A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under 1,200 kg (2,600 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.
|Group name||Mass (kg)|
|Extra Heavy satellite||> 7,000|
|Heavy satellite||5,001 to 7,000|
|Large satellite||4,201 to 5,000|
|Intermediate satellite||2,501 to 4,200|
|Medium satellite||1,201 to 2,500|
|Small satellite||601 to 1,200|
|Mini satellite||201 to 600|
|Micro satellite||11 to 200|
|Nano satellite||1.1 to 10|
|Pico satellite||0.1 to 1|
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
The nanosatellite and microsatellite segments of the satellite launch industry have been growing rapidly in recent years. 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, 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 US$7.4 billion.
In a surprising turn of events, the U.S. Department of Defense, which has 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.
The term "small satellite", or sometimes "minisatellite", often refers to an artificial satellite with a wet mass (including fuel) between 100 and 500 kg (220 and 1,100 lb), but in other usage has come to mean any satellite under 500 kg (1,100 lb).
Small satellite launch vehicle
Although smallsats have traditionally been launched as secondary payloads on larger launch vehicles, a number of companies currently are developing or have developed launch vehicles specifically targeted at the smallsat market. In particular, the secondary payload paradigm does not provide the specificity required for many small satellites that have unique orbital and launch-timing requirements.
Companies offering smallsat launch vehicles include:
- Rocket Lab's Electron (300 kg)
- Virgin Orbit's LauncherOne (500 kg)
- Astra's Rocket 3.3 (100 kg)
- Vaya Space's Dauntless (1000+ kg LEO 600+ kg SSO)
The term "microsatellite" or "microsat" is usually applied to the name of an artificial satellite with a wet mass between 10 and 100 kg (22 and 220 lb). However, this is not an official convention and sometimes those terms can refer to satellites larger than that, or smaller than that (e.g., 1–50 kg (2.2–110.2 lb)). 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".
In 2018, the two Mars Cube One microsats—massing just 13.5 kg (30 lb) 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 Galactic announced LauncherOne, an orbital launch vehicle designed to launch "smallsat" primary payloads of 100 kg (220 lb) 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 Galactic has been working on the LauncherOne concept since late 2008, and as of 2015[update], 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 (~20 kg (44 lb) range) each with 1-m imaging resolution." The program was cancelled in December 2015.
In April 2013, Garvey Spacecraft was awarded a US$200,000 contract to evolve their Prospector 18 suborbital launch vehicle technology into an orbital nanosat launch vehicle capable of delivering a 10 kg (22 lb) payload into a 250 km (160 mi) orbit to an even-more-capable clustered "20/450 Nano/Micro Satellite Launch Vehicle" (NMSLV) capable of delivering 20 kg (44 lb) payloads into 450 km (280 mi) circular orbits.
The Boeing Small Launch Vehicle is an air-launched three-stage-to-orbit launch vehicle concept aimed to launch small payloads of 45 kg (100 lb) into low Earth orbit. The program is proposed to drive down launch costs for U.S. military small satellites to as low as US$300,000 per launch ($7,000/kg) and, if the development program was funded, as of 2012[update] could be operational by 2020.
The Swiss company Swiss Space Systems (S3) has 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 250 kg (550 lb) into low Earth orbit.
The term "nanosatellite" or "nanosat" is applied to an artificial satellite with a wet mass between 1 and 10 kg (2.2 and 22.0 lb). 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 1600 nanosatellites have been launched as of August 2021.
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 1.33 kilograms (2.9 lb) 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 8 kg (18 lb) Earth-imaging satellites to replace a constellation of five 156 kg (344 lb) 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 (non-disaster) imaging data collection. As costs lower and production times shorten, nanosatellites are becoming increasingly feasible ventures for companies.
Nanosatellite developers and manufacturers include EnduroSat, GomSpace, NanoAvionics, NanoSpace, Spire, Surrey Satellite Technology, NovaWurks, Dauria Aerospace, Planet Labs and Reaktor.
