Very soon, the automatic interplanetary station (AMS) of the Japanese Aerospace Exploration Agency (JAXA) "Hayabusa-2" (jap. はやぶさ2 - "Sapsan-2"). This station has been moving towards its cherished goal for more than three and a half years, and now it has almost reached it. Soon we will learn a lot about the asteroid (162173) Ryugu, but for now it is worth considering the Japanese device itself.
AMS "Hayabusa-2" in the representation of the artist.
The station will explore (162173) Ryugu for more than a year, simultaneously lowering four small probes onto its surface at once. In December 2019, if all goes according to plan, AMS will fly back to Earth with soil samples. And in December 2020, these samples will be delivered to Earth in a special capsule.
Purpose of the AMC
The target of the AMS is the asteroid (162173) Ryugu, or 1999 JU 3 . The asteroid was discovered on May 10, 1999 as part of the LINEAR project at the Socorro Observatory. The celestial body got its name - Ryugu - in September 2015, and just because of the launch of a probe to it. This name comes from Japanese mythology, in which Ryugu-jo is the underwater palace-residence of the dragon Ryujin, the ruler of the underwater world and the sea element. According to legend, the palace is built of white and red corals in the deepest part of the ocean and is very richly furnished.
(162173) Ryugu is a typical near-Earth asteroid from the Apollo group. Belongs to the dark spectral class C, subgroup (according to SMASS) - Cg. Asteroids of this class are characterized by a very low albedo (0.03 - 0.10), the spectrum of the Cg subclass has bright features in the short-wavelength part (<550 нм) и становится плоским или слегка красноватым в остальной. Астероиды класса С очень распространены: более 75% всех известных астероидов принадлежат именно к этому классу.
(162173) Ryugu. In the near future, better images of this celestial body will be obtained. Credit: JAXA.
Size (162173) Ryugu is estimated at 920 meters. By no means the largest asteroid known to us. Perihelion ( point of orbit closest to the sun) is 0.96 AU, and aphelion ( the farthest point of the orbit from the sun) - 1.42 a.u. Crosses the orbit of Earth and Mars. The period of rotation around its axis is 7.63 hours, and its axis of rotation is perpendicular to the orbit (i.e., the asteroid rotates, as it were, “on its side”). The period of revolution around the Sun is 1.3 Earth years.
Orbit of asteroid (162173) Ryugu (1999 JU 3).
Previous Japanese mission
Hayabusa-2, as the name implies, is not the first Japanese station launched to study asteroids. The first Japanese station was the Hayabusa AMS, launched on May 9, 2003 to the asteroid (25143) Itokawa. This asteroid, unlike (162173) Ryugu, is smaller and belongs to the S class. Both devices have a similar design.
"Hayabusa" in orbit (25143) Itokawa in the representation of the artist. More details about the differences between the devices will be discussed later in the article.
The launch of the first Japanese station, Hayabusa, was carried out from the Uchinoura Space Center, located in Kagoshima Prefecture, using a Mu-5 solid-propellant launch vehicle (LV). The approach of the probe to the asteroid occurred in September 2005, but the soil was delivered to Earth only in the summer of 2010.
Moreover, this soil was delivered with grief in half: the specialists in charge of the mission faced a huge number of problems in the work of the AMC. During the flight to the celestial body, a strong solar flare occurred, which disrupted the solar panels, and there were also problems with ion engines. This reduced the maneuverability of the apparatus to a minimum. Because of this, the spacecraft reached the asteroid only in September 2005, and not in July. But the problems with the probe did not end there. When Hayabusa flew (finally) to the asteroid, experts discovered a new problem: several gyroscopes broke down on the AMC. After some time, the station began to approach the surface, in total, it had to carry out three short landings on Itokawa - one trial and two regular ones. But the first landing was unsuccessful due to a series of failures. In addition, the device was supposed to release a tiny Minerva robot to the surface. This small cylindrical device (diameter 12 cm, length 10 cm) was equipped with three cameras, solar panels and a transmitter. However, contact with Minerva could not be established. The device, according to experts, missed the asteroid, flying into space. The most recent landing involved a new attempt to take soil from the surface. But even here everything went awry: at the moment of closest approach to the surface of the asteroid, the computer crashed, the device lost orientation and damaged one of the engines. And then the experts completely lost contact with him ...
