Hubble Life Extension Initiatives

2-Gyro Science Mode

Attitude control using 2 gyros + another sensor (MSS, FHSTs, FGS) to achieve high quality science with only 2 gyros.  

Implemented (2005-2009)  

1-Gyro Science Mode

Attitude control with 1 gyro + combination of MSS, CSS, FHSTs, FGS, and B-field model. Performance equivalent to 2-gyro mode.

Implemented (2024)

Two Reaction Wheel Reduced Gyro Science Mode

Science mode using 2 wheels and reduced gyros, with magnetic torquers in place of the missing wheel, and CSS, MSS, and gyros as sensor input to Kalman Filter. Extends science mission if two wheels fail.

Feasibility Study & Peer Review Complete (2014)

Alternate Roll Control Feasibility/Efficacy

Develop an alternate roll control capability to minimize science impacts of an FGS failure.

Investigating

Reduced-Wheel Reduced-Gyro Safemode

In the event of two reaction wheel failures, RGRW safemode uses magnetic torquers as actuators in the wheel-less axis and CSS, MSS as sensor input to the Kalman Filter.

Implemented (2012)

Kalman Filter Sun Point (KFSP) Safe Mode

Sun point control law using combination of CSS, MSS, and any number of gyros.   

Implemented (2008)

Reaction Wheel Speed Reduction During Slews

Modify command generator to reduce maximum wheel speeds during maneuver, reducing probability of RWA component failure.

Implemented (<2005)

Fixed Head Star Tracker Shutter Management

Reduce use of FHSTs to minimize FHST shutter cycles/wear and ensure bright object FHST protection.

Implemented (<2005)

SI C&DH B-Side Science Operations

Restores a level of SI C&DH redundancy.  BSO leverages the remaining SI C&DH Side B operational capacity in tandem with new functionality in HST486 FSW, modifications to NSSC-1 FSW, Science Instrument FSW, STScI and GSFC Ground Systems, and Operational Procedures.

Scheduled (2026)

Science Data Formatter Temperature Mitigation

Minimize post-SM4 Bay 10 temperature excursions and increase expected operational life of Science Data Formatter.

Implemented (2011)

Science Instrument Hybrid Modes

Identify potential science mode configurations of the remaining viable science instrument assets. ACS and STIS complete (2010).  WFC3 and COS initial prep complete, next step triggered on failure.

Feasibility Study Complete (2010)

Science Instrument Power Train Side Switch

Prepare for science instrument power train side switch.  Used on orbit for ACS in 2006/2007.  COS and WFC3 preparations completed in 2013. Recovery within 7 days after anomaly investigation.

Preparation Complete (2006,2013)

NSSC-I Memory Module Failure

Develop NSSC-I FSW recovery process needed for possible memory module failure. Shorter recovery and quicker return to science.

Preparation Complete (2006)

Enhanced Capability of Loading Alternate 486 CPMs

Loading backup 486 computer CPMs via 1553 interface

Implemented (2016)

Single SSR Operations

Procedures ready for single SSR Ops. Eng/Sci partition size adjustable, recommended reduce Eng by 45%.

Preparation Complete (2013)

I&C Contingency Response Options

Define all onboard comm related failure paths and response philosophies to significantly reduce recovery time.

Complete (2011)

HST Data Management System Side Switch

Prepare in advance for a full S/C side switch; used in 2008 & 2021 for SI C&DH side switch. Shorter recovery; quicker return to science.

Implemented (2008 & 2021)

Autonomous Reset after Solid-State-Recorder Lockup

HST486 computer commands a reset of a locked-up SSR

Feasibility Study Complete (2013)

Thermal Control of Equipment Bays 5 and 8

Asymmetric roll constraints before blankets installed during SM4.  Maintains bays/subsystems within thermal limits.

Implemented (2009)

MA Transmitter Cycle Reduction  

Reduce MAT cycles by maximizing concurrent scheduling and eliminating unnecessary events w/o added risk. MATs are needed for real-time engineering telemetry. Reduced MAT cycles by ~37%.

Implemented (2006)

S-Band Single Access Transmitter Management

Use of two SSATs in operations rather than only one. Longer services resulting in reduced SSAT cycles.

Implemented (<2005)

Power System Charge Optimization

Optimize charging and operations to maximize battery life. Taper charge extends NiH2 battery life and minimizes state-of-charge losses.

Implemented (2006)

Solar Array Slew Optimization

Reduces the number of slews by approximately 50% while maintaining sufficient power output.

Implemented (1993)