The truth about space traffic management

Those familiar with air traffic management architectures understand the constraints of aircraft flying in the atmosphere, vehicle dynamics and command and control techniques. Unfortunately, space traffic has many more degrees of freedom and much less control capability. Add to this the completely uncontrolled nature of space debris and the reality that most debris objects cannot be tracked and motion cannot be accurately measured or simulated.

In fact, orbiting debris is a product of negligence. Over the first 60 years of space flight, mission plans ended with the completion of in-space operations. Satellites were shut down and left in their orbits, subject to natural influences. Little thought was given to any collateral effects of objects "adrift" in space, because "space" was thought of as "big."

An analogy might be the ocean disposal of waste items, where junk gets lost in the vastness of the seas, either by sinking to the bottom or by simply drifting with ocean currents. By contrast, a "drifting" satellite remnant in low orbit is travelling at a speed in excess of 7.3 km/sec (16,300 mph). Since orbiting objects can travel in all directions, collisions between satellites and debris can occur at speeds of over 14.6 km/sec (32,600 mph).

Of the suspected hundreds-of-thousands of dangerous debris objects in low orbits, only about 35,000 are 5 cm (2 inches) or larger in size, and only these can be tracked. The vast majority of the 1014+ junk items remain beyond current tracking capabilities, but are nevertheless dangerous in terms of causing significant damage to operating satellites. T

he detrimental effects of space junk grow worse each year, putting international space systems increasingly at risk as our communications, science and security networks rely ever more heavily on the interconnected system of satellites orbiting above our skies.

While we understand weather and have learned techniques to deal with it, the impact and disposition of orbital debris are not fully understood. Unlike weather, space junk is man-made and, if not properly dealt with, will significantly hinder the world's future economy and security.

It is a growing threat to space-based communications, weather forecasting, banking processes, scientific exploration, Earth observation and future space tourism. Space commerce is growing, and as this industry expands the need for an effective traffic management system will become critical to commercial growth and exploitation of space.

At the moment, there are no viable programs in place to deal with orbital debris, even though new satellites continue to be launched. In fact, more than 50,000 new satellites may enter service in the next few years. New launches contribute to the already-large orbital debris population.

With over 60 countries operating in space, the exponentially growing problem of orbital debris will take international collaborations and partnerships to conceive and develop innovative solutions and strategies as part of a worldwide space traffic management architecture. Inaction could lead to a total shut down of space activities. But, it may already be too late.