19 Mar 2004
(Source: Johns Hopkins University Applied Physics Laboratory)
MESSENGER Mission News
March 19, 2004
This week's Webcam image shows MESSENGER in Florida undergoing final testing and preparation for launch in May. The spacecraft's solar panels, removed before last week's shipment to the Astrotech Space Operations facility, can be seen on special stands awaiting reinstallation.
The distinctive, temporary red covers have been removed from the two antenna assemblies, allowing an excellent view of the actual antenna systems. Shown in this image is the back antenna assembly; each assembly is actually four antennas. While at Mercury the low-gain antenna will be used only for spacecraft-to-Earth (downlink) communication at low data rates, while the phased array antennas will provide downlink capability at higher data rates (averaging 9 kilobits per second). The fanbeam actually serves as two antennas, providing both uplink and downlink at moderate data rates (523 bits per second, for downlink).
Over the course of the Mercury orbital mission MESSENGER should return at least 78 gigabits of compressed science data, enabling scientists to unravel the origin and evolution of this mysterious planet.
Remaining tasks before launch include final alignment of spacecraft components and scientific instruments, fueling, spin balancing and mating to the Delta II rocket's third stage.