Mission: Hayabusa 2 Options

[climber]

Great help as our team in the world cup is to start any moment now!

Congratulation!

[RedSky]

The shape at this point reminds me more of Balok's warning buoy...

[Roman Tkachenko]

[JRehling]

Amazing, the diversity that we see in small bodies.

This is what granular NaCl (table salt) looks like under a microscope.

[Hungry4info]

We're now less than 100 km from the asteroid, and the asteroid's size should be about 100 pixels in Hayabusa 2's camera.

[MahFL]

We're now less than 100 km from the asteroid, and the asteroid's size should be about 100 pixels in Hayabusa 2's camera.

The approach speed has slowed a lot to 0.28ms, which of course is sensible.

[pandaneko]

I had an interesting experience today. As usual, I accessed the main web page of Hayabusa 2 and the speed was
something like 53m/s, very slow as somebody remarked, at walking pace, and then I doubted my vision.

The number in the speed of 53m/s seemed to have changed in a very short while my eyes were off the display
unit. I was not sure if the number that I was seeing was the number that I had seen, so I kept watching and
within a few seconds I realised that the number was indeed changing in front of my eye balls.

In fact, the speed kept going down over the next 30 or 40 seconds. It kept going down, and down, until it
reached 28m/s and it is staying there.

This episode was around PM12:38 or 12:39 local JST today (20 June 2018).

My current hope is that since the home height is 20km, and the remaining distance shown is as far as to that
home position we may start seeing something on the Haya2 control panell display window for OCN-W1 at around
30,40km height, no?

There is also something else I now understand about the speed. The speed shown on the main web page is the
absolute value of the vector quantity and the actual speed of approaching Ryugu is the projetion, hence
can be slower (usually).

At this rate of going, though, we may be having a clear view of Ryugu within the next 24 hours?

P

[Guest_mcmcmc_*]

I had an interesting experience today. As usual, I accessed the main web page of Hayabusa 2 and the speed was
something like 53m/s, very slow as somebody remarked, at walking pace, and then I doubted my vision.

I guess you forgot a dot: 0.53 m/s ; it's now moving very slow, just 53 cm/s, or 2 km/h (just a walk)

I realised that the number was indeed changing in front of my eye balls.

In fact, the speed kept going down over the next 30 or 40 seconds. It kept going down, and down, until it
reached 28m/s and it is staying there.

I think they are not realtime data, but simulated data got from here:
http://www.hayabusa2.jaxa.jp/hy2sc2/data/hy2_trj.txt

But they periodically update these data, so probably data "before today" are actual recorded data, data "after today" are "scheduled operations".

This episode was around PM12:38 or 12:39 local JST today (20 June 2018).

I see a speed change in simulator at 03:40, and difference between GMT and JST is exactly 9 hours, hence simulator raw data are expressed in GMT timezone:
(columns are: epoch, date PosX, PosY, PosZ, Vx, Vy, Vz)

CODE

58289.131944 2018/06/20T03:10:00.0    -0.4659     0.7610    93.8383   0.048573  -0.019267  -0.841132
58289.138888 2018/06/20T03:20:00.0    -0.4367     0.7494    93.3336   0.048760  -0.019289  -0.841202
58289.145833 2018/06/20T03:30:00.0    -0.4074     0.7378    92.8289   0.048946  -0.019311  -0.841271
58289.152777 2018/06/20T03:40:00.0    -0.3780     0.7262    92.3241  -0.001617  -0.001874  -0.275698
58289.159722 2018/06/20T03:50:00.0    -0.3790     0.7251    92.1586  -0.001572  -0.001881  -0.275781
58289.166666 2018/06/20T04:00:00.0    -0.3799     0.7240    91.9931  -0.001527  -0.001888  -0.275864

These are the officially planned correction maneuvres:
20/6: TCM06
22/6: TCM07
24/6: TCM08
26/6: TCM09
27/6: Arrival maneuvre

In simulator :
22/6: from 0.29 to 0.09 m/s at 00:30 GMT

CODE

58291.000000 2018/06/22T00:00:00.0     0.3463     0.2734    46.4971   0.010890  -0.003859  -0.299322
58291.006944 2018/06/22T00:10:00.0     0.3529     0.2711    46.3175   0.010939  -0.003867  -0.299424
58291.013888 2018/06/22T00:20:00.0     0.3594     0.2688    46.1378   0.010988  -0.003875  -0.299525
58291.020833 2018/06/22T00:30:00.0     0.3660     0.2664    45.9581  -0.002735  -0.000503  -0.091445
58291.027777 2018/06/22T00:40:00.0     0.3644     0.2661    45.9032  -0.002738  -0.000505  -0.091550
58291.034722 2018/06/22T00:50:00.0     0.3628     0.2658    45.8482  -0.002741  -0.000508  -0.091656

24/6: from 0.126 to 0.012 at 00:30 GMT:

CODE

58293.006944 2018/06/24T00:10:00.0    -0.1110     0.1121    27.4438  -0.002419  -0.001353  -0.126452
58293.013888 2018/06/24T00:20:00.0    -0.1125     0.1112    27.3679  -0.002413  -0.001356  -0.126605
58293.020833 2018/06/24T00:30:00.0    -0.1139     0.1104    27.2919   0.003327  -0.000321  -0.012317
58293.027777 2018/06/24T00:40:00.0    -0.1119     0.1102    27.2844   0.003304  -0.000322  -0.012470

26/6: from 0.061 to 0.002 at 01:10 GMT

CODE

58295.034722 2018/06/26T00:50:00.0    -0.0201     0.0277    21.0608  -0.001681  -0.000683  -0.061627
58295.041666 2018/06/26T01:00:00.0    -0.0211     0.0273    21.0237  -0.001692  -0.000685  -0.061832
58295.048611 2018/06/26T01:10:00.0    -0.0221     0.0269    20.9866   0.001988  -0.000297   0.002685
58295.055555 2018/06/26T01:20:00.0    -0.0209     0.0267    20.9881   0.001961  -0.000298   0.002481

27/6: from 0.026 to stop.

