Hubble’s Advanced Camera for Surveys Instrument Resumes Science, Investigation Continues
November 9, 2021 | NASAEstimated reading time: 2 minutes

NASA is continuing work to resolve an issue that has suspended science operations on the Hubble Space Telescope. The science instruments entered a safe mode configuration on Oct. 25 after detecting a loss of specific data synchronization messages.
The Hubble team is focusing its efforts to isolate the problem on hardware that commands the instruments and is part of the Science Instrument Command and Data Handling Unit. Specifically, the team is analyzing the circuitry of the Control Unit, which generates synchronization messages and passes them onto the instruments.
While analyzing the Control Unit, the team is working to identify potential workarounds for the issue. These include possible changes to instrument flight software that could check for these lost messages and compensate for them without putting the instruments into safe mode. These workarounds would first be verified using ground simulators to ensure they work as planned.
Over the weekend of Oct. 30, the team prepared to turn on parts of the Near Infrared Camera and Multi Object Spectrometer (NICMOS) instrument to collect data on this issue, allowing the team to determine how frequently this problem occurs. Installed in 1997, NICMOS has been inactive since 2010, when the Wide Field Camera 3 became operational. NICMOS allowed the team to use an instrument to collect information on these lost messages while keeping the active instruments off as a safety precaution. Since NICMOS was recovered on Nov. 1, no additional synchronization messages have been lost.
The team is now taking steps to recover Hubble’s Advanced Camera for Surveys (ACS) instrument from safe mode and start collecting science with that instrument at the beginning of next week. The team will make the decision on Sunday after analyzing the latest data. If a lost message is seen before then, the decision to activate ACS will also be revisited. The team is proceeding cautiously to ensure the safety of the instruments and avoid additional stresses on the hardware. Therefore, only ACS will be used in this capacity next week. ACS was selected as the first instrument to recover as it faces the fewest complications should a lost message occur.
Over the next week, the team will continue analyzing the Control Unit design diagrams and data associated with the lost messages to determine what may have caused this problem. They will also be looking into potential instrument software changes that could help address it. Once the team better understands the frequency of the problem and has determined the time needed to implement possible software changes, they will discuss a plan for returning the other instruments to science operations.
Suggested Items
Advancing Aerospace Excellence: Emerald’s Medford Team Earns Space Addendum Certification
06/30/2025 | Emerald TechnologiesWe’re thrilled to announce a major achievement from our Medford, Oregon facility. Andy Abrigo has officially earned her credentials as a Certified IPC Trainer (CIT) under the IPC J-STD-001 Space Addendum, the leading industry standard for space and military-grade electronics manufacturing.
Sierra Space Announces Opening of New “Power Station” Technology Center in Colorado as Defense Operations Grow
06/27/2025 | BUSINESS WIRESierra Space, a leading commercial space company and defense tech prime that is building a platform in space to benefit and protect life on Earth, announced a technology center expansion aimed at scaling up the production and delivery of the company’s groundbreaking Surface Mount Technology (SMT) solar power systems, including production for national defense applications.
AST SpaceMobile & Fairwinds Technologies Demonstrate World’s First Tactical NTN Connectivity Over Standard Mobile Devices
06/27/2025 | BUSINESS WIREAST SpaceMobile, Inc. the company building the first and only space-based cellular broadband network accessible directly by everyday smartphones, designed for both commercial and government applications, announced the successful demonstration of the world’s first Non-Terrestrial Network (NTN) tactical satellite communications delivering high-throughput data, voice, and video using unmodified mobile devices in collaboration with Fairwinds Technologies.
Pacific Defense Secures Launch for MOSA Space RF Payload
06/27/2025 | BUSINESS WIREPacific Defense, the leading provider of Modular Open Systems Approach (MOSA) products, announced it has secured the inaugural launch for its Moonraker MOSA space Radio Frequency (RF) payload on board the K2 Space Gravitas Mission in February 2026.
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
06/27/2025 | Nolan Johnson, I-Connect007While news outside our industry keeps our attention occupied, the big news inside the industry is the rechristening of IPC as the Global Electronics Association. My must-reads begins with Marcy LaRont’s exclusive and informative interview with Dr. John Mitchell, president and CEO of the Global Electronics Association. For designers, have we finally reached the point in time where autorouters will fulfill their potential?