Session
Session VIII: Instrument/Science Missions
Abstract
The Experiment for X-ray Characterization and Timing (EXACT) is a simple spectrometer designed for the purpose of measuring hard X-rays (HXRs) from solar flares with high time precision. Solar flares and coronal mass ejections are the sources of the most extreme space weather events. The plasma and energetic particles ejected in these events, when Earth-directed, pose radiation risks to spacecraft and astronauts, and in extreme cases could endanger the Earth's power grid. While the effects of these solar eruptive events are starting to be well characterized, the acceleration mechanisms for the high-energy particles produced are not understood.
The EXACT sensor measures bremsstrahlung HXRs from flare-accelerated electron populations to investigate their origins. The primary objectives of the project are to monitor HXR flares in the declining phase of Solar Cycle 24 and serve as a pathfinder for a simple, cost-effective HXR spectrometer that will be a high- energy counterpart to the soft X-ray monitor aboard the GOES set of spacecraft. EXACT will also perform precise timing studies of solar HXRs to investigate time-of-flight effects of electron beams and their acceleration site heights, and can perform serendipitous science in conjunction with other Xray observatories.
To achieve these objectives, EXACT is a 3-axis-stabilized, sun-pointed, 3U CubeSat that uses a highenergy radiation sensor with photon time tagging to 1 µs. This high-precision time-tagging will allow the instrument to serve the additional purpose of testing/demonstrating the concept of spacecraft relative ranging using gamma-ray burst timing. It is therefore a dual-use sensor that can serve as a relative position, navigation and timing instrument for GPS/GNSS-denied satellite operations, independent of its solar purposes.
Due to its simplicity and high time precision, EXACT is a versatile instrument useful for both solar and astrophysical high-energy sources. EXACT will serve as a pathfinder for a set of CubeSats that can provide continuous, long-term solar HXR monitoring, and can, with serendipitous co-observations, perform groundbreaking new science in the study of solar flare-accelerated electrons, helping to understand the basic generation of the powerful solar sources of space weather.
EXACT: Experiment for X-Ray Characterization and Timing
The Experiment for X-ray Characterization and Timing (EXACT) is a simple spectrometer designed for the purpose of measuring hard X-rays (HXRs) from solar flares with high time precision. Solar flares and coronal mass ejections are the sources of the most extreme space weather events. The plasma and energetic particles ejected in these events, when Earth-directed, pose radiation risks to spacecraft and astronauts, and in extreme cases could endanger the Earth's power grid. While the effects of these solar eruptive events are starting to be well characterized, the acceleration mechanisms for the high-energy particles produced are not understood.
The EXACT sensor measures bremsstrahlung HXRs from flare-accelerated electron populations to investigate their origins. The primary objectives of the project are to monitor HXR flares in the declining phase of Solar Cycle 24 and serve as a pathfinder for a simple, cost-effective HXR spectrometer that will be a high- energy counterpart to the soft X-ray monitor aboard the GOES set of spacecraft. EXACT will also perform precise timing studies of solar HXRs to investigate time-of-flight effects of electron beams and their acceleration site heights, and can perform serendipitous science in conjunction with other Xray observatories.
To achieve these objectives, EXACT is a 3-axis-stabilized, sun-pointed, 3U CubeSat that uses a highenergy radiation sensor with photon time tagging to 1 µs. This high-precision time-tagging will allow the instrument to serve the additional purpose of testing/demonstrating the concept of spacecraft relative ranging using gamma-ray burst timing. It is therefore a dual-use sensor that can serve as a relative position, navigation and timing instrument for GPS/GNSS-denied satellite operations, independent of its solar purposes.
Due to its simplicity and high time precision, EXACT is a versatile instrument useful for both solar and astrophysical high-energy sources. EXACT will serve as a pathfinder for a set of CubeSats that can provide continuous, long-term solar HXR monitoring, and can, with serendipitous co-observations, perform groundbreaking new science in the study of solar flare-accelerated electrons, helping to understand the basic generation of the powerful solar sources of space weather.
