News / Science & Technology

Vague Predictions as Satellite Falls to Earth

In this image provided by NASA this is the STS-48 onboard photo of the Upper Atmosphere Research Satellite (UARS) in the grasp of the RMS (Remote Manipulator System) during deployment, from the shuttle in September 1991. The satellite is 35 feet long, 15
In this image provided by NASA this is the STS-48 onboard photo of the Upper Atmosphere Research Satellite (UARS) in the grasp of the RMS (Remote Manipulator System) during deployment, from the shuttle in September 1991. The satellite is 35 feet long, 15

At this very moment, the U.S. Department of Defense's Joint Space Operations Center is tracking thousands of pieces of space junk orbiting our Earth.  But, even as the Upper Atmosphere Research Satellite known as UARS comes hurtling back toward our planet, experts say it is hard to determine just when or where it will reenter the atmosphere.

Both the Department of Defense and NASA say it is nearly impossible to precisely predict where and when free-falling space debris will reenter the atmosphere, let alone strike or splash down on the planet.

Major Michael Duncan is the deputy chief of space situational awareness at the Defense Department's Joint Space Operations Center, known as JSpOC.  He says radars, telescopes and even assets in space provide positional data for orbital debris.  A team strings those data points together to create orbits.

"And with the right software you can take an orbit and from where it is right now you can predict where it will be, you know, one, two, three hours from now," Duncan said.

He said a five-member team at JSpOC works 24 hours a day, seven days a week, collecting updates from around the world.  

"We take in about 450,000 observations per day, and that helps us track the 22,000 space objects that we track currentl," he said.

Major Duncan said UARS is easy to track because it is about the size of a school bus.  But even with all the data points, high-tech software, and the team's accurate predictions, there are multiple variables that can have an effect on when and where debris will reenter.  

For instance, Duncan said, it is impossible to determine the way the debris will react once it reaches the atmosphere.

Like a stone skipping across a lake, space junk can bounce across the upper atmosphere.  And, Duncan said, even JSpOC's reentry predictions come with a window of plus or minus 15 minutes.

"But even that plus-or-minus 15 minutes can be a track of 5,000 miles difference," he said.

Most of UARS is expected to disintegrate as it reenters Earth's atmosphere.  

Mark Matney, an orbital debris scientist at NASA's Johnson Space Center in Texas, says a craft's orientation can even have an effect on how fast it decays.   

"It's basically an inert object, and so it can be tumbling.  Let's just say it's tumbling in such a way that it presents a large area or small area, it could speed up the rate at which it decays or slows it down," he said.

Matney says solar activity is another variable.

"Sometimes the energy from the sun goes up a little bit and causes the atmosphere to heat up and actually expand, and when that happens, it can accelerate the decay rate of the satellite.  If the solar activity were to go down, it would actually cause the atmosphere to cool and contract, and so the spacecraft would not encounter quite as much atmosphere and would slow down its decay," he said.

Major Duncan at JSpOC notes there was a solar storm last week that immediately changed the satellite's anticipated reentry by three days.

UARS was launched 20 years ago and decommissioned in 2005.  Matney says times and technologies have changed since 1991.

"Unfortunately, because UARS is an older satellite, it was not designed with the capability to do a targeted reentry, and we've done that before.  The Compton Gamma Ray Observatory is a good example where we actually were able to target its reentry over the Pacific Ocean, out in the middle of the ocean where it wouldn't hurt anybody," Matney said.

Still, NASA says the likelihood of UARS hurting anyone is slim.  The U.S. space agency says it has no confirmed reports of a person ever being injured or property being significantly damaged by falling debris.

And, given that more than two-thirds of the planet is covered by water, it is likely that UARS will land with a splash and not a thud.

You May Like

Will Cuba Follow the Southeast Asia Model?

