Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Space debris in the spotlight
by Staff Writers
Berlin,. Germany (SPX) Feb 15, 2012


Laser research.

Every year, the number of small items of debris in space rises by tens of thousands. This number is currently based on estimates, as it has not been possible to track space debris accurately.

Researchers at the German Aerospace Center are developing an optical observation system with a powerful laser, the pulses from which can detect particles only a few centimetres in diameter and allow determination of their orbits. The concept was tested for the first time in January 2012, in collaboration with the Laser Station in the Austrian city of Graz.

This is the first time that the orbits of spent launcher components have been measured using a laser in Europe. In the future, an even more powerful laser will be capable of deflecting these particles out of their orbits, causing them to incinerate as they re-enter Earth's atmosphere.

The laser station in Graz is a part of the Space Research Institute (Institut fur Weltraumforschung; IWF) of the Austrian Academy of Sciences (Osterreichischen Akademie der Wissenschaften; OAW), and the laser beam it sent up into space was able to detect more than 20 different launcher components at distances of 500 to 1800 kilometres. This search for space debris was based on calculations performed by researchers at DLR Stuttgart, and involved detecting them and measuring their distance from Earth.

"This provides us with confirmation that our idea really works," explained Adolf Giesen, Director of the DLR Institute of Technical Physics. Even though the space debris tracked during this test was several metres across in size, the success of the experiment is an important step forward for the researchers. "At present, we are developing and building a system to detect space debris.

This will incorporate a laser with higher pulse energy, enabling the detection of significantly smaller items. When this becomes operational, it should be possible to locate objects measuring just 10 centimetres across."

The destructive power of space debris

The need to track space debris, even down to sizes of just one centimetre, and to calculate the orbits of that debris, is growing with each passing year. Decommissioned satellites or spent upper stages of launch vehicles can collide with one another and disintegrate into smaller pieces.

When two satellites collide, such as in the event involving Iridium 33 and Kosmos-2251 in February 2009, a large amount of space debris is generated. There are so many pieces of debris, both large and small, in orbit at altitudes between 800 and 1400 kilometres that active satellites run the risk of getting damaged by it.

"In the event of a collision, even an item with a diameter of one centimetre can completely destroy a satellite," explains Wolfgang Riede, Head of the Active Optical Systems Department at the DLR Institute of Technical Physics.

Space debris orbits at roughly eight kilometres per second, so if it collides with an object travelling in the opposite direction, the relative impact speed can usually be as high as 14 kilometres per second. Evasive manoeuvres are only effective if the positions of the debris can be calculated with great precision.

Conventional radar and telescope observations are only able to accomplish this to a limited extent; for this reason, a number of unnecessary avoidance manoeuvres, each consuming a great deal of propellant, must be performed. Even avoidable collisions are a potential consequence of imprecise orbital data; this was the case in February 2009, when the necessary change in orbit was not performed.

The physicists at DLR Stuttgart have set themselves an ambitious target to be reached by 2014. They are currently designing a transceiver unit and a laser that will send 1000 pulses per second from Earth into space and then record the light reflected from space debris at very high resolution.

"We will send high-intensity pulses of laser light up into space, and then quite literally count the individual photons reflected back to us," explains Institute Director Giesen. The surfaces of launcher and satellite debris are very difficult to detect, as they range from matte black to highly reflective. Not only that, but the researchers must also take into account the perturbing influence of the atmosphere.

Nevertheless, the small number of returning photons is still enough to determine the range, direction of travel and position of items of space debris with great precision. Transferred to the ground, it is difficult to find a suitable example to demonstrate the remarkable level of precision; it will be something akin to being able to tell which hand a person in the Baltic Sea is holding up, as viewed from the site of the future observation station in Stuttgart.

Reducing the risk to satellites
After building up a catalogue containing as many of these small debris items as possible and recording their current orbits, the next step - that of reducing the amount of space debris - can follow.

"If the amount of space debris continues to increase, we will eventually cease to be able to operate satellites in the more densely populated orbits," states Giesen. "Their service life would be greatly shortened."

One solution to this could use extremely powerful lasers. When such a laser is directed onto an item of debris, material would evaporate from its surface, reducing its velocity.

Even if that retardation only amounted to 200 metres per second, it would be sufficient to ensure the orbit's decay in the following years, and the debris would eventually burn up upon entry to the denser layers of Earth's atmosphere. Giesen estimates that this method could become operational in about 10 years.

"We would be continuously reducing the amount of debris in space," he explains. "If this fails, there will be so much space debris in Earth orbit 20 to 30 years from now that vitally important near-Earth orbits will become unusable."

.


Related Links
DLR Institute of Technical Physics
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Publicity and Panic for Satellite Re-Entries
Sydney, Australia (SPX) Jan 31, 2012
Space agencies struggle with the technical issues surrounding uncontrolled satellite re-entries. It's hard to predict when or where a bird will finally come down. Usually, the low risk of any damage arising to people or property generates a relaxed response to the problem. This may be justified, but it's not always perceived this way by the general public. Falling satellites may not be a m ... read more


TECH SPACE
China publishes high-resolution full moon map

Manned Moon Shot Possible by 2020

NASA Mission Returns First Video From Lunar Far Side

A Moon Colony by 2020

TECH SPACE
Martian Carbon Dioxide Clouds Tied To Atmospheric Gravity Waves

NASA kills Mars deal with Europe

No future for Mars?

Scientists say Obama Mars cuts to hit research

TECH SPACE
Study: 'Crippleware' raises consumer anger

NASA Reaches Higher With Fiscal Year 2013 Budget Request

Sierra Nevada Delivers Flight Test Vehicle Structure

Space tours to the Moon - why not?

TECH SPACE
Space-tracking ship Yuanwang VI concludes trip

China's new rockets expected to debut within five years

China announces new launch rockets

China's satellite navigation sector annual output predicted to reach 35 bln USD in 2015

TECH SPACE
Advanced Communications Testbed for Space Station

Europe's ATV space ferry set for launch to Space Station

Unique Testbed Soon Will Be in Space

Europe's Automated Transfer Vehicle is integrated on Ariane 5

TECH SPACE
ILS Proton Successfully Launches SES-4

ESA's new Vega launcher scores success on maiden flight

Europe delighted as new rocket notches up success

NASA Seeks Game Changing Technology Payloads for Suborbital Research Flights

TECH SPACE
Elements of ExoPlanets

New super-Earth detected within the habitable zone of a nearby star

Russia to Start Own Search for Extrasolar Planets

Planets Circling Around Twin Suns

TECH SPACE
Lockheed Martin-Built Milstar Satellite Surpasses 10-Year On-Orbit Design Life

Space debris in the spotlight

A mineral way to catalysis?

Cisco appeals EU's Microsoft-Skype merger approval




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement