Hubble telescope back in service

The Hubble Space Telescope is again conducting experiments after a mechanical failure crippled the groundbreaking observatory for three weeks.

In a statement Saturday, NASA officials said the telescope was brought back online Friday and conducted its first experiment since Oct. 5. During almost three decades orbiting Earth, Hubble is credited with having expanded understanding of the solar system and how it formed.

On Oct. 5, the telescope put itself into “safe mode” after the failure of one of its six gyroscopes, which keep the telescope pointed accurately for extended periods of time

as it sends data back to scientists. The failure was expected as it “had been exhibiting end-oflife behavior for approximately a year,” NASA officials said at the time.

The failure brought the number of lost gyroscopes to three. Hubble needs just three gyroscopes to be fully operational, and the Oct. 5 failure would have left the telescope with the necessary three — except that another was rotating at excessively high rates, NASA officials said.

It had previously been shut off.

But NASA says it has fixed the problem and put safeguards into place so that it doesn’t happen again.

“Last week the operations team commanded Hubble to perform numerous maneuvers, or turns, and switched the gyro between different operational modes,” the space agency’s Saturday statement said. This “successfully cleared what was believed to be blockage between components inside the gyro that produced the excessively high rate values.”

Astronomers, no doubt, are relieved. During the era when NASA operated its own space shuttles, astronauts could service the telescope, and they did so five times before the shuttle program was shuttered in 2011. Now, NASA has no way to get astronauts to the telescope for repairs.

The telescope can operate — albeit at a lower functional level — with two, or even just one, working gyroscope.

Hubble’s successor, the James Webb Space Telescope, also is experiencing trouble.

Initially expected to launch in 2007 and cost $500 million, Webb has been delayed until March 2021 — assuming it gets congressional approval to continue after development costs breached the $8 billion cap set in 2011. NASA estimates it now needs $9 billion.

Webb is meant to revolutionize the world’s understanding of planet and star formation.

Photos by Melissa Phillip / Staff photographer Visitors tour mockup sections of the International Space Station at Johnson Space Center during an open house Saturday. The tour of NASA’s facilities marks the first time in five years that the Houston space center was open to the public.