MEDIA RELEASE

Early Warning Satellites Ready for Challenge . . .
STORM FORECAST!

Australian and United States military staff at the Joint Defence Facility at Nurrungar in Woomera (SA) are preparing for a storm from outer space.

They're expecting a storm of Leonids – dust sized 'comet crumbs' which trail Comet 55P/Tempel Tuttle.

Potential for Leonids showers (fewer than 1,000 entries to Earth's atmosphere per hour) occur annually.

Storms of Leonids (more than 1,000 entries per hour) such as the one expected early next Wednesday morning (Nov 18) occur only once every 33 years.

Leonids don't pose a threat to what's on earth: in fact the particles burning up as they strike Earth's atmosphere provide quite a spectacle – like a shower of stars.

And they didn't pose much of a threat last time there was a Leonid storm – in 1964 .  .  . because there were very few satellites.

But they do threaten the estimated 300 to 400 satellites now circling Earth.

While they have the potential to damage virtually any satellite, the main concern for the Joint Defence Facility Nurrungar (JDFN) – which plays a vital role in missile warning – is the potential 'sandblasting' of their Defence Support Program (DSP) satellites.

"The consequences of a meteoroid strike on a satellite range from unnoticeable to catastrophic," said the Deputy Commander JDFN, Wing Commander Jim Walker. "Their velocity is about 72 kilometres per second.

"Fortunately, the particles are generally small and the likelihood of one greater than the thickness of a paperclip striking a satellite is less than 0.1 per cent."

"However, there is a high probability – 90 to 95 per cent – that particles less than the thickness of a piece of paper may strike a satellite."

WGCDR Walker said that Australians and Americans have been training for a potential increase in satellite anomalies which the Leonid storm, expected between 0511 and 0711 Central Standard Time next Wednesday, could cause.

"Local engineers drafted contingency plans to mitigate the most probable anomalies which would result from an impact," he said.

"Satellite operations centre personnel have also compiled a comprehensive Leonids binder that contains background information from the internet, recent magazines articles and higher headquarters guidance.

"JDFN staff will convene a special analysis team during the height of the storm in case there is a meteoroid impact."

WGCDR Walker added that civilian contractors, who assist the Australian and US Defence personnel in attending to the well-being of satellites, will increase satellite 'state-of-health' monitoring and that contractors and satellite operators will independently watch for malfunctions.

"Colonel Thomas Meade, the Commander of the JDFN and I have a great team to handle any eventuality," he said. "All JDFN personnel have trained hard to prepare for the upcoming Leonids storm which is likely to peak for between two and three minutes within the two hours when the event will take place.

"While some workers will be locked inside, sweating out the storm, many Woomerites plan to head into the Donga or bush to take advantage of their remote location and enjoy the beauty of the spectacle."

Further information . . .

Tony Underwood: (02) 62652703, (0419) 213 885