In the ten years of nanosat launches prior to 2014, only 75 nanosats were launched. Launch rates picked up substantially when in the three-month period from November 2013–January 2014 94 nanosats were launched.
One challenge of using nanosats has been the economic delivery of such small satellites to anywhere beyond low Earth orbit. By late 2014, proposals were being developed for larger spacecraft specifically designed to deliver swarms of nanosats to trajectories that are beyond Earth orbit for applications such as exploring distant asteroids.
Nanosatellite launch vehicle
With the emergence of the technological advances of miniaturization and increased capital to support private spaceflight initiatives in the 2010s, several startups have been formed to pursue opportunities with developing a variety of small-payload Nanosatellite Launch Vehicle (NLV) technologies.
NLVs proposed or under development include:
- Virgin Orbit LauncherOne upper stage, intended to be air-launched from WhiteKnightTwo similar to how the SpaceShipTwo spaceplane is launched.
- Ventions' Nanosat upper stage.
- Nammo/Andøya North Star (polar orbit-capable launcher for a 10 kg (22 lb) payload)
- As of April 2013[update], Garvey Spacecraft (now Vector Launch) is evolving their Prospector 18 suborbital launch vehicle technology into an orbital nanosat launch vehicle capable of delivering a 10 kg (22 lb) payload into a 250 km (160 mi) orbit.
- Generation Orbit is developing an air-launched rocket to deliver both nanosats and sub-50 kg microsats to low Earth orbit.
Actual NS launches:
- NASA launched three satellites on 21 April 2013 based on smart phones. Two phones use the PhoneSat 1.0 specification and the third used a beta version of PhoneSat 2.0
- ISRO launched 14 nanosatellites on 22 June 2016, 2 for Indian universities and 12 for the United States under the Flock-2P program. This launch was performed during the PSLV-C34 mission.
- ISRO launched 103 nanosatellites on 15 February 2017. This launch was performed during the PSLV-C37 mission.
The term "picosatellite" or "picosat" (not to be confused with the PicoSAT series of microsatellites) is usually applied to artificial satellites with a wet mass between 0.1 and 1 kg (0.22 and 2.2 lb), although it is sometimes used to refer to any satellite that is under 1 kg in launch mass. Again, designs and proposed designs of these types usually have multiple picosatellites working together or in formation (sometimes the term "swarm" is applied). Some designs require a larger "mother" satellite for communication with ground controllers or for launching and docking with picosatellites.
Picosatellites are emerging as a new alternative for do-it-yourself kitbuilders. Picosatellites are currently commercially available across the full range of 0.1–1 kg (0.22–2.2 lb). Launch opportunities are now available for $12,000 to $18,000 for sub-1 kg picosat payloads that are approximately the size of a soda can.
The term "femtosatellite" or "femtosat" is usually applied to artificial satellites with a wet mass below 100 g (3.5 oz). Like picosatellites, some designs require a larger "mother" satellite for communication with ground controllers.
Three prototype "chip satellites" were launched to the ISS on Space Shuttle Endeavour on its final mission in May 2011. They were attached to the ISS external platform Materials International Space Station Experiment (MISSE-8) for testing. In April 2014, the nanosatellite KickSat was launched aboard a Falcon 9 rocket with the intention of releasing 104 femtosatellite-sized chipsats, or "Sprites". In the event, they were unable to complete the deployment on time due to a failure of an onboard clock and the deployment mechanism reentered the atmosphere on 14 May 2014, without having deployed any of the 5-gram femtosats. ThumbSat is another project intending to launch femtosatellites in the late 2010s. ThumbSat announced a launch agreement with CubeCat in 2017 to launch up to 1000 of the very small satellites.[needs update]
In March 2019, the CubeSat KickSat-2 deployed 105 femtosats called "ChipSats" into Earth orbit. Each of the ChipSats weighed 4 grams. The satellites were tested for 3 days, and they then reentered the atmosphere and burned up.
