ALE-2
{{Infobox spaceflight
| name = ALE-2
| mission_type = Space entertainment, atmospheric science
| operator = ALE Co., LTD
| COSPAR_ID = 2019-084A
| SATCAT =
| website = https://star-ale.com/en/technology/
| spacecraft_type =
| launch_date = 6 December 2019, 08:18 UTC{{cite web |url=https://rocketlabcorp.com/missions/missions-launched/running-out-of-fingers/ |title=Running Out Of Fingers |publisher=Rocket Lab |access-date=2025-06-03}}
| launch_rocket = Electron
| launch_site = Rocket Lab LC-1
| launch_contractor = Rocket Lab
| disposal_type = Orbital re-entry
| decay_date = 19 April 2023
| orbit_reference = Geocentric
| orbit_regime = Low Earth
| orbit_periapsis =
| orbit_apoapsis =
| orbit_inclination = 96.8°
| orbit_period =
| apsis = gee
| programme = ALE
| previous_mission = ALE-1
| next_mission = ALE-3
}}
ALE-2 was a satellite built and operated by ALE Co., LTD for space entertainment and atmospheric science. As the company's first satellite with on board propulsion, ALE-2 was to release artificial meteors into Earth's atmosphere, 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.{{cite conference |url=https://ieeexplore.ieee.org/document/9026234 |url-access=subscription |title=Design and Evaluation of Thruster Control Approach for Micro-satellite ALE-2 |last1=Sato |first1=Yuji |last2=Fujita |first2=Shinya |last3=Kuwahara |first3=Toshinori |last4=Shibuya |first4=Yoshihiko |last5=Kamachi |first5=Koh |last6=Kawaguchi |first6=Junichiro |last7=Kubo |first7=Yuki |last8=Nada |first8=Yuichiro |last9=Ohashi |first9=Kaoru |date=12 January 2020 |publisher=IEEE |book-title= |pages= |location=Honolulu, Hawaii |conference=2020 IEEE/SICE International Symposium on System Integration |doi=10.1109/SII46433.2020.9026234 |access-date=3 June 2025}}
Overview
ALE-2 is ALE Co., LTD's second satellite, following the ALE-1 launched in January 2019. As ALE-1 did not have on-board propulsion, the company intended ALE-2 to be the first satellite to release artificial meteors. ALE-2 was developed by ALE Co., LTD, along with Tohoku University and Nihon University.{{cite web |url=https://web.tohoku.ac.jp/astro/sat/index.html |title=Kuwahara Laboratory Tohoku University |publisher=Tohoku University |access-date=2025-06-03 |language=ja}}{{cite press release|date=December 6, 2019|title=航空宇宙工学科 阿部新助准教授が共同研究開発をしている、(株)ALE 人工衛星2号機 ALE2が、エレクトロンロケットにて軌道投入成功！世界初の実験へ。|url=https://www.cst.nihon-u.ac.jp/news/detail/20191206_491.html|language=ja|publisher=Nihon University|access-date=June 3, 2025}} ALE-2 was to controllably release particles to the opposite direction of the satellite's direction of travel, which would allow them to re-enter Earth's atmosphere as artificial meteors.{{cite conference |url=https://tohoku.elsevierpure.com/en/publications/orbit-design-and-analysis-of-artificial-meteors-generating-micro- |title=Orbit Design and Analysis of Artificial Meteors Generating Micro-satellites |last1=Shibuya |first1=Yoshihiko |last2=Kuwahara |first2=Toshinori |last3=Sato |first3=Yuji|last4=Fujita |first4=Shinya |last5=Watanabe |first5=Hayato |last6=Mitsuhashi |first6=Yui |date=25 October 2021 |publisher=Tohoku University |book-title=Proceedings of the International Astronautical Congress |pages= |location=Dubai |conference=28th IAA Symposium on Small Satellite Missions 2021 at the 72nd International Astronautical Congress |access-date=3 June 2025}}
On 6 December 2019, an Electron rocket sent ALE-2 to low Earth orbit as part of the ″Running Out Of Fingers″ launch. ALE-2 was placed in orbit with an altitude of {{convert|400|km}}, lower than the International Space Station to eliminate any chance the particles released by ALE-2 would pose a risk to the astronauts at the station. The satellite was equipped with thrusters to counter atmospheric drag and keep its altitude between {{convert|375|to|400|km}}, the optimal height to release the artificial meteor particles.
