On December 11, NASA engineers gathered impatiently at the Jet Propulsion Laboratory in Pasadena, California, to watch a video of the shot, wondering if it would be in the original high resolution they had hoped for.
It was a relief for them. For the first time, high-definition video — this one of a lab employee’s cat named Taters — was broadcast from a distance of 18.6 million miles, or nearly 80 times the distance from Earth to the moon, the furthest on record.
The demonstration was part of NASA Optical communications in deep space An experiment aimed at improving communications infrastructure outside Earth’s orbit. For example, if humans wanted to go to Mars, larger amounts of data would need to be transmitted over a longer distance. This demonstration was another step towards such a possibility.
“This would be the same capability you would want to have if you were sending an astronaut to the surface of Mars or something like that,” said Dr. Abhijit Biswas, the project’s technology expert. “You want to have a constant connection with them.”
The demonstration was performed with the help of NASA’s Psyche spacecraft, which was launched on October 13 with the aim of exploring an asteroid of the same name. The DSOC experiment uses laser communications, rather than traditional radio frequencies, in an attempt to transmit large amounts of data at faster rates over greater distances. (The video shows Taters chasing a laser pointer. In 1928, a figurine of the cartoon character Felix the Cat was used to test TV broadcast.)
Transmitted data rates of 267 Mbps are comparable to rates on Earth, which often range between 100 and 300 Mbps. But Dr. Biswas urged caution regarding the results of the demonstration.
“This is the first step,” he added. “There are still significant requirements for ground infrastructure and things like that to take something that is a proof of concept to turn it into something practical and reliable.”
The video was transferred using Aviation laser transceiver, which is one of several pieces of new hardware being deployed for the first time. The DSOC system consists of three parts: a transmitter and receiver, mounted aboard the Psyche spacecraft, and two components on Earth: a ground-based laser transmitter (about a 90-minute drive from the laboratory) and a ground-based laser receiver at the Palomar Observatory in Southern California.
“It’s a bit amazing to finally be able to do all of this,” said Dr. Meera Srinivasan, project operations lead.
Dr. Biswas and Dr. Srinivasan, along with other NASA engineers, have been developing this technology for decades. The focus was to expand the scope of optical communications technology that was already being used in satellites orbiting much closer to Earth. Initially, before Saiki’s mission, the team hit roadblocks because the signal was too weak. So NASA developed technologies to expand capabilities. Dr Biswas said deep space is the “new frontier”.
To begin the cat video recording process, the ground transmitter first sends out a laser beam. The aim had to be precise. Psyche then shut down that signal and sent the content, which had been previously uploaded by the NASA team, to the receiver. For the transmission to work, it must be done during a cloud-free night, allowing for adequate line of sight.
“There are many small steps,” Dr. Biswas said. “Everyone has to fall into place at the right time. And that’s the scary part because we’re doing this for the first time. This has never been done before. It’s not like, ‘Oh, we know if you do this, it’s going to happen.'” We kind of We work our way through all of these things.
“Once everything works, it seems so easy. Why were we worried in the first place?” he added.
Now, the DSOC project aims to test its limits. At the end of June, NASA engineers expect to be able to transmit from 10 times the distance: 186 million miles.
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