Decision to restore ties between US and Cuba has some debating whether it will lead to enhancement or regression of democracy for Communist island nation More

Kenyan Designer Finds Her Niche in Fashion Industry

‘Made in China’ fabrics underlie her success More

Report: CIA, Israel's Mossad Killed Senior Hezbollah Commander

The Washington Post story says Imad Mughniyah was killed instantly by a bomb "triggered remotely" from Tel Aviv by Mossad agents More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Jefferson's Library Continues to Impress, 200 Years Lateri
X
Deborah Block
January 31, 2015 12:12 AM
Two hundred years after the U.S. Congress purchased a huge collection of books belonging to former President Thomas Jefferson, it remains one of America’s greatest literal treasures and has become the centerpiece of Washington’s Library of Congress. VOA’s Deborah Block reports.
Video

Video Jefferson's Library Continues to Impress, 200 Years Later

Two hundred years after the U.S. Congress purchased a huge collection of books belonging to former President Thomas Jefferson, it remains one of America’s greatest literal treasures and has become the centerpiece of Washington’s Library of Congress. VOA’s Deborah Block reports.
Video

Video Egypt's Suez Canal Dreams Tempered by Continued Unrest

Egypt plans to expand the Suez Canal, raising hopes that the end of its economic crisis may be in sight. But some analysts say they expect the project may cost too much and take too long to make life better for everyday Egyptians. VOA's Heather Murdock reports.
Video

Video Threat of Creeping Lava Has Hawaiians on Edge

Residents of the small town of Pahoa on the Big Island of Hawaii face an advancing threat from the Kilauea volcano. Local residents are keeping a watchful eye on creeping lava. Mike O’Sullivan reports.
Video

Video Pro-Kremlin Youth Group Creatively Promotes 'Patriotic' Propaganda

As Russia's President Vladimir Putin faces international pressure over Ukraine and a failing economy, unofficial domestic groups are rallying to his support. One such youth organization, CET, or Network, uses creative multimedia to appeal to Russia's urban youth with patriotic propaganda. VOA's Daniel Schearf reports.
Video

Video Filmmakers Produce Hand-Painted Documentary on Van Gogh

The troubled life of the famous 19th century Dutch painter Vincent van Gogh has been told through many books and films, but never in the way a group of filmmakers now intends to do. "Loving Vincent " will be the first ever feature-length film made of animated hand-painted images, done in the style of the late artist. VOA’s George Putic reports.
Video

Video Issues or Ethnicity? Question Divides Nigeria

As Nigeria goes to the polls next month, many expect the two top presidential contenders to gain much of their support from constituencies organized along ethnic or religious lines. But are faith and regional blocs really what political power in Nigeria is about? Chris Stein reports.
Video

Video Rock-Consuming Organisms Alter Views of Life Processes

Scientists thought they knew much about how life works, until a discovery more than two decades ago challenged conventional beliefs. Scientists found that there are organisms that breathe rocks. And it is only recently that the scientific community is accepting that there are organisms that could get energy out of rocks. Correspondent Elizabeth Lee reports.
Video

Video Paris Attacks Highlight Global Weapons Black Market

As law enforcement officials piece together how the Paris and Belgian terror cells carried out their recent attacks, questions are being asked about how they obtained military grade assault weapons - which are illegal in the European Union. As VOA's Jeff Swicord reports, experts say there is a very active worldwide black market for these weapons, and criminals and terrorists are buying.
Video

Video Activists Accuse China of Targeting Religious Freedom

The U.S.-based Chinese religious rights group ChinaAid says 2014 was the worst year for religious freedom in China since the end of the Cultural Revolution. As Ye Fan reports, activists say Beijing has been tightening religious controls ever since Chinese leader Xi Jinping came to office. Hu Wei narrates.
Video

Video Theologians Cast Doubt on Morality of Drone Strikes

In 2006, stirred by photos of U.S. soldiers mistreating Iraqi prisoners, a group of American faith leaders and academics launched the National Religious Campaign Against Torture. It played an important role in getting Congress to investigate, and the president to ban, torture. VOA's Jerome Socolovsky reports.
Video

Video Former Sudan 'Lost Boy' Becomes Chess Master in NYC

In the mid-1980’s, thousands of Sudanese boys escaped the country's civil war by walking for weeks, then months and finally for more than a year, up to 1,500 kilometers across three countries. The so-called Lost Boys of the Sudan had little time for games. But one of them later mastered the game of chess, and now teaches it to children in the New York area. VOA’s Bernard Shusman in New York has his story.
Video

Video NASA Monitors Earth’s Vital Signs From Space

The U.S. space agency, NASA, is wrapping up its busiest 12-month period in more than a decade, with three missions launched in 2014 and two this month, one in early January and the fifth scheduled for January 29. As VOA’s Rosanne Skirble reports, the instruments being lifted into orbit are focused on Earth’s vital life support systems and how they are responding to a warmer planet.

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More

All About America

AppleAndroid