Accession Number:

AD0912593

Title:

Space Precision Attitude Reference System (SPARS) Phase II.

Descriptive Note:

Final rept. 4 Apr 71-28 Feb 73,

Corporate Author:

HONEYWELL INC ST PETERSBURG FL AEROSPACE DIV

Report Date:

1973-03-01

Pagination or Media Count:

339.0

Abstract:

The primary objectives of the SPARS Phase II program were to design and fabricate a Mod II SPARS and to subject SPARS to a series of environments as part of a Limited Qualification Testing LQT program. The LQT was aimed at identifying weaknesses in the basic design that could prevent subsequent successful flight qualification of the total system. In support of this primary objective a laboratory for calibration and system level testing of SPARS was established flight software was developed in SPL SPL compilers were brought to an operational status the Star Sensor Assembly SSA and photodetector were space qualified and SPARS on-orbit performance was established via simulation and analysis of test results. Based on analysis and LQT results, the Mod II SPARS is capable of performance in the 8-10 arc second 3 axis, 1 sigma range. The performance requirement of 4 arc seconds was not met because of star sensor and IRA alignment changes caused by exposure to vibration, shock and temperature environments. Aimed at meeting the 4 arc second performance requirement, the following design changes are recommended a Thermally isolate the SABAs from the base assembly, b Improve IRA and SSA mounting stability by positional doweling, bolting and base assembly stiffening, and c Reduce the thermal operating range of SPARS. As a result of the Phase II program it was also concluded that a The current method of SSA calibration is marginal for SPARS performance levels and it is recommended that an improved calibration technique be developed for future applications and b SPL is a viable approach to flight software.

Subject Categories:

  • Space Navigation and Guidance
  • Astronautics
  • Unmanned Spacecraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE