A group of engineers thinks it’s found a cheaper way to use high-altitude satellites to deliver global coverage.
Neel V. Patel in MIT Technology Review writes: "A new study led by engineers at The Aerospace Corporation and published in Nature Communications proposes a counterintuitive approach that turns these degrading forces into ones that actually help keep these satellites in orbit. If it worked, it would mean just four satellites could provide continuous global coverage for a fraction of the cost.
"The team ran simulations that looked at what types of orbital configurations could best turn degrading forces into ones that actually fostered a stable, circular orbit. Instances where, say, the sun’s gravity would normally break the constellation apart could now bind the constellation together. The simulations were for four-satellite constellations that would spend at least 6,000 days (16.4 years in orbit).
"After analyzing the simulations using the Blue Waters supercomputer at the University of Illinois at Urbana-Champaign, the team found two models that could work. In one, the constellation completes an orbit in a 24-hour period, at an altitude of 22,000 miles, and achieves continuous coverage for about 86% of the globe. The other works on a 48-hour period at an altitude of 42,000 miles and covers 95% of the globe. Any areas that experienced outages would face no more than about 80 minutes of downtime a day.
Granted, the internet speeds would be slower because of the extra time it takes to send the signal from a much higher orbit. “For most people using data systems, however, an additional quarter-second delay is difficult to sense, since there are so many other delays in computers and data networks,” says Roger Rusch, the president of telecom consulting firm TelAstra."
