ALE-2 was a satellite built and operated by ALE Co., LTD for space entertainment and atmospheric science. ALE-2 was intended to release metal particles into Earth's atmosphere to generate artificial meteors, but plans were cancelled due to a malfunction of the deployment system. ALE-2's artificial meteors were to be used to study re-entry dynamics and upper atmosphere phenomena.[2]
ALE-2 is ALE Co., LTD's second satellite, following the ALE-1 launched in January 2019. While ALE-1 was a rideshare payload and needed to first descend to a lower altitude to release the artificial meteors,[3] ALE-2 was launched as a primary payload and was deployed directly to an altitude ideal for releasing the artificial meteors. Thus ALE-2 became ALE Co., LTD's first attempt at creating artificial meteors. The satellite was designed to controllably release particles in the direction opposite to its motion, allowing them to re-enter Earth's atmosphere as artificial meteors.[4] ALE-2 was developed by ALE Co., LTD, along with the Tohoku University Space Robotics Laboratory and Nihon University.[5][6]
On 6 December 2019, an Electron rocket sent ALE-2 to low Earth orbit as part of the ″Running Out Of Fingers″ launch.[1] ALE-2 was placed into a 400km (250mi) orbit, lower than the International Space Station to eliminate any possibility that particles released by ALE-2 would pose a risk to the astronauts at the station.[4] Unlike ALE-1, which had no on board propulsion, ALE-2 was equipped with thrusters to counter atmospheric drag and keep its altitude between 375 to 400km (233 to 249mi), the optimal height to release the artificial meteor particles.[2]
On 4 April 2023, ALE ended the operations of ALE-2 as the orbital altitude of the satellite decreased following the depletion of onboard fuel.[7] ALE-2 decayed from orbit on 19 April 2023.[8][9]
For propulsion, the satellite was equipped with an ALEx supercritical thruster manufactured by Patchedconics, LLC. The ALEx engine was made from COTS components,[12] and used a non-toxic green propellant.[13][10] ALEx had a total of four thruster nozzles.[2]
In February 2020, ALE announced that a malfunction of the shooting star deployment mechanism prevented ALE-2 from releasing artificial meteor particles.[14] Nevertheless, a simulation of the deployment was conducted in orbit.[15] The satellite's thrusters experienced power failures while the satellite was in eclipse, as the DC/DC converter for the thrusters did not function properly when the battery voltage was too low.[10]
12Shibuya, Yoshihiko; Kuwahara, Toshinori; Sato, Yuji; Fujita, Shinya; Watanabe, Hayato; Mitsuhashi, Yui (25 October 2021). "Orbit Design and Analysis of Artificial Meteors Generating Micro-satellites". Proceedings of the International Astronautical Congress. 28th IAA Symposium on Small Satellite Missions 2021 at the 72nd International Astronautical Congress. Dubai: Tohoku University. Retrieved 3 June 2025.
↑Shibuya, Yoshihiko; Sato, Yuji; Tomio, Hannah; Kuwahara, Toshinori; Fujita, Shinya; Kamachi, Koh; Watanabe, Hayato (21 January 2021). Development and Demonstration of the Mission Control System for Artificial Meteor Generating Micro-satellites. 2021 IEEE/SICE International Symposium on System Integration. Iwaki, Fukushima: IEEE. doi:10.1109/IEEECONF49454.2021.9382604.