After some time, the connection was still restored. But the ion engine could not be restarted until 2009, and for a long time the return of the station with soil to Earth was a big question. But in June 2010, the station nevertheless flew to the Earth, shooting off a capsule with soil samples. The capsule landed near the Woomera test site in southern Australia, and the Hayabusa itself burned up in the Earth's atmosphere, completing its long and difficult mission.
Return to Earth capsule with soil. Polygon Woomera. The picture was taken with a long exposure. Credit: NASA/Ed Schilling.
Hayabusa burned up in Earth's atmosphere... Credit: Ames Research/NASA.
When creating the Hayabusa-2 AMS, the Japanese analyzed all the failures and accidents on the previous mission. And so far, fortunately, the new station has no problems.
"Hayabusa-2"
The station was designed and manufactured by the Japanese company NEC Toshiba Space Systems.
The Hayabusa-2 station was launched on December 3, 2014 from the Tanegashima Space Center in Kagoshima Prefecture. The H-IIA launcher was used to launch.
The mass of the device at the start is 609 kg. Dimensions - 1 × 1.6 × 1.25 m. Energy source - solar panels. At a distance of 1 AU solar panels will provide up to 2.4 kW of power, and in the aphelion of the asteroid (1.4 AU) - 1.4 kW.
Four modified μ10 ion thrusters were installed on the Hayabusa-2, each of which provides thrust up to 10 mN. The previous AMS "Hayabusa" also had μ10 engines, but they had less thrust (8.5 mN each). The working fluid is xenon. The motor can be operated in four switching steps with 250W/500W/750W/1000W (1kW) in each step respectively. An improved system for supplying the working fluid to the engines was also installed on Hayabusa-2.
Ion engines are used as main engines. Shunting engines run on hydrazine.
Instead of the parabolic reflector antenna installed on the Hayabusa, a flat antenna (operating at a frequency of 32 GHz) with a high gain was installed. A very similar antenna was installed on the Akatsuki AMS. Communication between the Earth and the apparatus will be maintained in the Ka-band. However, Japan lacks its own stations for receiving / transmitting signals in this range, therefore, for communication, the Japanese mainly use the NASA Deep Space Network (DSN) and the European ESTRACK space communications network.
AMS "Hayabusa-2" during assembly. Credit: JAXA/NEC.
AMS "Hayabusa-2" during the approach to the asteroid in the representation of the artist.
At Hayabusa-2, the orientation system was also improved. New, more reliable gyroscopes were installed. And now there are four of them at once, and not three, as it was on Hayabusa.
An all-metal shock charge is installed on the AMS Small Carry-on Impactor (SCI), consisting of a copper projectile and an explosive charge (plasticized HMX) to form an impact core. The entire weight of the SCI is 18 kg, of which 4.7 kg are explosives. The mass of the copper plate, from which the shock core will be formed, is 2.5 kg. The charge will have to form an artificial crater, exposing deeper material. The station will investigate this material in the future. For safety reasons, Hayabusa-2 itself will be in the shadow of the asteroid at this moment, and the explosion will be carried out on its illuminated side (that is, on the opposite side from the AMS). Therefore, the station will not be able to observe the explosion. But how to be? To observe the explosion, the station will release a special device - DCAM 3, and the camera will be on it. DCAM 3 will transmit the image to the Hayabusa-2 AMS itself, and it will already transmit data to Earth. DCAM 3 will begin surveying (162173) Ryugu from the moment it separates from AMC.
The DCAM 3 device detachable from the AMS is based on the IKAROS probe. And the latter, by the way, was tested in space just a few years before the launch of Hayabusa-2.
IKAROS model at the 61st International Astronautical Congress. Prague. Credit: ISAS/JAXA/Pavel Hrdlicka.
Hayabusa-2 was equipped with quite a few cameras: three optical navigation cameras (ONC-T, ONC-W1, ONC-W2), a CAM-C on the sampler and a thermal infrared camera (TIR). The latter is a thermal imager, that is, it can determine the surface temperature of (162173) Ryugu. There is also a lidar and a spectrometer.
