Astronomy & Space

Hayabusa 2 cleared for second landing on asteroid – Astronomy Now

July 6, 2019 • By
Artist’s idea of the Hayabusa 2 spacecraft touching down on asteroid Ryugu. Credit score: JAXA/Akihiro Ikeshita

Floor groups have authorized plans for Japan’s Hayabusa 2 pattern return mission to briefly land on asteroid Ryugu for the second time on 11 July, aiming for a focused touch-and-go to assemble materials uncovered by an explosive impactor launched by the robotic explorer in April.

Officers from the Japan Aerospace Exploration Company, or JAXA, introduced the choice on 27 June after weeks of surveys, apply approaches and deliberations to make sure the Hayabusa 2 spacecraft can safely contact down on the rugged web site, which is strewn with boulders and rocks that might pose hazards to the probe.

The target of this touch-and-go touchdown is to gather a second set of samples from the carbon-rich asteroid for return to Earth.

Hayabusa 2 is within the ultimate stretch of an almost 18-month exploration marketing campaign at asteroid Ryugu earlier than firing its ion thrusters late this yr for the return journey to Earth. Thus far, the mission has achieved a pinpoint touchdown and takeoff from the asteroid, deployed three daughter probes to hop round Ryugu’s floor, and carved a brand new crater on the asteroid after dropping an explosive cost.

Yet one more touch-and-go touchdown and the discharge of the mission’s ultimate cell floor scout are deliberate within the coming weeks.

Hayabusa 2 gathered a primary batch of samples from Ryugu’s floor in February after executing a pinpoint landing on a special a part of the 900-metre (0.5 mile) broad asteroid.

The robotic explorer’s sampling mechanism works by firing a steel bullet into the asteroid as soon as the probe’s sampler horn, which extends from one aspect of the spacecraft, contacts the floor. The projectile is designed to blast away rock and dirt on the asteroid’s floor, then direct the fabric by means of the sampler horn into a set chamber contained in the Hayabusa 2 spacecraft.

Whereas there isn’t a direct approach to measure how a lot pattern Hayabusa 2 collected in February, scientists stated telemetry information broadcast again to Earth prompt the sampling system labored as designed.

In early April, Hayabusa 2 launched the Small Carry-On Impactor, an explosive system that drove a copper mass into the asteroid to create a brand new crater, uncovering rocks that had been buried beneath Ryugu’s floor, maybe for billions of years.

Scientists will goal the 11 July touchdown a brief distance from the recent crater, the place they imagine materials ejected by the affect fell. The brand new samples could embrace pristine subsurface specimens which have escaped radiation and different asteroid weathering impacts from daylight and excessive temperature swings.

Hayabusa 2’s optical navigation digicam captured this view of asteroid Ryugu from a distance of 6 kilometers (Four miles) on July 20, 2018. Credit score: JAXA

A second profitable sampling try would make Hayabusa 2 the primary mission to gather a subsurface specimen from an asteroid for return Earth.

Assuming the touch-and-go snags a pattern that was uncovered by the mission’s explosive impactor, scientists anticipate the fabric will include info from the early formation of the Photo voltaic System 4.6 billion years in the past, similar to natural molecules that grew to become the constructing blocks for all times.

“Subsurface materials are particularly valuable for sensitive organics,” scientists wrote in a mission replace final month.

Engineers designed Hayabusa 2 to gather samples from as much as three areas on the asteroid, however mission managers have dominated out gathering a 3rd pattern. The mission solely wanted one pattern to fulfill minimal success standards.

Throughout preparations for the second sampling try, Hayabusa 2 dropped a goal marker onto the asteroid on 30 Might to assist the spacecraft information itself towards the touchdown zone. The probe additionally took high-resolution photographs of the realm to assist scientists determine if they need to press forward with one other landing.

Officers mulled the scientific benefit and security dangers of a second touchdown try, and the bottom staff finally elected to go forward with the landing.

Hayabusa 2 had till this month to attempt for a second landing. Ryugu is nearing the purpose in its orbit closest to the Solar, and rising temperatures on the asteroid will prohibit the spacecraft from touchdown later this yr, officers stated.

Whereas Hayabusa 2 explores Ryugu, NASA’s OSIRIS-REx mission is surveying asteroid Bennu earlier than transferring in to gather a pattern there in 2020 for return to scientists on Earth in 2023.

OSIRIS-REx is designed to deliver dwelling no less than 60 grams (2.1 ounces) of samples from Bennu, considerably greater than Hayabusa 2. However OSIRIS-REx is simply anticipated to gather a single pattern from one location on Bennu’s floor.

As soon as the second pattern assortment is full, Hayabusa 2 is anticipated to deploy the final of its 4 daughter probes to hop across the asteroid’s floor.

Hayabusa 2’s return journey to Earth is scheduled start in November or December, with re-entry of the mission’s sample-carrying descent capsule set for late 2020 over Australia, the place restoration groups will decide up the specimens for evaluation in laboratories in Japan and the USA.

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Observe Stephen Clark on Twitter: @StephenClark1.