Although the chance of an asteroid impacting Earth is small, even a relatively small asteroid of about 500 feet (about 150 meters) across carries enough energy to cause widespread damage around the impact site. launched Wednesday, November 24 at 1: 21 a.m. EST on a
Illustration of the DART spacecraft. Credit: NASA
Scientists and engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are checking the flight path of the mission and running computer simulations that predict how the impact might change Dimorphos’ orbit. The team will also make telescopic observations to determine the amount and composition of dust and volatiles (easily vaporized material) released during the impact.
“We are an independent check on the mission’s trajectory calculations,” said Brent Barbee, dynamics verification and validation lead and DART flight dynamics support lead at Goddard. Goddard used its in-house-developed Evolutionary Mission Trajectory Generator (EMTG) to provide independent verification and validation of the DART mission trajectories at various stages of the mission’s development and evaluate the ability of the mission to adapt to missed thrust and other contingencies.
“We also used the EMTG to support independent trajectory optimization studies for DART. These studies assessed the best flight paths for the spacecraft given its goals, capabilities, and limitations,” said Bruno Sarli of Goddard and Heliospace Corporation, Berkeley, California, a member of the DART trajectory optimization team.
Goddard scientists are also helping to calculate how the impact will change the orbit of Dimorphos, using a specialized binary (double) asteroid dynamics simulation code developed by the mission’s investigation team to model the orbital and rotational motion of the Didymos system. The Goddard group curated a version of the tool for the DART mission, adding features and functionality. “Our simulation results shed light on how DART’s impact will change the dynamics of the system in ways that are detectable via remote observations,” said Barbee.
“Prior to launch, these simulations helped verify that the DART impact would meet mission requirements even in impact circumstances that are not ideal,” adds Joshua Lyzhoft of Goddard, who performs dynamics simulation development, modeling, and analysis for DART. “We will also be updating the simulations during the mission using observations to help ascertain how much DART’s impact changed the momentum of Dimorphos, which is an important goal of the mission.”
The double asteroid dynamics algorithms and code are very complex and computationally intensive, according to the team. “One of the important features Goddard added to the code is the ability to execute it using parallel distributed computing so that the simulations complete in reasonable amounts of time,” said Barbee. “When the system is observed post-impact that will be the first time such impact effects are observed and the first time such observations will be compared to and used to calibrate dynamics simulations for a double asteroid.”
The spacecraft will intercept Didymos’ moonlet in late September 2022, when the Didymos system is within about 6.8 million miles (11 million kilometers) of Earth, enabling observations by ground-based telescopes and planetary radar to measure the change in momentum imparted to the moonlet.
Goddard scientists will be performing additional observations to add to the mission’s scientific return. “We’ll determine the amount of dust released during impact, as well as the amount and nature of any potential volatiles, through high-resolution radio-telescope observations with the Atacama Large Millimeter Array (