Small satellites usually require innovative propulsion, attitude control, communication and computation systems.
Larger satellites usually use monopropellants or bipropellant combustion systems for propulsion and attitude control; these systems are complex and require a minimal amount of volume to surface area to dissipate heat. These systems may be used on larger small satellites, while other micro/nanosats have to use electric propulsion, compressed gas, vaporizable liquids such as butane or carbon dioxide or other innovative propulsion systems that are simple, cheap and scalable.
Small satellites can use conventional radio systems in UHF, VHF, S-band and X-band, although often miniaturized using more up-to-date technology as compared to larger satellites. Tiny satellites such as nanosats and small microsats may lack the power supply or mass for large conventional radio transponders, and various miniaturized or innovative communications systems have been proposed, such as laser receivers, antenna arrays and satellite-to-satellite communication networks. Few of these have been demonstrated in practice.
Electronics need to be rigorously tested and modified to be "space hardened" or resistant to the outer space environment (vacuum, microgravity, thermal extremes, and radiation exposure). Miniaturized satellites allow for the opportunity to test new hardware with reduced expense in testing. Furthermore, since the overall cost risk in the mission is much lower, more up-to-date but less space-proven technology can be incorporated into micro and nanosats than can be used in much larger, more expensive missions with less appetite for risk.
Small satellites are difficult to track with ground-based radar, so it is difficult to predict if they will collide with other satellites or human-occupied spacecraft. The U.S. Federal Communications Commission has rejected at least one small satellite launch request on these safety grounds.
- Canadian Advanced Nanospace eXperiment Program
- DRAGONSat picosatellite
- Micro air vehicle
- Nanosatellite Launch System
- Satellite formation flying
- Student Space Exploration & Technology Initiative
- University Nanosatellite Program
- AMSAT Amateur Satellite Corp.
- Rocket Lab
- "Smallsats by the Numbers" (PDF). brycetech.com. 1 January 2020.
- 2014 Nano/Microsatellite Market Assessment (PDF) (Report). annual market assessment series. Atlanta, Georgia: SEI. January 2014. p. 18. Archived (PDF) from the original on 22 February 2014. Retrieved 18 February 2014.
- Messier, Doug (2 March 2015). "Euroconsult Sees Large Market for Smallsats". Parabolic Arc. Archived from the original on 5 March 2015. Retrieved 8 March 2015.
- Foust, Jeff (12 June 2015). "Smallsat Developers Enjoy Growth In Launch Options". Space News. Retrieved 13 June 2015.
- Erwin, Sandra (24 January 2023). "Space Force not buying large satellites for the foreseeable future". SpaceNews. Retrieved 25 January 2023.
- "Small Is Beautiful: US Military Explores Use of Microsatellites". Defense Industry Daily. 30 June 2011. Archived from the original on 13 December 2012. Retrieved 12 December 2012.
- Tristancho, Joshua; Gutierrez, Jordi (2010). "Implementation of a femto-satellite and a mini-launcher" (PDF). Universitat Politecnica de Catalunya: 3. Archived (PDF) from the original on 3 July 2013. Retrieved 12 December 2012.
- Werner, Debra (12 August 2013). "Small Satellites & Small Launchers: Rocket Builders Scramble To Capture Growing Microsat Market". Space News. Retrieved 13 March 2021.
- "Rocket Lab Electron (rocket)". Rocket Lab Electron (rocket). 31 July 2022. Retrieved 31 July 2022.
- "Virgin Orbit Service Guide" (PDF). Virgin Orbit Service Guide. 29 July 2019. Retrieved 29 July 2019.
- "Astra Reaches Orbit". Astra (Private Space Company). 22 November 2021. Retrieved 7 December 2021.
- "Vaya Space Launches in 2023". Vaya Space (Private Space Company). 22 November 2021.
- Boyle, Alan (4 June 2015). "How SpaceX Plans to Test Its Satellite Internet Service in 2016". NBC News. Archived from the original on 5 June 2015. Retrieved 5 June 2015.
