SATELLITE CLASS BY MASS

There are many ways to classify satellites. These categories can be by function, by type of orbit or by mass. We will discuss satellite's functions and orbit in our next articles but for now, we will focus on satellite's classification by mass.

Satellite's mass has direct impact on its cost, its development cycle and its launcher. The larger the satellite, the bigger is the development cost. This is because larger satellites carries more equipment such as redundancy modules, propellant, and more solar panels. Also, since it has more components and the lifetime and reliability expectation is higher, design reviews and tests conducted are also more than smaller satellites. Finally, larger satellites occupy larger space in the rocket, entailing higher launch cost.

The names of the categories by mass is not an official convention. We can still, however use it for generic purposes:

1. Large satellite - 1000 kg
2. Medium-sized satellite - 500 kg to 1000 kg
3. Small satellites: 
• Minisatellite - 100 kg to 500 kg
• Microsatellite - 10 kg to 100 kg
• Nanosatellite - 1 kg to 10 kg
• Picosatellite - 0.1 kg to 1 kg
• Femtosatellite - < 0.1 kg

Everything that falls under 500kg is usually tagged as small satellites. Small satellites are becoming the trend in the past years, with several groups opting to develop and launch satellites under this category. This is because small satellites are easier to develop, have shorter timeline, and have lower cost - both launch and development. Of course, there is a trade-off on moving to small satellites in terms of capabilities and performance. As such, constellations are becoming a popular means to get around these trade-offs.

Small satellites are usually used for technology demonstration or experiments and for experiential learning. Some universities let students develop small satellites as part of their graduate thesis or dissertation. A popular platform for this are called cubesatellites which falls under the nanosatellite category. Cubesatellites are unique because they follow a certain standard for measurement. We'll have more of this later.

How do I choose my satellite's size?

 

Actually, there a lot of factors when you are deciding how big your satellite is going to be. Probably the most important ones are the available budget and the satellite's mission. If the budget is very tight, you might only be able to afford a small satellite. On the other hand, if the budget is not an issue, you can start with identifying a mission that will solve your local problem, and from there design the satellite. The size will then depend on the required components to realize the mission. We will also have more of this later.