Satellites provide vital space-based communications and directional guidance, but the launching of larger satellites is normally a significant financial investment. As a result, smaller satellites are being launched more frequently—with smaller price tags—enabling more commercial enterprises and educational institutions to explore the benefits of satellite communications.
In terms of size, as a comparison, larger satellites have typically weighed more than 1000 kg and cost millions of dollars to launch into orbit. On the other hand, smaller satellites can weigh as little as 1.5 kg at a fraction of the expense of larger satellites.
The first satellite, the Soviet Union’s Sputnik 1, was launched in 1958 and weighed 83 kg. The first U.S. satellite, Explorer 1, launched the following year and weighed 14 kg. Although having a much smaller payload than the Soviet spacecraft, it carried a cosmic-ray detector, temperature sensors, and a microphone, revealing how smaller satellite payloads, if properly managed, could perform useful functions.
Non-government small satellites were launched by various organizations, including radio amateurs. The first amateur radio satellite, Oscar 1, was a secondary payload of the larger Thor-DM21 Agena B satellite set in orbit in 1961. With time, smaller satellite users took advantage of improvements in technology, such as the capability to reprogram a satellite’s microcomputer from the ground.
DARPA was responsible to reducing the costs and development times of smaller satellites through its LightSat initiative, while a pair of schools helped push the educational use of small satellites in the 1990s. Those schools, California Polytechnic State University and Stanford University, invited graduate students to develop CubeSats weighing about 1.5 kg for many different experiments. More than 800 CubeSats have been launched to test various navigation and control technologies and they, in turn, are encouraging smaller businesses to explore space-enabled services as part of their business plans.
See “How Small Satellites Are Providing Low-Cost Access to Space,” IEEE The Institute, March 2019, pp. 06-07.