This document establishes the requirements for the Mars Global Surveyor spacecraft. Section 1 contains definitions; all other sections contain requirements.
The following definitions of terms and abbreviations are used in this document.
The spacecraft bus comprises all assemblies, engineering subsystems, associated flight software, and miscellaneous hardware that constitute the spacecraft without the science instruments. It includes all propellant required by the spacecraft after injection, as well as government-furnished property (GFP) used, excluding the payload.
Included as a part of the spacecraft bus is a stub adapter or other means which provide the spacecraft side of the interface with the L/V-to-S/C separation plane.
The payload consists of the complement of the science instruments provided as GFP.
The spacecraft is the composite of the spacecraft bus and the payload after integration.
The Delta launch vehicle is the Delta II 7925 configuration consisting of a solid motor augmented first stage, a liquid propulsion restartable second stage, a spin- stabilized solid propulsion third stage, and a payload fairing.
The third stage consists of all assemblies, subsystems, associated flight software, and miscellaneous hardware used to inject the spacecraft onto the heliocentric trajectory to Mars from low-Earth orbit.
The ground support equipment (GSE) comprises the ground hardware and software required to verify and check out the elements of the spacecraft during fabrication, assembly, testing, prelaunch, launch, and post- launch operations.
The mission operations system (MOS) consists of the complement of ground hardware, software, procedures, and personnel used to conduct flight operations.
The launch phase extends from the start of the launch countdown to separation of the spacecraft from the Delta third stage.
The cruise phase extends from separation of the spacecraft from the third stage to the initiation of the orbit insertion sequence. It includes initial checkout of the spacecraft, and the required trajectory correction maneuvers (TCM) and calibrations.
The orbit insertion phase extends from the initiation of the Mars orbit insertion (MOI) sequence until the spacecraft is declared ready to collect mapping phase science data. During this phase, the insertion into the mapping orbit will be accomplished, and the spacecraft configured to commence science data collection.
The mapping phase is the time period during which science data are returned from the Mars mapping orbit. It extends 687 Earth days after the end of the orbit insertion phase, from approximately January 1998 through November 1999.
Upon completion of mapping phase, the spacecraft shall function primarily as a relay satellite for the remainder of the 5-earth-year on- orbit design life. This phase is from approximately November 1999 through November 2002.
A DSN pass is defined as a single continuous 10-hour period during which a Deep Space Network (DSN) station is available for spacecraft tracking, commanding, and telemetry return.
Near-circular, 400-km index altitude orbit.
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