Space communication has a fascinating history, one that spans the twentieth century and a multitude of technological advances. The remote-controlled camera, for example, wasn’t the first device developed for spaceflight. In 1926, an 8-year-old boy named Frank Malina built a remote-controlled camera launched from a balloon and photographed the Earth from 400 miles above. It was followed by cameras that beamed pictures back to Earth using radio signals, but these early systems were unreliable. It wasn’t until 1956 that NASA used one of these early cameras to transmit the first photograph from space.
If you’re looking to explore outer space, you’re going to have to change a few things about your life. You won’t be able to buy gas for a car or drive your car to work, and you’ll need to start living off food that you grow yourself. But don’t worry; this blog is here to ease your fears.
Basics
NASA and other agencies have sent messages to and from the International Space Station for years using radio waves. With funding for commercial spaceflight on the rise, space communications may finally be able to move beyond government space programs, opening up new technological possibilities for space travel.
Space communication is the transmission of messages using electromagnetic waves. The Federal Communications Commission (FCC) regulates space communications in the United States; however, private citizens are generally exempt from the regulations governing space communication. The FCC requires license holders to broadcast only at specific frequencies, known as radio frequency (RF) bands. These bands are classified according to how much radiofrequency energy they emit.
Ground networks
Ground networks (or ground stations) allow spacecraft to communicate while in space. Spacecraft don’t only need to communicate with ground stations on Earth but also with the stations that fly in space.
A ground network is the communications link that sends signals from a spacecraft to ground stations or from ground to spacecraft. A ground station is a facility where researchers, engineers, and support staff can send and receive communications to and from spacecraft.
Bandwidth
Bandwidth is the amount of data transmitted in a given period of time. It is a measurement used to quantify the amount of data that can be transmitted over a specific air or fiber-optic channel at a certain frequency. For example, a single 256Kbps channel might carry audio data (voice), while a single 128Kbps channel might carry video data (video). There are four types of bandwidths: (Kbps) Kilobits per second, (Mbps) Megabits per second, (Gbps) Gigabits per second, and (Tbps) Terabits per second.
Data rates
Modern data rates on deep space missions are higher than ever. The bandwidth on a deep space mission can exceed 10 (Gbps) gigabits per second. But bandwidth isn’t the only constraint on data rates. Grinders, or the opposite process of reducing the size of data, so it travels faster, also play an important role, especially in deep space missions.
The Apollo missions were way ahead of their time in terms of data. On Apollo 11, the crew transmitted 300 TV-quality images of Earth from the moon. But bandwidth isn’t the only constraint on data rates, especially when sending data from space to Earth. You have to consider latency, or the time it takes for the data to travel from the sender to the receiver. If the latency is too long, the transmission will be choppy. The Apollo missions transmitted data at 10 Mbps (bits per second). It took about 0.4 seconds for a packet of data to travel from the spacecraft to the ground and about 0.8 seconds for the data to make it back to Earth.