Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Safe and efficient de-orbit of space junk without making the problem worse

02.08.2010
Global Aerospace Corporation (GAC) announced that Dr. Kristin L. Gates will present a paper on de-orbiting space junk at the August 2 Artificial and Natural Space Debris session of the AIAA Astrodynamics Specialists Conference in Toronto, Ontario, Canada.

Dr. Gates will describe GAC's Gossamer Orbit Lowering Device (GOLD) for safe and efficient removal from Low Earth Orbit (LEO) of dangerous space objects. The patented GOLD system concept uses a very large ultra thin balloon envelope to increase the aerodynamic drag by a factor of several hundred.

This will cause the space junk to enter the earth's atmosphere quickly and burn up. It will reduce the natural orbit decay of some objects from centuries to months. The computer-generated figure illustrates a GOLD system de-orbiting a large scientific observatory.

The envelope material is thinner and lighter than sandwich bag material. It takes a very small amount of gas to inflate it in the almost perfect vacuum of space. The system will work even though it will get punctured many times by small debris objects and tiny meteoroids. Despite these small holes, the total leak rate will be very small. The pressurization system will very easily keep up with the leakage. In the very unlikely event that a large object hits the very thin envelope, it will not cause that large object to break up into new fragments. Therefore, the operation of GOLD itself cannot make the orbital debris environment worse as could be the case with some alternative approaches that others have suggested.

Although the ultra thin envelope could be the size of a sports field (100 m diameter) when inflated, it is so thin that it can be folded and stowed in a surprisingly small volume (a medium size suitcase). It is most economical to attach it to a spacecraft or rocket upper stage before launch and deployed after the end of mission. However, GOLD could be attached to existing large debris objects using an orbital robot. For large, dense objects that could pose a hazard to people or property on the ground during reentry, GOLD can be used to aim the reentry safely into an ocean.

Space debris is a growing problem in many orbital regimes despite international debris mitigation guidelines and policies. The recent collision of an operational Iridium satellite and a defunct Russian satellite underscores the need for an ability to safely de-orbit large objects from popular, congested orbital regions. Currently, there are many hundreds of old spacecraft and rocket bodies orbiting the Earth at the same altitudes as operating spacecraft. As these abandoned objects continue moving through space, collisions with other objects create a shotgun effect of new debris objects, each of which could kill an operating spacecraft. Orbital debris - or space junk - refers to all these large orbiting objects as well as the cloud of smaller objects due to explosions of these systems and collisions with other objects. Even if we do nothing, the problem will get worse for centuries to come. But it's a difficult problem to solve. People have suggested many approaches to de-orbiting space junk, such as using existing on-board chemical propulsions systems, electrodynamic tethers, gravity gradient-oriented drag tapes, boom-deployed drag sails or solar pressure sails. In many cases, while these de-orbit devices are operating there is an increased chance of having a collision with something else and creating new junk. With GOLD there is a negligible increase in the chance of creating new dangerous orbital debris and once the object is removed from orbit, that particular threat is gone forever.

Although the use of on-board propulsion systems do not increase the chance of creating new debris, many spacecraft do not have such propulsion systems, and for those that do, there is always the temptation to use the propulsion system to extend the mission, depleting the fuel that would be needed to bring the spacecraft down. The GOLD system actually weighs less than the propellant needed to do the same job and it is very inexpensive, and this means it is more cost-effective to add a GOLD system before launch than to carry the extra fuel.

We tend to think of space as being a complete vacuum, but there are enough molecules and atoms out to several hundred miles to produce a small but noticeable drag that slowly reduces the orbital altitude of spacecraft. GOLD takes advantage of this effect and increases it by a factor of several hundred. The air out at these altitudes has a very small density. Sun spot activity is known to follow an eleven-year cycle, with an associated cycle in the radiation coming from the sun. At "solar max", the extra radiation causes the Earth's atmosphere to bloom outward, increasing the average air density in LEO by a factor of three. When GOLD is attached to a spacecraft, it is usually beneficial to wait until solar max to use it because it then brings down that satellite three times faster than average.

There are three basic applications for GOLD. The first application is to attach GOLD to satellites and rocket stages that are planned for launch. GOLD is then inflated, de-orbiting the object at the end of its useful life. The second application is in an active debris removal program, which may be important if the orbital debris problem is ever to be reduced. Several GOLD devices could be carried to orbit by an orbital robot and placed on existing space junk like the defunct spacecraft that struck the Iridium satellite, permanently removing them from orbit and making the environment safer. GAC has found that that GOLD is very effective in the 750 to 900 km altitude, high inclination orbit regime, which is a highly used portion of space and where the Iridium satellite was located. In a third application, some large space objects require controlled, targeted de-orbit and reentry because too much material survives reentry and reaches the Earth's surface where it can jeopardize the safety of people or property. In this application, when GOLD has reduced the orbit to the point of imminent entry, the large envelope is allowed to deflate under natural conditions to reduce drag and defer reentry a few days. After making good orbit predictions and using careful timing, the envelope is fully inflated at the correct point in the orbit to achieve a substantial atmospheric drag sufficient for prompt and safe reentry into the ocean.

In summary, the operation of GOLD has a lower risk of disabling other operational satellites and a lower risk of creating large orbit debris objects than competing de-orbit concepts or the derelict satellite itself. In addition, GOLD does not require an operating satellite to provide attitude stabilization or power as with propulsive de-orbit. GOLD can be integrated onto the satellite prior to launch or attached to derelict satellites by robots. De-orbit from LEO can be reduced, in some cases, from many centuries to as little as a few months. Finally, GOLD can assist civilian, commercial and military space satellite operators in meeting their obligations to mitigate the growing space debris problem in a cost effective and low risk way.

Kerry T. Nock | EurekAlert!
Further information:
http://www.gaerospace.com

Further reports about: Earth's magnetic field Orbit iridium propulsion systems

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>