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Hayabusa terminated its long term propulsion on March 27th. According tothe orbit
estimated on March 31st, it was confirmed that the resulted trajectory will pass through
the target point as planned. In the BR-BT plane, the final spot in the figure clearly shows
the guidance and navigation made the intended point precisely reached. However,
according to the trajectory predict in the inertial frame, the trajectory shows a more sharp
bend motion after it passes the Earth. It is due to the guidance error that still remains with
respect to the target. The project team has introduced an alterative ion engine operation
configuration from last November. The configuration conceals us from looking into an
important information that affects the ion engine thrust magnitude, and this leads to the
unexpected trajectory control error. As this loci indicate, swingby schemes are very
sensitive to the guidance error generally, while the method is a mighty power to greatly
amend the trajectory and useful. This thing is what we frequently face, when we
adopt the swingby, in other word, the gravity assist operation.
From now on until June, Hayabusa is guided through several times of ion engine burns to
accurately target the landing area. Being assisted by the NASA Deep Space Network,
by being monitored all the time via the ground stations in real time, the subsequent
corrections will be rigorously performed with this error excluded thoroughly.



Fig.1: Closest distance to Earth when Hayabusa flies ballistically from the moment designated.

Fig.2: The plane is normal to the approach velocity to Earth, and the horizontal axis corresponds to a crossing line with the equatorial plane. Sun is in the left hand side. Plots show the points where Hayabusa flies through this plane.

Fig.3: Trajectories relative to Earth in inertial frame. The plane corresponds to the ecliptic plane.

Notes: Dates designated in the left figure do not indicate the return dates.

 

Hayabusa completed the correction TCM-2
Jun 8, 2010 Up!!

Hayabusa completed the correction TCM-2
Jun 1, 2010 Up!!

Hayabusa Caotured its Home Earth
May 17, 2010 Up!!

Hayabusa completed the correction TCM-1
May 10, 2010 Up!!

Hayabusa successfully completed its initial correction(TCM-0)
May 6, 2010 Up!!

Hayabusa about to enter into Earth's gravity sphere
Apr121, 2010 Up!!

Hayabusa about to enter into Earth's gravity sphere
Apr 1, 2010 Up!!

Hayabusa traversed over south pole and will fly-by at night side of Earth
Mar 26, 2010 Up!!

Hayabusa will skim the geosynchronous orbit
Mar 23, 2010 Up!!

Hayabusa now at the Final Guidance Phase
Mar 12, 2010 Up!!

Hayabusa, passes within half of the Moon's distance
Mar 8, 2010 Up!!

Hayabusa, now will pass within Moon's distance
Feb 26, 2010 Up!!

Hayabusa is skimming the Moon
Feb 18, 2010 Up!!

Hayabusa, Right on the Course
Feb 15, 2010 Up!!

Hayabusa will will pass at two times as far distance as to the Moon
Feb 9, 2010 Up!!

Hayabusa will approach within 1 million km from Earth
Feb 1, 2010 Up!!

Hayabusa Approach in Order with Two More Months of Ion Engines Burn Left
Jan 21, 2010 Up!!

Hayabusa on a path passing through Earth's gravity sphere
Jan 14, 2010 Up!!

Hayabusa about to enter into Earth's gravity sphere
Jan 8, 2010 Up!!

Hayabusa about to enter into Earth's gravity sphere
Jan 4, 2010 Up!!

more detail

 
 
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