Space Situational Awareness

SSA Seeks To Prevent Orbital Collisions, Malicious Attacks

In our highly interconnected, tech-dependent, early-21st century world, little everyday thought is given to the massive conglomeration of hardware circling the Earth, which makes our modern lives possible.

Countries with active space programs (and in recent years, commercial entities like Elon Musk’s SpaceX venture) have been sending up satellites and other items, into near-earth orbital paths, and the volume of these launches is beginning to increase the risk of collisions between them.

“The risk of a collision is equal to the square of the objects in orbit,” says longtime space veteran Joe Carroll. “Space Situational Awareness (SSA) is borrowed from a military term used by Air Force pilots—checking their ‘six’ to see who’s behind them, and so on.” Because there are collision hazards which need to be tracked, Carroll says, the mission of monitoring such dangers was given to the US military almost a decade ago, and in its role as a space going “traffic regulator”, the Air Force looks for orbiting satellites or debris that are on intersecting trajectories. A collision between a GPS satellite for example, and a communications platform, could have far-reaching, devastating effects.

Compounding these existing risks, are the ongoing threats of a malicious or hostile power deliberately killing a satellite by blasting fragmentary objects in its path. “China did an ASAT (anti-satellite) test a few years back, and its debris is still up there”, Carroll notes. Then, there are countries like North Korea, whose unannounced ballistic missile tests cross over and through the orbital planes of functioning, essential hardware. There’s no easy fix for that, Carroll says. “You can throw money at it, you can try to make agreements, but there’s few easy solutions.”

The Defense Department, however, is making a major investment in SSA. In 2014, the Air Force made nearly 700,000 alerts for possible orbital collisions, according to the General Accounting Office. The DoD plans to steer $6 billion into real-time monitoring of all the spaceborne debris that has accumulated in near-Earth orbit over the past six decades. A comprehensive radar-tracking apparatus, called the Space Fence, along with additional SSA projects, and an “operationally responsive” satellite, make up key components budgeted for development through 2020.

However, unofficial sources say the military is more interested in focusing on its role as a threat monitor, while moving the traffic-regulation role to a civilian agency or company. While efforts like Space Fence, which can detect and plot the movements of objects “anywhere in its wide field of view”, according to contractor Lockheed Martin, will greatly increase our view of the area of low orbit, a comparable effort, using telescopes of the type and size built by Planewave Instruments, are also feasible—and less costly. A coordinated ring of such optical devices, spread out around the globe, could permit the Air Force to concentrate on discovering, and responding to, attempts by an adversary to destroy the satellites of the United States or her allies.

SSA is poised to take on growing importance in the coming years, both to protect orbiting hardware, and manned space exploration, including the International Space Station (ISS). Fifty-year-old “space junk” is just as dangerous as the ASAT projects China and Russia are known to be working on. The implementation of the DoD initiatives, perhaps in conjunction with a commercial effort, can enable us to proverbially “check our ‘six’”, before a valuable, irreplaceable satellite is lost to a collision or other causes.