Nav: Home

How to get rid of a satellite after its retirement

September 01, 2015

Researchers at University of La Rioja (Spain) have developed a new method to eliminate artificial satellites in Highly Elliptical Orbits when they finish their mission. The methodology, which allows for a reduction of both cost and risk, has been tested with the European Space Agency INTEGRAL mission, which will re-enter into the Earth's atmosphere in order to disintegrate in 2029.

The problem of space debris is one of the main challenges that aerospace engineers have to face, due to the danger it poses to satellites. In this context, members of the Scientific Computing Group (GRUCACI) at University of La Rioja have developed a method to eliminate satellites in Highly Elliptical Orbits (HEO) when they finish their mission.

HEO orbits are very eccentric (the farthest position can be ten times farther from the Earth than the nearest) and inclined (60 degrees or more with respect to the equator); their evolution is strongly influenced by the gravitational effects of the Earth's equatorial bulge and the pull from the Moon and the Sun.

Both effects can cause satellites placed in this type of orbits to cross two 'protected' regions (Low Earth Orbits, LEO, and Geostationary Orbits, GEO) during long periods of time, thus increasing the risk of collisions with the numerous satellites operating in them. In addition, the probability of an uncontrolled re-entry into the lower layers of the Earth's atmosphere also increases.

"Our research has focused on taking advantage of the same gravitational effects that affect HEO orbits so as to reduce the cost of eliminating the satellites which operate in them once they have reached retirement", Roberto Armellin, co-author of the work, explains to Sinc.

"Some propellant needs to be reserved in order to perform the satellite disposal manoeuvres, so it cannot be used to extend the mission duration, which makes it more expensive", the researcher adds, "so we have developed a methodology aimed at reducing the amount of propellant needed, and hence the associated cost".

The researchers have undertaken their study, which they have published in the journal Advances in Space Research, as a mathematical optimization problem in which several objectives have to be simultaneously fulfilled, and they have solved it by means of an evolutionary algorithm -based on biological evolution-.

They have also used their own orbit propagator software, which is designed to propagate the evolution of an orbiter during 100 years in just a few seconds. This program allows finding the best conditions and instants for satellites to re-enter into the Earth's atmosphere, where they can safely disintegrate with minimum risk for other satellites.

Validity of the method tested on INTEGRAL

In order to prove the effectiveness of their methodology, the researchers have applied it to the European Space Agency (ESA) INTEGRAL mission, an advanced gamma-ray space observatory launched in 2002.

"The simulation results suggest designing manoeuvres so that the INTEGRAL satellite re-enters into the Earth's atmosphere, and subsequently disintegrates, during the period of time from September 2028 to July 2029, in a controlled way and with a cost which is reduced by the amplification of natural gravitational effects", Armellin points out.

This solution coincides with the real strategy adopted by ESA to eliminate INTEGRAL, which has fired its engines four times this year so as to re-enter safely and with a reduced cost on February 2029.

The latest regulations of ESA about space debris require that, once the end of life has been reached, if a satellite continues to cross the LEO protected region it must re-enter into the Earth's atmosphere and disintegrate before 25 years. INTEGRAL is going to comply with these regulations, even though it was not obliged to, due to its launch date.

The study of the GRUCACI team also proves that it is possible to select some latitude regions such that the satellite re-entry takes place with minimum risk to cause damage to populated areas of the Earth.
-end-
Reference:

Roberto Armellin, Juan F. San-Juan and Martín Lara. "End-of-life disposal of high elliptical orbit missions: The case of INTEGRAL". Advances in Space Research 56 (3): 479-493, August 2015.

