DANDE

Image: University of Colorado at Boulder
Image: University of Colorado at Boulder

DANDE, the Drag and Atmospheric Neutral Density Explorer, is a spherical satellite with a diameter of 46 centimeters and a mass of ~50 Kilograms hosting a number of science sensors to provide data on the satellite drag environment in the low-thermosphere in addition to other atmospheric measurements.

The satellite was designed by students at the University of Colorado. DANDE is spin stabilized, spinning at 10RPM. For drag measurements, the satellite has to be as spherical as possible. Therefore, it features small body mounted solar panels to provide electrical power.

DANDE hosts two primary instruments – an accelerometer suite and the Wind and Temperature Spectrometer that are aligned together to enable velocity vector scanning. The accelerometer suite measures acceleration and deceleration due to local variations in atmospheric densities and in-track winds. The system is comprised of six commercial-grade accelerometers that are mounted radially within the satellite sphere.

Photo: University of Colorado at Boulder
Photo: University of Colorado at Boulder

The six accelerometers are rotated through the velocity vector of the spacecraft at a known rate depending on spacecraft spin rate creating a sinusoidal signal output on the six channels. The amplitudes of the output indicate the drag acceleration. Averaging the six measurements provides an accurate acceleration measurement due to atmospheric drag. The accelerometer suite is 10 by 11.5 by 6.3 centimeters in size weighing 1.3 Kilograms.

The Wind and Temperature Spectrometer measures the atomic densities of the local neutral atmosphere using a Small-Deflection Energy Analyzer to study the kinetic energy of neutral particles such as atomic Oxygen and molecular Nitrogen. Particle impacts are detected by a Microchannel Plate. The instrument is 10 by 10 by 7.5 centimeters in dimensions with a mass of 1.6 Kilograms.

Drag measurements are supported by precise tracking via ground-based assets.