[Interview file]'Hayabusa 2'returns after 6 years... What gift to'drop' on Earth?

The Japan Aerospace Research and Development Organization (JAXA) asteroid probe'Hayabusa 2'has returned to Earth.

[Report File] The district of Hayabusa 2 that was introduced to readers through the report file "Hayabusa2, finally on the way back to the earth" last November (▶ [Report File] Hayabusa2, finally on the way back to the earth) The return journey was all over in a year or so.

It's been a while since we've been delivering the news of the asteroid probe Hayabusa2, so it would be polite to briefly explain Hayabusa2.

Hayabusa (peregrine falcon) is an asteroid probe developed by Japan. The first was launched in 2003 and landed on the asteroid'Itokawa' and returned in 2010.

At the time of return, No. 1 dramatically dropped a capsule containing a sample of Itokawa's fine particles onto the earth, and the body burned white and extinguished by the frictional heat upon entering the atmosphere.

The successor, Hayabusa 2, was launched in 2014, and after 6 years of space travel, this time it returned to the Earth Sphere.

Hayabusa 2 is the way to go to the asteroid'Ryugu (Yonggung)', which is about 300 million km away from Earth in a straight line.

Although the straight line distance is 300 million km, in order to minimize fuel consumption, the actual total travel distance is 5.24 billion km round trip by adopting the'gravity swing' and the navigation method incorporated by calculating the revolution period.

It was on June 27, 2018, three and a half years later, when it was launched in December 2014 (based on JAXA announcement), and seven small exploration robots (rovers) were placed on the surface of Ryugu while staying in the air for about a year and a half. Settled, measured soil samples, and more.

In particular, some of these are recorded as'world's first'.

A plurality of small exploration robots laid down on the surface of an asteroid.

Realization of the precision at the time of landing on the asteroid surface within the range of 60cm, creating an artificial crater and observing the process and results in detail, landing at two points of the same celestial body (Ryugu), celestial objects other than the Earth and the moon It is a collection of'underground material' from

Of course, the reason Hayabusa 2 attracted the most attention was that Ryugu's soil samples were collected both above and below ground.

On February 22 of last year, Hayabusa 2 performed the so-called'touch down', which went down to the surface from above Ryugu and collected the soil from the surface and took off immediately.

Next, on April 5th, a collision device was activated to create an artificial'crater' on the surface of Ryugu.In simple terms, a'bullet' containing a small amount of explosives was fired on the surface of the asteroid to lightly blow the ground.

On July 11th, Hayabusa 2 landed on this site again and collected soil below the surface.

After that, Hayabusa 2 stayed a little longer above Ryugu and began returning to Earth on November 13 last year.

It was estimated that the asteroid Ryugu, which Hayabusa 2 was headed for, contained a lot of organic matter.

Therefore, if you compare and analyze the soil above and below Ryugu, which Hayabusa 2 brought, it is highly anticipated that you will be able to get a clue to the situation at the time the solar system was born.

This is because subterranean soils are expected to show less change due to the effects of sunlight or radiation.

It is also expected to contribute to the study of the origin of seawater and life on Earth through follow-up studies on the soil of Ryugu.

Although Hayabusa 2 is said to have returned to Earth, the main body does not enter the Earth's atmosphere like its senior Hayabusa 1.

Hayabusa 2 separates a capsule containing a soil sample from the asteroid Ryugu and heads back to space tomorrow (5th).

This target is the asteroid '1998KY26' located in the Apollo asteroid group, and it is a celestial body that is expected to be rich in organic matter like Ryugu.

Hayabusa 2 is expected to arrive on this asteroid in 2031.

So, what about the capsules containing samples of the ground and underground soil samples of the asteroid Ryu-gyu, separated from Hayabusa 2?

The capsule begins to fall to Earth after falling off Hayabusa 2 tomorrow (5th) afternoon.

After entering the atmosphere at a high speed of 12 km per second, the capsule, which has been reduced by deploying a built-in parachute at an altitude of 10 km, is expected to land on the surface at dawn the day after tomorrow (6th).

The entire capsule landing process is fully automated, and JAXA has set the landing point in the Umera Desert in southern Australia.

JAXA's recovery team detects the beacon signal from the capsule to determine the landing point and then runs to the site by helicopter.

The capsule retrieval process is similar to that of Hayabusa1, which brought particulate matter from the asteroid Itokawa in 2010, but this time, the change is to extract the gas inside the capsule immediately after retrieving the capsule and undergo a simplified analysis.

The intention is to analyze gases that may have been released by the soil itself during storage.

After that, the capsules are placed in a dedicated airtight container and transported to Japan.

JAXA moves the capsules to the Space Science Research Institute in Sagamihara, Kanagawa Prefecture, near Tokyo, and separates the capsules and samples in an environment designed not to mix with Earth's material.

In this process, it is expected that how many samples each Hayabusa 2 took when landing twice at Ryugu will be revealed.

After that, JAXA distributes 60% of the total sample to each institution inside and outside Japan, including NASA, for research purposes, and 40% will be stored until more precise analysis techniques are available in the future.

In Japan, where many people still remember the end of Hayabusa 1, which delivered a particle sample of the asteroid Itokawa to Earth and burned it, it is an atmosphere that greatly welcomes Hayabusa 2's return this time.

In addition, the main body is showing great interest in the story of separating the capsule containing the sample and then leaving for another asteroid exploration.

Perhaps for the Japanese, the return of Hayabusa 2 in a cluttered atmosphere due to the re-proliferation of corona is a great comfort.