Epsilon launched from the Mu Pad at the Uchinoura Space Center in Japan at 00:50 UTC on Oct. 12. This launch marked the sixth flight of JAXA’s Epsilon rocket, and the launch vehicle was to loft a rideshare mission into orbit consisting of RAISE-3 and numerous other satellites.
Live coverage by JAXA of the launch showed what appeared to be a stage 3 ignition failure, followed by a callout that the flight termination system (FTS) was activated. It’s the first Epsilon launch not to reach orbit.
RAISE-3 stands for RApid Innovative payload demonstration Satellite-3 and the satellite was to provide on-orbit demonstrations for seven different components that were selected from public consultation. The RAISE-3 satellite was built into a square shape that features one body-mounted solar panel that uses Photovoltaic power generation.
RAISE-3 has dimensions of 1 m by 0.8 m by 1 m and a mass of 110 kg.
Once launched by Epsilon, RAISE-3 was to operate in a Sun-synchronous orbit at an altitude of 560 km and an inclination of 97.6 degrees. In total, the mission period for RAISE-3 was expected to last 13 months plus an additional month after launch for on-orbit checkouts and initial operations.
Some of the secondary payloads on this mission included MAGNARO, MITSUBA, KOSEN-2, WASEDA-SAT-ZERO, and FSI-SAT.
The launch site for this mission is situated at JAXA’s Uchinoura Space Center, which is located on the Japanese island of Kyushu in Kagoshima Prefecture. The spaceport has been in operation since 1962. Before the establishment of JAXA in 2003, the center was known as the Kagoshima Space Center.
Epsilon is JAXA’s small launch vehicle, comparable to Northrop Grumman’s Minotaur series of rockets as the first few stages utilize solid rocket motors.
The rocket first flew in 2013 when Epsilon launched on a demonstration flight from the Mu Pad at the Uchinoura Space Center. This is the same launch complex that the M-V rocket used.
The Epsilon rocket is derived from different hardware from the H-IIA and M-V rockets. The M-V rocket, or the Mu-5, was a vehicle that utilized stages using only solid fuel. M-V flew between February 1997 and September 2006 and suffered only one launch failure.
In order to improve launch costs, Japan developed the Epsilon launch vehicle. The first stage of Epsilon uses an SRB A3 solid rocket motor, which is the same solid rocket motor that is utilized on the H-IIA rocket. For the H-IIA, two SRB A3 motors are used as strap-on boosters.
At launch, the Epsilon rocket lifted off from the Mu Pad at the Uchinoura Space Center. It then headed downrange of the launch site over the Pacific Ocean.
After first stage burnout, the payload fairings separated, exposing the vehicle to the environment of space. Next, the second stage separated from the first stage.
Soon after, the second-stage solid rocket motor ignited. After second-stage burnout, the second stage spin should have stabilized itself prior to third-stage separation. Following this, the third stage was to ignite as the vehicle continues to ascend.
After burnout, the Post-Boost Stage, which holds the payload, was to separate from the third stage. The Post-Boost Stage would then conduct two separate burns to perfect the orbit.
After the second burn, the Post-Boost Stage would have released the RAISE-3 satellite into its initial orbit. This Post-Boost Stage would then later individually release the secondary payloads into their specific orbits.
Transitioning to H-3 and Epsilon-S
JAXA and Mitsubishi Heavy Industries have been working on preparing the H-3 for its inaugural flight, which is currently scheduled to occur in the current fiscal year, which ends on March 31, 2023.
The H-3 rocket is the successor to the H-IIA and H-IIB rockets. It will also be the launch vehicle for the HTV-X resupply craft, which will fly to the International Space Station (ISS). The HTV-X is the successor to the H-II Transfer Vehicle.
Like the H-IIA, the H-3 is an expendable launch vehicle.
Recently, JAXA released an image of the H-3’s first-stage rocket engine known as the LE-9 installed on the first stage of the H-3. This comes as the agency has found a solution to turbine vibration problems that have previously plagued the development of the engine.
The LE-9 engine uses Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) and operates in the expander bleed cycle. The H-3 has the option of using three or two LE-9 engines in the first stage.
The first stage of the H-3 is currently being assembled inside the Vehicle Assembly Building at JAXA’s Tanegashima Space Center (TNSC) ahead of the planned first-stage Stage Combustion Test (CFT). The H-3 will utilize the Yoshinobu Launch Complex, otherwise known as LA-Y at Tanegashima.
The latest Epsilon launch comes as JAXA and prime contractor Mitsubishi Heavy Industries have been in a transition period with them preparing for the first flight of the H-3 launch vehicle and with only five more flights of the H-IIA remaining.
With the development of the H-3 rocket and the retirement of H-IIA, there will be an effect on the Epsilon rocket program. The Epsilon-S is being developed which will utilize technologies from the H-3 and lower costs further.
The SRB-3 solid rocket motor, which is designed to be utilized as a strap-on booster on the H-3, will be utilized as the first stage of the Epsilon-S.
(Lead image: Epsilon sits on the launch pad before the rocket’s fifth launch in November 2021. Credit: JAXA)