What Are the 7 Largest Satellites?
What Are the 7 Largest Satellites?
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Artificial satellites are a cornerstone of modern technology, providing essential services such as communication, navigation, weather forecasting, and Earth observation. Over the decades, satellites have grown significantly in size and complexity, with some massive structures orbiting the Earth and other planets. In this article, we will explore the seven largest artificial satellites ever built, discussing their purpose, size, and importance. Whether you're a space enthusiast, an engineering professional, or someone interested in the technologies that power our modern world, this guide will offer valuable insights into the largest satellites ever constructed.
The International Space Station (ISS) is the largest artificial satellite ever built, and it serves as a living space and laboratory for astronauts from around the world. Launched in 1998, the ISS orbits the Earth at an altitude of about 400 kilometers (250 miles) and has a mass of over 420,000 kilograms (925,000 pounds). The station’s total length is about 109 meters (357 feet), and it provides a habitable environment for six astronauts at a time.
The ISS is a symbol of international cooperation, with contributions from NASA, Roscosmos, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA). Its primary purpose is to conduct scientific research in a zero-gravity environment, contributing to advancements in fields such as biology, physics, and materials science.
Mass: 420,000 kg (925,000 lbs)
Dimensions: 109 m (357 ft)
Purpose: Scientific research, international collaboration
The Hubble Space Telescope (HST) is one of the most famous artificial satellites and the second largest space telescope in operation. Launched in 1990 by NASA and the ESA, Hubble orbits the Earth at an altitude of about 547 kilometers (340 miles). Its primary mirror is 2.4 meters (7.9 feet) in diameter, and the entire structure weighs around 11,000 kilograms (24,000 pounds).
Hubble has provided breathtaking images of distant galaxies, nebulae, and stars, transforming our understanding of the universe. The data it has collected has led to significant discoveries, including the accelerated expansion of the universe and the existence of supermassive black holes.
Mass: 11,000 kg (24,000 lbs)
Length: 13.2 m (43.5 ft)
Purpose: Space observation, astrophysics research
The Terra satellite, part of NASA's Earth Observing System (EOS), was launched in 1999 to monitor Earth’s climate and environmental changes. It is a large satellite, weighing about 5,190 kilograms (11,440 pounds), and it carries five scientific instruments designed to study the Earth's atmosphere, land, and oceans. Terra orbits the Earth at an altitude of 705 kilometers (438 miles), providing data used for climate models, weather forecasting, and natural disaster monitoring.
Terra has been instrumental in observing the effects of climate change, deforestation, and ocean temperatures, making it one of the most important Earth observation satellites in history.
Mass: 5,190 kg (11,440 lbs)
Dimensions: 7 m x 12 m (23 ft x 39 ft)
Purpose: Earth observation, environmental monitoring
Launched in 2002, Envisat was the European Space Agency's largest Earth observation satellite, weighing in at a massive 8,211 kilograms (18,100 pounds). The satellite carried ten sophisticated instruments that observed the Earth’s atmosphere, oceans, land, and ice caps. Envisat orbited the Earth at an altitude of 800 kilometers (497 miles) and played a critical role in monitoring climate change, deforestation, and natural disasters.
Despite losing contact with Envisat in 2012, its data continues to be invaluable for climate research. It remains one of the largest and most important Earth observation satellites ever launched.
Mass: 8,211 kg (18,100 lbs)
Length: 26 m (85 ft)
Purpose: Earth observation, environmental monitoring
The GOES-R series satellites are part of NOAA’s (National Oceanic and Atmospheric Administration) next-generation geostationary weather satellites. Each satellite in the series weighs around 5,192 kilograms (11,440 pounds) and operates at an altitude of approximately 35,786 kilometers (22,236 miles). The GOES satellites monitor weather patterns, provide real-time images of storm systems, and offer critical data for predicting natural disasters such as hurricanes and tornadoes.
GOES-16 and GOES-17 have revolutionized weather forecasting with their high-resolution imagery and rapid scanning capabilities, making them some of the most advanced meteorological satellites in history.
Mass: 5,192 kg (11,440 lbs)
Purpose: Weather monitoring, disaster prediction
The Tracking and Data Relay Satellites (TDRS) are a series of communication satellites that form NASA’s TDRSS (Tracking and Data Relay Satellite System). TDRS-3, launched in 1988, was one of the largest communication satellites of its time, weighing around 2,270 kilograms (5,000 pounds). The TDRS system is critical for maintaining communication between Earth-based stations and various spacecraft, including the ISS and Hubble Space Telescope.
These satellites orbit at an altitude of about 35,800 kilometers (22,300 miles) and play a key role in transmitting data for NASA’s space missions.
Mass: 2,270 kg (5,000 lbs)
Purpose: Space communications, data relay
The Inmarsat-4 F1 satellite is one of the largest commercial communication satellites, launched in 2005 by Inmarsat, a British telecommunications company. This satellite, part of the Inmarsat-4 series, weighs around 5,960 kilograms (13,133 pounds) and provides global mobile communication services. Operating from geostationary orbit at an altitude of 35,786 kilometers (22,236 miles), Inmarsat-4 F1 delivers voice, broadband internet, and data services to ships, aircraft, and remote locations around the world.
Mass: 5,960 kg (13,133 lbs)
Purpose: Global communication, data services
The world’s largest artificial satellites are technological marvels that serve various critical functions, from scientific research and space observation to communication and weather monitoring. These satellites, with their immense size and advanced capabilities, are a testament to human ingenuity and the collaborative efforts of space agencies, scientists, and engineers across the globe. As technology advances, we can expect even larger and more sophisticated satellites to enter orbit, continuing to expand our understanding of space and improving life on Earth.
