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When you’re on a flight to Florida, you’re probably thinking about which book you should read on the beach…not about the chances your plane will collide with a rocket launching from Cape Canaveral! You might assume that the professionals tracking your plane also know when and where rockets are in the air. But you’d be wrong.
And we’re living in the age of commercial space flight. In 2022 alone, there were a record-setting 180 successful rocket launches around the world! The off chance that something goes wrong between a plane and a rocket is higher than ever. So to keep us safe in this rocket-filled world, engineers and air traffic controllers have to reinvent the way we keep track of rockets.
[♪ INTRO] Let’s start with why rockets are effectively invisible to air traffic controllers. It’s all because of space history. When humans started going to space, each launch was a massive undertaking run by federal agencies like NASA. And to keep commercial airplanes from hitting those rockets, air traffic controllers borrowed the technique that the military used to clear airspace for practice exercises. They declared a temporary no-fly zone known as a Special Activities Airspace. For several hours, airplanes had to detour around these areas, which could range anywhere from 90 to 4400 square kilometers surrounding the launch pad.
With such large empty swaths of airspace around a rocket, the Federal Aviation Administration, or FAA, didn’t need to know where that rocket was at all times. Strategically speaking, having to clear out such a large airspace wasn’t that big of a deal when NASA was launching one or two rockets a year. But now that there are nearly 200 launches a year worldwide, including ones run by private companies, the technique is pretty inefficient. It’s wasteful, too. Planes fly longer routes around rocket launches and use a lot more fuel. For just one rocket launch in 2018, 563 flights were delayed, and those planes flew an extra 64,500 kilometers in total.
But the system also needs a revamp because of safety. Now, even if there weren’t any airspace restrictions to separate planes and rockets, there’s still not a huge chance a rocket would actually hit a plane, or vice versa. Rockets have to be pretty zippy to get up into space, so they leave the airspace that commercial planes fly through pretty quickly. The real concern is damage from the debris that rockets drop. Two types of rocket debris exist: pieces that are intentionally ejected, and pieces that fall back to Earth due to any number of accidents.
The stuff that engineers plan to eject is made from materials with low melting temperatures. So, after it’s ejected, it burns up in the atmosphere at way higher altitudes than commercial planes fly. Meanwhile, debris from accidents can fall through commercial airspace. And what’s worse, it often ends up spreading out over a pretty wide area. For example, when the space shuttle Columbia disaster happened, it generated 38,000 kilograms of debris that ended up covering an area 1000 kilometers long by 40 kilometers wide. But NASA had only planned to close airspace in a 48 kilometer circle around an emergency shuttle landing.
It’s incredibly fortunate that no commercial aircraft was struck by anything. Nine planes flew through the debris zone during the 40 minute period when pieces were falling, and no system was in place to warn them. And if you’re wondering if a plane ever has had the misfortune of getting struck, the answer is yes. In 1996, space debris hit a Chinese plane, cracking its windshield and forcing it to land, although no one knows exactly what the debris was. And an emergency landing is the best case scenario in accidents like these. Air traffic controllers strive to avoid collisions while keeping no-fly zones as small as possible. Currently, if something goes wrong, someone at NASA or the rocket company has to email or call the FAA to alert them, which can take a long time and open the door for human error. It would take around 13 minutes for a plane to maneuver away from an accident, but debris could fall through commercial space in as little as four minutes. To address this, the FAA is developing the Space Data Integration system (SDI) which will allow planes to adjust their route within the first minute and a half of an accident occurring. SDI will allow the FAA to track rocket launches in real time, and assign rockets their own bubbles of space that are much smaller than the 16.7 kilometer wide bubbles currently assigned to commercial planes. To make sure this system is reliable, computer scientists are working on algorithms such as Markov Decision Process and Monte Carlo Simulation to help the FAA predict and protect planes from flying through debris fields. To learn more about this, check out Brilliant’s 23 lesson Applied Probability course, and get a 30 day free trial and 20% off an annual premium Brilliant subscription. Because you’re watching SciShow, you can get a special deal! Find those savings at Brilliant.org/SciShow or at the link in the description below. [♪ OUTRO]