|HAXDT payload mounted on the HASP gondola, which is being prepared for the thermal vacuum chamber at NASA's Columbia Scientific Balloon Facility in Palestine, TX on August 3, 2012|
Grad student prepares payload for HASP flight
The University of Minnesota’s High Altitude X-ray Detector Testbed (HAXDT) is a high altitude balloon payload currently under development by Masters student Patrick Doyle and Professor Demoz Gebre-Egziabher to test and validate the performance of a compact X-ray detector and its associated flight hardware. This project is part of their research into deep space X-ray navigation, which uses X-ray pulsars as navigation beacons, much as we use GPS satellites for navigation on Earth. HAXDT is supported by the Minnesota Space Grant Consortium.
This payload is configured to be flown on the High Altitude Student Platform (HASP), which is designed to carry twelve student payloads to an altitude of 36 kilometers with flight durations of up to 20 hours using a small volume, zero pressure balloon. HASP is supported by the NASA Balloon Program Office and the Louisiana Space Consortium, and has annual flights in September from the Columbia Scientific Balloon Facility (CSBF) base in Fort Sumner, New Mexico. The inaugural HAXDT launch onboard HASP is scheduled to occur on September 3, 2012. HAXDT GPS position and temperature data as well as a video stream of the flight will be available on the HASP website during flight operations.
The HAXDT payload consists of a flight computer and daughter board, onboard flash storage, attitude and navigation sensors (IMU and GPS), a power regulation and protection circuit, and a small detector capable of capturing high energy photon events and its associated hardware, with components generously donated by Lockheed Martin Space System Company's Advanced Technology Center and Amptek, Inc. The flight computer and attitude determination package has been developed by the Uninhabited Aerial Vehicle (UAV) Research Group at the University of Minnesota. The UAV Group's flight code has been custom edited to perform attitude determination while collecting data from an X-ray detector.
The payload is designed to conform to CubeSat infrastructure standards, based on one or more cubes with internal dimensions of 10 cm x 10 cm x 10 cm. A single cube is known as a 1-U, or unit volume, configuration. The HAXDT payload is in a 2.5-U configuration and is composed of 6061-T6 aluminum. The CubeSat infrastructure allows the payload to be easily reconfigured to accommodate additional hardware components and future upgrades to X-ray detector hardware. The payload is ultimately being designed to test the system in space, thus the CubeSat model provides a flexible platform that can be modified for future space flight opportunities. Such modifications could include solar panels for onboard power and a shielded detector capable of being pointed at various X-ray sources.
The goal of the detector experiment on this inaugural flight of the HAXDT payload is to collect a time history of detected photons along the flight trajectory. The payload’s navigation and attitude sensors will provide an accurate position and orientation of the HAXDT payload, thus allowing the detector data to be examined for sources such as the sun or other energetic celestial bodies. It is anticipated that the flight will launch during the day and last up to 20 hours, thus the sun will set during the flight and a noticeable drop in photon events should be apparent. It is also anticipated that periods of higher photon flux can be examined and related to the payload’s position in order to examine the sky for possible celestial bodies capable of emitting high-energy cosmic rays.