Session
Technical Session X: Advanced Technologies III
Abstract
The main objective of Project POPACS (Polar Orbiting Passive Atmospheric Calibration Spheres) is to measure the changes in density of the auroral zone upper atmosphere, in response to various solar stimuli, such as flares and CMEs. The mission consists of deploying three 10 cm diameter Aluminum spheres into an elliptical polar orbit and tracking them as they make repeated perigee passes in the upper atmosphere, with special emphasis on perigee passes within both the northern and southern auroral zones. The spheres have identical external dimensions and surface compositions, and thus identical drag coefficients, but they have different masses (1, 1.5, 2 kg) to vary their ballistic coefficients, which will cause them to spread out in right ascension along the original orbit. The Aluminum spheres will be coated with space-rated flat white paint so they can be both radar tracked by the U.S. Space Command and optically tracked by a world-wide network of university students and amateur observers with “Go To” telescopes. The observers will track the spheres, exchange their observations with each other, and calculate the density of the atmosphere above 325 km at the location of the perigee passes. POPACS will be launched during Solar Maximum 24, which is expected to peak in early 2013, and accordingly, the mission will be on a fast-track timeline: project start to launch and operation in 12 months! One of the mission enablers is the 3U Canisterized Satellite Dispenser (3U CSD) developed by Planetary Systems Corporation. While having similar internal dimensions to the P-POD (CubeSat launcher) design, the 3U CSD has key features that provide higher payload mass capability (6Kg), tabbed preload system to guarantee a stiff and modelable load path to the CubeSats, a higher ejection velocity, lower overall volume, mounting features to allow fastening of the CSD at any of the six faces, a 15 pin in-flight disconnect allowing battery charging and communication from the outside of the CSD into the payload while in the launch pad or on orbit, and a reusability that allows a separation test to be conducted at will without any consumables hundreds of times to guarantee reliability. The CSD will be qualified to levels exceeding Mil-Std-1540 for thermal vacuum, vibration and shock. The paper will provide details of the dispenser and POPACS designs, as well as descriptions of the mission concept of operations and the program’s scientific research objectives.
Presentation Slides
Counting Down to the Launch of POPACS (Polar Orbiting Passive Atmospheric Calibration Spheres)
The main objective of Project POPACS (Polar Orbiting Passive Atmospheric Calibration Spheres) is to measure the changes in density of the auroral zone upper atmosphere, in response to various solar stimuli, such as flares and CMEs. The mission consists of deploying three 10 cm diameter Aluminum spheres into an elliptical polar orbit and tracking them as they make repeated perigee passes in the upper atmosphere, with special emphasis on perigee passes within both the northern and southern auroral zones. The spheres have identical external dimensions and surface compositions, and thus identical drag coefficients, but they have different masses (1, 1.5, 2 kg) to vary their ballistic coefficients, which will cause them to spread out in right ascension along the original orbit. The Aluminum spheres will be coated with space-rated flat white paint so they can be both radar tracked by the U.S. Space Command and optically tracked by a world-wide network of university students and amateur observers with “Go To” telescopes. The observers will track the spheres, exchange their observations with each other, and calculate the density of the atmosphere above 325 km at the location of the perigee passes. POPACS will be launched during Solar Maximum 24, which is expected to peak in early 2013, and accordingly, the mission will be on a fast-track timeline: project start to launch and operation in 12 months! One of the mission enablers is the 3U Canisterized Satellite Dispenser (3U CSD) developed by Planetary Systems Corporation. While having similar internal dimensions to the P-POD (CubeSat launcher) design, the 3U CSD has key features that provide higher payload mass capability (6Kg), tabbed preload system to guarantee a stiff and modelable load path to the CubeSats, a higher ejection velocity, lower overall volume, mounting features to allow fastening of the CSD at any of the six faces, a 15 pin in-flight disconnect allowing battery charging and communication from the outside of the CSD into the payload while in the launch pad or on orbit, and a reusability that allows a separation test to be conducted at will without any consumables hundreds of times to guarantee reliability. The CSD will be qualified to levels exceeding Mil-Std-1540 for thermal vacuum, vibration and shock. The paper will provide details of the dispenser and POPACS designs, as well as descriptions of the mission concept of operations and the program’s scientific research objectives.
