31-year-old piece of hardware not working very well: Hubble telescope back in safe mode over 'synchronization issues'

James Webb Space Telescope in line for a December flight

The veteran Hubble Space Telescope (HST) tripped back into safe mode yesterday, leaving science operations suspended while the latest technical woe is investigated.

The problem this time is "synchronization issues with internal spacecraft communications," according to the observatory's social media orifice, normally awash with stunning imagery snapped by the telescope.

Hubble’s science instruments went into safe mode on Monday after experiencing synchronization issues with internal spacecraft communications. Science observations have been temporarily suspended while the team investigates the issue. The instruments remain in good health.

— Hubble (@NASAHubble) October 25, 2021

It is only a few short months since the HST was last forced into safe mode, where it languished for weeks due to payload computer problems. Despite worries that the ageing hardware might be beyond repair, engineers were able to switch to a backup payload computer and resume the spacecraft's science work.

The NASA and ESA collaboration was launched aboard a Space Shuttle in 1990 and has returned observations to Earth for three decades. There is every chance it could continue working for another decade or more – if this latest snafu can be resolved.

While servicing the HST is no longer viable using the Space Shuttle (which upgraded the spacecraft over five missions, the last of which was in 2009), replacements are in the works. One, the James Webb Space Telescope (JWST), is in line for a ride on an Ariane 5 rocket in December, having finally made it to Europe's Spaceport in French Guiana.

JWST engineers will have heaved a sigh of relief as the booster successfully lofted a payload of 11,210kg (10,264kg of satellites and the rest made up of adapters and truss structures) last week.

The JWST is also a collaboration between multiple agencies including NASA and ESA. The launch is currently scheduled for 18 December and the telescope is expected to arrive at the second Lagrange point 30 days later, during which time it will unfurl its solar array, sunshield, and communication antennas.

While Hubble's science instruments remain in good health despite the latest issue, another trip into safe mode is a reminder that the JWST cannot come soon enough. ®