How We Use Space Every Day
- 30th Oct 2018
- Author: Joshua Critchley-Marrows
When someone mentions space, what do you think about? Martian rovers, the International Space Station, alien planets … These incredible feats of exploration are pushing the boundaries of our understanding of life, the universe and everything, but how does this relate to you and daily life here on Earth? How does a small space probe orbiting around the rings of Saturn affect us in the slightest?
If it weren’t for these missions, most of today’s interconnected web of technology would not be possible.
Probably the most significant scientific marvel to come out of the space race is the satellite, with the launch of Sputnik 1 in 1957. Today there are over a thousand satellites flying over our heads every day at speeds nearly up to 8,000 metres per second, helping us communicate, capture, and navigate our daily lives.
GPS – navigating and tracking daily life
One such satellite, or I should say satellites, are the world’s Global Navigation Satellite Systems (GNSS). You probably know it under a different name, GPS.
This constellation of satellites above our heads is the reason we can navigate our way around the planet with ease.
A good example is Google Maps on your phone, which uses GNSS every time you see the little dot on the screen. Your mobile uses signals from these satellites to measure the distances between a receiver, i.e. your phone, and the constellation. By combining these distances, you know where you are.
This Headsqueeze video from BBC Earth Lab gives a good intro to how satellite navigation works:
In order to keep track of planes, rail, and even taxis, companies rely heavily on GNSS. Every plane coming into land must be carefully tracked in order to prevent collisions and monitor for strange behaviour. Trains are monitored for efficient signalling, time of arrival predictions, and to find and fix issues with the network. When you use a taxi app, the driver needs to know where you are, and you need to know where your ride is.
Originally, GNSS was limited to just the GPS satellites, which are a US military asset with special permission for the public to use a limited and temporary set of signals. Now however, new GNSS are being launched across the world, such as Beidou (China), GLONASS (Russia), QZSS (Japan), and Galileo (Europe). These new satellites allow other nations to control their access to satellite navigation, which is now embedded in daily activities such as car sat navs, traffic signals, and banking transactions. Any loss of access to navigation satellites could cripple a country’s economy, which is why big nations are keen to launch and control their own satellite constellation, rather than rely on the goodwill of the United States or Russia. More satellites also mean more accuracy worldwide.
To find out more, check out this fascinating BBC article: What Would Happen If All the Satellites Stopped Working?
Eyes on Earth
Another key aspect to life on Earth today are the satellites that observe Earth from space.
Using very high definition cameras and lenses, these so-called ‘remote sensing satellites’ can study the Earth from a global perspective to map our cities, oceans, forests, deserts, towns, and climate.
For example, Google Earth has been created solely through use of Earth observation satellites such as Digital Globe and WorldView. Farmers use these images to monitor their crops’ water levels and to inspect for signs of bugs and pests in their fields.
These critical operations take place daily and not just on farms.
Continuous monitoring of Arctic sea ice is key to understanding the effects of climate change on our planet. Every year, scientists observe that the level of frost in the North pole is slowly disappearing, thanks to NASA and Japanese Earth Observation satellites. We now know that this loss is due to climate change and global warming, but the rate of change is closely linked to the sea ice levels in the Arctic.
Only by satellites monitoring these trends from space can we better understand our relationship with the Earth.
Hundreds of mini satellites
But in order to continuously monitor the planet, huge constellations containing hundreds of satellites that span the whole planet are needed.
Several space companies have now achieved this, including Planet Labs which has over 150 mini satellites, called ‘CubeSats’, in Earth orbit. These spacecrafts are great for a global view, but they can’t capture very high-resolution images due to their size (most don’t exceed the size of a 30 cm ruler). So they are supplemented by several bigger satellites in a higher orbit to capture the Earth in more detail.
Iridium uses much bigger satellites to achieve the more detailed Earth, but at a much higher expense since they are heavier, bulkier and more expensive to build.
Every day, these cooperating satellite constellations fly over our heads. They are continuously communicating with our smartphones, cars, televisions, and computers, helping us to know where our next holiday should be, when we should expect it to rain, and what would be the best route into school or work.
Back in the 1960s, the first astronauts could hardly have dreamed where their missions would take the world!
Without many of us realising it, space has become embedded in our daily lives, economies, and scientific research. It’s not just about going out there – it’s also helping us live global, interconnected lives back here on Earth. Our international, globalised society is only possible through using space.
To check out some satellites yourself, you can use NSL’s rinex ON app to see which GNSS satellites your phone is currently connected to, or ESA’s Copernicus Sentinel app to track Europe’s Earth Observation satellites.
About the author: Joshua Critchley-Marrows is a GNSS Engineer for NSL (Nottingham Scientific Ltd)
