Small Satellites

Last week, the Indian Space Research Organisation launched 104 satellites using 1 rocket and earned praise from across the world including its rival, Elon Musk. Only 3 of these satellites were from India (including the Earth Observation mission), 96 of them were from the US. Of these, 88 came from just one company, Planet Labs.

Planet labs was set up by former NASA researchers to provide Earth images for agriculture, defense, forestry and civil infrastructure. With the latest constellation Flock 3p, the company expects to have 144 satellites in orbit allowing it to image all the Earth’s landmass every day. Flock 3p was launched at an altitude of 500km in Sun Synchronous Orbit.

The company builds its own satellites called Dove. Each Dove carries a camera that gives 3-5m resolution images on the ground (for reference, civilian GPS offers a 95% confidence interval of 7.8m).  Go to their website to see their images. You can see the images of Redding and see how the same area looks across seasons as vegetation comes in Fall and disappears in the Summer.

The reason small companies like Planet Labs are able to mass produce tiny satellites is thanks to the CubeSat standard. A CubeSat is made of 10*10*11.35 cm sized units weighing less than 1.33 kg. The idea was that while launches carried large payload satellites, there was often space and weight capacity left over in the rocket which was getting wasted. CubeSats were designed to fit alongside with the regular payload drastically reducing the cost of launching them.

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A CubeSat from Norway

This allowed a lot of satellites to be launched to try specific experiments which would have otherwise been very hard to justify at the higher cost of an exclusive launch. The increased participation also meant that a lot of components common to CubeSats could be mass produced. For instance, on May 2013, Estonia launched its first ever satellite. It consisted of a single cube unit called ESTCube-1 and was used to test a solar wind sail. The satellite lived for almost 2 years and resulted in 29 bachelor’s, 19 master’s dissertations, 5 doctoral theses and 4 startups. The total cost of the project was about 100,000 euros.

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ESTCube-1 Illustration

Similarly, in 2009, Switzerland had launched its first satellite SwissCube-1, also a CubeSat using an ISRO PSLV rocket. That satellite studied Earth’s nightglow and was later used for amateur radio.

Under the new US administration, NASA funded climate study programs are expected to decline. The importance of small, cheap commercial imaging satellites could grow.

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