Live updates: DART asteroid space mission
The DART mission spacecraft is scheduled to collide shortly with a near-Earth asteroid.
Ahead of impact with Dimorphos at around 7:14 p.m. ET, here’s what’s happening, according to Elena Adams, the DART mission systems engineer at the Johns Hopkins University Applied Physics Laboratory.
4 hours before impact:
The spacecraft has become completely autonomous. Even though a team is watching data come into the command center “the spacecraft has to do everything,” Adams said during a briefing on Thursday. At this point, the spacecraft is guiding itself toward Didymos, the larger asteroid in the system. It does this with the help of an instrument called the Didymos Reconnaissance and Asteroid Camera for Optical navigation, or DRACO, which will grab images of both celestial bodies and support the spacecraft’s guidance system.
“It starts tracking it. It starting to guide itself toward Didymos,” Adams said, referring to the bigger asteroid that is already visible. The smaller asteroid, Dimorphos, the mission’s main target, is Didymos’ moon.
1 hour before impact:
Dimorphos will come into view for the first time. The spacecraft will see the moon as “just one pixel” in the video of the DRACO camera, Adams said. Prior to Didymos and Dimorphos coming into view as tiny pinpricks of light a few hours before the collision, the camera is likely to be completely black. They will grow larger and larger until Dimorphos fills the entire frame just before impact.
“We’re going to execute a bunch of maneuvers, all autonomously,” she said, describing how the spacecraft will be guided toward Dimorphos. While this is happening, the spacecraft will point the solar rays at the sun, which then sends data back to Earth at the rate of one image per second.
“After that we are going to precision lock,” Adams said. “Which means we are now starting to ignore Didymos and we are only going to Dimorphos.”
2 1/2 minutes before impact:
The first photos of Dimorphos will be taken. Though it was discovered more than two decades ago, scientists have never seen what this asteroid looks like.
“And then it will say ‘loss of signal,’ and we’ll all celebrate,” Adams said.