NASA launches first mission to test asteroid deflection

The probe will spend about a year traveling to an asteroid system more than 6.5 million miles from Earth. The mission’s target is Dimorphos, a space rock about 525 feet across, orbiting a much larger asteroid called Didymos, which is about 2,500 feet across.

According to NASA, neither Dimorphos nor Didymos pose a threat to the planet, but the system is a “perfect testing ground” for whether crashing a spacecraft into an asteroid can effectively change its speed in space. Is.

Next Fall, NASA Will Break the Dart Spacecraft into Dimorphos At a speed of about 15,000 mph. Telescopes on Earth have been studying Didymos and its “moonlet” dimorphos for decades, said Nancy Chabot, a planetary scientist at the Johns Hopkins University of Applied Physics, and have observed that the small space rock returns to its larger one once every 11 hours and 55 minutes. surrounds the counterpart. Leading laboratory and mission coordination.

Chabot and his colleagues want to see if a cosmic collision could alter Dimorphos’ nearly 12-hour orbit. NASA estimates that the maneuver will change the orbital speed of the space rock by only a fraction of a percent — a difference of only a few minutes — but the change should be detected by ground-based telescopes.

“It’s not going to destroy the asteroid — it’s just going to give it a little nudge,” she said at a news briefing earlier this month. “It’s going to deflect its path around a really large asteroid, so we’re demonstrating asteroid deflection in this double asteroid system.”

The test will destroy the Dart probe, but a small, Italian-built CubeSat that the spacecraft will deploy more than a week before the crash will bring back photos of the impact and its aftermath.

a Follow-up mission developed by the European Space Agency Didymos will conduct a more detailed check of the system and assess the outcome of the dart probe’s deflection. That mission, known as HERA, is scheduled to launch in October 2024.

According to NASA, no known asteroid larger than 450 feet has a significant chance of hitting the planet in the next 100 years, but the agency said so far only a fraction of smaller near-Earth objects have been found.

The agency’s Planetary Defense Coordination Office is tasked with searching for near-Earth objects that are potentially dangerous to the planet, including those that venture within 5 million miles of Earth’s orbit, and Objects that cause significant damage when they hit the surface.

If a large space rock is found on a collision course with Earth in the future, tests such as the Dart mission could help NASA respond to the threat.

“It’s very rare for an asteroid to impact Earth, but it’s something we want to know ahead of time,” said Lindley Johnson, a planetary defense officer at NASA Headquarters in Washington, DC.