What is a CubeSat & other picosatellites

What is a nanosatellite?

In mass-classification and in strict terms, a nanosatellite (nanosat, nano-satellite) is any satellite with mass from 1 kg to 10 kg. In this database, "nanosatellite" covers all CubeSats, PocketQubes, TubeSats, SunCubes, ThinSats and non-standard picosatellites, unless otherwise stated.

All are part of the same CubeSat revolution and modern electronics technology leap. Limiting to 1-10 kg would be confusing and troublesome. 1U CubeSat can be 0.8 kg, but also 1.3 kg. 6U can be less or more than 10 kg. Most masses are not public.

Upper limit in this database is 10 kg for non-standard types of nanosats and 27U CubeSat (30-40 kg). Lower limit is 1p PocketQubes and custom picosatellites over 100 g and SunCubes that can be less than 100 g.

Chipsats are not included. Breakthrough Starshot calls them nanocrafts, but they also could be attosatellites (attosats). They will be a big leap in the future: "gram-scale wafer, carrying cameras, photon thrusters, power supply, navigation and communication equipment."

Satellite mass classification

  • Large satellites: >1000 kg
  • Medium satellites: 500 to 1000 kg
  • Small satellites: < 500 kg
    • Minisatellites: 100 to 500 kg
    • Microsatellites: 10 to 100 kg
    • Nanosatellites: 1 to 10 kg
    • Picosatellites: 100 g – 1 kg
    • Femtosatellites: 10 g – 100 g
    • Attosatellites: 1 g – 10 g
    • Zeptosatellites: 0.1 g – 1 g
  • CubeSat sizes:
    • From 0.25U to 27U
    • From ~0.2 kg to ~40 kg

Small satellite (smallsat) is any satellite below 500 kg. This term should be used rarely, there can be large differences between sizes and capabilities.

What is a CubeSat?

CubeSats (cubesatellite, cube satellite) are a type of nanosatellites defined by the CubeSat Design Specification (CSD), unofficially called the CubeSat standard. Dimensions:

  • 1U CubeSat is   10 cm × 10 cm × 11.35 cm.
  • 2U CubeSat is   10 cm × 10 cm × 22.70 cm.
  • 6U CubeSat is   20 cm × 10 cm × 34.05 cm.
  • 12U CubeSat is 20 cm × 20 cm × 34.05 cm.
  • Smallest existing CubeSat design is 0.25U and largest is 27U.
  • Smallest launched CubeSat is 0.25U and largest is 12U as of 2019 January. Very soon 16U from US or 20U from China.

There are 2 different classes of deployers/dispensers:
1. First type is the classic 4 rails in the corners. It's recommended to be aware of the specfications of modern deployers, because dispensers from ISIS and NanoRacks allow larger deployables, wider solar panels and thinner rails compared to original P-POD. For example

  • extruded height can be 9 mm instead of 6.5 mm and
  • can be up to 2 kg per 1U which should not cause problems with launch providers.

2. Second type is tabs on Planetary Corp Systems (PSC) dispensers. The 13 CubeSats that will fly on SLS in 2018 will use them.

CubeSat rails vs tabs
CubeSats with Rails or Tabs comparison by Planetary Systems Corporation (PSC)

CubeSat sizes

CubeSat sizes from 1U to 16U
CubeSats sizes from 1U to 16U by ECM Space (ExoLaunch)

Getting started with building CubeSats

First reading:

Things to watch out for:

  • On-board flight software and mission control software (MCS) are vital and often forgotten or ignored when putting together an Excel sheet of subsystem costs from online shops. Some level of customization for mission requirements is likely too depending on the mix of subsystems and payload. MCS is already required from the integration and testing phases. Companies like Kubos and Bright Ascension provide both flight-proven and well integrated solutions.
  • Second set of hardware for parallel software development and operations rehersals after launch is highly recommended.
  • Most modern deployers allow for larger extrusions, higher mass and smaller rails than the mechanical requirements from the CubeSat Design Specification (CSD). Deployments from P-POD are becoming rare.
  • Launch Providers table includes some CubeSat launch costs. These are similar to the final prices. Free or cheaper launches are possible in some cases, but be careful with flight heritage and possible delays. CubeSat launch costs depend on units and not on the exact spacecraft mass. It is not recommended to estimate the dollar per kg price of rockets as that does not include deployers and many other relevant expenses.