Optical navigation cameras(English) Optical Navigation Cameras, ONC) are used for remote sensing, as well as when the station approaches (162173) Ryugu. The ONC-T camera has a viewing angle of 6.35°×6.35° and a filter system. ONC-W1 and ONC-W2 are already wide-angle cameras (65.24°x65.24°), operating in the range from 485 to 655 nm.
Near IR spectrometer(English) Near-Infrared Spectrometer, NIRS3) is designed to analyze the composition of the asteroid matter.
Thermal imager TIR(English) Thermal-Infrared Imager) will be used to determine the surface temperature of (162173) Ryugu in the range of -49 to 150°C (224-423K). The temperature is determined using a two-dimensional microbolometric grating. The spatial resolution of TIR is 20 m at a distance of 20 kilometers and 5 cm at a distance of 50 meters.
Lidar device measures the distance from the spacecraft to the surface of the asteroid. The principle of operation is as follows: a directed beam from a radiation source is reflected from the target (asteroid surface), returns to the source and is captured by a highly sensitive receiver; response time is directly proportional to the distance to the surface. And if you know the response time and the speed of light, then you can easily determine the distance from the surface of the asteroid to the probe.
Soil sampling system similar to the one installed on the Hayabusa, but is, unsurprisingly, more advanced. The collection will take place using a special sampler, which is a special tube. When the AMC touches the surface of the asteroid with it, the automation will fire a special cone-shaped tantalum projectile inside the tube. A projectile with a mass of five grams will crash into the surface of the asteroid at a speed of 300 m/s and lift up part of the regolith. The latter, moving in microgravity, will independently fall into a special collection. But even if this mechanism does not work, the possibility of collecting samples still remains: the engineers additionally installed another special mechanism that can pick up and lift the regolith.
A special camera was also installed on the sampler CAM-C. It will record the process of collecting regolith by the station.
landing probes
"Hayabusa-2" will lower several miniature probes to the surface of the asteroid at once, some of them are placed in special containers: MINERVA-II-1 (contains ROVER-1A and ROVER-1B), MINERVA-II-2 (contains ROVER-2) and MASCOT. AMS will leave them at a height of 60 meters above the asteroid. After the containers will slowly sink to the surface (if their speed is less than the first space speed for (162173) Ryugu). The acceleration of free fall on such a small celestial body is very small, so nothing threatens the devices.
ROVER-1A and ROVER-1B, developed by JAXA and the University of Aizu, are cylindrical in shape with a diameter of 18 cm and a height of 7 cm. Each device weighs 1.1 kg. They have two cameras (wide angle and stereo camera) and a thermometer. But even more interesting is how they will move on the surface of the asteroid. Inside them are small electric motors, on the axis of which an eccentric is installed. The rotation of the motor with an eccentric leads to a change in the center of gravity, and under the influence of inertia, movement occurs: the devices bounce over the surface, so that they can easily move along it in microgravity.
The container MINERVA-II-2 will accommodate ROVER-2. This device was developed by several universities led by Tohoku University. It is an octagonal prism capable, like ROVER-1A and ROVER-1B, of moving on the surface. The diameter of the circumscribed circle around the base is 15 cm, the height is 16 cm. The mass is 1 kilogram. It has two cameras, a thermometer and an accelerometer, and also has LEDs operating in the visible and ultraviolet ranges. They are designed to illuminate the dust flying over the asteroid.
All these devices are powered by solar panels.
MASCOT(English) Mobile Asteroid Surface Scout) is the largest landing probe of all. It has larger dimensions: 29.5 × 27.5 × 19.5 cm. Weight - 9.6 kg. MASCOT is equipped with an infrared spectrometer, a magnetometer, a radiometer and a camera. Able to move around the surface of an asteroid in the same way as other probes. It was developed by the German Air and Space Center (DLR) in cooperation with the National Center for Space Research of France (CNES). The device is equipped with a lithium-ion battery, its charge should be enough for 16 hours of continuous operation.
Communication of all these devices with the Earth, as in the case of DCAM 3, will be carried out through AMC.
