Satellites on the blink
There are over 500 of them keeping a watchful eye over us from the skies... No, not guardian angels, satellites. Could we cope without them?
It’s easy to go about your daily life oblivious to them, but satellites have been playing an increasingly important role ever since the launch of Sputnik, the first artificial satellite.
‘Fifty years ago we didn’t have satellites and we coped fine, but now we’ve become very reliant on them,‘ says Dr Sima Adhya, a satellite insurer at Sciemus.
Satellite TV addicts might be among the first to notice a satellite failure, but the impacts would be felt by everyone sooner or later.
The transport industry’s reliance on GPS would be quick to cause hiccups, sending Satnav systems on the blink and leaving taxi drivers and couriers who’d thrown out their paper maps stranded.
Air traffic control is expected to switch from radar to GPS. ‘GPS systems can track where an airplane is at any given time, as well as their speed, whether they’re descending or climbing,’ explains Adhya. Luckily, radar would still be used as a back up system, so failing satellites wouldn’t cause complete chaos.
In remote areas of the world, satellites provide internet and mobile phone network access, so people in these areas would be cut off, leaving many in relative isolation.
Cows and criminals on the loose
Perhaps surprisingly, GPS problems could also impact upon Australian farmers, who recently began to resort to GPS transmitters to keep tabs on their livestock. In the USA, tagging criminals with GPS is also fairly common.
Without satellite images to base predictions upon, weather forecasts would be another immediate casualty. Facing the dilemma of whether to take your umbrella out might be a pain, but no forecast equally means no advance warning for natural disasters such as flooding, hurricanes or tornadoes.
The loss of satellite snapshots would also hinder scientific research in the longer term. From their unique vantage point, satellites produce many useful images, allowing scientists to map deforestation or monitor Antarctic ice coverage for example. Turning their gaze to outer space, satellites such as the Hubble Space Telescope have also helped us explore our universe.
Here to stay
In a few decades, a satellite meltdown could become an even bigger disaster as we come to rely on satellites more heavily. ‘The satellite industry is one of the biggest growth areas,’ says Adhya, ‘people are thinking of new uses for them all the time.’
Artist's impression of solar power station in space
Some of these ideas include setting up solar power stations in orbit, or creating space elevators to serve as ‘ladders’ for launching spacecraft. It has even been suggested that satellites orbiting Mars could help make the red planet more hospitable for humans. ‘The idea is to set a constellation of large mirrors that reflect light onto the surface of Mars to concentrate the light and warm it up,’ explains Adhya.
Space is a perilous place to be, with plenty of potential hazards for our satellites to dodge. Despite what’s at stake, there’s no need to panic as satellite doomsday is unlikely to occur.
Solar flares are a real threat to satellites, spewing high energy particles that can interfere with delicate systems. Solar weather is closely monitored to avoid any glitches, and in some circumstances, if there is a risk of damage occurring, satellites can be switched off temporarily. ‘If they’re turned off they’re much less likely to suffer,’ says Adhya.
While space weather remains a threat, satellites’ biggest enemies might just be the lack of elbow room. As more and more satellites are launched, there is an ever-increasing likelihood of collisions occurring. ‘It is a risk and it will get worse,’ warns Adhya, ‘There have been a handful of instances of satellites colliding with each other, but many more involving smaller objects. These small objects might just be a nut or a bolt, but travelling at about 10 km/s it can wipe out a satellite.’
Whilst larger objects are monitored closely, smaller chunks of so called ‘space junk’ are harder to pin down. This means that if a collision does occur, the debris created can go on to cause further accidents. ‘There’s a cascade effect,’ comments Adhya.
Space junk is therefore quite a big worry, but we have yet to find a viable mechanism to clear the Earth’s orbit. ‘Lots of people are working on systems to go and collect bits of old satellites but that technology is still decades away,’ says Adhya, ‘And even if it works it will be very expensive.’
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