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Double Asteroid Redirection Test (DART)

NSSDCA ID: DART
COSPAR ID: 

Description

The Double Asteroid Redirection Test (DART) mission is designed to evaluate the kinetic impact technique by striking an asteroid with a spacecraft at high relative velocity and observing the resulting change in orbit. The test involves flying the DART spacecraft at high relative velocity into the smaller of two asteroids that are co-orbiting in a binary pair, and using Earth-based observations before and after the impact to study the effects on the orbit. It will also carry the LICIA Cube CubeSat, which will be released prior to the encounter to image the impact and its result.

The primary objective is to assess kinetic impact as a method for redirection of any future asteroids found to be on a trajectory to impact Earth, with the primary goals: (1) perform a full-scale demonstration of the spacecraft kinetic impact technique for deflection of an asteroid; (2) measure the resulting asteroid deflection, by targeting the secondary member of a binary NEO and measuring the resulting changes of the binary orbit; and (3) study hypervelocity collision effects on an asteroid, validating models for momentum transfer in asteroid impacts.

Mission Profile

DART is scheduled for launch on 22 July 2021. It will head to the binary S-type asteroid system 65803 Didymos, consisting of a primary, Didymos A, roughly 0.8 km in diameter, and a secondary, Didymos B, roughly 160 meters across. It will reach Didymos in September 2022, taking images during approach to constrain the size and shape of Didymos A and B. Impact is planned for 27 September 2022. The LICIA Cube will be released about two days before impact. In the last 4 hours before impact, DART will employ the DRACO and SMARTNav systems to target the asteroid. During this time it will also be returning detailed images of the surface (better than 20 cm/pixel at impact) of Didymos B to pinpoint the exact impact site within one meter and to determine the local surface geology for later impact modelling.

The spacecraft will fly into Didymos B at approximately 6.65 km/sec. The final images returned 2 seconds before impact will have a resolution of 3 cm/pixel. After impact, Earth-based observations will continue in order to characterize the resulting change in orbit of Didymos B induced by the impact. The distance to Earth at impact will be approximately 11.2 million km. (The ESA Hera mission is proposed to fly by Didymos in 2026 for followup observations.)

The mass of the Didymos system is estimated at 528 billion kg, with Didymos B at 4.8 billion kg. The impact will target the center of figure of Didymos B and should decrease the orbit by roughly 10 minutes. Details of the surface structure, impact, and changes in the orbit recorded by ground-based observatories and the DART and LICIA Cube images will be used to determine the efficiency of impact kinetic energy transfer.

Spacecraft and Subsystems

The spacecraft is a box-shaped main bus with two large solar panel wings and a total mass of approximately 650 kg. Propulsion will be provided by the NASA Evolutionary Xenon Thruster (NEXT) ion engine. It will carry a single instrument, the Didymos Reconnaissance and Asteroid Camera for OpNav (DRACO), which will provide images for the Small-body Maneuvering Autonomous Real-Time Navigation (SMARTNav) algorithm to be used for guidance, navigation, and control operations in targeting the asteroid. DRACO uses a 20.8 cm aperture, F/12.6 telescope with a field of view of 0.29 degrees providing images at a resolution of about 0.5 arcsec/pixel. The Roll Out Solar Arrays (ROSA) are designed to produce 6.6 kilowatts.

LICIA Cube

The LICIA Cube is a 6U CubeSat provided by the Italian Space Agency. It will be carried along with DART to Didymos and released approximately 2 days before the DART impact. LICIA Cube will perform a separation maneuver to follow behind DART and return images of the impact, the ejecta plume, and the resultant crater as it flies by. It will also image the opposite hemisphere from the impact. LICIA Cube is 3-axis stabilized and has a propulsion capability of 56 m/s. The onboard imager has a 7.6 cm aperture, F/5.2 telescope, and an IFOV of 2.9 arcsec/pixel.

Alternate Names

    Facts in Brief

    Launch Date: 2021-07-01
    Launch Vehicle: Unknown
    Launch Site: ,
    Mass: 650 kg
    Nominal Power: 6600 W

    Funding Agency

    • National Aeronautics and Space Administration (United States)

    Discipline

    • Planetary Science

    Additional Information

    Questions and comments about this spacecraft can be directed to: Dr. David R. Williams

     

    Personnel

    NameRoleOriginal AffiliationE-mail
    Dr. Cheryl ReedProject ManagerApplied Physics Laboratoryheryl.reed@jhuapl.edu
    Dr. Andrew F. ChengProject ScientistApplied Physics Laboratoryandrew.cheng@jhuapl.edu
    Dr. Andy RivkinProject ScientistApplied Physics LaboratoryAndy.Rivkin@jhuapl.edu
    Dr. Tom StatlerProgram ScientistNASA Headquartersthomas.s.statler@nasa.gov
    Dr. Scott BellamyMission ManagerNASA Marshall Space Flight Centerkelly.scott.bellamy@nasa.gov
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