Atmospheric Neutral Density Experiment - 2 (ANDE-2) - 09.17.14
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Science Objectives for Everyone
Atmospheric Neutral Density Experiment - 2 (ANDE-2) consists of two microsatellites launched from the Shuttle payload bay, that 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 and decay of objects in orbit.
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United States Department of Defense Space Test Program, Johnson Space Center, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Department of Defense (DoD) - Retired
ISS Expedition Duration
March 2009 - October 2009
Previous ISS Missions
ANDE-2 will be operated on Space Shuttle mission 2JA. The precursor to ANDE-2, Space Test Program-H2-Atmospheric Neutral Density Experiment (STP-H2-ANDE) was performed on STS-116/12A.1.
- Atmospheric Neutral Density Experiment - 2 (ANDE-2) objectives are to measure atmospheric density and composition in low Earth orbit (LEO) and to better characterize the parameters used to calculate a satellite's drag coefficient.
- This experiment consists of two microsatellites, called ANDE Active (AA) spacecraft (Castor) and the ANDE Passive (AP) spacecraft (Pollux), that are launched from the Space Shuttle cargo bay.
- These spherical satellites are 19 inches in diameter and will be tracked by the Satellite Laser Ranging systems and the Space Surveillance Network.
The main objective of Atmospheric Neutral Density Experiment - 2 (ANDE-2) is to measure the total atmospheric density between 100 and 400 km. The density data that is gathered will be used to improve orbit determination calculations of the orbits of resident space objects.
ANDE-2 consists of two spherical micro satellites. These satellites are launched from the Space Shuttle cargo bay into a circular orbit just below the International Space Station altitude.
Both satellites will be tracked by the Satellite Laser Ranging (SLR) system and the U.S. Space Surveillance Network (SSN). These satellites have the same dimensions, but 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.
Understanding the atmospheric effects on spacecraft in low Earth orbit will lead to improved calculations for orbit determinations and collision avoidance.
Improving calculations that are used when observing orbits, may lead to advancements in the fields of mathematics and physics on Earth.
ANDE-2 uses two spherical microsatellites which are launched from the Space Shuttle cargo bay. Both satellites are 19 inch diameter spheres, have a mass of 50 and 25 kg, and are constructed of aluminum. The surface of both spheres 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. 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.
ANDE will be launched from the Space Shuttle cargo bay. The two microsatellites 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.
ANDE, RAFT, NMARS, & FCAL Operations
NASA Image: S127E012325: Atmospheric Neutral Density Experiment 2 (ANDE-2) is released from the shuttle's payload bay by STS-127 crew members. ANDE-2 consists of two spherical micro-satellites which 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.
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