Blog

What is considered a small satellite?

Why “small satellite” needs a clear definition 

If you’re new to space projects, you’ll quickly encounter the term “small satellite” or “smallsat.” But what is considered a small satellite? The definition matters because it affects everything from launch costs and licensing to subsystem choices and software architecture. 

This article breaks down the main classes of small satellites, explains how they differ from traditional spacecraft and highlights why software has become a critical factor in their success. 

The standard small satellite categories

Although definitions vary slightly between agencies, most of the space industry recognises the following classes based on mass: 

Category	Mass range	Typical uses
Minisatellites	100–500 kg	Earth observation, communications, tech demos
Microsatellites	10–100 kg	Constellations, remote sensing, rapid prototyping
Nanosatellites	1–10 kg	University projects, science experiments, IoT
CubeSats	Modular 10×10×10 cm units (~1.3 kg per “U”)	Academic and commercial missions

These categories aren’t just labels. They drive decisions about power systems, communications, redundancy and ground operations (1). 

For more on how these definitions affect mission risk, see our article on “Small satellite mission failure rates”.

Small satellites vs. traditional spacecraft 

Traditional large satellites often weigh several tonnes, cost hundreds of millions of pounds and require years of development. Small satellites, by contrast, offer: 

• Lower cost: A CubeSat launch can be under £250,000. 

• Faster development cycles: 12–24 months is typical. 

• Greater flexibility: Easier to experiment and iterate. 

But they also have constraints: limited power, less shielding from radiation, and fewer redundancies. This makes software reliability and integration even more important. 

Common applications for small satellites 

• Earth observation: Imaging, environmental monitoring, disaster response.
• Communications: Narrowband IoT, experimental broadband, regional coverage. 

• Science & technology demonstration: Test new sensors or materials before scaling up. 

• Education: Give students hands-on experience with real space missions. 

These use cases often prioritise quick development and cost control — exactly where proven software frameworks can save time and reduce risk (1). 

The role of CubeSats

CubeSats deserve special mention because they’ve become the de facto standard for entry-level space missions (2). A 3U CubeSat (roughly 30×10×10 cm) weighs under 5 kg and can host cameras, radios or even propulsion. Standardised dimensions mean easier integration with deployers and launch vehicles. 

For newcomers asking “can I create my own satellite?” CubeSats are usually the starting point. Read our article “Can I create my own satellite?”,  for a step-by-step overview of what’s involved. 

How classification influences launch & licensing

Launch brokers and regulators often use mass category to set prices and review paperwork. For example: 

• Launch costs: Charged per kilogram. 

• Frequency licensing: Some categories have pre-coordinated spectrum. 

• Insurance: Premiums depend on mission class and risk profile. 

Knowing where your spacecraft sits in the classification table early can streamline approvals and budget planning. 

Software considerations for small satellites

Smaller spacecraft mean tighter constraints on power, memory and communications. Flight software has to be lean but robust, and ground systems must handle intermittent contact windows efficiently. 

Our software platforms are built with these challenges in mind, enabling teams to start small and scale up to full constellations without rewriting everything from scratch. Learn more about how we build long-term space software expertise. 

Typical development timeline

Although small satellites can be built faster than traditional spacecraft, it’s still a significant undertaking(1). A typical microsatellite project might look like: 

• 3–6 months: Mission definition and preliminary design. 

• 6–12 months: Subsystem procurement and integration. 

• 3–6 months: Environmental and functional testing. 

• Launch & operations: Ground segment setup, rehearsals and post-launch commissioning. 

Each phase has software touchpoints, from mission planning tools to flight software testing to ground station interfaces. 

Future trends in small satellite design

• Higher-performance payloads: Advanced imaging and AI processing onboard. 

• Propulsion & de-orbit systems: For collision avoidance and regulatory compliance. 

• Integrated software & services: Seamless link between spacecraft and ground. 

We are at the forefront of this last trend, helping operators manage complex missions with scalable, proven software frameworks. 

More than just size

“What is considered a small satellite?” is more than a technical definition. It’s a signal of how space exploration has changed — from a slow, costly process to something agile and accessible. By understanding the classifications and planning for their unique challenges — especially in software — organisations can deliver successful missions on time and on budget. 

Resources