DALBIT-2: An earth-based lander testbed for space flights

Professor Sejin Kwon’s research team has developed an Earth-based lander testbed called ‘DALBIT-2’, which is a flying platform operating on the ground to validate planetary landing technologies prior to the actual space mission.

Article | Fall 2020

As the second and third phases of the Korea Lunar Exploration Program, the Republic of Korea is planning to put a lander on the moon and a near-Earth asteroid during the 2030s. The program is expected to be a cornerstone for securing the core technologies needed for space exploration by further upgrading Korea’s fast-growing space technologies. However, putting a lander on the surface of an extraterrestrial bodies is a challenging task. For the success of the nation’s lunar landing mission planned for 2030, the lander system must be fully verified through ground flights of a lander spacecraft.

To prevent and mitigate such failures, a test platform that can operate on the ground to validate key planetary landing technologies before the actual space missions have been actively developed and tested around the world. An Earth-based lander testbed is a flying vehicle serving the role of a risk-reduction platform and performs vertical takeoff, vertical landing, lateral movement, and hovering maneuvers to emulate the terminal phase of the lander’s descent stage called a ‘powered-descent’.

 

In the preparation for Korea’s future space missions, Professor Sejin Kwon’s research team has developed an Earth-based lander testbed called ‘DALBIT-2’ which is capable of vertical liftoff and vertical landing flight. The newly-developed Earth-based lander testbed weighs 25 kg and is equipped with four miniature monopropellant thrusters. The avionics, which controls the thrust of the propulsion system and handles command and data communication, is mounted on the testbed for the remote autonomous flight demonstration. Monopropellant thrusters use highly-concentrated hydrogen peroxide as a propellant and operate in pulse-mode to offset the reduced system weight due to the flight operation. Through the flight demonstration, basic flight performance such as vertical takeoff and landing, hovering, and soft-landing capabilities were verified safely on the ground.

All parts, including thrust-modulated monopropellant thrusters and avionics, which are key elements of the Earth-based lander testbed, were designed by KAIST and manufactured with the help of its partners. Space Solution Co., Ltd. manufactured and supplied components by combining a fast-response valve and thrusters that can control thrust by adjusting valve opening time. The avionics’ specifications were determined by the Satellite Technology Research Center (SaTReC) and designed/manufactured by Nara Space Technology. The frame supporting the structure of the vehicle was self-produced using 3-D printing technology.

 

Professor Sejin Kwon’s research team aims to develop an Earth-based lander testbed that is capable of a long duration, fully-autonomous flight in the future. To that end, the research team is planning to add eight thrusters with a 5N thrust to the testbed for attitude control purposes. A large capacity ultra-light propellant tank is needed for the long-duration, fully-autonomous flight demonstrations. Inocom Co., Ltd. signed an MOU to develop and supply carbon composite propellant tanks that can be used for the testbed.