Engineers troubleshooting a fault with the Wide Field Camera 3 aboard the Hubble Space Telescope say the problem could be a hardware issue or a software glitch of some sort. If the former, the camera could be switched over to a redundant set of electronics and resume normal operations. If the latter, engineers may be able to reset the software, clearing the error and, again, resuming normal operations and observations.
Either way, engineers with NASA and the camera’s builder, Ball Aerospace, are confident they can restore the instrument to good health.
“We’re going to do a few more tests the next couple of days,” Thomas Brown, head of the Hubble Space Telescope mission office at the Space Telescope Science Institute. “There’s no rush because there’s plenty of other science with the other three instruments. So there’s no reason to rush. The first goal here is to do no harm.”
If the problem is software related, “we would power cycle it, clear the error and see if it comes back up,” Brown said. “If it does then we’re good. If it looks like there’s still a problem, we would maybe have to go to the redundant electronics. Or maybe not. It depends on the nature of the problem.”
The camera was built with two independent sets of control electronics to handle just this sort of problem. The backup set, or channel, has never been used and is in pristine condition if needed.
Installed during the fifth and final space shuttle servicing mission in 2009, the Wide Field Camera 3 is one of Hubble’s premier science instruments, along with the Cosmic Origins Spectrograph, the Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph.
The WFC3 makes observations in near-infrared light and at ultraviolet-visible wavelengths. The anomaly that cropped up on 8 January affected the ultraviolet-visible channel. The infrared channel was operating normally at that time.
Despite the camera issue and the normal wear and tear of orbital operations, Brown said Hubble should remain operational through 2025 if not longer.
“The engineers at NASA frequently update their analysis of how reliable the critical subsystems are and the instruments are,” he said. “On the critical subsystems, all those (reliability) curves are over 80 percent until January 2025 and the instruments are all over 85 percent. … We have every reason to believe Hubble will be operating until 2025 if not longer.”
As for the ongoing partial shutdown of the U.S. government, including NASA, Brown said Hubble has not yet been affected.
“The shutdown is not affecting us (at the Space Telescope Science Institute), and the flight operations people at Goddard (Space Flight Center) are considered essential,” he said. “As far as troubleshooting this anomaly on Wide Field Camera 3, we’ve been having anomaly review board discussions off and on for the past couple of days, and we have all the experts from the flight ops team and the people who built the instrument at Ball Aerospace. They’re also not affected by the shutdown. We have all the right experts on the line troubleshooting things. So we’re fine right now.”