Fun CubeSat quotes

It all started as a university education program satellite. It was kind of funny. I didn't think that people would criticize it as much as they did, but we got a lot of feedback, you know, "That's the dumbest idea I've ever heard. Nobody's going to use this toy." We said, "Who the heck cares. We'll go ahead and use it. We're using it for education."
A chat with Bob Twiggs by Stephen Clark, 2014, spaceflightnow.com
Another thing that was kind of funny is we had no interest from NASA or any of the military organizations. It just wasn't anything they were interested in, so it was all funded without any funding from those aerospace organizations. I'm kind of glad that NASA didn't help us, or we'd probably never got it done.
It was developed for the education of students. If you make it small, they can't put much in it, so they get it done quicker, and hopefully you can get it launched for a lot less money. I don't think Jordi Puig-Suari at Cal Poly or myself had any idea that we'd see days like this. A chat with Bob Twiggs by Stephen Clark, 2014, spaceflightnow.com
Early launch providers were Russian. We did go to some of the American launch providers, Lockheed Martin comes to mind, and they said, "If you give us a half-million dollars, we'll study it, and then if it makes economic sense for us to launch it, we'll do it." We kept asking them to take some of the lead (ballast) off and fly some of these things as secondaries, but they just didn't go along with it. I was really disappointed that the aerospace industry couldn't see the benefit other than profits from it. They couldn't see the educational benefit from it, and the potential of the educational benefit turning into commercial applications. Now, you see the commercial applications coming along with Skybox Imaging, with Planet Labs. Oh my goodness, they look like they have a tremendous economic potential. A chat with Bob Twiggs by Stephen Clark, 2014, spaceflightnow.com


CubeSats are becoming too large for many applications like education. Smaller and even cheaper spacecraft will be a better option. PocketQubes are 5 cm cubes compared to 10 cm CubeSats.

  • 1p is 5 cm × 5 cm × 5 cm.
  • 3p is 5 cm × 5 cm × 17.8 cm.

The concept was announced in 2009 at the 2nd European CubeSat Symposium. As of early 2020, 10 PocketQubes have been launched in total. First 4 from from UniSat satellites and the latest rest with Alba Orbital on their own developed deployers for rideshare launches.

There are also 2 types of PocketQubes: MRFOD and CubeSat dispenser compatible.

MRFOD PocketQubes

MRFOD has a backplate that slides into deployer rails. Only MRFOD type of PocketQubes have been launched to space using the Morehead-Roma FemtoSat Orbital Deployer (MRFOD) onboard UniSat-5 satellite.

3p MRFOD PocketQube
3p MRFOD PocketQube by Radius Space

CubeSat type PocketQubes

8 would fit and be deployed from a 1U CubeSat dispenser. This was the original idea, but none have been launched. It requires close cooperation between manufactures or a single organisation must launch all at the same time.

CubeSat compatible PocketQube concept
CubeSat compatible PocketQube concept by Radius Space

Fun PocketQube quotes

Like in the early days of CubeSats, many people at this moment regard PocketQubes as merely educational toys rather than promising platforms. At TU Delft we however want to demonstrate that this is a misconception. The small size of PocketQubes will force us to think differently about space technology and the development thereof. In short, TU Delft wants to be pioneers in a relatively under-explored class of satellites and a point of reference to everyone in this field. Delfi-PQ Mission, Delft University of Technology
“TU Delft can’t compete,” said Jasper Bouwmeester. Space technology companies, especially those based in the US, get up to hundreds of millions in venture capital funding. Universities research groups don’t have access to that sort of money and the field of CubeSat development is currently dominated by private industry. According to Bouwmeester, TU Delft had three choices: leave the field, develop only very niche satellite applications or go smaller. The 5 x 5 x 18 cm prototype on his desk is the outcome of that decision. They anticipate launching these satellites one to two times per year. PocketQubes offer much to scientific progress, Delft University of Technology


TubeSats are 8.9 cm in diameter, 12.7 cm in length and weigh 0.75 kg. First 2 were launched in 2016 on TuPOD 3U CubeSat from GAUSS. Using a CubeSat to deploy 2 TubeSats makes launch costs comparable to 1U-2U CubeSat, but opportunities are very rare. Their only advantage seems to be simpler and less expensive deployer for rockets.

TubeSat kits were created by Interorbital Systems and cost only $8000 including free flight, which makes it affordable for many teams. They have sold 100+, but first orbital launch has been delayed by more than 7 years. Launching 24 TubeSats gives a revenue of $192,000, low considering all the expenses. Unless Interorbital starts with launches soon, there likely will not be a future for TubeSats.

Tancredo-1 and OSNSAT TubeSats
Tancredo-1 and OSNSAT TubeSats by GAUSS


SunCubes are 3 cm cubes. 1F is 3 cm × 3 cm × 3 cm and 3F is 3 cm × 3 cm × 9 cm. Goal is to make satellites even more affordable. None have been launched, but they were announced in 2016. 1U CubeSat might fit up to 27 single 1F SunCubes. Assuming $80,000 to launch 1U CubeSat then one SunCube launch might be only $3000!

Challenge could be filling 1U CubeSat with 27 SunCubes, unless all of them are from the same organization and part of a constellation. Deploying 27 SunCubes at the same time could also create problems with collisions and tracking, meaning one-by-one deployment might be needed. First SunCubes will be likely be launched from satellites (CubeSats) with other primary missions. As of 2021, none have been launched and possibly never will.

1F SunCube
1F SunCube by Arizona State University

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Created by Erik Kulu

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