IMAGE

USA

Imager for Magnetopause-to-Aurora Global Exploration - Also called Explorer 78 and MIDEX 1

Launch data:

Designation:26113 / 00017A
Launch date25 Mar 2000 - 20:34:43 UT
Launch site Va, SLC-2W
Launch vehicle: Delta 7326-9.5 (#D277)
Mission:Scientific: magnetosphere study
Earth orbit on Mar 25.90, 2000:
Perigee / Apogee 994 x 46115 km
Eccentricity 0.754
Inclination 89.93 deg
Period 858.98 min
Earth orbit on Dec 22.91, 2005:
Perigee / Apogee 1659 x 45213 km
Eccentricity 0.730
Inclination 89.77 deg
Period 853.88 min

The Image mission will use three dimensional imaging techniques to study the global response of the Earth's magnetosphere to variations in the magnetic activity of the Sun. It will be the first satellite that will take pictures of the magnetosphere as it changes shape.

The satellite is part of NASA's Midex program.

Specifications

Prime contractor Lockheed Martin
Platform LM100
Mass at launch 494 kg
Mass in orbit  
Basic shape  8-sided drum
Dimension2.25 m diameter x 1.52 m height
Solar array  
Stabilization spin-stabilized (0.5 rpm)
DC power 250 W
Design lifetime 2 years

The IMAGE spacecraft has 3 antennas for S-band communication with the ground: a medium-gain helix antenna and two low-gain omni-directional antennas.
Downlink rate: 2.28 Mbps (every 14.2 hours) plus a realtime transmission at 44 kbps.
Uplink rate: 2 kbps (once a week)
Communication via the Deep Space Network

Instruments

Image carries six instruments: HENA (High Energy Neutral Atom; 10-500 keV) imager, MENA (Medium Energy Neutral Atom; 1-30 keV) imager, LENA (Low Energy Neutral Atom; 10-500 eV) imager, FUV (Far Ultra-Violet) imager, EUV (Extreme Untra-Violet) imager, and RPI (Radio Plasma Imager).

HENA, MENA, and LENA synthesize images from the arrival directions and mass/energy of each neutral particle. (The energetic neutrals form an ephemeral population when energetic ions charge-exchange with the thermal population.) FUV carries three separate detectors: WIC (Wide Angle Camera) to image aurora in a broad band and high spatial resolution (based on the UVI aboard Polar), SI (Spectroscopic Imager) to image aurora at selected wavelengths, and GEO (GEOcorona) to image overall magnetospheric hydrogen atoms. EUV images the population of He+ through the resonantly scattered solar radiation at 30.4 nm wavelength. Finally, RPI consists of a pulsed transmitter (stepped 3 kHz to 3 MHz, 134 W peak) and a receiver, backed a radial dipole of 500 m length, another orthogonal 500 m dipole, and an axial 20 m dipole, to get echoes from boundary regions in the magnetosphere.
Ref: #7, #15, #27, #206 - update: 10.07.11