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




TECH SPACE
NRL Scientists Propose Mitigation Concept of LEO Debris
by Staff Writers
Washington DC (SPX) Jun 25, 2012


Schematic illustration of the suborbital dust deployment: A ballistic rocket is used to release dust in the path of debris fragments. The debris population is engulfed by the dust cloud, experiencing enhanced drag and results in the loss of debris altitude. The debris population descends to an altitude of X0 kilometers, within one debris revolution time, below which Earth's natural drag is sufficient to force reentry within a desired time. The dust cloud also descends under gravity and re-enters the atmosphere. For a larger version of this image please go here.

Physicist and Engineers at the U.S. Naval Research Laboratory Plasma Physics Division and Naval Center for Space Technology are researching a technique to 'sweep' Low Earth Orbit (LEO) debris from space using an Active Debris Removal (ADR) system of deployed micron-scale dust.

In LEO, below 2,000 kilometers, orbital debris can travel in excess of 8 kilometers per second, or greater than 17,000 miles per hour, wreaking havoc on invaluable space assets like the International Space Station (ISS), Hubble Space Telescope and numerous weather satellites, damaging solar arrays, instrument panels and solar shields.

The National Aeronautical and Space Administration (NASA) Orbital Debris Program Office estimates there are more than 21,000 orbital debris objects larger than 10 centimeters (roughly 4 inches) in diameter in LEO, and approximately 500,000 object particles between 1 and 10 centimeters, with the number of debris particles smaller than 1 centimeter in excess of 100 million.

In 2011, the National Research Council (NRC) conducted an exhaustive study to assess NASA's meteoroid and orbital debris program. The report concludes that LEO orbital debris is at the 'tipping point' - the threshold for collisional cascade, or Kessler effect, in which the number of objects in LEO is dense enough that collisions between objects could cause a cascade.

This exponentially increases the likelihood of further collisions and makes it increasingly risky to maintain space assets without clearing the debris population.

"Hundreds of near-misses occur each year between orbital debris and operational satellites," says Gurudas Ganguli, head, NRL Space Analysis and Application Section at the Plasma Physics Division. "Dust, similar to that which naturally fills the near-Earth environment, can be deployed artificially in a narrow altitude band to enhance drag on debris and force re-entry."

About 100 tons of cosmic dust is introduced daily in the Earth's environment naturally in the form of micrometeorites. In addition to this natural source, human space activity also introduces large quantities of dust in space regularly. However, this dust is distributed over a very large volume, making it too widely dispersed to affect orbital debris.

As Ganguli explains it, the essential idea is that dust, if artificially deployed on orbit in opposite direction to the debris trajectory, can induce an enhanced drag on the debris. The novelty is that by choosing the dust characteristics, for instance, mass density, size, etc., it is possible to synchronize the rate of dust and debris descent.

This offers the possibility to clear a very large volume of small debris by deploying a modest amount of dust, 20 to 40 tons, in a narrow layer and "sweeping" of the debris volume by the dust layer.

"It is well known that the natural drag due to neutral atmosphere decays satellite orbits," adds Ganguli. "We use the natural atmospheric drag to decay the deployed dust orbits and simultaneously use the dust to induce enhanced drag on the orbital debris.

Like the natural dust, most of the deployed dust as well as the small orbital debris will incinerate while reentering the Earth's dense atmosphere. So the environmental effect of releasing the dust is expected to be benign."

Research indicates that the dust based ADR system can be a cost effective means to clear deadly untrackable small orbital debris with manageable risks to existing space assets and can be developed with off-the-shelf type technologies in the near term.

This same concept can be utilized for removing larger debris with a suborbital dust deployment. Preliminary analysis suggests tungsten be a prime candidate for the dust because of its high density, relative abundance, availability in powder form and modest cost, all contributing factors to the efficiency and economy of the system.

.


Related Links
U.S. Naval Research Laboratory Plasma Physics Division
Naval Center for Space Technology
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








TECH SPACE
ISS to Build Up Meteorite Defenses
Moscow (RIA Novosti) Jun 25, 2012
Russian cosmonauts will conduct a space walk in August during which they will install additional anti-meteorite panels on the International Space Station (ISS), cosmonaut Yury Malanchenko said on Friday. Malanchenko, his U.S. and Japanese colleagues, Sunita Williams and Hoshide Akihiko, are scheduled to depart for a space mission on July 15. "We will have a space walk in August, whic ... read more


TECH SPACE
Researchers Estimate Ice Content of Crater at Moon's South Pole

Researchers find evidence of ice content at the moon's south pole

Nanoparticles found in moon glass bubbles explain weird lunar soil behaviour

UA Lunar-Mining Team Wins National Contest

TECH SPACE
Extensive Water in Mars Interior

Orbiter Out of Precautionary 'Safe Mode'

Researchers calculate size of particles in Martian clouds of CO2 snow

ESA tests self-steering rover in 'Mars' desert

TECH SPACE
Complex Challenges Solved In Tech Meetings For Commercial Crew Program

Boeing Completes Key Reviews of Space Launch System

Two NASA Visualizations Selected for Computers Graphics Showcase

NASA technology-sharing portal announced

TECH SPACE
Man Versus Machine on Shenzhou

Above and below, Chinese science soars

China conducts first manual space docking

That's No Lab, It's a Space Station

TECH SPACE
New Space Station Crew Confirmed

Spacewalk to work on ISS scheduled

Did You Say 1.2 Billion Particles Per Month?

Varied Views from the ISS

TECH SPACE
USAF officials announce milestone Atlas V launch

EVE Underflight Calibration Sounding Rocket Launch

ILS and AsiaSat Announce a New Contract for an ILS Proton Launch

A milestone in launcher preparations for Arianespace's fourth Ariane 5 flight of 2012

TECH SPACE
Forgotten Star Cluster Useful For Solar Science And Search for Earth Like Planets

SciTechTalk: Quick, name the planets!

Where Are The Metal Worlds And Is The Answer Blowing In The Wind

Metal-poor stars are rich with small planets

TECH SPACE
IT security problems shift as data moves to 'cloud'

Samsung eyes 10 mn mark for Galaxy S3 by end of July

ISS to Build Up Meteorite Defenses

Smartphones put writing on the wall for paid texts




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