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.{{cite press release|date=April 18, 2023|title=Announcement of the Termination of Operations for Second Satellite|url=https://star-ale.com/en/news/2023/04/18/2358559.html|publisher=ALE Co., LTD|access-date=June 3, 2025}} ALE-2 decayed from orbit on 19 April 2023.{{cite web |url=https://www.n2yo.com/satellite/?s=44824 |title=ALE-2 |work=N2YO.com |access-date=3 June 2025}}{{cite news |last=Otsuka |first=Minoru |date=October 3, 2023 |title=「すごい流れ星が見えるかも」 400粒もの“流れ星の素”を積んだ人工衛星が近く大気圏再突入 |url=https://www.itmedia.co.jp/news/articles/2310/03/news182.html |language=ja |newspaper=Itmedia NEWS |access-date=2025-06-03}}
Spacecraft
ALE-2's satellite bus was developed by Tohoku University.{{cite conference |url=https://digitalcommons.usu.edu/smallsat/2021/all2021/155/ |title=In-orbit Demonstration of Reaction Control System for Orbital Altitude Change of MicroSatellite ALE-2 |last1=Sato |first1=Yuji |last2=Fujita |first2=Shinya |last3=Shibuya |first3=Yoshihiko |last4=Kuwahara |first4=Toshinori |date=August 2021 |publisher=Utah State University |book-title= |pages= |location=Logan, Utah |conference=35th Annual Small Satellite Conference |access-date=3 June 2025}} The ALE-2 satellite is covered in gold plating for better thermal control.{{cite tweet |author=ALE_human-made shooting star project/人工流れ星プロジェクト |user=ALE_StarAle |number=1235823701129490436 |title=「Close to the features of ALE-2! ②」 The ALE-2 covers material uses gold plating to properly control the satellite temperature✨ ALE-1 shines in silver and ALE-2 shines in gold, which are both very cool!! 😆 |date=6 March 2020}}
For propulsion, the satellite was equipped with an ALEx supercritical thruster manufactured by Patchedconics, LLC. The ALEx engine was made from COTS components,{{cite conference |url=https://jaxa.repo.nii.ac.jp/records/2000765 |title=高容積効率All-In-One 1Uスラスタの飛翔型モデルについて |last1=Kawaguchi |first1=Junichiro |last2=Yoneda |first2=Hiroaki |last3=Yasuda |first3=Shun |last4=Fujita |first4=Masahiro |last5=Kubo |first5=Yuki |date=18 January 2024 |publisher=JAXA |book-title=Proceedings of Space Transportation Symposium FY2023 |language=ja |pages= |location=Sagamihara, Kanagawa |conference=Space Transportation Symposium FY2023 |access-date=3 June 2025}} and uses non-toxic green propellant as fuel.{{cite web |url=http://www.patchedconics.com/index.html |title=Patchedconics Taps for Future with Space Technology |publisher=Patchedconics, LLC |access-date=2025-06-03}} ALEx had a total of four thruster nozzles.
Operation in orbit
In February 2020, ALE announed that a mulfunction of the shooting star deployment mechanism prevented ALE-2 from releasing artificial meteor particles.{{cite web |last=Wall |first=Mike |url=https://www.space.com/japan-shooting-star-satellite-artificial-meteor-shower-glitch.html |title=Japanese satellite filled with 'shooting star' pellets won't spawn artificial meteor shower after all |work=Space.com |date=15 May 2020 |access-date=31 March 2023}} Nevertheless, a simulation of the deployment was conducted in orbit.{{cite conference |url=https://ieeexplore.ieee.org/abstract/document/9382604 |url-access=subscription |title=Development and Demonstration of the Mission Control System for Artificial Meteor Generating Micro-satellites |last1=Shibuya |first1=Yoshihiko |last2=Sato |first2=Yuji |last3=Tomio |first3=Hannah |last4=Kuwahara |first4=Toshinori |last5=Fujita |first5=Shinya |last6=Kamachi |first6=Koh |last7=Watanabe |first7=Hayato |date=21 January 2021 |publisher=IEEE |book-title= |pages= |location=Iwaki, Fukushima |conference=2021 IEEE/SICE International Symposium on System Integration |doi=10.1109/IEEECONF49454.2021.9382604 |access-date=3 June 2025}} The satellite's thrusters experienced power failures while in eclipses, as the DC/DC converter for the thrusters did not function properly when the battery voltage was too low.
References
{{reflist}}
External links
- [https://star-ale.com/en/technology/ Our Satellites], ALE
{{Japanese space program}}
{{Orbital launches in 2019}}
{{Japan-spacecraft-stub}}