GREENBELT -- When folks at the Goddard Space Flight Center talk, Hubble listens.
And then the flying space telescope -- the size of a city bus with wings -- responds. It turns its myopic eye toward a speck of light in the galaxy and locks onto it. It snaps a picture of a storm swirling around Saturn. It waits until a spinning blue ball called Earth passes from its field of vision so it can peer into the heavens again.
All of this and so much more has gone on 24 hours a day, 365 days a year for three years and counting, because the Hubble Space Telescope never sleeps. In 100 bits of data per second, the billion-dollar space observatory receives instructions from this NASA installation: 100,000 commands a week, and that's just in pursuit of great science. There are 70,000 more, relayed by the Goddard crew, that control the telescope's internal operations.
Whispering to Hubble
For the next nine days, as the astronauts aboard the Shuttle Endeavour undertake a complex mission to repair the telescope's flawed vision and replace worn-out parts, a troop of engineers and mission planners at Goddard will be whispering in Hubble's ear. In much the same way that the astronauts' work is planned to the minute, so too is Hubble's.
Since Monday, the Goddard contingent has been working round-the-clock at a bank of computer consoles in Building 13 at the sprawling facility in suburban Prince George's County.
"We do everything they [astronauts] do up there, only we're on the ground and we're in shirt-sleeves," said Preston Burch, deputy project manager of telescope operations at Goddard.
Moves reflected in space
While that's not literally the case, many of the astronauts' maneuvers to fix Hubble during the five planned spacewalks will follow a Goddard-directed move by Hubble. Before the effort early today by the Endeavour crew to capture Hubble, the Goddard crew was to tell Hubble to fold up its satellite dishes, which extend on arms on either side of the craft. Before astronauts Kathryn Thornton and Tom Akers can replace Hubble's shaky solar panels early tomorrow, the telescope must retract them.
Astronomers at the Space Telescope Science Institute at Johns Hopkins University in Baltimore determine the kind of science observations Hubble makes. But the folks at Goddard physically program the telescope's computer to perform the work and monitor Hubble's operations to ensure it's doing its job.
Goddard crews also keep track of Hubble's internal systems, just as a physician might simultaneously monitor a patient's blood pressure, heart rate and temperature.
"The spacecraft itself is tremendously complex, and the planning that goes into its operation is tremendously complex," said Mr. Burch. "The observatory can't be pointed anywhere at any time. There are restrictions on where you can point Hubble."
They include such factors as the positions of the sun and the moon, and the proximity of fields of radiation that surround the Earth.
It takes about 660 people to operate the telescope, which one National Aeronautics and Space Administration official described as the world's "window into the universe" -- 450 people at the space telescope institute, 175 contract employees who operate the sophisticated computer network and 35 Goddard workers who oversee the operations.
For the 11-day mission, the Space Telescope Operations Center, known as STOCs, will be working according to a 367-page script. "That's our bible," said Mr. Burch.
Goddard workers have trained for the repair mission and participated in more than 16 simulations of the actual event, just as the astronauts and ground control specialists at the Johnson Space Center did.
"Obviously we're really expecting the unexpected," said Joe Rothenberg, the Hubble program manager at Goddard.
Once the shuttle crew returns the telescope to its orbit, Goddard crews will conduct more substantive checks of the instruments.
Depending on the success of the mission, Goddard engineers will begin powering up the telescope, calibrating the new gyroscopes and aligning the small mirrors installed to correct the telescope's flawed vision so that Hubble can get back to business.
That may take seven to 14 weeks.
"The first time we will have access to scientific images that will convince you and me and our scientific colleagues that we have been successful will be approximately the seven week point," said David Leckrone, the project scientist at Goddard.
The astronomers at the Space Telescope Science Institute in Baltimore have 11 possible science projects in the pipeline to take advantage of any improvement in Hubble's acuity.