CNN logo
Message Boards 

CNN Networks 

Quick News 
Video Vault 
News Quiz 

Pathfinder/Warner Bros

Barnes and Noble


Why did satellite Galaxy 4 go off course?

Animation shows how Galaxy IV lost its orientation Tuesday  
May 20, 1998
Web posted at: 9:07 p.m. EDT (0107 GMT)

(CNN) -- One satellite loses contact with Earth and the lives of people all over North America are disrupted.

When the Galaxy 4 satellite malfunctioned Tuesday night, it put pagers on the blink, caused transmission problems for television and radio networks and made some gas pumps refuse charge cards.

CNN's resident expert on satellite news-gathering blames a mechanical malfunction for disabling the satellite.

"There was a failure of one of the thrusters, one of the jets they use to keep the satellite in place," Dick Tauber said. (icon 253KB/23 sec. AIFF or WAV sound)

CNN's Ann Kellan explains what happened and what's being done to fix it.
icon 2 min. VXtreme video

Although his theory has not been confirmed, Tauber said he believes the thruster probably failed to shut off, perhaps after making a minor adjustment, and instead kept firing, sending the satellite into a spin.

Of the 500 satellites orbiting the Earth, 44 are over North America.

Animation of Galaxy 4
video icon 425KB/15 sec./240x180
295KB/15 sec./160x120
QuickTime movie

PanAmSat, the Greenwich, Connecticut-based company that owns Galaxy 4, owns 16 other satellites. The company is moving in a back-up satellite to take the place of Galaxy 4.

"It's ready to be used in case of emergencies like this," said Dan Marcus, a PanAmSat spokesman.

Like mechanical failures, the forces of nature can cause satellite malfunctions. Solar storms and meteor showers have disrupted orbiting satellites.

Of 500 satellites orbiting Earth, 44 are over North America  

The Leonid meteor shower expected in November is expected to be particularly heavy. And, although the meteors will be as tiny as grains of sand, they will be moving faster than speeding bullets -- which means they could do super damage to satellites.

The satellite carrying the Hubble Space Telescope, will be turned to angle its optics away from the incoming particles.

However, experts say that is no reason to panic.

"The possibility ... of 100 satellites being damaged or lost during this event is extremely low so we would not expect a disaster," said David Wensley of Sedgwick Space Services.

Correspondent Ann Kellan contributed to this report.


Message board:

Related story:

Related sites:

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.

Infoseek search  


Watch Science & Technology Week on CNN for more sci-tech stories.

Message Boards Sound off on our
message boards & chat

Back to the top

© 1998 Cable News Network, Inc.
A Time Warner Company
All Rights Reserved.

Terms under which this service is provided to you.
Read our privacy guidelines.