Session
Technical Session II: Future Missions 1
Abstract
Gamma-ray bursts (GRBs) are the most brilli ant events in the uni verse. We describe a system design concept to study a gamma-ray burst (GRB) dark energy mission that would utilize two di fferent methods to tightly constrain the properties of dark energy. Both methods hold great promise for determining the expansion history of the uni verse. The concept for our mission calls for fo ur small spacecraft placed at L2 in the Earth-Sun system. One minisatellite (ESat) would carry arrays of X-ray and gamma- ray detectors for determining isotropic-equivalent energy and peak energy of the burst spectrum, while three identical microsatellites (JetSat) would carry high throughput optical photometers fo r determining jet-break time from the burst afterglows. The mission concept also incorporates six dedicated, ground-based 2-m telescopes with integral fie ld spectrographs distributed in longitude for promptly determining GRB redshifts. Several possible orbits were evaluated for the GDEM constellation. We have concluded that the L2 orbit is superior to LEO because, (a) fewer vehicles will be needed, (b) Earth and Moon ecl ipses can be avoided by the choice of a wide halo orbi t or minimized by a small-ampl itude Lissajous orbit; and (c) all satellites can point anywhere in the anti -solar hemisphere at any time.
Presentation Slides
System Architecture for the Gamma-Ray Burst Dark Energy Mission (GDEM)
Gamma-ray bursts (GRBs) are the most brilli ant events in the uni verse. We describe a system design concept to study a gamma-ray burst (GRB) dark energy mission that would utilize two di fferent methods to tightly constrain the properties of dark energy. Both methods hold great promise for determining the expansion history of the uni verse. The concept for our mission calls for fo ur small spacecraft placed at L2 in the Earth-Sun system. One minisatellite (ESat) would carry arrays of X-ray and gamma- ray detectors for determining isotropic-equivalent energy and peak energy of the burst spectrum, while three identical microsatellites (JetSat) would carry high throughput optical photometers fo r determining jet-break time from the burst afterglows. The mission concept also incorporates six dedicated, ground-based 2-m telescopes with integral fie ld spectrographs distributed in longitude for promptly determining GRB redshifts. Several possible orbits were evaluated for the GDEM constellation. We have concluded that the L2 orbit is superior to LEO because, (a) fewer vehicles will be needed, (b) Earth and Moon ecl ipses can be avoided by the choice of a wide halo orbi t or minimized by a small-ampl itude Lissajous orbit; and (c) all satellites can point anywhere in the anti -solar hemisphere at any time.