Conclusion
Thanks to the Hayabusa-2 AMS, people will be able to learn a lot of new things, albeit about a small, but unusual and interesting world. New knowledge will help us learn a lot about the solar system, for example, about its evolution. JAXA has already stated that they want to try to find organic molecules on (162173) Ryugu. Scientists, finding / not finding them, will be able to understand more about the role of asteroids in the origin of life on Earth.
The Japanese, having analyzed all the shortcomings of the previous mission, created a new, more reliable apparatus. The station still has a lot of work to do, but there are no problems with it yet. Let's hope they don't.
Image copyright Jaxa et al. Image caption The first images showed that the asteroid Ryugu has the shape of a spinning top or spinning top
The Japanese space probe Hayabusa 2 has reached its target, the asteroid Ryugu, which is shaped like a spinning top. The journey took three and a half years.
The task of the probe is to study the asteroid and deliver samples of the rocks of which it consists to Earth. The probe will send a small lander to the surface of Ryugu, which should deliver a number of instruments to the surface of the asteroid.
Dr. Makoto Yoshikawa, project manager, spoke about the forthcoming work program for the Japanese probe: "First of all, we will study the surface topography very carefully. Then we will choose a landing site. That is where rock samples will be collected."
- Astronomers explore a dumpling-shaped space object
Then a copper rod equipped with an explosive charge will be fired from the side of the probe towards the asteroid. When the probe moves away from it at a safe distance, the charge will be detonated, and the rod will rush at high speed to the surface of the asteroid.
Image copyright JAXA / Akihiro Ikeshita Image caption Hayabusa-2 will launch a copper impact pin towards the surface of the asteroid, which will knock out a small crater"This impact device will create a small crater on the surface. Probably next spring we will land our lander in it to get samples of the rocks lying under the surface of the asteroid," Yoshikawa said.
According to Dr. Yoshikawa, a professor at Japan's Space Research Institute, the asteroid Ryugu appears to have an unexpected shape.
Asteroids of this shape - about 900 meters in diameter - usually rotate rapidly around their own axis, making a complete revolution in 3-4 hours. But Ryugu has a longer day - it lasts seven and a half hours.
“Many of the participants in our project believe that in the past this asteroid rotated much faster, but something happened and this rotation slowed down. We don’t know what exactly caused this slowdown, and this is a very interesting question,” says the professor.
The Hayabusa-2 probe will spend about a year and a half in orbit around the asteroid, examining this celestial body, which is located 290 million km from Earth.
Image copyright DLR Image caption On board the probe there is a MASCOT scientific instrumentation unit developed by German scientists. It will land on the surface of an asteroidDuring this time, several landing modules will be landed on the surface of the asteroid, including mobile laboratories and a block of scientific instruments developed in Germany.
The asteroid Ryugu belongs to type C, which is considered relatively primitive. This means that organic materials and hydrates can appear on its surface. Studying the asteroid's chemical composition could give scientists new insights into the early evolution of the solar system.
The surface of the asteroid has undergone severe erosion over billions of years under the influence of the solar wind and other cosmic factors. That is why Japanese scientists consider it important to obtain fresh samples of its rocks from a crater knocked out by a copper rod.
The probe carries a lidar, or laser range finder, which is used to maneuver the probe around the asteroid. It illuminates the target with a laser beam and measures the exact distance to it. On Tuesday, June 26, scientists were able to use lidar to successfully determine the distance to the asteroid's surface.
In December 2019, it is planned to launch a probe with obtained rock samples from an orbit around an asteroid to Earth.
The first apparatus of the Hayabasa (Falcon) series was launched in 2003. In 2005, he reached the asteroid Itokawa. Despite a number of technical difficulties, the probe returned to Earth in 2010 with rock samples from the asteroid.
17:23 28/09/20180 👁 880
AstronomyCosmonauticsAdventures of Hayabusa-2 16:40 28 Sep. 2018 Difficulty 3.1 Hayabusa-2 sent the most detailed image of the surface of the asteroid Ryugu An image of the surface of Ryugu taken by the Hayabusa-2 ONC-T camera from a distance of 64 meters. JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, Aizu University, AIST
The Hayabusa-2 interplanetary station sent the most detailed photograph of the surface of Ryugu to date, taken during the landing of MINERVA-Ⅱ 1. It turned out that the surface layer of Ryugu consists of larger particles than the soil of the Itokawa asteroid studied by the Hayabusa mission, according to a press release on the mission's website.
