NASA Prepares for Potentially Damaging 2011 Meteor Shower
By Leonard David | Space.com
NASA is assessing the risk to spacecraft posed by the upcoming 2011 Draconid meteor shower, a seven-hour storm of tiny space rocks that has the potential to ding major Earth-orbiting spacecraft like the crewed International Space Station and Hubble Space Telescope.
The meteor shower risk assessment is actually more art than science, and there has been some variation in the projected intensity levels of the 2011 Draconids by meteoroid forecasters. But spacecraft operators are already being notified to weigh defensive steps.
Current meteor forecast models project a strong Draconid outburst, possibly a full-blown storm, on Oct. 8, 2011, according to William Cooke of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Ala.
The Draconids do present some risk to spacecraft, Cooke confirmed. They could potentially become the next significant event in low-Earth orbit as far as meteoroids are concerned, he added.
Cooke and Danielle Moser of Stanley, Inc., also of Huntsville, presented their Draconid data at Meteoroids 2010 - an international conference on minor bodies in the solar system held May 24-28 in Breckenridge, Colo. The conference was sponsored in part by NorthWest Research Associates/CoRADivision, NASA, Los Alamos National Laboratory and the Office of Naval Research.
Less flashy, but risk exists
The yearly Draconids are not known for their bright meteor displays, Cooke said.
Predicted intensity rates for 2011 span an order of magnitude, he added, with maximum Zenithal Hourly Rate, or ZHR, ranging from a few tens to several hundred as viewed by a single observer.
A Marshall Space Flight Center Meteoroid Stream Model based on radar and optical observations of past Draconid showers suggests that the maximum rate will be several hundreds per hour.
So why the worry?
Cooke said that a significant fraction of spacecraft anomalies produced by shower meteoroids are caused by electrostatic discharges when meteoroid meets satellite.
And while no spacecraft electrical problems were reported during the strong Draconid outbursts of 1985 and 1998, he said that the lack of past anomalies should not be taken as carte blanche for satellite operators to ignore in 2011.
The chance of electrical anomalies is low, however, due to the Draconids slow speed, Cooke pointed out.
"We’re already working with NASA programs to deal with spacecraft risk," Cooke said. "I imagine when the word gets out there will be a Draconid outburst, I’ll get the usual calls from comsat companies as well as government space programs," he told SPACE.com.
Out on the limb
The International Space Station is heavily armored against orbital debris.
That being the case, "we don’t expect anything to go wrong there," Cooke said.
However, the Draconids will appear above the Earth’s limb making it a spectacular looking out-the-windows celestial show for the space station crew.
"I have no concerns about the space station. Even if the Draconids were a full-scale meteor storm I would be confident that the space station program would take the right steps to mitigate the risk," Cooke said.
The most radical step would be to reorient the space station, Cooke said.
"But frankly, given the flux levels, I don’t think they are going to have to do that," he added. "But that’s their call. I’ll give then the flux levels and they’ll make the decision."
One measure that space station officials could take, he added, is not to perform spacewalks during the shower.
For the Hubble Space Telescope, if its operators deem the risk high enough, they will point the observatory away from the Draconid radiant – the point from which the shower appears to emanate.
"Any time you take a mitigation strategy, like changing a spacecraft’s attitude or turning off high-voltage, that incurs risk as well," Cooke said.
Caution is key
Each spacecraft is unique, and components have differing damage thresholds, so programs are encouraged to conduct analyses to determine whether or not mitigation strategies are necessary for their vehicles ahead of next year’s Draconids.
Cooke said that the spacecraft threat from meteor showers in the past – particularly the 1998 Leonids – produced more hype than hypervelocity impacts.
"We really didn’t understand what was going on," he added. "Now we have a much better feel. But the Leonids did sensitize spacecraft operators to worry about meteor showers. Perhaps, sometimes, they worry more than they should."
In early 2011, Cooke said that he’ll be revising his Draconid prediction – also making use of data from other forecasters around the globe – which will be released to spacecraft operators.
"There’s also an awful lot of windage in there too," Cooke added. "We’re like the weather reporters...our forecast changes...and the general trend is always downward," Cooke said.
Still, caution is the watchword.
"Because we can now forecast them, we have a way of putting it. If you are hit by a sporadic [meteor], it’s an act of God. If you are hit by a shower meteoroid, it’s an act of negligence," Cooke said.
Article from: Space.com
Images - The Best of Leonid Meteor Shower
Some of the Worst Space Debris Moments in History
NASA Wants You ... to Help Find Meteorites
NASA on crusade to debunk 2012 apocalypse myths
NASA’s LCROSS ’plume’ a no-show
"Meteorite" burns on Israel beach?
Meteorite Hits Mexico Leaving 30 Meter Crater in Ahuazotepec Municipality
Possible Perseid Meteor Outburst - August 12th
Latest News from our Front Page
Three-year-old ultra-Orthodox Jewish children told 'the non-Jews' are 'evil' in worksheet produced by London school
Documents seen by The Independent show children are taught about the horrors of the Holocaust when they are still in kindergarten at the Beis Rochel boysâ€™ school in north London.
A whistle-blower, who wished to remain anonymous, has shown The Independent a worksheet given to boys aged three and four at the school. In it, children were asked to complete questions ...
The Unsafe Child: Less Outdoor Play is Causing More Harm than Good
The third grade classroom that was visiting our nature center for the day consisted of mostly boys–rowdy, loud and rambunctious boys. As we started out into the woods, the children spoke loudly to each other in anticipation of what was to come. After playing a quick game and explaining the ground rules, it was time for free play. As soon ...
Rights group demand police need warrant to access data
American citizens should be able to rest safe in the knowledge that no one has the right to pry into their digital records, where they have been and how long they stayed there.
The Supreme Court has just received a brief from the Electronic Frontier Federation (EFF) stating that this should certainly be the case. However, in the case of Davis v. ...
Murder Rates Rising Sharply in Many U.S. Cities
Cities across the nation are seeing a startling rise in murders after years of declines, and few places have witnessed a shift as precipitous as this city [Milwaukee]. With the summer not yet over, 104 people have been killed this yearâ€“after 86 homicides in all of 2014.
More than 30 other cities have also reported increases in violence from a year ...
Bulgaria - Islamic State Terrorists Caught Crossing Into Europe Posing As Refugees
Bulgarian authorities near the Gyueshevo border checkpoint detained the five men, aged between 20 and 24, late on Wednesday, Bulgarian broadcaster NOVA TV reported.
The men were stopped by a border guard, who they attempted to bribe with a “wad of dollars.” However, they were searched and Islamic State propaganda, specific Jihadists prayers and decapitation videos were found on their phones.
|More News » |