Mars is far from Earth, which makes communication with it difficult. This delicate communication becomes increasingly important as we launch more and more craft towards the red planet. It will become absolutely critical when we send people there.
So what can be done to increase the speed of communications between the blue and red planets of our solar system? A paper from researchers primarily based in Spain looks at different network topologies that could help solve some of the communication issues.
Typically, communication with Mars is through a system known as the Deep Space Network (DSN). It’s basically a collection of giant earth-based communications satellites spread across the globe. Their primary purpose is to communicate directly with every probe launched beyond Earth’s orbit, including those surrounding Mars. Some ground systems on Mars also use satellites orbiting the planet, such as the Mars Reconnaissance Orbiter (MRO), which then broadcasts these signals to the DSN.
Mixed signals
The Mars Reconnaissance Orbiter took this image of the Martian ice cap.
There are several issues with this setup, including the single point of failure and the size of the equipment needed to send the signals back, and the fact that the Sun interrupts communications for a good portion of the time. If one of the DSN satellites fails or, even worse, if the MRO stops working, communications with most science equipment on the Red Planet could become much more difficult. Network engineers on Earth build redundancy paths specifically to avoid this single point of failure problem.
Some signals lose their strength even without the presence of an atmosphere in space. So to effectively send high-speed information over long distances, the antennas on this ship must be massive. Sometimes they exceed the size of the fairing they are launched into, although there are techniques for unpacking an antenna in space itself. But an even bigger communication challenge is the Sun.
It may not look like it, but about 30% of the time Earth cannot communicate directly with Mars. This is mainly because they are on opposite sides of the Sun – or almost, anyway. Radiation emitted from our home star scrambles most, if not all, communications, making it nearly impossible to talk to missions like Spirit and Perseverance when the planets are so aligned.
Enter SolarCom
NASA’s first generation tracking and data relay satellite was launched in the 1990s.
To circumvent these problems, Paula Betriu and her colleagues at JPL and the Universitat Politècnica de Catalunya have designed software called SolarCom to analyze the availability, availability, and speed of different types of network topologies. Two stood out for their significant increase in speed and reliability – a Lagrange point configuration and what they call a “bead constellation”.
Placing relay satellites at different Lagrange points, mainly those between the Sun and the Earth, would seem a fairly obvious solution. This would greatly reduce interference when planets face each other in the solar system. This could potentially increase that availability to over 90% – a big boost in Mars exploration capabilities, but still not as good as a Pearl Constellation.
This configuration, which mimics a large spherical cloud of satellites in different but complementary orbits, could achieve network connection rates of up to 100%. However, it could be much more expensive as it would require more satellites overall. With launch costs dropping, that might not be such a big deal in the near future, though.
However, there are still issues with increasing bandwidth to Mars, including the networking hardware currently in place on most relay satellites. The Tracking and Data Relay Satellite (TDRS), which is one of NASA’s primary means of relaying information over large distances around the Earth, was originally launched in the 1990s, and even its last third-generation satellite is already five years old, which is almost a lifetime by networking equipment standards.
All of this means there’s still a lot of work to do before humanity can download crisp, real-time video from Mars. But as a potential crewed mission begins to draw closer, more attention is sure to be drawn to our ability to communicate with it, and software packages like SolarCom will help determine the best way to do this.
This article was originally published on Universe today by Andy Tomaswick. Read the original article here.