CE-2 flyby of Toutatis Options

[Liss]

http://www.lpi.usra.edu/sbag/meetings/jan2...CE_Toutatis.pdf

That's interesting:
(1) Revised flyby timeline, shifted some 5 seconds against the 15 Dec images;
(2) Authors claim to calculate distances from asteroid size, not from times;
(3) Yet again time intervals between images are too small to fit the pairs of distances.

[Paolo]

and here is the image sequence. the complete sequence should include something more than a hundred images resolving Toutatis

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[Paolo]

Daniel Fischer (cosmos4u on twitter) has published this regression graph of the distances and times in the prez. they seem to make quite some sense

[machi]

This is composite image from last four published images (with highest resolution).
Resolution is ~4.5 m/pix.

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[tasp]

Thanx for the composite image!

The 'divot' (lower right) is even more interesting at this resolution; the grooves, or scratchesif you will, are parallel to each other and to the sides.

[Decepticon]

Excellent work!

[Paolo]

I got a copy of the video that was embedded in the SBAG presentation from the author (hint: her address is on the first slide)
I will not redistribute it, but here are some of the frames. note that the quality and compression seem a lot better than we have seen until now

Attached thumbnail(s)

 

[Paolo]

just found a paper (marked "for academic exchange only") that gives some technical overview of the asteroid flyby target selection

that paper has now been published in a proper peer-reviewed journal:
Near-Earth asteroid flyby trajectories from the Sun–Earth L2 for Chang’e-2’s extended flight

[Paolo]

papers to be presented at the Beijing IAF congress in September:
Relative Distance Estimation Between the Asteroid 4179 and Chang'E II Based On Spaceborne Opitcal Images
Combined Orbit Determination for CE-2 and Toutatis Based on Optical Imaging Data at Fly-by

[Paolo]

the latest issue (5 2013) of SCIENCE CHINA Technological Sciences http://tech.scichina.com:8082/sciE/CN/volumn/current.shtml has a bunch of papers (in Chinese) on the CE-2 flyby of Toutatis.
nothing yet on the English version of the journal http://tech.scichina.com:8082/sciEe/EN/volumn/current.shtml

[Phil Stooke]

The first one is a summary of the CE2 mission with some Moon images. Two more on the trajectory, navigation etc., but not actually anything on the Toutatis observations yet. Unless I missed something.

Phil

[Paolo]

you are right.
one of the papers (the one on page 478) seem to describe how they determined the flyby distance from the monitoring camera images

[Paolo]

still more papers in the 8 June issue of the journal
tech.scichina.com:8082/sciE/CN/volumn/volumn_6667.shtml
from a quick look, they seem to be mostly engineering papers

[Explorer1]

Closest approach was apparently less than a kilometer from the surface, according to this new post! :0

http://www.planetary.org/blogs/emily-lakda...2-toutatis.html

Talk about good aim, and Toutatis's slow rotation! Hats off to the Chang'E navigators!

[Paolo]

one of the papers at this year's IAC had a closest distance of 1,564 +/- 10 m. from the center of mass, I think