A CubeSat is a small satellite built to a standard size. One unit, called 1U, is a 10 cm cube, and larger CubeSats stack units into sizes such as 3U, 6U, and 12U. The standard lets universities and companies reuse parts and share rides to orbit.
Builders use CubeSats for science, for testing new technology in space, and for mission concepts that fly many satellites together as constellations and swarms.
The standard shape and size also reduce transport and deployment costs. Most CubeSats fly bolted to a rocket where space is available.
CubeSat Defined
A CubeSat is a small satellite that follows set rules for its shape, size, and weight. The National Aeronautics and Space Administration (NASA) calls any satellite under 300 kg (1,100 lb) a small satellite.
The base CubeSat is the 1U, a 10 cm cube with a mass of about 1 to 1.33 kg. NASA describes CubeSats as a class of nanosatellites.
The strict standards lower costs. Companies can mass-produce components and sell parts off the shelf, so building a CubeSat costs less than building a highly customized small satellite. The common shape and size also reduce transport and deployment costs.
CubeSat Unit Sizes and Mass
Larger CubeSats stack units; LightSail was a three-unit (3U) CubeSat. NASA’s CubeSat 101 lists 1U, 1.5U, 2U, 3U, 6U, and 12U. The table gives the two sizes whose dimensions the guide states.
| Size | Dimensions stated in CubeSat 101 | Mass stated in CubeSat 101 |
|---|---|---|
| 1U | 10 x 10 x 11 cm | About 1 to 1.33 kg |
| 3U | 10 x 10 x 34 cm | Not given here |
A 3U is 34 cm long, a little more than three times the 11 cm length of a 1U (3 x 11 = 33). NASA compares LightSail, a 3U CubeSat, to a loaf of bread. This page does not give dimensions or mass for the 1.5U, 2U, 6U, and 12U sizes; check NASA’s CubeSat 101 before you plan a payload around them.
Origin of the CubeSat Standard
The CubeSat standard began in 1999 as a collaboration between two professors. Jordi Puig-Suari was a professor at California Polytechnic State University (Cal Poly). Bob Twiggs was a professor at Stanford University’s Space Systems Development Laboratory.
Their original goal was affordable access to space for university scientists. The standard exists so universities and companies can reuse parts and share rides to orbit. The strict standards let companies mass-produce CubeSat components and sell them off the shelf.
NASA Ames launched its first CubeSat, GeneSat, in December 2006. That was seven years after the standard was written (2006 minus 1999).
Routes to Orbit for a CubeSat
Most CubeSats reach orbit bolted to a rocket where space is available.
The first CubeSat dispenser was the Poly-Picosatellite Orbital Deployer (P-POD), built by Cal Poly. A P-POD holds up to three units in any combination that adds to 3U. That means three 1U satellites, a 1U and a 2U, two 1.5U satellites, or one 3U. The dispenser bolts onto the launch vehicle, and its door opens when the rocket sends an electrical signal, releasing the CubeSats. Other dispensers exist now, including ones sized for 6U satellites.
The International Space Station (ISS) offers a second route. A CubeSat can travel up on a station resupply mission and be released from the station in a specially designed deployer. One CubeSat left the ISS a different way: in 2014, a cosmonaut tossed Peru’s Chasqui 1 by hand during a spacewalk. NASA’s guide notes this has been done but is not standard.
NASA’s CubeSat Launch Initiative (CSLI) uses both routes. It flies qualified CubeSats as auxiliary payloads on launches with excess capacity, or deploys them from the ISS. NASA pays for the ride, and the team sends NASA a report on its results in return.
The ELaNa-III mission shows the rocket route in practice. It launched on 28 October 2011 on a Delta II from Vandenberg, as part of the Suomi NPP mission, and deployed five CubeSat missions. Our rideshare program explainer covers shared launches.
Missions CubeSats Have Flown
NASA describes CubeSats as a cost-effective platform for three kinds of work: science, technology demonstrations, and advanced mission concepts that use constellations and swarms.
LightSail is one example in NASA’s guide. It was a 3U CubeSat that flew in 2015 as an auxiliary payload on a U.S. Air Force X-37B mission, launched on 20 May 2015. It carried a Mylar solar sail of 32 square meters (344 square feet). Members of the public funded it through The Planetary Society.
NASA also names GeneSat, NASA Ames’ first CubeSat in December 2006.
Cost Drivers for a CubeSat Mission
A CubeSat has no standard price, and NASA’s CubeSat 101 guide says so directly. NASA names four things that drive the cost: mission complexity, the experience of the personnel, project duration, and any specialized hardware.
NASA groups the spending into four common categories: materials, labor, environmental testing, and travel.
Two facts pull the total down. Off-the-shelf components cost less than custom parts, because the standard lets companies mass-produce them. For qualified projects, the CSLI pays for the launch.
Gaps in the Public Record
The facts this page draws on do not include how many CubeSats exist or how many launch each year, and NASA gives no typical build price. Verify any such figure at the source.
The page also gives no dimensions or mass for the other sizes. See the CubeSat 101 guide and NASA’s smallsats and CubeSats page for the agency’s overview, and confirm size figures there before planning a payload.
Related OrbitalIntel Explainers
- Satellite bus explained: the platform that carries a CubeSat’s power, pointing, and radio hardware.
- How satellites work: the basics every CubeSat shares with larger spacecraft.
- LEO satellites explained: the low Earth orbit band, for comparison with other orbits.
- Geostationary orbit explained: how the much higher geostationary orbit differs.
- All satellite explainers: the full satellites hub.