[meteorite-list] Hayabusa 2 Probe Confirmed on Good Trajectory After Earth Flyby

[Ron Baalke]

http://spaceflightnow.com/2015/12/14/asteroid-probe-confirmed-on-good-trajectory-after-earth-fly
by/

Asteroid probe confirmed on good trajectory after Earth flyby
by Stephen Clark
SpaceFlight Now
December 14, 2015 

A Japanese space probe picked up just the right amount of speed when it 
flew by Earth earlier this month, using the planet's gravity to slingshot 
toward an asteroid scientists think is a primordial leftover from the 
ancient solar system, mission managers said Monday.

The Hayabusa 2 spacecraft passed about 3,090 kilometers (1,920 miles) 
above the Pacific Ocean near the Hawaiian islands Dec. 3, returning to 
Earth's vicinity exactly one year after its launch from Japan.

Ground controllers intended to use Earth's gravity to give the Hayabusa 
2 spacecraft a boost, bending its trajectory to intercept asteroid Ryugu 
in June 2018 with the help of further steering impulses from the probe's 
ion propulsion system.

The results of the flyby showed Hayabusa 2 is on the correct path after 
the Dec. 3 encounter, which turned the probe's orbit by about 80 degrees 
and increased its speed 1.6 kilometers per second (3,579 mph) relative 
to the sun's position, according to the Japan Aerospace Exploration Agency, 
or JAXA.

The extra speed will propel Hayabusa 2 outward from Earth's orbit toward 
Ryugu, a near-Earth asteroid that spends most of its time farther from 
the sun than Earth.

Hayabusa 2 is in good health after the Earth flyby, JAXA said in a press 
release Monday.

"I would like to express my deep gratitude to all pertinent parties and 
people and those who are supporting our operation," said Yuichi Tsuda, 
Hayabusa 2's project manager. "All the Hayabusa 2 project team members 
have been working together and will continue our challenging voyage.

"The Hayabusa 2 gained orbit energy through the swing-by to leave the 
Earth," Tsuda said in a statement. "The target is the asteroid Ryugu. 
'See you later, people on Earth!'"

As of late Sunday, U.S. time, the Hayabusa 2 spacecraft was 4.15 million 
kilometers (2.6 million miles) from Earth, about 10 times the distance 
of the moon.

Hayabusa 2 will spend about a year-and-a-half in the vicinity of asteroid 
Ryugu beginning in mid-2018, dropping four small landers - three from 
Japan and one from Germany - to the asteroid's surface.

The main spacecraft itself will descend to the 900-meter (3,000-foot) 
asteroid several times, scooping up bits of rock for collection into a 
chamber. Hayabusa 2 will head back to Earth in 2020 and drop a landing 
capsule to a parachute-assisted touchdown in Australia with the asteroid 
material.

[Images]
This series of images from Hayabusa 2's optical navigation camera show 
Earth as the probe approached for the Dec. 3 flyby. Credit: JAXA

Hayabusa 2 is Japan's second asteroid sample return mission.

The Hayabusa spacecraft visited asteroid Itokawa in 2005, but technical 
problems prevented the spacecraft from gathering the intended samples. 
Hayabusa successfully landed back on Earth in 2010, and scientists harvested 
microscopic specimens from the return capsule.

NASA plans to launch its own asteroid sample return probe named OSIRIS-REx 
in September 2016, heading to a different object to collect rocks and 
return to Earth in 2023.