Landing on Ryugu – A Surface with a View of Boulders

The boulder-strewn surface of asteroid Ryugu. (Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

COLOGNE, Germany (DLR PR) — In early October 2018, the Mobile Asteroid Surface Scout (MASCOT) lander is expected to be in operation for approximately 16 hours on the Ryugu asteroid. The selection of the landing site will take place this August. The ideal site must firstly offer the MASCOT team engineers excellent conditions for a safe landing and stable operation on the asteroid, while providing the researchers with a wealth of new and productive measurements.


MASCOT’s Asteroid Landing – Preparations, Risks and Last-minute Decisions

Asteroid Ryugu photographed by Japan’s Hayabusa2 spacecraft. (Credit: JAXA)

COLOGNE, Germany (DLR PR) — Scientists and engineers have been waiting nearly four years for the Japanese Hayabusa2 spacecraft – which is carrying the Mobile Asteroid Surface Scout (MASCOT) lander that was developed and constructed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) – to reach its destination: the asteroid Ryugu. With the approach and arrival having taken place on 27 June 2018, the landing is now within reach.


Imaging Ryugu from an Altitude of 6 km

Figure 1: Asteroid Ryugu from an altitude of 6km. Image was captured with the Optical Navigation Camera – Telescopic (ONC-T) on July 20, 2018 at around 16:00 JST. (Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

TOKYO (JAXA PR) — Hayabusa2 arrived at asteroid Ryugu on June 27, after which the spacecraft remained at a distance of about 20km (the Home Position) to continue to observe the asteroid. During this time, the spacecraft was maintaining a hovering altitude of 20km above the asteroid surface. In the week of July 16, operations were begun to lower this hovering altitude, eventually bringing the spacecraft to less than 6km from the asteroid surface. One of the images taken at that time is shown in Figure 1.


Two Pieces of a Cosmic Puzzle: Hayabusa2 and OSIRIS-REx

Originally published by OSIRIS-REx Mission/University of Arizona
Republished with permission

It began with dust. Before there were asteroids, or planets, or people – about 4.6 billion years ago – a cloud of dust and gas swirled in the cosmos. At the center, a star began to form.

With heat and shock waves, clumps of this ancient dust coalesced into droplets of molten rock called chondrules. These chondrules and dust became the building blocks of the Solar System. Eventually, chunks of material as large as asteroids, and even planets, formed from this cloud and organized according to the laws of physics around a newly born star: our Sun.


Hayabusa2 Arrives at Asteroid Ryugu

Asteroid Ryugu photographed by Japan’s Hayabusa2 spacecraft. (Credit: JAXA, University of Tokyo and collaborators)

TOKYO (JAXA PR) — JAXA confirmed Hayabusa2, JAXA’s asteroid explorer rendezvoused with Ryugu, the target asteroid.

On June 27, 2018, JAXA operated Hayabusa2 chemical propulsion thrusters for the spacecraft’s orbit control.*

The confirmation of the Hayabusa2 rendezvous made at 9:35 a.m. (Japan Standard Time, JST) is based on the following data analyses;

  • ・The thruster operation of Hayabusa2 occurred nominally
  • ・The distance between Hayabusa2 and Ryugu is approximately 20 kilometers
  • ・Hayabusa2 is able to maintain a constant distance to asteroid Ryugu
  • ・The status of Hayabusa2 is normal

From this point, we are planning to conduct exploratory activities in the vicinity of the asteroid, including scientific observation of asteroid Ryugu and surveying the asteroid for sample collection.

*Hayabusa2 operation hours: 7:00 a.m. (JST) through 3:00 p.m. (JST), June 27. The thruster operation was pre-programmed in the event sequence earlier on the day and the command was automatically executed.

New Images of Asteroid Ryugu from Hayabusa-2

Asteroid Ryugu imaged by Hayabusa2 from between 220 ~ 100 km. (Credit: JAXA)

Comment by Project Scientist, Sei-ichiro Watanbe

The direction of the rotation is reversed compared to the Earth, with a rotation period of about 7.5 hours.

The diameter of Ryugu is about 900m, which is consistent with the prediction from ground observations. However, since the distance between the spacecraft and Ryugu is not precisely determined, there is still some uncertainty in the exact diameter at this time.


Hayabusa-2 Approaches Asteroid Ryugu

Hayabusa-2 spacecraft (Credit: Akihiro Ikeshita / JAXA)

TOKYO (JAXA PR) — On June 3, 2018, ion engine operation was completed and the final approach to the asteroid begun. By photographing the asteroid with the Optical Navigation Camera, optical navigation (precisely “hybrid navigation using optical and radiometric observations”) can be used to approach Ryugu while accurately estimating the trajectory of the spacecraft and asteroid.


Hayabusa2 has Detected Ryugu

The first image of asteroid Ryugu from Hayabusa2. (Credit: JAXA)

TOKYO, March 1, 2018 (JAXA PR) — On February 26, 2018, Hayabusa2 saw its destination -asteroid Ryugu- for the first time! The photographs were captured by the ONC-T (Optical Navigation Camera – Telescopic) onboard the spacecraft. Images were taken on February 26th.

The distance between Ryugu and Hayabusa2 when the images were taken is about 1.3 million km. Ryugu as seen from Hayabusa2 is in the direction of the constellation Pisces.

“Now that we see Ryugu, the Hayabusa2 project has shifted to the final preparation stage for arrival at the asteroid. There are no problems with the route towards Ryugu or the performance of the spacecraft, and we will be proceeding with maximum thrust,” explains Project Manager, Yuichi Tsuda.

The ONC-T was developed under collaboration between JAXA, the University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, The University of Aizu, the National Institute of Advanced Industrial Science and Technology (AIST).

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