Small satellite


A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under. 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.

Rationales

One rationale for miniaturizing satellites is to reduce the cost; heavier satellites require larger rockets with greater thrust that also have 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 and 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:
  • Constellations for low data rate communications
  • Using formations to gather data from multiple points
  • In-orbit inspection of larger satellites
  • University-related research
  • Testing or qualifying new hardware before using it on a more expensive spacecraft

    History

The nanosatellite and microsatellite segments of the satellite launch industry have been growing rapidly in the 2010s. Development activity in the range has been significantly exceeding that in the range.
In the range alone, fewer than 15 satellites were 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 2015–2019 with a market value estimated at.
By mid-2015, many more launch options had become available for smallsats, and rides as secondary payloads had become both greater in quantity and easier to schedule on shorter notice.
In a surprising turn of events, the U.S. Department of Defense, which had for decades procured heavy satellites on decade-long procurement cycles, is making a transition to smallsats in the 2020s. The office of space acquisition and integration said in January 2023 that "the era of massive satellites needs to be in the rear view mirror for the Department of Defense" with small satellites being procured for DoD needs in all orbital regimes, regardless of "whether it's LEO MEO or GEO" while aiming for procurements in under three years. The smaller satellites are deemed to be harder for an enemy to target, as well as providing more resilience through redundancy in the design of a large distributed network of satellite assets.
In 2021, the first autonomous nanosatellites, part of the Adelis-SAMSON mission, designed and developed by the Technion and Rafael in Israel were launched into space. In 2023, SpaceX launched a 20cm quantum communication nano satellite developed by the Tel Aviv University, it is the world's first quantum communication satellite. TAU's nanosatellite is designed to form a quantum communication network as well as communicate with Earth through an optical ground station.

Classification groups

Small satellites

The term "small satellite", or sometimes "minisatellite", often refers to an artificial satellite with a wet mass between, but in other usage has come to mean any satellite under.
Small satellite examples include Demeter, Essaim, Parasol, Picard, MICROSCOPE, TARANIS, ELISA, SSOT, SMART-1, Spirale-A and -B, and Starlink satellites.

Small satellite launch vehicle

Although smallsats have traditionally been launched as secondary payloads on larger launch vehicles, a number of companies began development of launch vehicles specifically targeted at the smallsat market. In particular, with larger numbers of smallsats flying, the secondary payload paradigm does not provide the specificity required for many small satellites that have unique orbital and launch-timing requirements.
Some USA-based private companies that at some point in time have launched smallsat launch vehicles commercially:
The term "microsatellite" or "microsat" is usually applied to the name of an artificial satellite with a wet mass between. However, this is not an official convention and sometimes those terms can refer to satellites larger than that, or smaller than that. Sometimes, designs or proposed designs from some satellites of these types have microsatellites working together or in a formation. The generic term "small satellite" or "smallsat" is also sometimes used, as is "satlet".
Examples: Astrid-1 and Astrid-2, as well as the set of satellites currently announced for LauncherOne
In 2018, the two Mars Cube One microsats—massing just each—became the first CubeSats to leave Earth orbit for use in interplanetary space. They flew on their way to Mars alongside the successful Mars InSight lander mission.
The two microsats accomplished a flyby of Mars in November 2018, and both continued communicating with ground stations on Earth through late December. Both went silent by early January 2019.

Microsatellite launch vehicle

A number of commercial and military-contractor companies are currently developing microsatellite launch vehicles to perform the increasingly targeted launch requirements of microsatellites. While microsatellites have been carried to space for many years as secondary payloads aboard larger launchers, the secondary payload paradigm does not provide the specificity required for many increasingly sophisticated small satellites that have unique orbital and launch-timing requirements.
In July 2012, Virgin Orbit announced LauncherOne, an orbital launch vehicle designed to launch "smallsat" primary payloads of into low Earth orbit, with launches projected to begin in 2016. Several commercial customers have already contracted for launches, including GeoOptics, Skybox Imaging, Spaceflight Industries, and Planetary Resources. Both Surrey Satellite Technology and Sierra Nevada Space Systems are developing satellite buses "optimized to the design of LauncherOne". Virgin Orbit has been working on the LauncherOne concept since late 2008, and, is making it a larger part of Virgin's core business plan as the Virgin human spaceflight program has experienced multiple delays and a fatal accident in 2014.
In December 2012, DARPA announced that the Airborne Launch Assist Space Access program would provide the microsatellite rocket booster for the DARPA SeeMe program that intended to release a "constellation of 24 micro-satellites each with 1-m imaging resolution." The program was cancelled in December 2015.
In April 2013, Garvey Spacecraft was awarded a contract to evolve their Prospector 18 suborbital launch vehicle technology into an orbital nanosat launch vehicle capable of delivering a payload into a orbit to an even-more-capable clustered "20/450 Nano/Micro Satellite Launch Vehicle" capable of delivering payloads into circular orbits.
The Boeing Small Launch Vehicle is an air-launched three-stage-to-orbit launch vehicle concept aimed to launch small payloads of into low Earth orbit. The program is proposed to drive down launch costs for U.S. military small satellites to as low as per launch and, if the development program was funded, could be operational by 2020.
The Swiss company Swiss Space Systems announced plans in 2013 to develop a suborbital spaceplane named SOAR that would launch a microsat launch vehicle capable of putting a payload of up to into low Earth orbit.
The Spanish company PLD Space was born in 2011 with the objective of developing low cost launch vehicles called Miura 1 and Miura 5 with the capacity to place up to into orbit.

Nanosatellites

The term "nanosatellite" or "nanosat" is applied to an artificial satellite with a wet mass between. Designs and proposed designs of these types may be launched individually, or they may have multiple nanosatellites working together or in formation, in which case, sometimes the term "satellite swarm" or "fractionated spacecraft" may be applied. Some designs require a larger "mother" satellite for communication with ground controllers or for launching and docking with nanosatellites. Over 2300 nanosatellites have been launched as of December 2023.
A CubeSat is a common type of nanosatellite, built in cube form based on multiples of 10 cm × 10 cm × 10 cm, with a mass of no more than per unit. The CubeSat concept was first developed in 1999 by a collaborative team of California Polytechnic State University and Stanford University, and the specifications, for use by anyone planning to launch a CubeSat-style nanosatellite, are maintained by this group.
With continued advances in the miniaturization and capability increase of electronic technology and the use of satellite constellations, nanosatellites are increasingly capable of performing commercial missions that previously required microsatellites.
For example, a 6U CubeSat standard has been proposed to enable a satellite constellation of thirty five Earth-imaging satellites to replace a constellation of five RapidEye Earth-imaging satellites, at the same mission cost, with significantly increased revisit times: every area of the globe can be imaged every 3.5 hours rather than the once per 24 hours with the RapidEye constellation. More rapid revisit times are a significant improvement for nations performing disaster response, which was the purpose of the RapidEye constellation. Additionally, the nanosat option would allow more nations to own their own satellite for off-peak imaging data collection. As costs lower and production times shorten, nanosatellites are becoming increasingly feasible ventures for companies.
Some examples of nanosatellites are the ExoCube, ArduSat, and SPROUT. Nanosatellite developers and manufacturers include EnduroSat, GomSpace, NanoAvionics, NanoSpace, Spire, Surrey Satellite Technology, NovaWurks, Dauria Aerospace, Planet Labs and Reaktor.