Leonard David's INSIDE OUTER SPACE

Earth clutter. This artist’s view shows the broad scope of space debris circling the planet, hundreds of miles above sea level, at the same height where low-Earth orbit satellites operate. The spatial density of debris objects increases at high latitudes. Note that the size of the debris elements in this image is greatly exaggerated compared to the size of Earth.
Credit: European Space Agency.)

The National Center for Atmospheric Research (NCAR) in Boulder, Colorado is part of a collaborative effort to help satellites dodge space junk.

Testing is under way for implementation of a system that models the effects of space weather on satellite orbits.

The Atmospheric Density Assimilation Model (ADAM) is designed to take into account real-time information on satellite tracks and space weather to predict future satellite paths as much as 72 hours in advance.

ADAM has been commissioned by the U.S. Air Force and brought into testing mode this summer.

Atmospheric drag

The ADAM project is being spearheaded by the private firm, the Atmospheric & Space Technology Research Associates, LLC in Boulder, in collaboration with NCAR, the University of Colorado Boulder, and the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center also in Boulder.

“Space debris is a big problem for satellite operations,” said Liying Qian, NCAR’s principal investigator on ADAM.

Another NCAR participant, Stan Solomon, noted that interest in the problem is on the rise: “There is more concern and awareness of space-junk issues, and more recognition that atmospheric drag is the major uncertainty in tracking it.”

Steer around debris

As you read this, there are roughly 19,000 pieces of space debris being tracked. But there’s nothing that can be done to change any path of a chunk of space junk. Instead, satellite operators have to adjust spacecraft orbits to steer around the debris.

As noted in an NCAR press statement: “To project those orbital adjustments accurately, scientists need to know how the density of the atmosphere is evolving in the low-Earth orbit (LEO) zone, several hundred miles above the surface. Both everyday heating by the Sun and occasional solar storms cause the upper atmosphere to expand. This exerts added drag on LEO satellites, pulling their orbits closer to Earth. Atmospheric waves propagating from below can also influence upper atmospheric density, a topic now being studied in the DEEPWAVE field project.”

The international DEEPWAVE project makes use of novel instruments — based in New Zealand – that will provide an unprecedented view of gravity waves, a major shaper of atmospheric variability at multiple heights.

Cone of trajectories

Similar to NOAA hurricane guidance, ADAM will help users produce a “cone” of possible future trajectories of space debris, together with projected satellite tracks, according to the NCAR release.

With the initial ADAM model now complete, the next phase is a round of testing that began in June and will continue through the summer of 2015 at the Air Force Research Laboratory.

Once finalized, ADAM could eventually be used in both military and commercial settings.