The automatic interplanetary station "Hayabusa-2" was launched into space on December 3, 2014 and is designed to deliver soil samples from the near-Earth asteroid 162173 Ryugu, which belongs to class C asteroids. The device successfully arrived at the asteroid on June 27 and reached a stable 20-kilometer around him. According to the plan, the scientific program of the mission will last a year and a half, during which the device will explore Ryuga from orbit, and during the approach to it, it will shoot at the surface with an SCI (Small Carry-on Impactor) device, consisting of a copper projectile and an explosive charge, thereby researchers will have the opportunity to study the composition of the upper soil layer of the asteroid, as well as the MASCOT (Mobile Asteroid Surface Scout) and MINERVA-Ⅱ 2 descent modules. 2020. More information about the mission, its tasks and tools can be found in our material "Collecting the Past Bit by Bit".
On September 21, 2018, the Hayabusa-2 station descended to a height of 55 meters from the surface of Ryugu and dropped two small MINERVA-II 1 descent modules onto it. The Rover-1A and 1B modules have a diameter of 18 centimeters each, a height of 7 centimeters and a weight of about 1.1 kilograms. They are equipped with cameras, sensors for measuring ground temperature, optical sensors, an accelerometer and a gyroscope, and are able to move along the surface of the asteroid due to the jump mechanism. On September 22, confirmation of the successful landing of the modules came to Earth, which are now in working condition and send new photographs taken during movements on the surface of Ryugu.
During the descent, when Ryugu was 64 meters away, the orbiter was able to obtain the most detailed image of the asteroid's surface, uneven and strewn with boulders of various sizes, using its ONC-T (Optical Navigation Camera - Telescopic) onboard camera. Subsequently, another ONC-W1 camera acquired an image of a larger area from a distance of 70 meters from the surface of the asteroid. The predecessor of Hayabusa-2, the Hayabusa (or MUSES-C) mission, which operated from 2003-2010 and explored the S-class near-Earth asteroid (25143) Itokawa, obtained the clearest image of its surface from a distance of 63 meters, which shows that, unlike Ryugu, Itokawa's surface layer consists of smaller particles, ranging in size from a few millimeters to several centimeters.
"Hayabusa-2" is not the first and not the last soil survey project. In July 2005, a surface survey
MOSCOW, June 25 - RIA Novosti. New photos of the asteroid Ryugyu taken from a distance of 40 kilometers point to the strange nature of its rotation, a large number of gravitational anomalies and the existence of an unusual mountain at its equator. All this will complicate the landing of the Hayabusa-2 probe on its surface, JAXA says.
The Dawn probe received new photos of the mysterious pyramid on CeresThe interplanetary station Dawn, which worked for a year in the orbit of Ceres, transmitted to Earth new detailed photographs of the mysterious mountain Akhuna, which, upon closer examination, turned out to be not a pyramid, but a "flat" cone."Now we know that the asteroid is 'lying on its side' - its axis of rotation is perpendicular to the orbit. On the one hand, this makes it easier for us to land, but on the other hand, we found many large craters and a mountain at the asteroid's equator, which will complicate it. In addition, The force of gravity is not in all regions of Ryugyu was directed strictly "down", - said Yuichi Tsuda (Yuichi Tsuda), one of the leaders of the mission.
The Hayabusa-2 probe, whose purpose is to study and take samples from the asteroid Ryugyu, was launched into space in early December 2014. It will return to earth the first 100% "pure" samples of the primary matter of the solar system.
The Japanese spacecraft reached its target in early June and began a lengthy deceleration and rendezvous procedure with the asteroid. The shape of the asteroid repeatedly "changed" as the probe approached the celestial body and the quality of the images improved.
At first, it seemed to scientists that he looked like a perfect ball, then - like a "dumpling" or a ball of dango, a national Japanese sweet. Later series of images and a peculiar video taken by Hayabusa-2 in mid-June showed that it has a more angular shape and looks like a sugar cube or a spar crystal.
