President Trump's proposed 2018 budget calls for an end to NASA's controversial Asteroid Redirect Mission.
Congress and the science community deemed it a failure from the start.
Former President Barack Obama first mentioned the asteroid mission in a 2010 speech, when he announced the cancellation of a Bush-era program to return humans to the moon. Instead, Obama wanted to focus on Mars and called for a manned mission to an asteroid as a stepping stone to the red planet.
But when NASA formally announced ARM in 2013, it was scaled back to a robotic mission. It was scaled back again in 2015 when NASA announced that the spacecraft would collect part of an asteroid, rather than the entire thing, and place it in orbit around the moon for humans to study on future missions.
By 2014, NASA had yet to build the spacecraft or identify a target asteroid. People began to question the mission's scientific merit, including NASA's Small Bodies Assessment Group and the National Research Council. Even Buzz Aldrin spoke out against it.
NASA continued to promote ARM's value in future missions to Mars, claiming it would test critical propulsion and navigation systems for manned flights.
But at a 2016 House Committee on Science, Space and Technology meeting, Congress members questioned the mission's relevance to Mars. They also criticized the mission for not having a clear timeline. Rep. Lamar Smith called it "uninspiring" and "misguided."
Congress recently passed a bill that gave $19.5 billion to NASA for 2017. The bill asked NASA to find alternative missions to ARM that would be more cost effective and scientifically beneficial to the agency's Mars efforts.
And Trump's budget would force NASA to do just that. The proposal would officially cancel ARM, putting an end to the mission that never could.