Two microsatellites launched from the Shuttle payload bay will measure the density and composition of the low Earth orbit (LEO) atmosphere while being tracked from the ground. The data will be used to better predict the movement of objects in orbit.Principal Investigator(s)
United States Department of Defense Space Test Program, Johnson Space Center, Houston, TX, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Department of Defense (DoD) - RetiredISS Expedition Duration
September 2006 - April 2007
14Previous ISS Missions
STP-H2-ANDE is a unique investigation that has not been operated in microgravity.
ANDE consists of two spherical micro satellites, the Mock ANDE Active (MAA) spacecraft and the Fence Calibration (FCal) spacecraft. These satellites were launched from the space shuttle cargo bay into a circular orbit
just below the ISS altitude. The ANDE mission's main objective is to measure the total atmospheric density and composition between 100 and 400 km. The density data that is gathered will be used to better characterize the parameters used to calculate a satellite's drag coefficient and improve orbit determination calculations of resident space objects.
Both satellites will be tracked by the Satellite Laser Ranging (SLR) system and the U.S. Space Surveillance Network (SSN). These satellites have similar dimensions, but are constructed of different materials and have different masses. Because of the difference in mass, the satellites will drift apart over time. Observing the satellites' position will provide a study on spatial and temporal variations in atmospheric drag associated with geomagnetic activity. The FCal sphere will also be used to perform calibrations for the U.S. Radar Fence.
Understanding the atmospheric effects on spacecraft in Low Earth Orbit will lead to improved calculations for orbit determinations and collision avoidance.Earth Applications
Improving calculations that are used when observing orbits, may lead to advancements in the fields of mathematics and physics here on Earth.
ANDE uses two spherical micro satellites, the Mock ANDE Active (MAA) and the Fence Calibration (FCal), which are launched from the Space Shuttle cargo bay. The MAA satellite is a 19 inch diameter sphere, has a mass of 50 kg, and is constructed of aluminum. The surface of the MAA sphere contains an embedded array of sensors including 30 retro reflectors, six laser diodes for tracking, and six photovoltaic cells for determining orientation and spin rate. The FCal satellite is 17.5 inches in diameter, has a mass of 75 kg, and is constructed of nickel-plated brass. The FCal spacecraft is also fitted with 30 retro reflectors, six phototransistors, and four whip antennae. Both spheres also have thermal monitor systems. The ANDE spacecraft are located inside the Internal Cargo Unit (ICU). The ICU is made of three aluminum sections. Each section is separated by a light band separation system. Once ejected from the cargo bay, the ICU will separate and deploy the ANDE spheres at a safe distance from the shuttle.Operational Protocols
ANDE will be launched from the Space Shuttle cargo bay. The two micro satellites will be contained inside the ICU canister. Once the ICU canister is a safe distance from the Space Shuttle, two micro satellites will be released at an altitude of approximately 350 km.
The ANDE satellite re-entered the earth’s atmosphere on December 25, 2007, over a year after deployment. Its orbital decay was tracked by the MAUI Laser Ranging Tracking Station. Because the satellite carried packet radio communications systems operating in the Amateur Satellite Service, ham radio volunteer ground stations were critical for telemetry feeds that included temperature and battery life. (Evans et al. 2009)
Nicholas A, Budzien SA, Healy L, DeYoung J, Davis M. Results from the Atmospheric Neutral Density Experiment Risk Reduction Mission. AIAA/AAS Astrodynamics Specialist Conference and Exhibit; 2008; Honolulu, HI.