The vehicle's predecessor, the Hayabusa probe, was launched into space in May 2003. This is the only spacecraft that has landed and taken off from the surface of a space body outside the Earth-Moon system. In 2005, he landed on the asteroid Itokawa, but due to problems, the sampling of the soil did not go according to plan.
His successor, as JAXA experts expect, will return to Earth at the end of 2020, if all procedures for collecting soil go according to plan, and the capsule with matter samples is not damaged during landing on the surface of our planet.
Soil sampling, despite the fact that Hayabusa-2 has already reached Ryugyu, will not happen soon. First, the probe must determine its exact orbit and correct it if necessary, and then comprehensively study the structure of the subsurface and the topography of the asteroid.
Only after that, the interplanetary station will approach the surface of Ryugyu and drop a kind of "explosive package" on it, which will expose and eject untouched material from the bowels of the asteroid. Hayabusa 2 will pick up this dust and vacuum-levitating pebbles on its second flyby of this point.
The presence of large depressions and mountains on the surface of the Ryugyu, according to Tsuda, came as a big surprise to scientists for several reasons. First, their presence speaks to the complex geological history of the asteroid, whose existence, as scientists previously believed, was ruled out by the theory of the formation of such bodies.
Secondly, the gravitational anomalies associated with them will significantly complicate the further approach of Hayabusa-2 to Ryugyu, the sampling of soil and the landing of a microrover on its surface. Nevertheless, the scientific team of the probe, as its leader notes, is full of optimism and is confident that the probe will overcome all such difficulties.
Two Japanese mini-robots MINERVA-II1A and MINERVA-II1B successfully landed on the surface of the asteroid Ryugu. Both are in good condition and are transmitting photographs and data from the asteroid, according to the Japan Aerospace Exploration Agency (JAXA) website.
Due to sunlight, the photo taken by the robot turned out to be white spots. Photo: twitter/haya2e_jaxa
The robots separated from the Japanese space probe Hayabusa-2 on September 21. At least one of them is now moving on the surface of the asteroid, the agency writes.
MINERVA-II1 are the world's first mobile exploration robots to land on the surface of an asteroid. Each robot weighs only one kilogram. For the first time, these robots were able to autonomously move around and take photographs on the surface of an asteroid.
“I was so moved by the fact that these small self-propelled vehicles are successfully exploring the surface of an asteroid, because we were not able to achieve this 13 years ago. I was particularly impressed by the close-up images taken on the surface of the asteroid,” said Makoto Yoshikawa, mission leader for the Hayabusa-2 project.
In total, the Hayabusa-2 probe team published three images taken by robots. The images turned out to be blurry, since the robot made one of them during the rotation, and the other - at the time of the jump. In addition, they turned out to be color spots due to the reflection of sunlight.
“Although I was disappointed with the blurry image, the important thing here is that it was made by a self-propelled vehicle. Moreover, the photograph taken at the moment the robot jumped to the surface of the asteroid confirmed the effectiveness of such a movement mechanism,” said Tetsuo Yoshimitsu, responsible for the MINERVA-II1 project.
What is the mission of Hayabusa 2?
The Hayabusa 2 mission began in 2014. Its cost is $ 150 million. The Hayabusa-2 space probe flew to the Ryugu asteroid for three and a half years and reached it at the end of June.
The tasks of the probe are to study the asteroid and deliver samples of the rocks of which it consists to Earth. “First of all, we will study the surface topography very carefully. Then we choose a landing site. It is there that rock samples will be collected, ”said Yoshikawa, project leader.
The diameter of the asteroid Ryugu is about 900 meters, it makes a complete revolution around its axis in seven and a half hours. It is located 290 million km from Earth. Hayabusa 2 will spend about a year and a half in orbit around Ryugu.
The MINERVA-II1A robot took this photo after separation from the spacecraft. In the lower right corner is the surface of the asteroid Ryugu. Photo: twitter/haya2e_jaxa
Ryugu belongs to the class C asteroids, which are considered relatively primitive. This means that organic materials and hydrates can appear on its surface. Studying the chemical composition of Ryugu could help scientists understand the early evolution of the solar system.
