By Yoon Sojung
The music video for the BTS hit "Dynamite," a text message saying "Wait for me, Mr. Moon" and photos of the moon revolving around Earth.
These are part of data sent by Danuri, Korea's first lunar orbiter, from space.
Videos, photos and text messages comprised the data received from the spacecraft, the Ministry of Science and ICT, Korea Aerospace Research Institute (KARI), and Electronics and Telecommunications Research Institute (ETRI) said on Nov. 7.
The data was sent through the orbiter's space internet mounted device developed by ETRI to help transmit data in space, where connectivity is often disrupted. The think tank had previously conducted two tests of the device, first on Aug. 25 with KARI and the Jet Propulsion Laboratory of the National Aeronautics and Space Administration (NASA) of the U.S. at a distance of 1.21 million km and again on Oct. 28 at a distance of 1.28 million km to confirm the gizmo's space internet transmission.
On Aug. 25, Danuri sent files of the BTS music video "Dynamite" and photos of ETRI buildings, both of which had been saved on the orbiter. On Oct. 28, ETRI sent text messages to Danuri "five by five," an English-language expression denoting good connectivity in wireless communication, and the message "It's going well. Wait for me, moon"; the craft also resent these messages to the institute.
Because of unstable connectivity, space internet requires data segmentation before transmission for storage. Information received through the device was passed to ETRI via the communication device (node) of NASA and KARI.
The ministry praised the results of this test, saying it was conducted around three times farther than the communication distance of 380,000 km for mission purposes.
Danuri also unveiled photos of the revolution between Earth and the moon and the former passing the latter. Using a high resolution camera developed by KARI, the orbiter took photos of the moon's orbit once a day from Sept. 15 to Oct. 15. On Sept. 24, Danuri took 15 photos that vividly showed the process of the moon passing Earth.
Among photos of the moon's revolution taken by Danuri, those snapped on Oct. 9 auspiciously observed a gamma ray burst also seen in the U.S. and Europe through a gamma ray spectrometer developed by the Korea Institute of Geoscience and Mineral Resources.
The ministry said this was the first gamma ray explosion related to the birth of a black hole observed by humans.
On Nov. 2, Danuri completed a trajectory correction maneuver to correct a lunar orbit error. As of Nov. 7, 94 days after its launch, the orbiter was moving toward the moon at a speed of 0.54 km from 1.05 million km away from Earth. It will navigate about six million km until Dec. 7, enter lunar orbit and slow down to approach its mission orbit at the end of next month.
More information on Danuri is available on its official homepage: https://www.kari.re.kr/kplo.