LONG LIFE DIGITAL ATTITUDE CONTROL SYSTEM: ESTIMATE OF COMPUTATIONAL REQUIREMENTS,
Abstract
The report is the second in a series aimed at determining the requirements and configuration for a long-life satellite attitude control system in which all logic and computation functions are performed in a time-shared general purpose digital computer. The purpose of this report is to derive accurate estimates of the requirements imposed upon the digital computer by the attitude control equations. A programming specification based on these equations is first presented. Based on that specification, estimates of the computational requirements of the attitude control task are derived in terms of required memory storage and computation speed for typical spaceborne computers. The attitude control program is found to require 877 instructions and 226 words of data storage. This requirement represents 9.3 percent of the storage capacity of a Univac 1824 or 13.5 percent of the capacity of an IBM 4 pi computer. The computation speed requirement is estimated to be 24,300 equivalent adds/sec, which represents 19.4 percent of the 1824's speed capability, or 12.2 percent of the capability of the 4 pi. It is therefore concluded that the appreciable advantages in weight, power, and reliability resulting from the use of an available general purpose digital computer for satellite attitude control can be achieved at a very reasonable cost in terms of computer utilization. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1967
- Accession Number
- AD0659163
Entities
People
- William K. Clarkson
Organizations
- The Aerospace Corporation