Keeping an eye on Hubble
Meet Nzinga Tull, Hubble Systems Anomaly Response Manager
What does your role at NASA involve and how long have you been in it for?
One of my primary roles is as an Anomaly Response Manager who uses systems engineering expertise to coordinate anomaly investigations and lead anomaly response and recovery efforts. After 13 years on the Hubble mission operations team earlier in my career, I rejoined the team in November 2018.
How long did the problem with Hubble take to diagnose and how serious was the issue? Hubble has an extensive, automatic data-monitoring system that sends system engineers ‘alert’ signals when something goes wrong; so we were alerted immediately when the payload computer first halted on 13 June. There were about two weeks of dedicated anomaly investigations before we began planning to recover the payload by activating back-up components. The meticulous development and testing of the recovery procedures took about 2.5 weeks to complete in parallel with on-going root cause analysis before the on-orbit recovery was attempted.
The issue with the Power Control Unit (PCU) was serious enough to halt the science mission but we still don’t know for sure if the issue is permanent.
Is it possible that the same issue with the payload computer could happen again and is there anything that can be done to prevent the problem from recurring?
If it is a transient problem that can be improved, say, if the Power Control Unit sits cold for some time, we may still have some redundant functionality down the road. But, for now, we are prioritising the continuity of the science mission and we will continue to operate Hubble using the backup components.
What is next for Hubble now the issue is fixed? How long is the space telescope expected to be in operation for?
Now that payload computer is working again, we have re-started the science instruments and they are back to collecting the amazing images that make Hubble a beloved resource with astronomers and the stargazing public. The systems engineering team will continue to monitor and analyse telescope data to get ideas on how to optimise operations and extend mission life for years to come.