Lucy will visit a target-rich environment of Jupiter’s mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that’s never been visited before,” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, states in a release. “This is what Discovery Program missions are all about – boldly going to places we’ve never been to enable groundbreaking science.”