The AEPEX CubeSat Mission: Quantifying Energetic Particle Precipitation through Bremsstrahlung X-Ray Imaging

Fundamental gaps exist in the understanding and observation of energetic particle precipitation (EPP),a solar-terrestrial coupling mechanism that is vital for climatelogical modeling of the atmosphere and magnetosphere. The Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) mission is a 6U CubeSat that will measure energetic electron spectra and X-ray images in order to quantify the spatial scales and amount of energy input into the atmosphere, and therefore lost from the magnetosphere, via EPP. AEPEX includes two instruments; AEPEX’s FIRE (Focused Investigations of Relativistic Electron) instrument (AFIRE), a TRL 9 electron detector previously flown on the FIREBIRD mission; and the Atmospheric X-ray Imaging Spectrometer (AXIS), an instrument being developed at CU Boulder that will take novel images and spectra of 50–300 keV X-ray photons. This work describes the AEPEX mission overview, the detailed design and operation of AXIS, and initial test and calibration results

CubeSat Active Thermal Control via Microvascular Carbon Fiber Channel Radiator

Small spacecraft rarely have space for any thermal control subsystems and often must perform operations in “burst” mode as a result. The few spacecraft who do have control rely on low-complexity thermal control systems which conduct heat to the bus structure and then radiate the heat away. These simplistic techniques are sufficient for low power missions in Low Earth Orbit (LEO) but are not capable of dumping the heat produced in new mission profiles that are in development. This is due to small spacecraft incorporating increasingly advanced subsystems which have difficult thermal control requirements such as propulsion systems or high-power antennas. The University of Illinois at Urbana-Champaign, in partnership with NASA Ames Research Center, is developing a thermal control system for small spacecraft. This control system uses a deployable radiator panel made from carbon fiber with micro-vascular circulatory system for coolant. This paper is a follow-up on the previous year’s SmallSat conference. A bench prototype of the thermal control subsystem was designed and built. The prototype underwent a range of thermal and vibration tests at NASA Ames. Test results and lessons learned are presented. Moving forward, test conclusions will require some design parameters to be changed and the subsystem will reach TRL 6 by the end of the two-year program

The AEPEX Mission: Imaging Energetic Particle Precipitation in the Atmosphere through its Bremsstrahlung X-ray Signatures

The Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) mission is a 6U CubeSat that will monitor energetic electron precipitation from the radiation belts into the upper atmosphere. The primary instrument will image energetic (50&ndash;300 keV) X-rays produced in the atmosphere by bremsstrahlung, providing a near-direct signature of electron precipitation. An energetic electron detector will measure the precipitating electron spectrum, while the X-ray observations will be used to determine the absolute flux. X-ray images will be produced with 10-s time resolution and 50&ndash;100 km spatial resolution. The 6U spacecraft uses flight heritage spacecraft bus subsystems, including the attitude determination and control, electrical power, and command &amp; data handling systems. AEPEX is designed to be operated from low-Earth orbit at ~500 km altitude with a high inclination in order to cover the outer radiation belt. AEPEX will be the first spacecraft mission to measure X-rays in the 50&ndash;300 keV energy range emitted by Earth&rsquo;s atmosphere in response to radiation belt precipitation, and the first to image that precipitation from above.</p