Small Satellites
The Beginning of the Small Satellite Era
After the USSR’s Sputnik, the world’s first artificial satellite, was sent into the Earth’s orbit in 1957, the world’s superpowers have launched hundreds of satellites, competing for supremacy in space exploration in a series of increasingly ambitious and complex projects.
Since then, the mass of satellites/spacecraft have increased dramatically. The first and second Sputniks weighed 80 kg and 500 kg respectively, while the today’s International Space Station has a mass of 420,000 kg. However, it seems like the era of big and heavy satellites is over, the only exception being satellites used for military, astronomy, and specific communication purposes.
New Space is built around the concept of building less expensive satellites in shorter periods of time. Thanks to this, satellite manufacturers can decrease costs and achieve miniaturisation of electronic parts. As a result, satellite launches are now accessible even for companies, universities, schools and private individuals.
Why nanosatellites?
Apart from their size and cost, the biggest advantage of nanosatellites is a shorter time period required for their development. A medium- or large-sized satellite requires its designers to spend from 5 to 15 years on its development and placement in the right orbit.
There may be changes during a satellite’s operational lifetime, which means that its initially planned uses will no longer be commercially viable. What’s more, telecommunications technologies are constantly changing, causing conventional satellites to cease to use those of them that have been around for more than 15 years. It is impossible to constantly upgrade large-sized satellites; therefore, they cannot be modified even when a market or technological opportunity presents itself.
Depending on its specifications, a nanosatellite can be built and placed in orbit for 500,000 euros. In contrast, the cost of a conventional satellite can be as high as 500 million euros.
Launching a nanosatellite as part of a constellation enables to distribute mission-related risks amongst smaller segments; however, the failure of a large-sized satellite may jeopardise an entire mission.
As a general rule, nanosatellites are launched in low circular or elliptical orbits (altitudes of between 400 and 650 km) and travel at around 8 km per second. At this altitude and height, it takes them around 90 minutes to orbit the Earth, completing between 14 and 16 orbits a day. By orbiting closer to the Earth, they not only guarantee optimum conditions for land observation or communications, but are also better protected from solar and cosmic radiation.
The CubeSat Standard
CubeSats are a class of nanosatellites that use a standard size and form factor. The standard CubeSat size uses a "one unit" or "1U" measuring 10x10x10 cms and is extendable to larger sizes; 1.5, 2, 3, 6, and even 12U. Some companies have produced standards up to 27U. At the same time, smaller picosatellites, the so-called PocketQubes, about 1/8 the size of a CubeSat, have also been standardized.
Originally, they were developed in 1999 by California Polytechnic State University at San Luis Obispo (Cal Poly) and Stanford University to provide a platform for education and space exploration. The development of CubeSats has advanced into its own industry with government, industry and academia collaborating for ever-increasing capabilities. CubeSats now provide a cost-effective platform for science investigations, new technology demonstrations and advanced mission concepts using constellations, swarms disaggregated systems.
On January 24, 2021, SpaceX successfully launched a rideshare mission as one of its veteran boosters hoisted 143 small satellites — a new record for a single rocket — into space before nailing a landing at sea. Acting as a cosmic carpool, Elon Musk’s company launched 10 own Starlink satellites and 133 satellites for a broad variety of government and private customers, including 48 Earth imaging satellites dubbed SuperDoves from Planet, 17 tiny communications satellites for Toronto-based Kepler, and 30 small satellites for the US and Europe packaged by Berlin, Germany-based Exolaunch. Technology demonstrations and payloads, including satellite components, in-space laser communications and remote sensing of interest to the U.S. military in particular.
The mission is expected to deposit the flat-paneled Starlink satellites in a unique polar orbit — a first for its broadband fleet that will help provide coverage to customers in Alaska and other polar regions. Following a successful liftoff, the Falcon 9's first stage landed on SpaceX's drone ship "Of Course I Still Love You" in the Atlantic Ocean. The catch marked the 73rd recovery of a first-stage booster for SpaceX and the first catch of the 2021 year for the company's main drone ship, after receiving some needed refurbishments.