How to Build a Satellite

Summary

This video provides a comprehensive overview of satellite design and engineering, covering key systems such as the satellite bus, power, propulsion, and thermal control. It explores the challenges of maintaining communication in space through TT&C systems, the need for precise temperature regulation due to extreme space conditions, and how advanced materials and systems are used to manage heat. The video also highlights Onshape, a cloud-based CAD platform for efficient satellite design, showcasing its collaborative features and user-friendly tools. A blend of technical insight and practical solutions for space missions.

Takeaways

• 😀 Satellites are complex machines designed to survive the harsh conditions of space, relying on multiple systems like the payload and bus to function effectively.
• 🌍 The mechanical structure of satellites is built with lightweight, durable materials like aluminum alloys and carbon fiber composites to withstand launch forces and space conditions.
• 🛠️ The satellite's on-board computer controls all functions, using radiation-hardened components to protect against cosmic radiation in space.
• ⚡ Solar panels are the primary source of power for satellites, with batteries storing energy to maintain operations during Earth’s shadow phases.
• 🛰️ Satellites use attitude control systems, including gyroscopes and star trackers, to orient themselves and keep payloads, solar panels, and antennas correctly aligned.
• 🌡️ Thermal control is critical in space due to extreme temperature fluctuations. Radiators, heat pipes, and insulation help maintain the satellite's temperature within safe limits.
• 🚀 Propulsion systems are used for orbit adjustments, station-keeping, and attitude control, with different types of propulsion selected based on the satellite’s mission requirements.
• 📡 Communication systems rely on high-gain antennas for data transmission and low-gain antennas for reliable command and telemetry reception, even under adverse conditions.
• 🌌 The vacuum of space presents challenges for thermal regulation, requiring systems like phase-change materials and thermostatic heaters to manage temperature variations.
• 💻 Onshape, the sponsor of the video, is a cloud-based CAD platform that allows engineers to design, model, and collaborate on mechanical systems and satellite components from anywhere.

Q & A

What are the two main parts of a satellite, and what do they do?

A satellite consists of two main parts: the payload and the bus. The payload carries the equipment necessary for the satellite's mission, such as cameras or communication devices. The bus contains the systems that keep the satellite operational, including power, propulsion, and communications systems.

Why is the mechanical structure of a satellite important, and what materials are typically used?

The mechanical structure of a satellite is crucial because it must withstand the intense forces during launch and operate effectively in space. Lightweight, strong materials like aluminum alloys and carbon fiber are commonly used to minimize mass while providing strength. These materials also need to resist outgassing in the vacuum of space.

What role does the onboard computer play in a satellite?

The onboard computer acts as the brain of the satellite, controlling everything from data processing to monitoring system health. It ensures the satellite functions as intended, even in the harsh environment of space, and must be protected from radiation through shielding and radiation-hardened components.

How do satellites generate power, and how is this power stored?

Satellites primarily generate power using solar arrays, which capture energy from the sun. This energy is stored in batteries to ensure the satellite continues to function when in Earth's shadow. To maximize efficiency, multi-junction solar cells are often used, as they capture a broader range of solar wavelengths.

What is the function of a satellite's attitude control system?

The attitude control system is responsible for adjusting and maintaining the satellite's orientation in space. This ensures that antennas are pointed toward Earth and solar panels are oriented toward the sun. Sensors and actuators, such as reaction wheels and magnetorquers, are used to control the satellite's attitude.

What types of propulsion systems are used in satellites, and why are they important?

Satellites use various propulsion systems, including cold gas, chemical, and electric propulsion. These systems help maintain orbit, adjust positions, and perform maneuvers. Cold gas propulsion is precise for small adjustments, while electric propulsion is highly efficient for long-duration missions.

How do satellites communicate with Earth, and what are the different types of antennas used?

Satellites communicate with Earth through downlinks and telemetry. They use high-gain antennas for high data rates and low-gain antennas for reliable communication, even when the satellite is in difficult positions. Low-gain antennas ensure communication is maintained even if the satellite's attitude control system is malfunctioning.

What are some challenges associated with thermal control in satellites?

Satellites face extreme temperature fluctuations in space due to the lack of an atmosphere. Components that face direct sunlight can become extremely hot, while those in Earth's shadow can rapidly cool. Thermal control systems, such as radiators, heat pipes, and insulation blankets, are used to maintain stable temperatures and prevent damage to sensitive components.

Why is thermal control so important for satellite components?

Thermal control is critical because extreme temperatures can damage sensitive components, such as batteries, electronics, and payloads. Some parts of the satellite need to be kept within specific temperature ranges to function correctly. Effective thermal management ensures the satellite's longevity and mission success.

How does Onshape help satellite engineers and designers with their work?

Onshape is a cloud-based CAD platform that simplifies the design process. It allows engineers to model parts, build assemblies, and produce drawings efficiently, all within a web browser. Onshape also provides version tracking, standard part libraries, and collaboration tools, enabling teams to work together seamlessly on complex projects like satellite design.