Japan's World-Class Original Aerospace Technology

Launch of the H-IIA rocket
Photo courtesy of Mitsubishi Heavy Industries/JAXA.

   Japan, which boasts some of the world's most advanced technological capabilities, has developed original technology in the field of aerospace. Japan carried out the first successful sample return of asteroid matter to Earth, and has been moving ahead with development of the world's first ultra-compact satellite that can fit in the palm of your hand. Japan also makes a great contribution as one of the 15 countries that help run the International Space Station (ISS).

Japanese High-Altitude Rocket Launch Technology

   The history of Japanese aerospace technology began in 1955 with the successful firing of a tiny 23-cm pencil rocket. Later, in 1970, Japan successfully launched its first artificial satellite from a rocket 16.5 m in length, the fourth such satellite launch in world history. The latest iteration of the Epsilon rocket is the result of more than half a century of research, and research continues advancing.

Photo courtesy of JAXA.

   Over the past few years, a Japanese corporation has been leveraging its experience of joint research with the Japan Aerospace Exploration Agency (JAXA) to build its own rocket and launch a service transporting satellites into space for research and other purposes. These initiatives combined with Japan's unique technological capabilities are breaking down the barriers to space.

Japanese Technology Used on the International Space Station (ISS)

   One of the ways in which Japan contributes to the ISS's operations is through the Japanese Experiment Module, also known as "Kibo," which means ‘hope’ in Japanese. This module, which was developed, assembled and later operated by Japan, is used on the ISS to conduct experiments in the low-gravity environment of space. The Kibo module is equipped with a mechanism called the JEM Small Satellite Orbital Deployer (J-SSOD), which launches ultra-compact satellites into orbit. This completely unique technology is used to run the "KiboCUBE" program, whereby satellites are put into orbit on behalf of developing countries that do not have their own means of launching satellites, contributing to the development of aerospace technology in developing countries.

A nano satellite released using J-SSOD. (Photo courtesy of JAXA/NASA.)

   Japan also operates "Kounotori" (meaning ‘stork’ in Japanese), a space station transfer vehicle that supplies the ISS with items such as water and food. Between 2011 and 2020, a total of nine Kounotori were launched, and each one successfully docked to the ISS, without a single failure. With its world-class precision and supply capabilities, Kounotori is a resupply method that the ISS cannot do without.

Left: An ISS robot arm attempting to grasp Kounotori. (Photo courtesy of JAXA/NASA.)
Right: An astronaut with fresh food delivered by Kounotori. (Photo courtesy of JAXA/NASA.)

Hayabusa: The World's First Explorer to Successfully Carry out a Sample Return from an Asteroid

   Hayabusa, meaning ‘falcon’ in Japanese, is a JAXA asteroid explorer that carried out the world's first successful sample return of material from an asteroid to Earth. The subsequent "Hayabusa2" further demonstrated Japan's technological capabilities.

Image of asteroid explorer Hayabusa2 touching down on the asteroid Ryugu. (Image courtesy of Ikeshita Akihiro.)

   Three devices were essential for Hayabusa2 to successfully carry out the sample return: a "small carry-on impactor," a "sampler horn" and a "reentry capsule." The small carry-on impactor is a device for creating an artificial crater on the surface of the asteroid. It fires a bullet weighing around 5 g at the surface of the asteroid at high speed to pulverize the surface into small pieces of asteroid matter which is then collected using a long tube called a "sampler horn." The asteroid matter is then loaded into the reentry capsule so that it can be taken back to Earth.
   The "helical spring" is worthy of special mention as it is essential for moving these three devices. This special part, developed by a Japanese corporation, uses the force of the spring to move the devices with precision. For example, the sampler horn is folded up when not in use, so the helical spring was required to unfold it so that the asteroid sample could be collected.

Image of the sampler horn of the Hayabusa2. The force of the special helical spring was used to move the sampler horn, small carry-on impactor and reentry capsule. (Image courtesy of JAXA.)

The helical spring consists of circular aluminum rings held together vertically with glass-fiber spring material. When the helical spring is pushed down by hand from the top, it shrinks and twists. When the hand is released, the force in the spring causes it to bounce back up. It is very strong and flexible. (Photo courtesy of Nippi Corp.)

Starting with Palm-Sized Satellites, Nano Satellites Will Change the Future of Space Development

   In 2003, a Japanese university carried out the first research into launching nano satellites. Nano satellites can be developed in far less time due to their small scale and relatively low costs compared to regular satellites, making it much easier for universities and small businesses to enter the field. This has led to more organizations taking part in research than ever before, and has spurred the creation of technology unique to Japan. The nano satellites are fitted with an ion engine 4 cm in diameter so they can change orientation in space, as well as the world's first "water engine," a safe and compact engine that uses water as a propellant. This water engine is a truly revolutionary technology—for example, it can power a satellite in orbit around the Earth for approximately two years, and can travel to the moon using just 200–300 g of water. These technologies have also been recognized by NASA, and are expected to change the future of space development.

Left: An ultra-compact ion engine 4 cm in diameter, developed by the University of Tokyo. (Photo courtesy of Koizumi Hiroyuki.)
Right: A nano satellite equipped with an ultra-compact water engine. Approximately 10 cm³ in size. (Photo courtesy of Pale Blue.)

Image of Japan's "EQUULEUS" spacecraft, which was launched on the next-generation rocket Space Launch System (SLS) as part of a NASA mission in November 2022. It will aim for the moon with its ultra-compact water engine, which uses water as propellant. (Photo courtesy of JAXA/NASA/University of Tokyo.)

   The new research field of space development is making advances all over the world. Japan's unique aerospace technology will make an even greater contribution to advances in space development in the future.