Mon. Jan 17th, 2022

In the early hours of the morning of Wednesday, November 24, NASA’s Double Asteroid Redirection Test (DART) was launched from Space Launch Complex 4 East at Vandenberg Space Force Base (SFB) in California. This spacecraft is the world’s first full-scale mission to demonstrate technologies that could one day be used to defend our planet against Near-Earth Asteroids (NEAs) that could potentially collide with Earth.

In short, the DART mission is a kinetic impactor that will evaluate a proposed method of deflecting asteroids. Over the next ten months, the DART mission will autonomously navigate towards the target asteroid – the binary NEA (65803) Didymos – and deliberately collide with it. If all goes according to plan, this will change the motion of the asteroid so that ground-based telescopes can accurately measure any changes.

The launch took place at. 01:31 EST (Tues. 23 Nov.rd22:31 PST) as the DART mission took off from the SLC-4E on top of a SpaceX Falcon 9 rocket. At 02:17 (23:17 PST), DART separated from the booster’s second stage and began sending telemetry data back to mission controllers minutes later. About two hours later, the spacecraft deployed the two 8.5-meter (28-foot) solar panels to power its Solar-Electric Propulsion (SEP) thruster.

Fourteen sequential Arecibo radar images of the near-Earth asteroid (65803) Didymos and its moon. Credit: NASA / Arecibo

The collaborative DART effort was built and led by the Johns Hopkins University Applied Physics Laboratory (JHUAPL). The mission is managed under NASA’s Planetary Defense Coordination Office and the Planetary Science Division, with support from several NASA centers. The mission is compromised by several elements provided by NASA, the European Space Agency (ESA) and other partner agencies. As NASA Administrator Bill Nelson explained in a recent NASA press release:

“DART turns science fiction into science facts and is a testament to NASA’s proactivity and innovation for the benefit of all. In addition to all the ways NASA studies our universe and our home planet, we are also working to protect that home, and this test will help in proving a viable way to protect our planet from a dangerous asteroid should one ever be discovered, ie on its way to Earth. ”

“At its core, DART is a mission of preparedness, and it is also a mission of unity,” said Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA’s headquarters. “This international collaboration involves DART, ASI’s LICIACube and ESA’s Hera studies and science teams, which will follow up on this groundbreaking space mission.”

The mission consists of two spacecraft, the 610 kg (1,340 lb) impact force, which relies on the NEXT ion thruster, a type of solar-powered electric propulsion that uses solar panels to power its NASA Evolutionary Xenon Thruster-Commercial (NEXT-C) engine. The target of this mission, named after the Greek word “twin”, consists of a major primary asteroid (65803) named Didymos and an orbiting moon named Dimorphos.

The artist’s impression of the DART mission’s encounter with NEA Didymos. Credit: NASA / JHUAPL

While (65803) Didymos measures about 780 meters (2,560 feet) in diameter, Dimorphos is less than a quarter of its size (160 m; 530 feet). This moon will be the primary target for DART, which will meet with the system between September 26thth and Oct. 1st, 2022. At this point, the orbit of the binary asteroid will bring it within 11 million km (6.8 million mi) from Earth, where DART will wait to collide with Dimorphos at a speed of about 6 km / s (4 mi / s).

Scientists estimate that this will shorten Dimorphos’ orbit around Didymos by several minutes, which they will accurately measure using ground-based telescopes. The results will be used to validate and improve the computer models currently used to predict the results of asteroid deflection. This change in velocity will be far easier to measure than a change in Didymos ‘orbital velocity (hence Dimorphos’).

The DART spacecraft will be accompanied by another spacecraft called the Light Italian CubeSat for Imaging of Asteroids (LICIACube), provided by the Italian Space Agency (ASI). This little CubeSat will piggyback with DART, disassemble ten days before the shock, and then capture images of the impact of the shock and the exhaust. About four years after DART hit the moon, ESA’s Hera the project will arrive at Didymos to perform detailed studies of both asteroids.

This test will provide vital data that will be used to develop enhanced preparations and strategies for asteroid defense. While Didymos does not currently pose a threat to Earth, it is classified as a “potentially dangerous asteroid.” This term applies to asteroids measuring 100 m (~ 330ft) or more in diameter and whose orbits bring them within 0.05 AU (7.5 million km) from Earth.

The artist’s impression of the Hera mission examining Dimorphos after the DART crash. Credit: ESA / Science Office

Previously, impacts from these objects of the same magnitude were thought to have caused extinction-level events (ELEs), such as the Chicxulub Impact Event, which triggered the extinction of the dinosaurs. As Lindley Johnson, planetary defense officer at NASA’s headquarters, said:

“We have not yet found any significant threat to the Earth, but we continue to search for the large population that we know is still to be found. Our goal is to find every possible effect, years to decades in advance, so that it can be deflected. with a capability like DART that is possible with the technology we currently have.DART is an aspect of NASA’s work to prepare the Earth should we ever face an asteroid hazard.

“Together with this test, we are preparing the Near-Earth Object Surveyor Mission, a space-based infrared telescope scheduled for launch later this decade and designed to accelerate our ability to detect and characterize the potentially dangerous asteroids and comets that come before for 30 million miles of the Earth’s orbit. “

Next week, DART will activate the only instrument it carries – Didymo’s Reconnaissance and Asteroid Camera for Optical Navigation (DRACO) – and take the first images of the spacecraft. In addition to its sophisticated navigation system, DART will rely on a number of Small-body Maneuvering Autonomous Real Time Navigation (SMART Nav) algorithms. These will allow the DART to identify and distinguish between the two asteroids and then target Dimorphos.

Image published by the European Space Agency showing DART affecting the binary asteroid system (65803) Didymos. Credit: ESA / AFP

Joan Marie is a Science Communicator, STEM Advocate and Aerospace Integration Engineer at NASA Kennedy Space Center (KSC). She and her colleagues worked through the night to prepare the DART mission for launch at Vandenburg SFB. “It felt great,” she said. “Being able to see (visually) the hard work our team has put into this launch was an incredible feeling.”

Also present was Andy Cheng, one of the DART study leaders at JHUAPL and the person who came up with the idea for DART. As he described it, it was a dream come true to see the mission he envisioned take flight:

“It’s an indescribable feeling to see something you’ve been involved in since the ‘word on paper’ scene becomes real and sent into space. This is only the end of the first act, and the DART research and engineering teams have a lot of work to do over the next year in preparing for the main event? DART Kinetic Impact on Dimorphos. But tonight we celebrate! “

Further reading: NASA

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