NASA has broken its own record by transmitting ultra-high-definition video over a distance of 31 million kilometres from deep space. The footage wasn’t of distant celestial bodies or spacecraft, but of a cat called Taters chasing the light from a laser pointer.
Abhijit Biswas at NASA’s Jet Propulsion Laboratory (JPL) tells New Scientist that Taters was chosen for the first transmission over that distance because one of the first television test broadcasts also featured a cat – the cartoon feline Felix. The inclusion of a laser pointer was a visual nod to the use of lasers in the transmission, he says.
“Apparently this cat is very fond of chasing laser pointers, so somehow that all came together in this video,” says Biswas.
The 15 seconds of footage was transmitted from NASA’s Deep Space Optical Communications (DSOC) experiment, which is hitching a ride on the Psyche spacecraft that launched in October to intercept an asteroid of the same name.
The video of Taters – a JPL employee’s pet – was shot and uploaded to the craft before launch. The film also shows Psyche’s orbital path, the telescope dome of the Palomar Observatory in California and technical information about the laser and its data transmission rate.
The DSOC experiment will send high-bandwidth test data to Earth during a two-year run, and is part of NASA’s long-term plan to use lasers rather than radios to transmit information from space. This will enable wider bandwidths and therefore faster data transfer rates that can carry complex scientific information and high-definition images and videos for future missions.
“DSOC is really a proof of concept which hopefully will make believers out of everybody that this can be done,” says Biswas. The technique had already been used to send data between the moon and Earth, but that is a mere 384,400 kilometres. He says longer distances than the Taters test should be possible in future.
One issue is ensuring the laser light is precisely directed so it hits the receiving station. “It’s a very narrow beam; at the distance that Psyche is right now, it [is] only a few hundred kilometres [wide by the time it reaches Earth],” says Biswas. “So if you mispoint it ever so slightly, you’ll be in the Pacific Ocean or somewhere else. You’ll completely miss. So that was something there was a lot of anxiety over.”
The video was transmitted at near-infrared wavelength by a laser transceiver and took 101 seconds to travel from the craft to Earth.
The 267-megabits-per-second message was received by equipment at the Hale Telescope at Palomar, before being transmitted over the internet to JPL in southern California, where the video was played in real time. That data rate makes DSOC faster than most domestic broadband connections.