KAGOSHIMA –
The Japan Aerospace Exploration Agency performed a floor firing take a look at of the second-stage engine for its Epsilon S small solid-fuel rocket on the Tanegashima Space Center in Kagoshima Prefecture on July 23.
JAXA adopted an engine primarily based on an older, confirmed design for the most recent take a look at after a collection of explosions involving a newly developed engine.
Epsilon S is Japan’s next-generation small satellite tv for pc launcher, developed because the successor to the Epsilon collection of solid-fuel rockets. The program is meant to offer Japan with a extra aggressive, dependable and versatile strategy to place small satellites into orbit whereas preserving the nation’s unbiased entry to area.
The authentic Epsilon rocket made its first flight from the Uchinoura Space Center in Kagoshima Prefecture in September 2013. It was developed as a lower-cost successor to the M-V rocket, which had launched Japanese scientific spacecraft however was costly and labor-intensive to function. Epsilon launched in depth computer-based launch checks and automation, decreasing the variety of personnel and the time required for launch preparations.
An upgraded model, generally known as the Enhanced Epsilon, was launched in 2016. Its bigger second-stage M-35 motor elevated launch capability and allowed the rocket to hold heavier satellites. The Epsilon household accomplished 5 profitable launches between 2013 and 2021, carrying scientific and technology-demonstration satellites together with Hisaki, Arase and RAISE-2.
The program suffered its first launch failure in October 2022, when Epsilon-6 was ordered to self-destruct after shedding management of its perspective throughout flight. The rocket and eight satellites had been misplaced. An investigation traced the failure to an issue within the second-stage attitude-control system.
Epsilon S was already beneath improvement as a extra commercially aggressive successor. The “S” represents the rocket’s intention of making stronger hyperlinks between Japan’s area program and private-sector satellite tv for pc operators. JAXA has developed the launcher with IHI Aerospace, which is predicted to take a bigger position in manufacturing and launch providers.
The design combines know-how from the Enhanced Epsilon with parts developed for Japan’s bigger H3 rocket. Its first stage relies on the H3’s SRB-3 strong rocket booster, whereas new second- and third-stage motors had been meant to enhance efficiency, simplify manufacturing and scale back prices. JAXA additionally sought to shorten the interval between receiving a satellite tv for pc and launching it, an essential requirement within the rising worldwide small-satellite market.
Development encountered a significant setback throughout a second-stage motor firing take a look at at JAXA’s Noshiro Rocket Testing Center in Akita Prefecture on July 14, 2023. The motor exploded lower than a minute after ignition, damaging the take a look at facility however inflicting no accidents. JAXA later concluded that a part of the ignition system had melted and scattered, damaging the encircling propellant and insulation.
After design adjustments, JAXA performed one other second-stage firing take a look at on the Tanegashima Space Center on November 26, 2024. That motor additionally exploded, about 49 seconds after ignition throughout a take a look at that was anticipated to final roughly 120 seconds. No one was injured, however the repeated failure pressured JAXA to rethink the engine’s design and delayed the rocket’s first flight.
To speed up this system’s restoration, JAXA deserted plans to make use of the newly developed second-stage motor for the preliminary model of Epsilon S and returned to a design primarily based on the confirmed M-35 motor utilized by the Enhanced Epsilon. The change reduces a number of the efficiency enhancements initially deliberate however lowers improvement threat and attracts on an engine with a longtime flight report.
The revised second-stage motor underwent a floor firing take a look at on the Tanegashima Space Center on July 23, 2026. It burned for roughly two minutes as deliberate, marking an essential step towards the primary Epsilon S launch, which JAXA is in search of to conduct throughout fiscal 2026.
Source: Kyodo