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Home / Science / Watertown Daily Times | Johns Hopkins engineers help NASA reconnect to the long-lost "zombie" satellite

Watertown Daily Times | Johns Hopkins engineers help NASA reconnect to the long-lost "zombie" satellite



BALTIMORE – When aerospace engineers launch a satellite, they do not expect it to last forever. When the NASA orbiter, known as IMAGE, disappeared into orbit after five years, few were alerted.

What stunned the field came last January, when an amateur satellite observer saw IMAGE re-enter the sky after a dozen years, still trying to talk to Earth.

"I've been in the field since the late 1

980s and it's almost never possible to find a lost spacecraft again, especially after such a long time," said Jeffrey JE Hayes. Program Manager for missions at NASA headquarters in Washington. "IMAGE is this zombie that has returned to life."

Now space scientists in the United States are working on the long-lost spaceship, trying to help NASA keep in touch and take control. Among them is a team at the Applied Physics Laboratory at Johns Hopkins University in Laurel, Md.

It was Bill Dove, an engineer who runs the Hopkins Laboratory Satellite Communications Facility, and his colleague Tony Garcia, senior engineer in the Space Exploration Sector the APL, which blocked communications with the $ 150 million vessel launched in 2000. They spent months downloading their signals and delivering them to NASA.

After restoring communication between the spaceship and the Earth The signal was strong for three weeks in February before it went out again. She returned weaker in March and came back sharply earlier this month.

The APL team has been monitoring the events throughout, and Dove, a 38-year veteran of the field, said he has never had a similar project

"We were presented with a rare and unique technical challenge," he said. "We continue to receive (radio communications) from IMAGE, and we help NASA as much as possible."

The story of IMAGE began towards the end of the last millennium, when scientists at the Southwest Research Institute of San Antonio, Texas and elsewhere set about exploring the relationship between solar wind – the stream of charged particles emerging from the Sun's upper atmosphere Space is flowing – and the magnetosphere, the huge, dynamic sphere of magnetic gas that surrounds and protects the earth, is exploring its inhabitants from the sun.

They wanted to learn more about how changes in the speed, density and temperature of the solar wind affect the Earth's atmospheric conditions – especially how they create and shape Aurora Borealis and Aurora Australis, the northern and southern lights

To this end, NASA designed and built the magnetopause Aurora Global Exploration Imager, the first spacecraft ever dedicated to producing visible images of the magnetosphere 9002] The agency launched IMAGE on March 25, 2000 – a solar powered 1.087 lb. heavy hexagonal satellite with six specialized imagers or cameras.

He orbited the Earth around the North and South poles 6505 kilometers high and provided the first comprehensive images of the plasma in the inner magnetosphere of the Earth, the plasma sphere.

Although astrophysicists know that the magnetosphere responds to solar winds when these winds reach speeds of several hundred kilometers per hour, it still attempts to "understand the actual mechanism in every detail," Hayes said.

IMAGE was unexpectedly good at giving answers. It transmitted images that led to 39 new discoveries, including some that confirmed theoretical predictions and others that identified new, unforeseen features.

NASA headquarters had just described it as the second most valuable space-physics mission when it suddenly became dark and unresponsive

Several theories came up, why – the one most cited was a short-circuited power converter – but there were no clear answer.

After months of trying to reestablish contact, NASA broke off The Mission and Its Financing

"At some point you need to reduce your losses," said Hayes, whose current projects include monitoring the Voyager program and the Hubble Space Telescope include.

Then last winter, Scott Tilley, a hobby astronomer at Roberts Creek, British Columbia, near Vancouver, was looking for another satellite on January 20 when he discovered an object that would be IMAGE if it were operational He signaled to NASA when he was asked by astounding officials, including Hayes, to supervise several of the agency's supervised Sky Observatory's more detailed tests.

Locations included Goddard's Space Flight Center in Greenbelt, Wallops Flight Facility on the East Coast of Virginia and White Sands Test Facility in Las Cruces, NM

Goddard found the new signal on Friday, January 26, but it was Hopkins APL, the next took decisive steps

Dove and Garcia chose the 60-foot satellite dish toward the spacecraft's expected location. This weekend Dove reconfigured the 56-year-old antenna to receive signals from IMAGE equipment, many of which had been outdated in recent years.

Garcia went to work on Monday.

He adjusted the antenna frame by seeing in half-degree increments, then the radio frequency of the moving object, which was exactly 44.44 kilobits per second

"Tony worked what I call his' magic," said Dove. "He used his over 30 years of experience to change the values ​​piece by piece until he cracked the code."

They had reached "telemetric lock". Data from the satellite flowed in.

Hopkins APL does not have the ability to interpret such data files, but the engineers sent them to NASA, which quickly used them to decode the object's spacecraft ID – 166.

Richard J. Burley, The Original IMAGE Head of Mission, Tilley emailed, and the Space Buffs tweeted the news across the world.

"NASA confirms that IMAGE is indeed alive!" He wrote.

Early information from the spacecraft was "housekeeping" data indicating his condition Hayes said that "is surprisingly healthy."

At least three major scientific instruments have been obstructed, Hayes said, and the instability of its signals – IMAGE "disappeared" once again, and its signals have swayed wildly – suggest that it is now "tumbling" through the room means his spin control is out of order.

The engineers have not yet made the two-way communication they would need to correct problems on the ship, let alone revive their original mission.

That kind of happy ending, Hayes said, would require engineers to show so clear control over the craft that NASA's review board would reinstate its funding flow at a time when competition for funds between missions is more intense than ever before.

Meanwhile, Dove, Garcia and their colleagues in Goddard, White Sands and elsewhere are working on their own time – taking advantage of the hours they can secure on NASA's busy global antenna network – to oversee IMAGE.

"We're still waiting for this epiphany, if we take the right path at the right time and not just take control, but take control," Hayes said. Yes, but I learned something important a long time ago: spacecraft do very strange things. "


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