Researchers analyzing samples brought to Earth by the Hayabusa-2 spacecraft published the first results of their work. They prove that life on our planet could indeed be brought from space. Or rather, not life itself, but the “building blocks” necessary for it, which, under favorable conditions, can form self-reproducing molecules like DNA and RNA. In this article, we talk about the Japanese Hayabusa missions, which, despite numerous failures, were able to expand our knowledge of the universe.
The first “Hayabusa” down
The Japanese space agency JAXA planned the first Hayabusa (peregrine falcon) mission to test ion thrusters, at that time an experimental development. The principle of operation of such a device is to create jet thrust by a stream of ionized particles. By the time the Hayabusa was launched, NASA’s Deep Space 1 experimental vehicle, equipped with an ion propulsion propulsion engine, had already set an acceleration record without using a gravity assist maneuver. Now ion thrusters are widely used on Starlink satellites, the BepiColombo Mercury probe and for orbit correction on the base module of the Chinese Tianhe orbital station.
The first Hayabusa mission was launched from Uchinoura on May 9, 2003. Three goals were set for the team of the apparatus: testing of marching ion engines, studying the asteroid Itokawa, and delivering soil samples from this cosmic body to Earth. Also, the probe carried a small robotic apparatus “Minerva” with a diameter of 12 and a length of 10 centimeters. He was equipped with three cameras. Two of them provided stereo imaging of objects at a distance of 10–50 centimeters from the robot, including individual dust particles, and one of them photographed distant objects. Also on the “Minerva” installed instruments to study the composition of the asteroid.
Trouble with Hayabusa began almost immediately after the start. The ion thrusters were constantly having problems, and a powerful solar flare that occurred after the launch of the probe into orbit ruined the solar panels. As a result, “Hayabusa” has practically lost the ability to maneuver. If, according to the original plans, already in June 2007 the station was supposed to return to Earth, then due to malfunctions, the deadline was shifted by as much as three years.
The device arrived at Itokawa three months late — in September 2005. The mission plan called for three landings on the asteroid: one trial and two research. But two of Hayabusa’s three gyroscopes were out of order, so that the mission was in jeopardy. The probe was plagued by failures — and the first landing was unsuccessful. The attempt to land Minerva on the asteroid also ended in failure: after the separation of the robot, it was not possible to establish contact with it, and it flew forever into space.
The second attempt to get closer to Itokawa brought new sorrows. Due to an error in the program sent from Earth, the Hayabusa lost its orientation during the closest approach, damaged one of the engines and lost contact with the Earth. However, later it was possible to restore it, and it turned out that the soil sample was nevertheless taken. Three years later, the Hayabusa team still managed to start the ion engine and send the probe to Earth. In 2010, the probe entered the Earth’s atmosphere and dropped a sample capsule that landed at the Woomera test site in Australia. The Hayabusa itself burned down.
Analysis of the capsule showed that the probe delivered 1,500 particles of matter no larger than 10 micrometers to Earth. “Hayabusa” became the first device that was able to carry out such a mission. Analysis of the samples showed that Itokawa is composed primarily of olivine, a silicate mineral containing iron and magnesium. The rocks turned out to be metamorphosed, that is, at some time they were heated to a temperature of about 800 degrees. This is only possible for a body larger than 20 kilometers in diameter, which means that Itokawa was once part of something larger.
Considering past mistakes
The technical problems of the first Hayabusa were taken into account when building the second probe and planning its mission. Hayabusa 2 was launched in 2014 and headed for Ryuga, a class C asteroid, the most common class, which includes 75% of near-Earth asteroids. The device was also equipped with an ion propulsion engine, and its purpose was to collect soil samples from Ryugu.
In mid-2018, Hayabusa-2 reached the asteroid Ryugu. Landing rovers Rover-1A and Rover-1B were lowered to the surface – the first such devices in history to operate on an asteroid. They were equipped with cameras for stereoscopic shooting and a jump mechanism for movement.
Two months later, the MASCOT apparatus, developed jointly by Germany and France, descended on Ryugu. It was equipped with a spectrometer, a magnetometer, a radiometer and a camera, as well as an engine that allowed moving around the asteroid. MASCOT collected the data and transmitted it to the Hayabusu-2.
After the work of the landers was completed, it was time for the climaxes of the mission. February 22, 2019 year “Hayabusa-2” landed on an asteroid. Having fired a tantalum rod at the surface, the probe collected scattered samples and returned to the object’s orbit again. After that, from a height of half a kilometer, the apparatus fired a copper blank from 4.5 kilograms of explosives. The collision created a crater, near which Hayabusa-2 made a second landing, collecting soil from deeper layers of the asteroid.
Having completed the collection, “Hayabusa-2” went to Earth. In 2020, passing near our planet, the device dropped a capsule with samples, which successfully landed at the same Australian Woomera test site. The Hayabusa-2 itself continues its journey and has embarked on an extended mission: flybys of two more asteroids are planned, which will occur in 2026 and 2031.