If you're planning to build a satellite at home, here are some top products you can purchase online to get started with a small satellite project, like a CubeSat:
Arduino Uno R3 Microcontroller Ideal for controlling various satellite components. Easy to program and widely used in DIY projects.
Raspberry Pi 4 Model B Perfect for running satellite operations and data management. Powerful and compact, used for space projects like Pi-Sat.
Adafruit Ultimate GPS Breakout – 66 channel A compact GPS module for real-time positioning and tracking. Great for satellite navigation and telemetry.
Sun Power Solar Cells Reliable small solar panels to power your satellite. Lightweight and efficient for CubeSat-sized projects.
XBee 3 RF Module Used for wireless communication between your satellite and ground station. Designed for long-range communication and low power consumption.
Tiny Circuits 9-Axis IMU (Inertial Measurement Unit) Essential for satellite orientation and stabilization. Measures acceleration, rotation, and magnetic field for accurate positioning.
Lipo Battery Pack 3.7V 10000mAh A reliable power source to store energy generated by solar panels. Lightweight and commonly used for small satellite projects.
CubeSat Structure Kit 3D-printed frame kits available for DIY satellite projects. A basic structure for housing your satellite's electronics.
TTGO LoRa SX1276 Module A radio communication module designed for long-range communication. Great for sending telemetry data from low Earth orbit.
MATLAB & Simulink Student Version Essential for simulating and testing your satellite’s functions, including orbit trajectories and control systems.
These products, along with open-source satellite kits, can give you a solid foundation to design and assemble a small satellite for educational or hobbyist purposes!
Building a fully functional satellite using the listed products is an exciting and complex project. Here's a step-by-step guide to help you assemble these components into a working satellite, such as a CubeSat:
Step 1: Define Your Satellite’s Mission
Before assembly, decide what your satellite will do. Whether it’s Earth observation, communication, or scientific experiments, defining the mission will help you choose the right sensors and equipment.
Step 2: Build the CubeSat Frame
Assemble the CubeSat Structure Kit Begin by constructing the physical frame of your CubeSat. These kits usually come with lightweight, durable materials such as 3D-printed parts or aluminum. Ensure the structure has enough space for components like the microcontroller, battery, and sensors.
Step 3: Design the Power System
Install the Solar Panels (Pololu High-Power Solar Cells) Mount the solar panels on the exterior of your CubeSat. These panels will provide continuous power to your satellite in orbit. Ensure that they are positioned to maximize exposure to sunlight when in space.
Connect the Battery Pack (Lipo Battery Pack 3.7V 10000mAh) Wire the solar panels to the LiPo battery to store energy. The battery will ensure your satellite has power even when it's in Earth's shadow.
Step 4: Set Up the Onboard Computer
Install the Raspberry Pi 4 Model B This serves as the “brain” of your satellite. It will process data and control operations. Connect the Raspberry Pi to the CubeSat’s power system via the battery pack. Add a microSD card with your pre-written code and data management software for the satellite's mission.
Integrate the Arduino Uno R3 Microcontroller Use Arduino to handle real-time tasks, like managing sensors or communication. It’s a complementary system to the Raspberry Pi, which handles the overall mission, while Arduino handles specific control tasks.
Step 5: Attach Sensors and Modules
Install the GPS Module (Adafruit Ultimate GPS Breakout) Attach the GPS module to track the satellite’s position in orbit. Program the GPS to report position data to the Raspberry Pi for logging and telemetry.
Mount the 9-Axis IMU (Tiny Circuits IMU) This module measures acceleration, rotation, and magnetic fields to stabilize your satellite. Connect it to the Arduino for real-time orientation and attitude control.
Step 6: Communication System
Install the XBee 3 RF Module This module handles communication between the satellite and your ground station. Attach the antenna to the exterior of the satellite frame for optimal signal reception.
Integrate the TTGO LoRa SX1276 Module LoRa offers long-range communication and is ideal for sending telemetry data. Connect the module to the Raspberry Pi and program it to transmit data to Earth.
Step 7: Write and Upload the Software
Create Control and Data Processing Software On the Raspberry Pi, write code that controls the satellite’s mission—whether it's capturing images, logging GPS data, or transmitting data back to Earth. Use Python, MATLAB, or Simulink to create algorithms that simulate orbital functions and process sensor data.
Upload the Control Code to Arduino Use the Arduino IDE to upload code that manages real-time control systems, such as adjusting the satellite’s orientation using the IMU data.
Step 8: Testing and Simulation
Simulate the Satellite’s Orbit and Functionality Before launch, test your satellite’s functionality using MATLAB & Simulink. Simulate its orbit, test communication ranges, and monitor the power system. Place the satellite in a vacuum chamber (if available) to test how it will function in space conditions.
Test Communication and Power Systems Ensure that your communication modules are working by setting up a ground station and testing data transmission. Test the solar panels and battery pack to confirm they are providing adequate power.
Step 9: Launch Preparation
Coordinate with a Launch Provider Once your CubeSat is fully assembled and tested, work with a launch provider such as SpaceX or Rocket Lab for a ride-share launch. Ensure your satellite meets their size, weight, and regulatory standards.
Obtain Regulatory Approvals Depending on your location, you may need licensing from local or international space authorities (such as the FCC in the U.S.) to launch and operate your satellite.
Step 10: Launch and Operate
Launch the Satellite Your satellite will be deployed into orbit by the launch provider.
Operate the Satellite from the Ground Use your ground station to communicate with your satellite, receive telemetry data, and monitor its mission progress.
Building a satellite at home is an ambitious yet achievable goal for hobbyists, engineers, and students. With these components, proper planning, and the right mission objectives, you can contribute to space research and innovation right from your home.