How is a satellite built?

Building a satellite is a structured process that goes from the initial idea to launch and in-orbit operations. ESA divides this lifecycle into several phases: it starts with mission analysis (Phase 0), in which objectives are defined and options are assessed; this is followed by the feasibility study and definition of high-level requirements (Phase A); then comes preliminary design and definition of critical interfaces (Phase B), during which measurable requirements and interfaces are established.

In Phase C, the detailed design of the satellite is completed (system, subsystems, and software).

Phase D involves the production of the Engineering Models and the Flight Model, along with the testing and qualification campaign; all subsystems are integrated and verified, and the vehicle is then shipped to the launch site.

After launch, Phase E covers the commissioning and operational life of the satellite, and finally, Phase F deals with disposal or deorbiting activities.

For small satellites (CubeSats, nanosats, or picosats), the process is similar but scaled down: the design must condense many functions into a compact volume, and often COTS (Commercial Off-The-Shelf) components are used — hardware and software available on the market that can replace in-house developments. The use of COTS is a strategy to reduce development and maintenance costs, and in the case of hardware, unit costs as well, thanks to economies of scale. In summary, COTS are ready-to-use functionalities or applications.

Even small satellites go through the production and testing of engineering models, structural analyses, and thermal and vibration tests, up to the flight version. The integration phase involves assembling subsystems (structure, power supply, onboard computer, radio, attitude sensors, and payload), creating electrical connections, and performing functional tests, before closing the satellite inside the deployer that will launch it.

What are the main phases of satellite construction?

The main stages can be summarized as follows:

1. Mission concept and requirements – definition of objectives, orbit, and payload.
2. Preliminary and detailed design – selection of architecture, mass/power budget, and system engineering.
3. Production of test models – creation of structural and engineering models, with vibration, acoustic, and thermal vacuum tests to qualify the design.
4. Integration and testing of the flight model – final assembly of the platform, payload integration, and final functional and environmental checks.
5. Launch and commissioning – installation in the dispenser, launch, early operations, and commissioning.
6. Operations and end of life – in-orbit management, software updates, deorbiting, or passivation at the end of the mission.

This scheme applies to satellites of any size; naturally, for picosatellites, miniaturization makes architectural choices more constrained and reduces the complexity of certain subsystems (often without propulsion and with simplified attitude control).
For these very small satellites, even during design and testing, a proto-flight approach is often adopted — testing the actual flight models directly to reduce costs and timelines.

Where are satellites physically assembled? And specifically, where does Apogeo Space build its own?

Apogeo Space has a complete infrastructure for the production and testing of picosatellites:

• Certified clean room – enables assembly in an environment with highly purified and filtered air, essential to prevent contamination during satellite integration.
  Functions as an Integration Laboratory, equipped with tools for mechanical and electronic assembly, wiring, and functional testing (oscilloscopes, spectrum analyzers, power benches).
• Thermal vacuum chamber (TVAC) – a state-of-the-art facility allowing environmental and qualification tests for satellites up to 16U in size; the chamber simulates the extreme temperatures and vacuum of space to verify satellite robustness.

Testing activities are carried out with specialized partner companies, using dedicated equipment: vibration and shock test benches, anechoic chambers for radio link verification, and calibration instruments for sensors and payloads.Thanks to these facilities, the company not only builds its own constellation but also aims to offer contract manufacturing services, leveraging the modularity of its picosatellites and its acquired know-how to adapt them to customers’ needs.