The payload computer — a NASA Standard Spacecraft Computer-1, or NSSC-1, system — is used to control and coordinate Hubble’s scientific instruments. The computer’s programs also analyze and manipulate the data it collects.
NASA engineers believe the problem is related to the Power Control Unit, or PCU, which ensures a steady voltage supply to the payload computer. The PCU is housed with the payload computer in the Science Instrument Command and Data Handling (SI C&DH) unit.
“The team’s analysis suggests that either the voltage level from the regulator is outside of acceptable levels (thereby tripping the secondary protection circuit), or the secondary protection circuit has degraded over time and is stuck in this inhibit state,” according to the NASA statement.
The telescope itself and science instruments remain “healthy and in a safe configuration,” the statement confirmed.
The Hubble Space Telescope, which orbits 340 miles above Earth’s surface, hasn’t always functioned flawlessly. A similar repair was performed in 2008, according to NASA, when another part of the SI C&DH unit failed. A servicing mission in 2009 then replaced the entire SI C&DH unit.
But it’s premature to give up on Hubble, said Don Lincoln, a senior scientist at the Fermi National Accelerator Laboratory.
“The best-case scenario is one in which both are operating, and we must wait for those clever engineers to work their magic to see if that is possible.”