DAPPER will be deployed from the vicinity of NASA’s Lunar Gateway or in cis-lunar space, and transfer to a frozen 50×125 km lunar orbit using Bradford Space Industries Xplorer deep space bus which has both high impulse and high delta-V. This orbit will facilitate the collection of 4615 hours of radio-quiet data over a 26.4-month lifetime for the baseline mission.
DAPPER’s science instrument consists of dual orthogonal dipole antennas and a tone-injection spectrometer/polarimeter based on high TRL components from the Parker Solar Probe/FIELDS, THEMIS, and the Van Allen Probes.
- Bradford's Xplorer Spacecraft Diagram
- Shows the communications antenna at the top and the spin axis on the bottom.
- The spacecraft is 80cm in height.
- The 4 propellant tanks are shown with the 4 RCS thruster triads.
- The 22-N thruster is shown at the bottom and the 4 body-mounted solar panels around the outside.
- The spacecraft will have 4 radial polarimeter antennas, bus avionics, RFSP, 2 keep-alive solar panels, and radiator.
- Spinning not only allows polarimetry but also stablizes attitude and temperature.
- DAPPER Instrument Diagram
- Details thermally robust antennas have been deployed in near-sun environment and in deep space.
- A basic illustration shows the wire spool, deployment stepper motor, deploy assist device (shown deployed), tip mass, approximately 3.3m fine wire and the motor controller. The EM resonance antenna is simplified for DAPPER.
- The photo shows the antenna spool as used for THEMIS.
- The last photo has the spectrometer/polarimeter used for Parker Solar Probe (a 2"x2" area is thermally regulated).