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Raumfahrt - JAXA´s Asteroid Explorer Hayabusa-2 auf Asteroid 1999 JU3 gelandet-Update-15

8.06.2019

Japan's Hayabusa2 spacecraft grabs epic close-up just 30 feet above asteroid

The Japanese asteroid-hunter had another photo opportunity when it dropped a target marker on asteroid Ryugu.

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The Japanese space agency, JAXA, has been circling the asteroid Ryugu with its spacecraft Hayabusa2 for almost a year now and the agency has even shot a cannonball at the space rock.

That shot kicked up debris that Hayabusa2 collected in February but the agency wanted to go again -- and collect debris from further inside Ryugu.

On May 30, Jaxa performed a daring maneuver that brought its spacecraft within 9 meters (approximately 30 feet) of Ryugu to drop a target marker on its surface. The success of the mission was documented by the spacecraft's official Twitter account (because it's 2019), but on June 5, the agency released a photo that is absolutely wild

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Let's pause for a second and consider this:

The above image comes from a 600-kilogram, refrigerator-sized robot traveling at about 15 miles per second, around 170 million miles from Earth. It shows the shadow of the Hayabusa2 spacecraft and just below that shadow a tiny, spherical shadow. That tiny shadow is the target marker being released onto the asteroid. Crazy, huh?

The image was captured by CAM-H, one of Hayabusa2's suite of instruments that has previously captured touchdown on Ryugu. The small monitor camera was built and installed on the spacecraft thanks to public donations.

We've seen some fantastic images from the surface of Ryugu during Hayabusa2's mission. Two tiny rovers were deployed on the asteroid's surface in 2018, providing some incredible close-ups. Hayabusa2 will move to sample the asteroid for a second time later this year, before returning to Earth with samples in December 2020. 

Quelle: Cnet

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Japanese probe readies for another possible touch-and-go on asteroid

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A camera on-board Hayabusa 2 captured this image of the target marker (the bright feature at bottom right) being released just above asteroid Ryugu on May 30. Credit: JAXA

Approaching the one-year anniversary since its arrival at asteroid Ryugu, Japan’s Hayabusa 2 spacecraft has deployed a target marker near an artificial crater created by an explosive charge in April, a guide post that could help the probe steer toward another pinpoint touchdown to collect a second batch of samples for return to Earth.

That assumes mission managers approve plans for a second touch-and-go landing on the asteroid. The maneuver would come with some risk, and scientists believe Hayabusa 2 has already retrieved enough asteroid material to meet minimum mission success criteria.

Hayabusa 2 approached within around 30 feet, or 9 meters, from Ryugu’s surface May 30 and dropped a bright white target marker over the location where an explosive impactor deployed from the spacecraft struck the asteroid in early April. Mission designers put the Small Carry-On Impactor on Hayabusa 2 to expose material from within the asteroid, bits of rock that were shielded from radiation and other asteroid weathering affects from sunlight and extreme temperature swings.

The spacecraft gathered samples from Ryugu’s surface in February. Engineers designed Hayabusa 2 to collect samples from up to three locations on the asteroid, but mission managers have likely ruled out gathering a third sample.

Hayabusa 2 tried to drop the target marker during a previous descent in mid-May, but the craft autonomously aborted its approach to the asteroid at an altitude of about 160 feet (50 meters) after its laser altimeter made an incorrect distance measurement. Ground controllers re-planned the descent and successfully completed the target marker’s deployment May 30.

The two close approaches over the freshly-carved crater last month provided high-resolution images for ground teams to analyze before a final decision on whether to proceed with a second sampling attempt.

Ryugu measures about 3,000 feet (900 meters) in diameter, and scientists classify it as a C-type asteroid, meaning it is rich in carbon and other building blocks necessary for life.

Developed and operated by the Japan Aerospace Exploration Agency, Hayabusa 2 arrived at Ryugu last June, and is set to depart the asteroid in November or December for the return cruise to Earth powered by ion thrusters. But first, Hayabusa 2 will release its fourth and final rover to hop across the asteroid, following the successfully exploration of Ryugu’s surface by three mobile robots last year.

The spacecraft will jettison a re-entry capsule protected by a thermal shield to plunge into Earth’s atmosphere in December 2020, when the return craft will parachute to a landing in Australia.

Scientists will transfer the asteroid specimens to laboratories for detailed analysis in hopes of learning more about the history of the solar system.

Quelle: SN

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Update: 12.06.2019

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Hayabusa2 probe's new target marker on asteroid only 3 meters off its mark

TOKYO -- A target marker released by Japan's Hayabusa2 space probe in late May to guide its landing onto the asteroid Ryugu fell just 3 meters away from the spot the probe was aiming for, the Japan Aerospace Exploration Agency (JAXA) said on June 11.

The drop is regarded as highly accurate given that Ryugu is located some 300 million kilometers away from Earth.

Hayabusa2 started descending toward Ryugu on June 11. The probe will examine the surface near the target marker in detail and determine whether to go through with a second landing, which follows an earlier one made in February.

The probe released the target marker from about 10 meters above the asteroid's surface on May 30. The marker is covered in reflective material and lights up when exposed to a flash from Hayabusa, acting like a lighthouse to guide the probe to the correct spot.

