¿ìè¶ÌÊÓƵ

You might have heard that by 2025 we’ll be watching a reality show set on Mars, Elon Musk will have begun selling the that will make humans a multiplanetary species and astronauts will be cruising around the Red Planet in .

But these dreams are in jeopardy because of a little-known problem: the deteriorating communications infrastructure between Mars and Earth. This set-up could be inoperative as soon the mid-2020s, leaving us unable to launch the next generation of landers and rovers, let alone get any useful scientific information from them. We need to get serious about building the interplanetary internet or, instead of colonising a new planet, we’ll be going nowhere fast.

To understand the problem, consider what happens when communications come from Mars today. When either of the Martian rovers currently trundling around wants to transmit something, they usually send it first to one of the five spacecraft orbiting the planet. These orbiters then relay the information to the Deep Space Network on Earth. This set of three facilities, each with an array of at least four antennae, is strategically placed around our planet so that any spacecraft can always communicate with at least one location.

Using this system to send a single, high-definition colour image from Mars to Earth takes at least 30 minutes. You can forget about the reality TV show. One 22-minute episode will take nearly six days to transmit – and that’s assuming that no competing information, like scientific instructions or requests for emergency medical assistance, needs to be relayed at the same time.

That has serious implications for even our simpler plans: a slew of landers and rovers due to visit Mars early next decade, including NASA’s Mars 2020 rover and SpaceX’s Red Dragon. The communications infrastructure lacks the bandwidth needed to cope with all five of the planned 2020s missions at once.

Running out of time

Spreading the missions out further won’t solve the problem, because even this limited communications system will soon disappear. The spacecraft are getting old and running out of fuel. Most won’t last beyond the mid-2020s.

NASA has been planning mitigation strategies for this problem for 20 years, but funding issues pushed it aside until recently. In 2014, NASA issued a call for orbiter ideas from companies, while also working on its own new orbiter concept.

However, delays in funding for the 2017 fiscal year held up development of the orbiter even further and it’s unclear whether it could still be launched in 2022 as hoped. After that, the next launch window to Mars isn’t until 2024. This means the crucial new orbiter won’t be there to provide descent and landing communications for anything that needs to touch down on Mars. The planned missions will just have to hope that the existing infrastructure holds up.

But many think we need to think bigger than just solving the next show-stopping problem. Vint Cerf, widely recognised as one of the fathers of the internet, started working on its space-based equivalent in 1998. Known as the interplanetary internet, it will have routers scattered around the solar system and may use lasers and complex codes to beam communications over long distances.

It won’t be ready in time to help the next rovers: its first node in space was installed on the International Space Station in 2009. Eight years on, there aren’t any more.

Indeed, the interplanetary internet may never be ready. Its development and launch keep being pushed back because of more immediate concerns. But one lesson to take from this saga is that Mars missions require more than seat-of-the-pants planning. Without communications and other basic infrastructures, everything else will fail. We should have started on it 20 years ago, but let’s at least not put it off any longer.