LUMIR

Delay-Tolerant Network (DTN) Payload

The Delay-Tolerant Network(DTN) payload offers communication service in space by connecting the space probe and a satellite. DTN is a communication technology that stores data on nodes, carries and then transmits when connected to another node. It is the communication solutions for deep space missions which experiences long delay or intermittent connectivity.

Necessity of Interplanetary Internet

Space environment requires different type of internet technology. Radio waves can be transmitted directly to Earth only when a satellite faces the Earth. Therefore, daily connection in space is limited, and radio waves can be lost during the long-distance travel. For instance, it takes more than 5 minutes at the speed of light for a radio wave to travel from Mars to Earth, and when the space communication is lost in the midway, the whole data transmission process has to start all over from the beginning.

To address these challenges, DTN uses multiple probes and satellites as a repeater. The use of space probes as communication nodes offers benefits such as signal transmission without disruption, reduced error rates, leading to higher utilization of space network.

Competitiveness of DTN

Korea’s successful launch of its first lunar probe KPLO (Korea Pathfinder Lunar Obiter) in August 2022 will make it the world’s 7th country to explore the Moon. Supporting scientific objectives is only a part of lunar mission-what the lunar probe KPLO actually represents is a country’s high-tech prowess, and Lumir is honored to demonstrate our technology leadership through Korea’s first lunar exploration operation.

Lumir’s DTNPL is a communication payload especially designed for Korea’s first lunar orbiter KPLO(Korea Pathfinder Lunar Orbiter) to perform experiments on delay-tolerant network in space environment. We realized lightweight and compact-sized with reliable internetworking by incorporating RTG4 FPGA - the new generation integrated circuits for space applications. Implementation of NASA-developed DTN software ION(Interplanetary Overlay Network) ensures reliable internetworking for space mission.

Roles of DTN

Upon KPLO’s reaching the moon, the DTN payload runs the test of transmitting texts, files, and images to ground stations in Korea and to the DSN(Deep Space Network). Moon-Earth two-way communications will be experimented for small-sized messages, while transmission from Moon to Earth will be performed for large size images.

Once DTN protocol is accepted as an international standard for deep-space network, orbiters from different countries can communicate with each other without disruption. The DTN architecture will be embedded in a Korean lander, enabling data collected by the lander and the rover sent to the Earth via any DTN-linked spacecraft orbiting around the Moon.