This time the target marker fell practically where JAXA had hoped, but since the surface of Ryugu is rocky, the space agency will conduct a detailed examination to determine whether it is a point where the probe can land again without hitting any rocks.

Hayabusa2 released its first target marker in October last year, landing about 15.4 meters away from the spot the probe's team was aiming for. Using this target marker as a reference point, the probe made a landing on a separate, smaller space on the asteroid in February. The probe is believed to have collected materials from the asteroid's surface.

In April, an artificial crater was created on the asteroid by firing an impactor from the probe onto the asteroid's surface in a historic first. This time, JAXA aims to make a second landing and obtain material from inside the crater.

(Japanese original by Tomohiro Ikeda, Science & Environment News Department, and Etsuko Nagayama, Opinion Group)

Quelle: The Mainichi

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201905160219

The Pinpoint Touchdown – Target
Marker 1A (PPTD-TM1A) operation

During the PPTD-TM1 operation between May 14〜16, the spacecraft descended to an altitude of about 50m before autonomously stopping the descent and beginning to rise. This abort by the spacecraft was due to an incorrect distance measurement by the laser altimeter (LIDAR) and meant that the target marker could not be dropped. Despite this, it was possible to image around the artificial crater at low altitude. The name of this next operation is ‘PPTD-TM1A’, denoting it as the second operation with almost the same plan as PPTD-TM1. PPTD stands for ‘Pinpoint Touchdown’ while ‘TM1’ refers to the separation of the first target marker for this touchdown.

In the previous PPTD-TM1 operation, the plan was to descend towards the region SO1 and drop the target marker. In PPTD-TM1A, the target marker will be dropped in area CO1, near area SO1. The location is shown in Figure 1.

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  • Figure 1: Region near the SCI collision point. This image was captured prior to generating the artificial crater.
    (Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

Figure 1 is the same image as shown in previous articles, displaying the surface of the asteroid before the generation of the artificial crater. Figure 2 shows the image taken as the spacecraft rose during the PPTD-TM1 operation. The addition of Figure 2 allowed the area around the artificial crater to be understood more clearly, and the area CO1 to be investigated in more detail. The examination revealed the possibility of a touchdown in area CO1. It was therefore decided to descend towards area CO1 and this time, drop the target marker in this region.

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Figure 2: Surface of the asteroid around the artificial crater imaged during the PPTD-TM1 operation. This is a superposition of two images taken from altitudes of about 0.5km and 0.6km. These images were captured on May 16, 2019 with the Optical Navigation Camera – Telescopic (ONC-T).
(Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

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  • Back ground images of Figure 2. (Left) From altitudes of about 0.5km. Image time: May 16, 2019, 11:36 JST(on-board time). (Right) From altitudes of about 0.6km. Image time: May 16, 2019, 11:39 JST(on-board time).
    (Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

The PPTD-TM1A operation will be performed from May 28〜30, 2019. The plan for the operation is almost the same as for PPTD-TM1. Preparation for the descent will take place on May 28 and the spacecraft will start the descent on May 29 at 12:06 JST (on-board time) at a speed of 0.4 m/s. On the same day at 22:26 JST, the spacecraft speed will be reduced to 0.1 m/s. The descent will continue to reach an altitude of about 35m on May 30 at 11:00 JST, and then to 10m at 11:23 JST, the lowest point. The target marker will be separated just before the lowest altitude is reached. The spacecraft will then soon begin to rise and return to the home position on May 31. The operation schedule is shown in Figure 3. Please be aware that the actual operation times may differ as the times listed here are the planned values.

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  • Figure 3: Schematic of PPTD-TM1A operation. (Credit: JAXA.)
    Note: Times listed may differ from the actual operation.

Figure 4 shows the sequence at low altitude. This is almost the same as for the PPTD-TM1 operation.

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Figure 4: PPTD-TM1A low altitude sequence operation. (Credit: JAXA.) 27.05.2019

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201905300159

Received time: UTC 2019-05-30 01:59

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Low descent observation operation
(PPTD-TM1B)

 

The low descent observation operation (PPTD-TM1B) will be conducted between June 11 - 13. As we successfully dropped a target marker in area CO1 during the PPTD-TM1A operation that was performed between May 28 – 30, a target marker will not be dropped during PPTD-TM1B, but observations will be taken near the artificial crater.

Preparations for the descent began on June 11 and the descent will begin on June 12 at 11:40 JST (on-board time) with the spacecraft descending at a speed of 0.4m/s. The speed will be reduced to 0.1 m/s at 22:00 JST on the same day. The spacecraft will read an altitude of about 35m on June 13 at 10:34 JST and then begin to ascend from 10:57 JST. The schedule of the operation is shown in Figure 1. Please be aware that the actual operation time may differ as the times shown are the planned values.

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  • Figure 1: Schematic of the PPTD-TM1B operation (credit: JAXA).
    Note: times listed may differ from the actual operation.

Figure 2 shows the operation sequence at low altitude.

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  • Figure 2: Low altitude sequence for PPTD-TM1B (credit: JAXA).

 

Hayabusa2 Project
2019.06.12

Quelle: JAXA

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