Atmospheric Neutral Density Experiment


The Atmospheric Neutral Density Experiment (ANDE) Risk Reduction flight was launched on Dec. 9, 2006 and deployed into orbit by the Space Shuttle Discovery on Dec. 21, 2006. The primary mission objective is to test the deployment mechanism from the Shuttle for the ANDE flight in mid 2009. Scientific objectives of the ANDE risk reduction flight include; monitor total neutral density along the orbit for improved orbit determination of resident space objects, monitor the spin rate and orientation of the spacecraft, provide a test object for the space surveillance network (SSN) sensors, both radar and optical.

Each of the two ANDE missions consists of two spherical spacecraft fitted with retro-reflectors for satellite laser ranging (SLR). The constant and well-determined cross section and surface properties of the ANDERR spacecraft provide an ideal set of objects for monitoring atmospheric drag and the calibration of SSN assets. The ANDE risk reduction mission spacecraft each contain a small lightweight payload designed to determine the spin rate and orientation of the spacecraft from on-orbit measurements and from ground based observations.

The two satellites are named after the heroic Spartan brothers, the Dioscuri, who rescued their sister Helen from Theseus. The her twins also sailed with the Argonauts. Castor was mortal while his brother Pollux qualified to be admitted to the godly congregation on Mount Olympus. They are eternally joined in the night sky as a constellation of the twins Gemini.

Both satellites will operate in the 2 meter amateur radio band. They will include an amateur radio experiment and are part of an educational outreach effort with high school and university students.

Launch date; July 2009, STS-127