With the successful Sept. 15 debut of its Epsilon rocket, the Japanese Aerospace Exploration Agency (JAXA) is advancing incremental improvements to the new solid-fueled launcher with commercial customers in mind.
“We are taking a two-step development plan to launch a low-cost, high performance Epsilon,” says Yasuhiro Morita, Epsilon program manager at JAXA. “We are aiming at the commercial market after the establishment of the next-generation Epsilon, and I hope to be very competitive.”
Morita says the prototype Epsilon rocket, known as the E-X, is able to loft 1.2 metric tons to orbit for about $38 million (¥3.8 billion), though the inaugural mission launched this month from Japan's Uchinoura Space Center cost closer to $53 million, a figure he says includes the rocket's intensive test regime.
By 2015, however, JAXA plans to launch an interim variant of the three-stage Epsilon, known as the E-1 Dash, which will incorporate enhancements, including lighter avionics components, to deliver payloads weighing 1.4 metric tons to low Earth orbit for $3.8 million per launch.
If these missions go well, JAXA hopes to debut a more powerful version of Epsilon in 2017 that will deliver 1.8 metric tons to low Earth orbit for $30 million per launch.
In the meantime, Morita says JAXA is preparing for the first E-1 Dash mission in December 2015, during which the rocket will loft the 335-kg Exploration of energization and Radiation in Geospace (ERG) spacecraft to an eliptical orbit at 200 km by 30,700 km altitude. If successful, the mission could be followed in 2016 with the launch of a 550 kg Earth observation spacecraft, known as the Advanced Satellite with New system Architecture for Observation (ASNARO 2), which the E-1 Dash would deliver to a sun-synchronous orbit at 500 km altitude.
Morito says candidate payloads for the next-generation E-1 mission in 2017 include JAXA's DPF gravitational wave mission and a Japanese lunar probe known as the Smart Lander for Investigating the Moon (SLIM).
Based on the solid-rocket boosters from Japan's heavy-lift H-2A and H-2B launch vehicles, the first stage of the E-X protoype was comprised of a solid-fueled booster topped by second and third stages derived from the third and fourth stages of JAXA's more powerful — and more costly — M-V rocket.
Morita says Epsilon's reduced costs are due in part to its launch preparation and operations processes that benefit from the a simple structure that requires less assembly than the M-V. But he says automating technical functions that typically performed by launch technicians is a major driver in reducing costs, a shift that will reduce the number of personnel conducting launches, including the use of mobile ground stations managed with the use of laptop computers.