HETE 2

USA

International Sat. n°:

USA satellite n°:

High-Energy Transient Experiment - Also called: Explorer 79

Launch data:

Designation:	26561 / 00061A
Launch date	09 Oct 2000 - 05:38:18 UT
Launch site	Kwajalein Missile Range (KMR) L-1011, RW06/24
Launch vehicle:	Pegasus-H (#F30/P-35)
Mission:	Scientific: gamma-ray astronomy
Earth orbit on:
Perigee/Apogee	592/634 km
Inclination	2°
Period

This satellite was funded to replace HETE which was lost right after launch. The launch site was chosen because it is optimum for equatorial orbits. The mission control center was in Cape Canaveral and communication channels were setup for remote control.

It will carry out the first multiwavelength study of gamma-ray bursts with UV, X-ray, and gamma-ray instruments mounted on a single, compact spacecraft. A unique feature of the HETE mission is its capability to localize GRBs with ~10 arc second accuracy, in near real time aboard the spacecraft, and to transmit these positions directly to a network of receivers at existing ground-based observatories, enabling rapid, sensitive follow-up studies in the radio, IR, and optical bands.

Specifications

Prime contractor	MIT
Platform
Mass at launch	123 kg
Mass in orbit
Dimension
Solar array
Stabilization
DC power
Design lifetime

Omnidirectional Gamma-Ray Spectrometer (Fregate)

Build by	CESR (France)
Instrument type	NaI(Tl); cleaved
Energy range	6 keV to > 1 MeV
Timing resolution	4 ms
Spectral resolution	~40% @ 6 keV; ~7% @ 662 keV
Effective area	120 cm^2
Sensitivity (10 sigma)	3 x 10^-8 erg/cm**2/s for 8-1000 keV
FOV	~ 2 pi sr
Angular resolution	~ 1 sr

Wide Field X-ray Monitor

Build by	RIKEN (Japan) and Los Alamos
Instrument type	Coded Mask with Position Sensitive Proportional Counter
Energy range	2 to 25 keV
Timing resolution	1 ms
Spectral resolution	~15% @ 6 keV
Effective area	200 cm^2 (each of 2 units)
Sensitivity (10 sigma)	8 x 10^-9 erg/cm^2/s for 2-10 keV
FOV	~ 2 sr (combined)
Angular resolution (1 sigma)	+-6 arcmin

Soft X-ray Camera

Build by	MIT CSR
Instrument type	4 CCD20 Detectors, 2 optical CCD22
Energy range	500 eV to 14 keV
Timing resolution	1 s
Spectral resolution	46 eV @ 525 eV, 129 eV @ 5.9 keV
Effective area	6.1x6.1 cm^2 (each of 2 units)
FOV	~0.91 sr
Dimension	10 cm x 10 cm x 17.5 cm

The spacecraft hardware and software is being developed by Aeroastro (USA).

Downlink frequencies: 137.963, 2255.5 & 2272 MHz

Ref: #7, #15 - update: 17.08.08