Astronauts journeying to and living on Mars aren’t exactly going to have wi-fi access, since the router doesn't rach quite that far into space. Enter lasers.
NASA is building a new antenna to add to its Deep Space Network (DSN) for transmitting messages to Mars-tronauts, along with 30 of the space agency’s probes and orbiters and floating telescopes that keep venturing deeper and deeper into the cosmos. DSS-23 will end up as a 112-foot antenna dish, the thirteenth in the network, under the clear skies of Goldstone, CA. The further away a spacecraft is flying, the larger the antenna needed to get in touch.
"The DSN is Earth's one phone line to our two Voyager spacecraft — both in interstellar space — all our Mars missions and the New Horizons spacecraft that is now far past Pluto," said NASA JPL Deputy Director Larry James. "The more we explore, the more antennas we need to talk to all our missions."
You can’t exactly risk having no signal when humans need to communicate all the way from Mars. DSS-23 will function not just as your average radio antenna. It’s also going to be tricked out with mirrors and a receiver made specifically for receiving laser signals. Faraway spacecraft that beam signals to Earth need something more powerful than radio. Lasers boost the data rate from the Red Planet, almost 170 million miles away, 10 times more than radio.
This kind of tech didn’t exist during the time of the Voyagers, which still communicate with the DSN. The thing is that the signals they transmit to DSN antennas are so weak that the power they do have is 20 billion times weaker than that needed to run a digital watch. While engineers have figured out a way to amp those signals, something like that still isn’t going to be enough when human lives are involved.
DSN antennas are positioned about 120 degrees apart around Earth so they can keep connecting with spacecraft even as the planet rotates. The capabilities of DSS-23 will be put to the test in a few years with NASA’s Deep Space Optimal Communications Project, which will involve the upcoming Psyche orbiter (headed to a metallic asteroid) beaming images and data to both DSS-23 and a relatively nearby observatory.
"Our hope is that providing a platform for optical communications will encourage other space explorers to experiment with lasers on future missions," Suzanne Dodd, director of the Interplanetary Network (which manages the DSN) said.
When the Artemis program starts launching manned missions to the Moon, NASA will also test out communication via laser to see how close we are to talking with astronauts on Mars.