Space 4 November 2026 4 MIN READ
Why CubeSats Changed Access to Space
A standard 10 cm unit made small satellites cheap to build and launch. Where the idea came from, how NASA flies them and what still takes months.
THE SHORT ANSWER
CubeSats are small satellites built from standard 10 cm units, an idea Cal Poly and Stanford began in 1999 to give universities cheap access to space. Standard parts and dispensers cut costs, and NASA covers the ride for qualified missions. The slow part is licensing and manifesting, which the guide puts in months.
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A standard that fits in a hand
NASA’s guide for first-time developers defines a small satellite as anything under 300 kg. A CubeSat is stricter: it has to follow a standard shape, size and weight. The basic unit is the 1U, a 10 cm cube. The guide lists its dimensions as 10 × 10 × 11 cm. Bigger sizes are built from units: 1.5U, 2U, 3U, 6U and 12U. A 3U is about 10 × 10 × 34 cm.
The mass limit has moved. The 2017 NASA guide gives a 1U as about 1 to 1.33 kg. Revision 14.1 of the Cal Poly CubeSat Design Specification, from February 2022, says a 1U is a 10 cm cube with a mass of up to 2 kg. The same revision says that many of its requirements were relaxed into guidelines, and that a launch provider’s own requirements take priority once a CubeSat is manifested on a launch.
Where the idea came from
The CubeSat project started in 1999 as a collaboration between Jordi Puig-Suari, a professor at California Polytechnic State University (Cal Poly) in San Luis Obispo, and Bob Twiggs, a professor at Stanford University’s Space Systems Development Laboratory. The specification says the aim was to reduce cost and development time, increase access to space and sustain frequent launches. NASA’s guide adds that the original intent was affordable access for the university science community, and that smaller universities, high schools, middle schools and elementary schools have since started their own programmes.
Why a standard makes it cheaper
The NASA guide gives two reasons. Standard dimensions let companies mass-produce components and sell off-the-shelf parts, so a CubeSat costs less than a highly customised small satellite. The standard shape and size also lower the cost of carrying the satellite to space and releasing it.
The second half of the standard is the dispenser, the box between the satellite and the rocket. The first was the Poly-Picosatellite Orbital Deployer, or P-POD, developed at Cal Poly. It holds up to three units and opens a door when the launch vehicle sends an electrical signal, releasing the satellites into orbit. Most CubeSats still ride by having a dispenser bolted onto a rocket where there is spare room. According to the guide, 6U satellites appeared in 2014, after a number of successful launches with the 3U dispenser.
Who gets a ride
NASA’s CubeSat Launch Initiative (CSLI) lets qualified CubeSats fly as auxiliary payloads on launches with spare capacity, or be deployed from the International Space Station. In the guide’s words, NASA covers the cost of the ride in exchange for a report on the results. The investigation must support at least one goal in NASA’s Strategic Plan, and proposals are requested once a year, usually in early August and due in November.
The guide says about half of CSLI missions run scientific investigations, most often on space weather and Earth science, and that 66% do technology development or demonstrations. Those shares add up to more than 100%, so some missions do both. It also notes that the low cost of development lets teams take higher risks than large NASA missions could.
The slow part is the paperwork, not the hardware
The guide’s timeline shows where the months go. It gives ranges for each stage, among them 1 to 12 months to secure funding, 1 to 36 months from selection to manifesting on a launch, 4 to 6 months for regulatory licensing and 10 to 12 months for flight-specific documentation. Mission operations can run for up to 20 years. Lowering the price of a launch seat did not remove the need for licences, reviews and testing.
Our take: the invention was the standard, more than the satellite. A fixed box let parts, dispensers and rides be bought separately, and that is what opened space to groups that could never afford a bespoke spacecraft. The same standard now has a mass limit that has changed and sizes that keep growing, so treat the numbers by the date of the document.
Questions and answers
What is a CubeSat unit?
A 1U is a 10 cm cube. NASA's 2017 guide lists 10 × 10 × 11 cm and about 1 to 1.33 kg; Cal Poly's Rev. 14.1 specification says a 10 cm cube of up to 2 kg.
Who invented CubeSats?
The project began in 1999 as a collaboration between Jordi Puig-Suari at Cal Poly and Bob Twiggs at Stanford's Space Systems Development Laboratory.
How does a CubeSat get into orbit?
In a dispenser fixed to a rocket or deployed from the International Space Station. The first dispenser, the P-POD, holds up to three units and opens a door on a signal from the launch vehicle.
Does NASA pay for launches?
Through its CubeSat Launch Initiative, NASA provides the ride for qualified CubeSats in exchange for a report on the results. The investigation must support a goal in NASA's Strategic Plan.
Do you agree?
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Sources
- CubeSat 101: Basic Concepts and Processes for First-Time CubeSat Developers (October 2017) · NASA CubeSat Launch Initiative / Cal Poly · Accessed
- CubeSat Design Specification Rev. 14.1 (February 2022) · The CubeSat Program, Cal Poly SLO · Accessed
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