- "Virgin Galactic relaunches its smallsat launch business". NewSpace Journal. 12 July 2012. Archived from the original on 15 July 2012. Retrieved 11 July 2012.
- Gruss, Mike (21 March 2014). "DARPA Space Budget Increase Includes $27M for Spaceplane". Space News. Archived from the original on 24 March 2014. Retrieved 24 March 2014.
- Stirone, Shannon (18 March 2019). "Space Is Very Big. Some of Its New Explorers Will Be Tiny. - The success of NASA's MarCO mission means that so-called cubesats likely will travel to distant reaches of our solar system". The New York Times. Retrieved 21 April 2019.
- Good, Andrew; Wendel, JoAnna (4 February 2019). "Beyond Mars, the Mini MarCO Spacecraft Fall Silent". Jet Propulsion Laboratory. NASA. Retrieved 5 February 2019.
- EXCLUSIVE: Virgin Galactic unveils LauncherOne name! Archived 14 May 2013 at the Wayback Machine, Rob Coppinger, Flightglobal Hyperbola, 9 December 2008
- Burn-Callander, Rebecca (22 August 2015). "Virgin Galactic boldly goes into small satellites, telling future astronauts 'you have to wait'". UK Telegraph. Archived from the original on 24 August 2015. Retrieved 24 August 2015.
- Lindsey, Clark (19 December 2012). "DARPA developing microsat constellation orbited with air-launch system". NewSpace Watch. Archived from the original on 26 May 2013. Retrieved 22 December 2012.
- Gruss, Mike (30 November 2015). "DARPA Scraps Plan To Launch Small Sats from F-15 Fighter Jet". SpaceNews.
- Messier, Doug (4 April 2013). "Garvey Nanosat Launcher Selected for NASA SBIR Funding". Parabolic Arc. Archived from the original on 9 April 2013. Retrieved 5 April 2013.
- Norris, Guy (21 May 2012). "Boeing Unveils Air-Launched Space-Access Concept". Aviation Week. Archived from the original on 26 March 2013. Retrieved 23 May 2012.
- Painter, Kristen Leigh (8 October 2013). "Spaceport Colorado lands agreement with Swiss space company Read more: Spaceport Colorado lands agreement with Swiss space company". The Denver Post. Archived from the original on 11 October 2013. Retrieved 21 October 2013.
- Peláez, Javier. "PLD Space, la empresa española camino de lanzar satélites e incluso alcanzar la Luna". Yahoo noticias. Yahoo. Archived from the original on 5 March 2016. Retrieved 19 April 2016.
- Kulu, Erik (4 October 2020). "Nanosatellite & CubeSat Database". www.nanosats.eu. Retrieved 28 August 2021.
- Verhoeven, C.J.M.; Bentum, M.J.; Monna, G.L.E.; Rotteveel, J.; Guo, J. (April–May 2011). "On the origin of satellite swarms" (PDF). Acta Astronautica. 68 (7–8): 1392–1395. Bibcode:2011AcAau..68.1392V. doi:10.1016/j.actaastro.2010.10.002.
- Swartwout, Michael A. "CubeSat Database". sites.google.com. Saint Louis University. Retrieved 1 October 2018.
- "NASA Venture Class procurement could nurture, ride small sat trend". SpaceNews. 8 June 2015. Retrieved 14 December 2020.
- CubeSat Design Specification Rev. 13 (PDF). The CubeSat Program (Report). California Polytechnic State University. 20 February 2014. Retrieved 14 December 2020.
- Tsitas, S. R.; Kingston, J. (February 2012). "6U CubeSat commercial applications". The Aeronautical Journal. 116 (1176): 189–198. doi:10.1017/S0001924000006692. S2CID 113099378.
- Liira, Panu (13 February 2018). "Why self-organizing companies take off - How 2 employees at a Finnish tech firm invented and built a space program". Business Insider Nordic.
