Leonard David's INSIDE OUTER SPACE

Schematic of the DART mission shows the impact on the moonlet of asteroid (65803) Didymos. Post-impact observations from Earth-based optical telescopes and planetary radar would, in turn, measure the change in the moonlet’s orbit about the parent body.
Credit: NASA

The Trump administration’s recently issued proposed NASA budget includes support for a new Planetary Defense program for near-Earth object detection and mitigation under the agency’s Planetary Science Division.

Part of the program is to bankroll the formulation of the Double Asteroid Redirection Test (DART) mission at $90 million in its first year. DART would collide with a double asteroid system as it passes near Earth, allowing observations of the impact’s effects on the motion of the system. Target of the kinetic impact is the smaller asteroid of Didymos, called Didymos B.

Overview of the DART spacecraft with the Roll Out Solar Arrays (ROSA) extended. With the ROSA arrays fully deployed, DART measures 12.5 meters (494 inches) by 2.4 meters (98.1 inches).
Credit: NASA

Change in momentum

DART would intercept Didymos’ moonlet in early October 2022, when the Didymos system is within 11 million kilometers of Earth, enabling observations by ground-based telescopes and planetary radar to measure the change in momentum imparted to the moonlet.

Brought up on Space X’s eleventh Dragon flight (CRS-11) to ISS, the ROSA array was tested on Expedition 52 on board the International Space Station (ISS) in June 2017. This was the first in-space test of ROSA. This image shows the ROSA fully extended.
Credit: NASA

DART would be the first demonstration of the kinetic impact technique to change the motion of an asteroid in space.  Crashing itself into the moonlet at a speed of approximately 6 kilometers per second, DART would utilize an onboard camera and sophisticated autonomous navigation software to enable the celestial collision.

Launch window

The DART mission is in Phase B, led by The Johns Hopkins University Applied Physics Laboratory in Maryland and managed by the Planetary Missions Program Office at Marshall Space Flight Center for NASA’s Planetary Defense Coordination Office.

The launch window for NASA’s DART spacecraft’s begins in late December 2020 and runs through May 2021.  It will intercept Didymos’ moonlet in early October 2022.

The DART spacecraft would make use of Roll Out Solar Arrays (ROSA). For in-space propulsion, DART taps the NASA Evolutionary Xenon Thruster – Commercial (NEXT-C) solar electric propulsion system.

One Response to “Playing DART with an Asteroid”