Usually associated with bad news, hearing the phrase “loss of signal” will be cause for celebration for the team behind NASA’s DART spacecraft due to crash into an asteroid on Monday.
Most NASA spacecraft last for years or even decades, but not the Double Asteroid Redirect Test mission. This space robot has a date with death.
NASA planetary defense officer Lindley Johnson told reporters Thursday he was “very confident” the DART would hit its target and be a success.
After launching last fall with SpaceX, the aircraft-sized spacecraft chased the binary asteroid system Didymos to test a game plan to save Earth when a giant space rock heads towards our planet . The method known as the kinetic impactor theory involves using DART as a battering ram at 15,000 mph and crashing it into moonlit Dimorphos, which orbits the larger asteroid Didymos.
ASTEROID-SMASHING DART MISSION IMAGES WILL HAVE TO BE ‘AMAZING’
DART mission systems engineer Elena Adams of the Johns Hopkins University Applied Physics Laboratory, which manages the mission for NASA, explains about 4 hours before impact, DART will work autonomously to navigate to its end.
Using a relative navigation system called SMART Nav, DART will focus on Didymos about an hour before impact, then slowly the smaller Dimorphos will focus. The spacecraft will send back images at approximately one frame per second.
“You’ll hear us say, ‘We’re in precision lock, which means we’re now starting to ignore Didymos, and we’re going towards Dimorphos… Then at two and a half minutes before impact, Smart NAV… will go out, and we’re just going to point the camera and take the most amazing pictures of this asteroid that we’re going to see for the first time,” Adams said.
Dimorphos, only about 530 feet across, won’t be entirely crisp and clear until moments before impact. The last image will be taken about 2.5 seconds before DART flies into the asteroid. Due to the 8-second delay between the DART signal and Earth, photos will continue to arrive at the mission operations center in Maryland.
While DART will return images until the end, its companion satellite, a tiny Italian CubeSat called LICIACube, will fly over the asteroid and continue to return images in the days and months following impact. The James Webb Space Telescope, ground observatories and other spacecraft will also be able to observe the asteroid impact from a distance.
Although it’s never been done before, NSA DART scientist Tom Statler says the team has a good idea of what happens when you launch a spacecraft onto an asteroid because of NASA missions. and from the Japanese Space Agency to other asteroids.
“We know DART is going to be shut down by Dimorphos for a reason,” Statler said. “The density of the DART spacecraft is actually not much different from the density of an asteroid. And so there’s no doubt that DART is going to run into a lot of material that can’t get out of the way.”
DART will not change the orbit of Didymos. It aims to alter the speed of the moon, Dimorphos, by a very small percentage.
“We’re moving an asteroid. We’re changing the motion of a natural celestial body in space,” Statler said. “Humanity has never done this before…it’s science fiction.”
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DART project manager Edward Reynolds said he wasn’t losing any sleep over the upcoming impact as the team ran simulations and tested the spacecraft’s navigation since launch, but that doesn’t mean it’s not hard to hit a 100-meter-diameter asteroid at 14,000 mph. task.
“We do things because they’re hard. We’re at the point where technology is emerging so we can use these emerging technologies to protect against these threats,” Reynolds said. “I think we’ve prepared for this moment, but I’m not worried about the spacecraft. I’m not worried about the algorithm.”
If DART is doing its job, it will stop returning a signal after 7 p.m. ET on Monday.
“And then we’ll celebrate,” Adams said.