- "SPROUT - Satellite Missions - eoPortal Directory". directory.eoportal.org. Archived from the original on 1 May 2016. Retrieved 3 May 2018.
- Barron, Rachel (6 April 2015). "Spire's Peter Platzer: the boss who never fires anyone". The Guardian. Archived from the original on 28 April 2016. Retrieved 21 April 2016.
- "Nanosats are go!". Technology Quarterly Q2 2014. The Economist. 7 June 2014. Archived from the original on 12 June 2014. Retrieved 12 June 2014.
On November 19th Orbital Sciences, an American company, launched a rocket from the Wallops Flight Facility in Virginia. It carried 29 satellites aloft and released them into low-Earth orbit, a record for a single mission. Thirty hours later, Kosmotras, a Russian joint-venture, carried 32 satellites into a similar orbit. Then, in January 2014, Orbital Sciences carried 33 satellites up to the International Space Station (ISS), where they were cast off a month later.
- Messier, Doug (11 October 2013). "NovaWurks Awarded Contract for DARPA Phoenix Project". Parabolic Arc. Archived from the original on 13 October 2013. Retrieved 13 October 2013.
- Cheredar, Tom (9 October 2013). "Dauria Aerospace lands $20M to grow its earth-monitoring nano satellite platform". VentureBeat. Archived from the original on 13 October 2013. Retrieved 13 October 2013.
- "Home - Reaktor Space Lab". Reaktor Space Lab. Retrieved 5 August 2018.
- Woo, Marcus (20 December 2014). "Designing a Mothership to Deliver Swarms of Spacecraft to Asteroids". Wired. Archived from the original on 17 December 2014. Retrieved 17 December 2014.
- Amos, Jonathan (11 July 2012). "Richard Branson's Virgin Galactic to launch small satellites". BBC News. Archived from the original on 13 July 2012. Retrieved 13 July 2012.
- Messier, Doug (2 July 2012). "DARPA Awards 6 Small Airborne Launch Vehicle Contracts". Parabolic Arc. Archived from the original on 5 July 2012. Retrieved 29 November 2012.
- Lindsey, Clark (28 January 2013). "North Star rocket family with hybrid propulsion". NewSpace Watch. Archived from the original on 20 June 2013. Retrieved 28 January 2013.
- "PhoneSat - home". Archived from the original on 23 April 2013. Retrieved 24 April 2013.
- "ISRO sets new world record, successfully places 104 satellites into Earth's orbit". India TV News. 15 February 2017. Archived from the original on 15 February 2017. Retrieved 15 February 2017.
- "DIY Satellite Platforms". KK Technium. 9 November 2012. Archived from the original on 13 December 2012. Retrieved 12 December 2012.
- Elizabeth Simpson (16 May 2011). "Chip satellites -- designed to blow in the solar wind -- depart on Endeavour's final launch". Cornell Chronicle. Archived from the original on 9 December 2012. Retrieved 6 December 2012.
- Clark, Stephen (13 April 2014). "Crowd-funded stowaway to deploy 104 tiny satellites". Spaceflight Now. Archived from the original on 16 May 2014. Retrieved 15 May 2014.
- "KickSat Nanosatellite Mission". European Space Agency. Archived from the original on 16 May 2014. Retrieved 15 May 2014.
- "KickSat Re-Enters Atmosphere Without Deploying "Sprite" Satellites".
- Jon Lackman (13 October 2015). "Itty-Bitty Satellites Could Carry Your Experiments to Space". Wired. Archived from the original on 9 February 2016. Retrieved 21 February 2016.
- "Swarm of 105 tiny Sprite ChipSats successfully deployed". New Atlas. 6 June 2019.
- "Stanford and NASA Ames researchers put inexpensive chip-size satellites into orbit". Stanford News. 3 June 2019.
- Dvorsky, George (9 March 2018). "California Startup Accused of Launching Unauthorized Satellites Into Orbit: Report". Gizmodo. Archived from the original on 20 March 2018. Retrieved 19 March 2018.