HRC Operations: Constraints, Restrictions & Limitations

Introduction

In operating the AXAF observatory there are actions that could damage or limit the usefulness or operation of the observatory or any of its subcomponents. These actions are cataloged in the TRW document AXAF Operations Constraints, Restrictions, and Limitations (OP05) also known as the CARD. The three types of "rules" are defined as follows:

Constraint: A constraint is a rule that must not be violated. Constraints are written against activities for conditions which are expected to cause irreversible hardware damage.
Restriction: A restriction is a rule that must not be violated unless the tradeoff between the activity and the risk is acceptable and approved by the AXAF operations manager. Restrictions are written against activities which are expected to cause irreversible degradation of hardware or instrument capability, or disruption in the AXAF mission schedule.
Limitation: A limitation is a rule which if violated will cause temporary loss of data, temporary degradation of components within the AXAF, subsystem inconvenience, or loss of operating time.

The HRC has a few activities that fall under the above rules. I solicited items for the list from the HRC IPI team suggesting some of my own and submitted the following list to the TRW operations group at Space Park.

HRC Activities to be Avoided

Constraints

HRC-C-001 HRC HOUSING DOOR MOVEMENT AND FOCUS SHUTTERS
HRC-C-002 HRC HOUSING PRESSURE AT MCP HV TURN-ON
HRC-C-003 HRC HIGH VOLTAGE POWER SEQUENCE
HRC-C-004 HRC MCP HIGH VOLTAGE LIMIT
HRC-C-005 HRC DETECTOR SWITCHING
HRC-C-006 HRC HIGH VOLTAGE AND DETECTOR SELECTION
HRC-C-007 HRC HIGH VOLTAGE AND ELECTRONIC CALIBRATION MODE
HRC-C-008 HRC Focus Shutters Movement and Housing Door
HRC-C-009 Spacecraft Power Bus Configuration for the HRC
HRC-C-010 HRC Electronics Power Configuration
HRC-C-011 HRC Power Internal Configuration

Restrictions

HRC-R-001 LOWERED MCP HV WHEN SLEWING
HRC-R-002 LOWERED MCP HV IN RADIATION ZONES
HRC-R-003 Bright Source observations with the HRC and an OTG
HRC-R-004 Minimum dither frequency with HRC at aim-point

Limitations

HRC-L-002 Closing the HRC Housing Door
HRC-L-003 HRC Door Operation during ACIS Observations
HRC-L-005 Telemetry Format Changes

$Log: index.html,v $

Revision 1.15 2001/11/08 14:46:10 juda

HTML "href" tag edits to convert to soft links

Revision 1.14 1999/01/26 18:35:00 juda

Changed descriptive text of HRC-C-009, HRC-C-010, and HRC-C-011

Revision 1.13 1999/01/13 19:24:08 juda

removed HRC-L-004 "HRC Autonomous Power-Up"

Revision 1.12 1999/01/06 16:29:48 juda

Added "Telemetry Format Changes" limitation

Revision 1.11 1998/10/14 13:43:59 juda

added 3 "HRC Power Configuration" Constraints

Revision 1.10 1998/09/21 18:24:38 juda

Reorganized layout of links to individual pages - categorized as "Constraints", "Restrictions", and "Limitations"

Revision 1.9 1998/06/29 18:56:10 juda

removed "?" from "HRC-C-008" and "HRC-L-004"

Revision 1.8 1998/06/17 19:25:19 juda

Added DOCTYPE declaration - Updated numbers to be consistent with TRW CARD version of 1998 May 15

Revision 1.7 1998/06/01 21:05:26 juda

Added "HRC Door Operation during ACIS Observations" limitation from J. Donaghy

Revision 1.6 1998/05/11 16:54:50 juda

Added $Log: index.html,v $

Added Revision 1.15 2001/11/08 14:46:10 juda

Added HTML "href" tag edits to convert to soft links

Added

Added Revision 1.14 1999/01/26 18:35:00 juda

Added Changed descriptive text of HRC-C-009, HRC-C-010, and HRC-C-011

Added

Added Revision 1.13 1999/01/13 19:24:08 juda

Added removed HRC-L-004 "HRC Autonomous Power-Up"

Added

Added Revision 1.12 1999/01/06 16:29:48 juda

Added Added "Telemetry Format Changes" limitation

Added

Added Revision 1.11 1998/10/14 13:43:59 juda

Added added 3 "HRC Power Configuration" Constraints

Added

Added Revision 1.10 1998/09/21 18:24:38 juda

Added Reorganized layout of links to individual pages - categorized as "Constraints", "Restrictions", and "Limitations"

Added

Added Revision 1.9 1998/06/29 18:56:10 juda

Added removed "?" from "HRC-C-008" and "HRC-L-004"

Added

Added Revision 1.8 1998/06/17 19:25:19 juda

Added Added DOCTYPE declaration - Updated numbers to be consistent with TRW CARD version of 1998 May 15

Added

Added Revision 1.7 1998/06/01 21:05:26 juda

Added Added "HRC Door Operation during ACIS Observations" limitation from J. Donaghy

Added line to record changes

Dr. Michael Juda
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Mail Stop 70
Cambridge, MA 02138, USA
Ph.: (617) 495-7062
Fax: (617) 495-7356
E-mail: mjuda@cfa.harvard.edu