First contact

Hayabusa2 probe touches down on asteroid Ryugu

The Japan Aerospace Exploration Agency (JAXA) said Feb. 22 that the space probe Hayabusa2 successfully touched down on the asteroid Ryugu at a location about 340 million kilometers from the Earth and likely collected samples of materials such as soil and rocks on the asteroid.

Ryugu has a diameter of about 900 meters and is in orbit between the Earth and Mars. It is believed to contain organic matter and water that can lead to life. Hopes are high that an analysis of the samples could help illuminate the origins of the solar system and living beings.

If the collection of samples from the asteroid is ultimately confirmed, it will mark only the second time the feat has occurred, with the first coming when the first Hayabusa landed on the asteroid Itokawa to collect samples in 2005.

“Today, the reach of mankind extended to a new and small asteroid,” Yuichi Tsuda, the Hayabusa2 project manager, said at a press conference.

At about 1:15 p.m. on Feb. 21, the JAXA control room in Sagamihara gave instructions for the Hayabusa2 to begin descending toward the asteroid from an altitude of 20 kilometers. Because one-way communication with Earth takes about 20 minutes, JAXA switched to automated controls from an altitude of 500 meters to allow the spacecraft to descend on its own.

From an altitude of 45 meters, Hayabusa2 began approaching a landing point free of rocks with a diameter of 6 meters near the equator, relying on a light-reflecting target marker that had been dropped on Ryugu’s surface. It successfully touched down at 7:29 a.m. on Feb. 22. A few seconds later, the spacecraft rapidly ascended and headed toward its original position 20 kilometers above Ryugu.

Hayabusa2 is designed to automatically fire a metal bullet into the surface of the asteroid using a cylindrical projector located at the bottom of the spacecraft almost at the same time that it touches down, and to collect rocks and soil ejected from the surface in a built-in capsule. The injection of a bullet has been confirmed, making it highly likely that the sample retrieval has been also successful.

Hayabusa2 is scheduled to make up to two more attempts

to collect samples by the end of July this year. One will involve the world’s first attempt at firing a bullet from above the asteroid to create a crater on the surface and carry back samples of unweathered soil from underground. The spacecraft is slated to leave Ryugu in late 2019 and return to the Earth in late 2020 to bring back the samples.

Asteroids are said to contain remnants left over from the formation of the solar system about 4.6 billion years ago. Ryugu is seen as a particularly promising candidate for containing water and organic matter that are essential for life. JAXA will examine the samples brought back by Hayabusa2 and use the findings to shine a light on the evolution of the solar system and the origin of life.

Supporters out in force

The control room at the Japan Aerospace Exploration Agency (JAXA) erupted with joy after the space probe landed successfully.

More than 200 spectators waited for Hayabusa2’s landing at a public viewing event at the Sagamihara City Museum in Sagamihara, where a live stream of the JAXA control room was shown on a large screen at the museum entrance. The museum is located next to JAXA’s Sagamihara Campus.

The spectators broke into applause when JAXA announced at around 8 a.m. that the probe had landed. Among them was a 63-year-old part-time worker from Chuo Ward, Sagamihara. “I thought Japan had the excellent technology to make the landing possible. I want Hayabusa2 to safely return to Earth,” he said.

The Yomiuri Shimbun People celebrate at a public viewing event at Sagamihara City Museum in Sagamihara on Feb. 22 after learning the space probe Hayabusa2 had landed on the asteroid Ryugu.

Courtesy of JAXA, others This image captured by Hayabusa2 during its ascent after touching down on Ryugu shows the surface of the asteroid, including a shadow of the spacecraft’s body.

The Yomiuri Shimbun Hayabusa2 Project Manager Yuichi Tsuda of the Japan Aerospace Exploration Agency speaks at a press conference in Sagamihara on Feb. 22.