The Spacecraft

Artist rendering of spacecraft

NASA DART Impactor

The DART spacecraft is a simple design - a kinetic impactor with a single instrument, the Didymos Reconnaissance and Asteroid Camera for OpNav (DRACO), which will observe the asteroid upon approach. DART will navigate to crash itself into Didymos B at a speed of approximately 6 km/s, aided by the DRACO camera and sophisticated autonomous navigation software.

Payload

The DART payload, Didymos Reconnaissance and Asteroid Camera for Op-nav (DRACO), is a high-resolution imager derived from the New Horizons LORRI camera to support navigation and targeting and to determine impact site and geologic context. The spacecraft is a single-string design with thruster-only control weighing about 500kg. The DART impact is directed at Didymos B with a relative velocity of about 6 km/s (13,000 mph)

Technologies

As a technology demonstration mission, DART also incorporates two key new technologies to further the state of the art for future missions in NASA's portfolio.

Electric Propulsion

Chemical propulsion systems store energy chemically in their propellants, but the energy created by electric propulsion systems comes from electromagnetically accelerating ions formed from the propellant.

SMART Nav

Precise, autonomous navigation is required for DART's kinetic impact to be successful. JHUAPL has developed a Small-body Maneuvering Autonomous Real-Time Navigation (SMART Nav) algorithm for DART; it is comprised of image processing and Guidance, Navigation and Control (GNC) algorithms that are a part of a navigation simulation. When DART impacts Didymos B, navigation is handed over to the on-board SMART Nav system. In addition to the navigation, the SMART Nav fuel management logic can determine the appropriate times for course corrections to optimize the efficient use of a limited propellant supply.

DART Mission Design - Path To Terminal Guidance

Autonomous Navigation and Targeting (SMART Nav)

@2022 Intercept (~10.9M km; 6.8M miles from Earth)


    Thumbnail of the Ascent / Boost
  1. Ascent / Boost
    • Direct Launch or Low-Thrust Spiral*
      • 6-9 months for Electric Propulsion
      • 108 km from target

  2. Thumbnail of the Cruise / Calibration
  3. Cruise / Calibration
    • Flyby of PHA allows sensor calibration and control-gain tuning
      • 7 months until impact
      • 108 km from target

  4. Thumbnail of the Target Detection / Coarse Acquisition
  5. Target Detection / Coarse Acquisition
    • Weeks prior to impact, seeker detects primary
      • 2 months until impact
      • 107 km from target

  6. Thumbnail of the Scene Classification
  7. Scene Classification
    • Seeker counts and classifies closely spaced objects
      • 3 hours until impact
      • 176,000 km from target

  8. Thumbnail of the Target Selection
  9. Target Selection
    • With sufficient confidence, SMART Nav selects target and locks on
      • 1.5 hours until impact
      • 38,000 km from target

  10. Thumbnail of the Homing Until Intercept
  11. Homing Until Impact
    • SMART Nav executes precision engagement and analyzes target uncertainties
      • Executed until final 2 minutes
      • 6.0 km/s impact

  12. Thumbnail of the Intercept Assessment
  13. Impact Assessment
    • Earth tracking and orbital assets quantify impact success

*15-18 months total flight time


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