On July 1, the Japan Aerospace Exploration Agency launched the new Advanced Land Observing Satellite 4 (ALOS 4) spacecraft. This is an advanced satellite for observing the Earth's surface (using an on-board synthetic aperture radar of the L—band type with a phased array antenna - PALSAR 3). It will be able, for example, to provide Japan with radar data to monitor areas affected by natural disasters.
Launch of the H3 rocket with the ALOS 4 spacecraft on board
Image source: © Kyodo via Reuters Connect
In connection with the launch of the satellite, I would like to talk about Japan's modern cosmonautics, what projects it is currently engaged in and what successes have been achieved.
Clear focus
I think it's no secret that Japan's cosmonautics has been greatly influenced by close cooperation with the United States. The good relations of the last decades have allowed Japanese cosmonautics to abandon several complex and costly programs and focus on more relevant ones for themselves. For example, Japan does not have its own national manned program, currently astronauts use American ships. There is also no own satellite grouping for geo—positioning - the country is small in size, apparently it is easier to use American GPS than to create your own analogue.
Japan has focused more on scientific tasks and the creation of spacecraft for telecommunications, geo-observations, as well as space exploration. In these niches, the Japanese were able to show themselves in all their glory. In principle, I got the impression that if Japanese specialists are doing something, they do it with maximum efficiency. So, Japan participates in the work of the International Segment of the ISS on an equal basis, for example, with the European Space Agency (ESA) and Canada, but Tokyo's contribution to the creation and development of the station is much more significant — 12.8% against 8.3% for ESA (investments, labor costs, creation of various devices, modules, etc. are taken into account).
Science of the Land of the Rising Sun
But Japan is even better at its own scientific missions. In some aspects, it was possible to move even further than the American NASA. The missions of Hayabusa and Hayabusa-2 are the most interesting and indicative in this regard (although their implementation was not without problems).
Launched on May 9, 2003 by the Japanese M-5 launch vehicle, the Hayabusa spacecraft was designed for a four-year mission. It was planned that he would return to Earth in June 2007, delivering a capsule with soil samples from the asteroid Itokawa. Two years later, the spacecraft reached the asteroid and began research, but the failure of two of the three gyroscopes jeopardized the entire mission. Despite these difficulties, the operators tried to carry out the initial plan. Landing on an asteroid and drilling the ground turned out to be almost impossible due to the low gravity. Therefore, for sampling, the designers came up with a very original way — the device practically "fell" onto the asteroid with a ground-intake device, and then sprung back. Hayabusa managed to execute several successful strikes and cope with a software error. However, during the approach to the asteroid, he damaged the ion engine. This extended the return trip by three years, and only in 2010 the device dropped a capsule with soil, which landed in the area of the Woomera landfill in southern Australia.
In 2014, the Hayabusa-2 mission was launched, the purpose of which was to collect soil samples from the Ryugu asteroid. Here, the Japanese implemented even more interesting and complex manipulations to obtain rock samples. The spacecraft fired a tantalum rod at the asteroid, after which it collected the scattered fragments of soil into a soil collector. To obtain samples from the depth of the asteroid, the device fired a copper block from a distance of 500 m using an explosive charge weighing 4.5 kg. A special capsule from the Ryugu asteroid arrived on Earth in 2020.
In addition, Hayabusa-2 landed Rover 1A and Rover 1B robot landing modules on the asteroid (designed to test movement around the asteroid using small jumps), as well as the MASCOT module (needed to search for organic molecules on the surface, provides micro-scale surface photography using a special camera). Hayabusa-2 itself, after shooting the capsule with samples, also continued to work — it is assumed that by 2031 it will get closer and photograph two more asteroids.
Little Moon Samurai
In Japan, the work of the Smart Lander for Investigating Moon lunar science station can also be called successful. SLIM was launched into space on September 6, 2023. Its main task was to demonstrate precision landing technology — to make a soft landing with unprecedented accuracy up to 100 m. For comparison: The landing accuracy of the Apollo 11 lunar module was about 20 km.
The landing of the SLIM module on the lunar surface took place on January 19, 2024 in the eastern part of the Cyril crater. During the descent to the Moon, the lander used a lunar crater recognition system based on convolutional neural networks and determined its current location using observation data from the SELENE lunar orbiter ("Kaguya"), launched by Japan in 2007. SLIM deviated from the target by only 55 m, making Japan the fifth country in the world to land its device on a natural satellite of the Earth.
However, it turned out that at an altitude of about 50 m there was a failure (and it almost collapsed) in one of the two main engines. Because of this, the landing took place with a strong lateral movement, as a result of which the spacecraft turned over on landing. In this regard, the SLIM solar panels worked inefficiently, charging only in a small interval at the end of the lunar day. But despite the lack of heating, the device was able to survive three lunar nights and continued to work — to the surprise of many specialists. It was only on May 27th that SLIM stopped contacting us.
Earthly affairs
In matters of creating spacecraft for remote sensing of the Earth, we can mention the satellite of a Japanese private company — Active Debris Removal by Astroscale-Japan (ADRAS-J), first shown to the general public in September 2023.
The purpose of the mission was the upper section of the H-IIA No. 15 medium-class launch vehicle (they say, as the first part of the space debris cleanup mission), which was launched by the Japan Aerospace Exploration Agency (JAXA) in 2009 (currently moving around the Earth at a speed of about 8 km/s in orbit with parameters 622×557 km and an inclination of 98.2 ° to the equator). In recent weeks, ADRAS-J has made several approaches to the stage and taken clear photographs of the object.
Some experts suggest that such a device can in principle be used as an inspection satellite to work in orbit. There are several high-resolution cameras and laser rangefinders on board the ADRAS-J. In my opinion (and not only), if we consider this startup from the point of view of combating space debris, it does not look perfect yet, but as a dual-use satellite inspector it is much more promising. It may well turn out that this is what it is being created for, and talking about space debris is only a convenient cover.
High-tech space?
For Japan, space is most often not a business story, since the cost of rockets and satellites is very high. The country cannot compete with other States in this aspect. For example, the H-II launch vehicle was designed to gain market share in the field of commercial satellite launches. However, with a launch cost of €188 million — twice as much as that of competitors (the Russian Proton and the European Ariane), the Japanese launch vehicle could not succeed here.
At the same time, I note in contrast to the well-established opinion that, they say, everything in Japan is extremely high-tech and almost at every step you can encounter robots unprecedented in other countries. Modern cosmonautics in all countries has its own specifics, while it is difficult for me to say that the Japanese is distinguished by some special innovation and progressiveness. Although it is true that Japanese cosmonautics shows excellent results in the development of complex modules of orbital stations and unique missions in deep space. And the story of the Hayabusa spacecraft alone, which took seven years to reach Earth with soil samples from an asteroid, could become the basis for a curious science fiction film.
