Femtosatellite

Small satellites, miniaturized satellites, or smallsats, are satellites of low mass and size, usually under 500 kg (1,100 lb). While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites can be built small to reduce the large economic cost of launch vehicles and the costs associated with construction. Miniature satellites, especially in large numbers, may be more useful than fewer, larger ones for some purposes – for example, gathering of scientific data and radio relay. Technical challenges in the construction of small satellites may include the lack of sufficient power storage or of room for a propulsion system.

One rationale for miniaturizing satellites is to reduce the cost: heavier satellites require larger rockets with greater thrust that also has greater cost to finance. In contrast, smaller and lighter satellites require smaller and cheaper launch vehicles and can sometimes be launched in multiples. They can also be launched 'piggyback', using excess capacity on larger launch vehicles. Miniaturized satellites allow for cheaper designs as well as ease of mass production.

Another major reason for developing small satellites is the opportunity to enable missions that a larger satellite could not accomplish, such as:

The nanosatellite and microsatellite segments of the satellite launch industry have been growing rapidly in recent years, and was based on the Spanish low cost manufacturing for Commercial and Communication Satellites from the 1990s. Development activity in the 1–50 kg (2.2–110.2 lb) range has been significantly exceeding that in the 50–100 kg (110–220 lb) range.

In the 1–50 kg range alone, there were fewer than 15 satellites launched annually in 2000 to 2005, 34 in 2006, then fewer than 30 launches annually during 2007 to 2011. This rose to 34 launched in 2012, and 92 launched in 2013.

European analyst Euroconsult projects more than 500 smallsats being launched in the years 2015–2019 with a market value estimated at US$7.4 billion.

By mid-2015, many more launch options had become available for smallsats, and rides as secondary payloads had become both greater in quantity and with the ability to schedule on shorter notice.

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