Space communication
You must have watched SCI-FI space exploration movies and of course, we all love them as well. Sometimes the movie characters who are on space missions usually do video calls without delay or interference & can easily communicate with their loved ones.
But is that really true? Unfortunately not.
Communication to and from space is a really challenging and hard to do. But NASA has experience and expertise to get space data to the ground.
NASA’s space communication and navigation(SCaN) program are what makes this communication possible, whether it's an astronaut at the space station, rovers to the mars, or the Artemis mission to the moon.
Let’s dive in and see some challenges of space communication, technologies, and capabilities that NASA uses to overcome those challenges.
1: Transmitters & Receivers
At a very basic level of wireless communication, two things are very important, A Transmitter and a Receiver. In this setting of the devices, the Transmitter encodes the message onto electromagnetic waves using modulation which changes the properties of the wave to represent the data. These waves are what make wireless communication possible. Once the message is encoded onto the wave, it is transmitted from the transmitter which travels through space towards the receiver. The receiver collects the transmission waves and demodulates them to obtain the final message.
2: antennas
Space communication involves more than pointing spacecraft’s antennas to the earth. We need powerful antennas on the earth as well to receive the transmission from the spacecraft. Fortunately, NASA has a global network of antennas around all seven continents.
Network engineers carefully plan communication between mission and spacecraft so that the antennas are ready to receive the message as soon as the spacecraft passes overhead.
3: Space Relays
In addition to direct-to-earth communication, NASA depends on space relay satellites in order to get their data delivered to the earth-based space station. I.e the space station communicates through Tracking and Data Relay Satellites (TDRS), which transmit data to ground stations in New Mexico and Guam. The recently launched Mars 2020 Perseverance rover will send data through orbiters around Mars, which forward the data to Earth.
4: Bandwidth
Bandwidth plays an important role in space communication. Higher the bandwidth can carry more data per second allowing the spacecraft to download the data more quickly.
Bandwidth can be defined as the capacity of a wired or wireless network to transmit a maximum amount of data from one point to another in a given amount of time.
NASA is dependent on radio waves for space communication but also developing ways to communicate with infrared lasers, which will offer missions higher data rates and effective communication mechanisms as never before.
5: Data Rate
The Data Rate is a term to denote Transmission speed or a number of bits transferred per second.
Higher bandwidth in space communication means higher Data Rate. Apollo radios sent grainy black and white videos from the moon. An upcoming optical terminal on Artemis 2 will send an ultra HD 4k video from orbit.
But wait, bandwidth is not only the factor which impacts space communication, we have other issues like the distance between the Transmitter and Receiver, the Size of antennas, the optical terminal they use, or the power available at either end.
6: Latency
Latency stands for the delay - in network communication latency is defined as the measure of the time required by a signal to travel from one point to another.
In space communication, The Latency is a major challenge as communication doesn’t occur instantly, they are bound by a speed limit, i.e the speed of light which is 186,000 miles per second.
For space crafts closer to earth, this communication latency is very small, almost negligible but as the distance grows latency increases.
7: Interference
In Space communication, Radio waves travel quite a large distance between receivers and transmitters. During the path, transmission signals get mixed with other radio signals emitted from the SUN and other celestial bodies, which degrades the data quality.
NASA uses detection and correction algorithms to curate the received data.
So these were some of the major challenges NASA or other space agencies face during a mission. Hope you enjoyed the article. Stay tuned with us to get more amazing updates on science and technology.
Tell Me what you think about these articles in the comments below, also tell me what you wanna know next.
