Monoprop Propulsion System
Because it is on a low-energy trajectory for its flyby of comet Wild 2 and return to Earth, aided by a gravity-assisted boost maneuver as it flies by the Earth for the first time, the Stardust spacecraft needs only a relatively modest propulsion system. This is provided by ultra pure hydrazine (N2H4) monopropellant.
Eight 1-lb Thrusters, Plus Eight 0.2-lb Thrusters
Thrusters are mounted in four clusters of 4 thrusters each.
Star Camera + IMU, Analog Sun Sensors Backup
The Stardust spacecraft is 3-axis stabilized in all mission phases, following separation from the launch vehicle. The primary attitude determination is via the star camera and the inertial measurement unit (IMU), and is backed up by analog sun sensors. The IMUs are needed only during trajectory correction maneuvers, and during the flythrough of the cometary coma when stars may be difficult to detect. Otherwise, the vehicle can be operated in an all-stellar mode.
Command & Data Handling
The RAD6000 is a central processing 32-bit unit embedded in the spacecraft's Command and Data Handling (C&DH) subsystem and provides computing capability for all spacecraft subsystems, including the payload elements. Electronic cards are provided to interface instruments and subsystems to the C&DH subsystem. 128 Mbytes of data storage is provided on the processor card, although the spacecraft uses approximately 20% of this for its own internal programs. The rest of the space in the memory is used for science programs and data storage for sending back to Earth 600 megabits (Mb) of images taken by the navigation camera, 100 Mb by the Comet Interstellar Dust Analyzer (CIDA) instrument, and 16 Mb by the Dust Flux Monitor (DFM).
Primary communication between the Earth and the orbiter is by use of the Deep Space Network (DSN) X-band (up/down) link and the orbiter’s deep space transponder developed for the Cassini spacecraft, a 15 Watt RF solid state amplifier, and a 0.6 meter (2 ft) diameter fixed high gain parabolic antenna.