MISSION

Spacecraft

Key Spacecraft Characteristics:

• Extensive redundancy using flight-proven assemblies from other Orbital and JPL spacecraft
• Ion propulsion system, based on the design validated on Deep Space 1
• Two 100 W (RF) traveling wave tube amplifiers, fixed 1.5 m high-gain antenna, 3 low-gain antennas, two small deep space transponders
• Solar array capable of producing more than 10 kW at Earth's distance from the Sun and more than 1 kW at Ceres's maximum distance
• Flight proven attitude control system used on Orbview, TOPEX/Poseidon ocean topography mission, and Far Ultraviolet Spectroscopic Explorer
• Simple hydrazine reaction control subsystem with two sets of six 0.9 N engines used on the Indostar spacecraft
• Command and data handling uses off the shelf components as used on the Orbview program
• Modular flight software based on design used on Orbview
• Core structure is graphite composite. Panels are aluminum core, some with aluminum facesheets and others with composite facesheets.

SPACECRAFT DIAGRAM

---

This figure depicts the Dawn flight system. Upper views are the same scale.

Key:

• HGA – High Gain Antenna
• LGA – Low Gain Antenna
• CSS – Coarse Sun Sensors
• GRaND – Gamma Ray and Neutron Detector
• IPS Thrusters – Ion Propulsion Thrusters
• RCS Thrusters – Reaction Control System Thrusters
• VIR – Visible and Infrared Mapping Spectrometer
• FC – Framing Camera

- Learn about Dawn's ion propulsion
- Read published article describing the mission: Dawn: A mission in development for exploration of main belt asteroids Vesta and Ceres