SEOUL, South Korea — South Korea’s robotic lunar orbiter Danuri successfully demonstrated “space internet” on its way to the moon by sending video and photo files, including a popular Korean band’s music video, at a distance of more than 1.2 million kilometers to Earth, said Korea Aerospace Research Institute (KARI), the spacecraft’s operator, Nov. 7.
The demonstration was conducted twice — Aug. 25 and Oct. 28 — using a space internet demonstrator developed by the Electronics and Telecommunications Research Institute (ETRI) here, validating an interplanetary internet connection using delay-disruption tolerant networking. The device was designed to test the data transmission capability in a space environment where disconnection of telecommunications frequently occurs. The tests were supervised by KARI, ETRI, and NASA Jet Propulsion Laboratory, according to KARI. While the first demonstration was conducted with the orbiter located about 1.21 million kilometers away from Earth, Danuri was 1.28 million kilometers from Earth for the second demo, according to KARI.
“The performance verification test is significant in that they were conducted at distances of about three times the communication distance of about 380,000 kilometers, which was the mission given to Danuri before launch,” the institute said in a Nov. 7 statement.
KARI also unveiled photos of the Earth and the moon’s orbit taken by the orbiter. Using a built-in high-resolution camera developed by KARI, the orbiter took photos at a distance of between 1.46 million kilometers and 1.548 million kilometers for a month from Sept. 15 to Oct. 15. The spacecraft took fifteen photos Sept. 24 from a distance of 1.544 million kilometers as the moon orbited Earth.
“These photos are meaningful in that the Danuri captured the process of the moon orbiting and passing the Earth,” KARI said in the statement.
Launched Aug. 4 on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station, the orbiter is traveling toward the moon at a speed of 0.54 kilometers per second to reach the moon’s orbit by Dec. 17, according to KARI. A series of propulsive maneuvers with the spacecraft’s thrusters will steer it into a circular, low-altitude orbit about 100 kilometers from the lunar surface by Dec. 31. After a brief period of commissioning and tests, the spacecraft’s yearlong mission is expected to begin in January.