FECYT - Spanish Foundation for Science and Technology

Related Atmosphere Articles:

Primitive atmosphere discovered around 'Warm Neptune'
A pioneering new study uncovering the 'primitive atmosphere' surrounding a distant world could provide a pivotal breakthrough in the search to how planets form and develop in far-flung galaxies.
NASA's MAVEN reveals Mars has metal in its atmosphere
Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results from NASA's MAVEN spacecraft.
Northern oceans pumped CO2 into the atmosphere
The Norwegian Sea acted as CO2 source in the past.
Study opens new questions on how the atmosphere and oceans formed
A new study led by The Australian National University has found seawater cycles throughout the Earth's interior down to 2,900km, much deeper than previously thought, reopening questions about how the atmosphere and oceans formed.
How a moon slows the decay of Pluto's atmosphere
A new study from the Georgia Institute of Technology provides additional insight into relationship between Pluto and its moon, Charon, and how it affects the continuous stripping of Pluto's atmosphere by solar wind.
Fossil fuel formation: Key to atmosphere's oxygen?
For the development of animals, nothing -- with the exception of DNA -- may be more important than oxygen in the atmosphere.
Researchers dial in to 'thermostat' in Earth's upper atmosphere
A team led by the University of Colorado Boulder has found the mechanism behind the sudden onset of a 'natural thermostat' in Earth's upper atmosphere that dramatically cools the air after it has been heated by violent solar activity.
New biochar model scrubs CO2 from the atmosphere
New Cornell University research suggests an economically viable model to scrub carbon dioxide from the atmosphere to thwart global warming.
Venus-like exoplanet might have oxygen atmosphere, but not life
The distant planet GJ 1132b intrigued astronomers when it was discovered last year.
Middle atmosphere in sync with the ocean
In the late 20th century scientists observed a cooling at the transition between the troposphere and stratosphere at an altitude of about 15 kilometers.

Related Atmosphere Reading:

The Atmosphere: An Introduction to Meteorology (13th Edition) (MasteringMeteorology Series)
by Frederick K. Lutgens (Author), Edward J. Tarbuck (Author), Dennis G. Tasa (Author)

The Atmosphere: An Introduction to Meteorology (14th Edition)
by Frederick K. Lutgens (Author), Edward J. Tarbuck (Author), Redina Herman (Author), Dennis G. Tasa (Author)

The Atmosphere: An Introduction to Meteorology (12th Edition)
by Frederick K. Lutgens (Author), Edward J. Tarbuck (Author), Dennis G. Tasa (Author)

Shifting Atmospheres: A Strategy for Victorious Spiritual Warfare
by Dawna DeSilva (Author)

Atmospheres
by Peter Zumthor (Author)

Meteorology: Understanding the Atmosphere (Jones and Bartlett Titles in Physical Science)
by Steven A. Ackerman (Author), John A. Knox (Author)

The Layers of Earth's Atmosphere (Spotlight on Weather and Natural Disasters)
by Elizabeth Borngraber (Author)

Essential Training for Shifting Atmospheres: A Strategy for Victorious Spiritual Warfare
by Dawna DeSilva (Author)

Prayers, Declarations, and Strategies for Shifting Atmospheres: 90 Days to Victorious Spiritual Warfare
by Dawna DeSilva (Author)

The Atmosphere: An Introduction to Meteorology (11th Edition)
by Frederick K. Lutgens (Author), Edward J. Tarbuck (Author), Dennis G. Tasa (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Dying Well
Is there a way to talk about death candidly, without fear ... and even with humor? How can we best prepare for it with those we love? This hour, TED speakers explore the beauty of life ... and death. Guests include lawyer Jason Rosenthal, humorist Emily Levine, banker and travel blogger Michelle Knox, mortician Caitlin Doughty, and entrepreneur Lux Narayan.
Now Playing: Science for the People

#492 Flint Water Crisis
This week we dig into the Flint water crisis: what happened, how it got so bad, what turned the tide, what's still left to do, and the mix of science, politics, and activism that are still needed to finish pulling Flint out of the crisis. We spend the hour with Dr Mona Hanna-Attisha, a physician, scientist, activist, the founder and director of the Pediatric Public Health Initiative, and author of the book "What the Eyes Don't See: A Story of Crisis, Resistance, and Hope in an American City".