Hubble, heal thyself

After more than two long weeks of being silent, the Hubble Space Telescope may be up and running as early as October 16, NASA scientists announced in a teleconference October 14.

For the past 18 years, Hubble’s large and versatile telescope has peered into the distant universe and made discoveries that changed the way scientists and stargazers alike look at the cosmos. Since its launch, data from Hubble have confirmed the existence of black holes, refined measurements of the age of the universe and its expansion rate and provided some of the evidence that the expansion rate is accelerating. But data abruptly stopped coming from Hubble on September 27, leaving scientists scrambling.

To get Hubble back on track, early in the morning on October 15, scientists will begin to transmit a series of remote commands, long binary strings of 0s and 1s, to instruct the orbiting observatory to switch its operations from the failed equipment to a backup “B” side unit. The team of scientists and engineers working on Hubble has devised and tested the process on a Hubble replica, said Jon Morse, director of the astrophysics division at the NASAGoddardSpaceFlightCenter in Greenbelt, Md., during the October 14 press teleconference from NASA headquarters in Washington, D.C.

Caused by a failure in a unit that collects data from Hubble’s observational tools and transmits it to Earth, the malfunction halted almost all scientific communications from Hubble. What’s more, a planned maintenance mission to Hubble slated to depart October 14 has been postponed until next year.

“This unit operated flawlessly for 18 years. Unfortunately, nothing lasts forever,” said Art Whipple, lead mission systems engineer for Hubble at NASA-Goddard.

Scientists are optimistic that the new configuration will get Hubble’s science data flowing to Earth again as early as October 15. But the complicated switch from the “A” side to the redundant “B” side will test equipment that has been idle since Hubble’s launch in 1990, posing unforeseeable complications and risks.

The harmful rays of the sun, extreme temperature changes during orbits and 18 years of cosmic debris may have rendered the backup as unusable as the original data handling unit. While the details have yet to be arranged, scientists plan to send a brand-new data handling unit up with astronauts on the planned Hubble maintenance mission, leaving Hubble with a much-needed spare.

In the meantime, a group of about 50 scientists headquartered at NASA-Goddard will coordinate and remotely perform the equipment switch. Since Hubble’s silence, the team has been feverishly working on the ground to ensure a smooth transition in space. In addition to practicing the change on an electrical replica of Hubble housed at NASA-Goddard, the team has contingency plans built in at each step of the procedure, Whipple explained.

“The team is ready to go,” Whipple said. “They are at their best when faced with something like this.”