What is Surveyor made of?
Most of the structure is composed of a honeycombed aluminum mesh with thin graphite epoxy sheets attached to the inside and outside faces. This combination is light, but extremely durable. The power producing cells on the solar arrays are made out of silicon and gallium arsenide.

What are the dimensions of Surveyor?
Surveyor measures about 10 meters from the tip of one solar array to the tip of the array on the opposite side. Not including the science instruments bolted to the top, the main body of the spacecraft is about 1.9 meters tall and 1.4 meters wide. The tallest science instrument adds another 1.1 meters to the height.

During mapping operations at Mars, the high-gain antenna will sit at the end of a two-meter boom attached to the main body of the spacecraft. This antenna will provide the primary means of communicating with the Earth.

How long did it take to build Surveyor?
The entire process took approximately two years. Mars Global Surveyor was approved for development in the Fall of 1993, shortly after the loss of Mars Observer. It is difficult to say when construction began because many of the parts for Surveyor were inherited spare parts from the construction of Mars Observer. However, final assembly of Surveyor began in August 1995, and the spacecraft was shipped to Cape Canaveral one year later in August 1996. Then, a several-month series of final tests were performed before the November 1996 launch.

How fast does Surveyor transmit data to Earth?
The answer depends on Surveyor's distance to the Earth. When Mars is farthest from the Earth during mapping operations (summer 1998), the maximum data rate will drop as low as 21,333 bits per second. When Mars is closest to the Earth (summer 1999), Surveyor will use a data rate of 85,333 bits per second. At times in between those two extremes, Surveyor will use a medium data rate of 42,667 bits per second. In contrast, modems on home computers transmit data at an average speed of 28,800 bits per second.

What happened to Surveyor's solar panel?
The solar panel on the -Y side of the spacecraft is fully deployed, but 20.5 degrees out of position. What happened is that a damper shaft in the solar array's deployment mechanism broke shortly after launch. Data form the spacecraft indicates that this event occurred 43 seconds after the array began unfolding from its launch-stowed configuration into its flight deployed configuration.

This damper is a device that was installed to minimize the mechanical shock of deployment by slowing the motion of the array during deployment. The flight team theorizes that the broken shaft caused the damper arm to wedge into the hinge joint connecting the solar panel to the spacecraft.

Efforts are underway to determine the best method to free the damper arm from the hinge joint. However, the -Y solar panel is currently generating full power, and the 20.5 degree position discrepancy does not pose a significant threat to the success of the mission.