CODE

58296.006944 2018/06/27T00:10:00.0     0.0015     0.0004    20.0315  -0.001256  -0.000355  -0.026044
58296.013888 2018/06/27T00:20:00.0     0.0008     0.0002    20.0158  -0.001276  -0.000356  -0.026261
58296.020833 2018/06/27T00:30:00.0     0.0000    -0.0000    20.0000   0.000038   0.000000   0.000323
58296.027777 2018/06/27T00:40:00.0     0.0000    -0.0000    20.0001   0.000012   0.000000   0.000105

Please note that the probe slightly accelerates between TCMs.
Additionally, if you plot position on a chart, you can see how the horizontal position slightly changes: they declared it's done to allow enough parallax to better determining positioning of the asteroid in 3d space.

[pandaneko]

Thank you!, mcmcmc

Yes, from -0.841 to -0.275 in z direction noted. I hope, though, that we are looking at real recorded data from
the probe, not simulated data from 30km away from my house here on the ground. ISAS control room is not far
from my house.

Your data set suggests that in 2 days' time on 22 June Hayabusa 2 will reach 45km position, and 27km position
on 24th, and finally the home position with a residual Z velocity of 0.000105m/s.

My gut feeling then is that we will begin to see something on ONC-W1 after 24 hours from now, we will have to,
because even the wide angle camera must be able to see Ryugu from a distance of less than 50km!

P

[pandaneko]

I am pleased to report that the display window for OCN-W1 on the Haya 2 control panell has been switched on.

There is nothing yet to be seen, but this display area has been totally dark until now. It is now bright, as you can
see below.

P

Attached thumbnail(s)

 

[pandaneko]

Just in case visitors new here wonder how to get to ONC-W1 display window here follows its URL.

http://haya2now.jp/
Haya2NOW control panell

P

[Guest_mcmcmc_*]

Thank you!, mcmcmc

Yes, from -0.841 to -0.275 in z direction noted. I hope, though, that we are looking at real recorded data from
the probe, not simulated data from 30km away from my house here on the ground. ISAS control room is not far
from my house.

Simulator data just updated after TCM06:
(last column is vertical speed)


TCM06
Previously:
20/6, 03:30 GMT

CODE

58289,145833 2018/06/20T03:30:00,0    -0,4074     0,7378    92,8289   0,048946  -0,019311  -0,841271
58289,152777 2018/06/20T03:40:00,0    -0,3780     0,7262    92,3241  -0,001617  -0,001874  -0,275698

Actually:
20/6 03:30 GMT

CODE

58289,145833 2018/06/20T03:30:00,0    -2,1929     1,8624   109,3749   0,036942  -0,015448  -0,734701
58289,152777 2018/06/20T03:40:00,0    -2,1707     1,8531   108,9340   0,004073  -0,007881  -0,381010

Size in ONC-T: 85
Size in ONC-W1: 8



Next TCMs:

TCM07:
Previously:
22/6 00:20 GMT

CODE

58291,013888 2018/06/22T00:20:00,0     0,3594     0,2688    46,1378   0,010988  -0,003875  -0,299525
58291,020833 2018/06/22T00:30:00,0     0,3660     0,2664    45,9581  -0,002735  -0,000503  -0,091445

Now planned:
22/6 00:20 GMT

CODE

58291,013888 2018/06/22T00:20:00,0     0,0525     0,3668    45,9209   0,023751  -0,010678  -0,403516
58291,020833 2018/06/22T00:30:00,0     0,0668     0,3604    45,6787   0,000331  -0,001437  -0,090479

Size in ONC-T: 206
Size in ONC-W1: 20


TCM08:
Previously:
24/6 00:30 GMT

CODE

58293,020833 2018/06/24T00:30:00,0    -0,1139     0,1104    27,2919   0,003327  -0,000321  -0,012317
58293,027777 2018/06/24T00:40:00,0    -0,1119     0,1102    27,2844   0,003304  -0,000322  -0,012470

Now planned for:
24/6 00:20 GMT

CODE

58293,013888 2018/06/24T00:20:00,0     0,1110     0,0421    27,2645   0,000560  -0,002306  -0,125539
58293,020833 2018/06/24T00:30:00,0     0,1114     0,0407    27,1891   0,002246  -0,000111  -0,011788

Size in ONC-T: 343
Size in ONC-W1: 33


TCM09:
Previously:
26/6 01:00 GMT

CODE

58295,041666 2018/06/26T01:00:00,0    -0,0211     0,0273    21,0237  -0,001692  -0,000685  -0,061832
58295,048611 2018/06/26T01:10:00,0    -0,0221     0,0269    20,9866   0,001988  -0,000297   0,002685

Now planned for:
01:10 GMT[/size]

CODE

58295,041666 2018/06/26T01:00:00,0     0,0003    -0,0002    20,9940  -0,002923  -0,000412  -0,061517
58295,048611 2018/06/26T01:10:00,0    -0,0015    -0,0004    20,9570   0,001754   0,000019   0,003058

Size in ONC-T: 463
Size in ONC-W1: 44



Arrival:


Previously:
27/7 00:20 GMT

CODE

58296,013888 2018/06/27T00:20:00,0     0,0008     0,0002    20,0158  -0,001276  -0,000356  -0,026261
58296,020833 2018/06/27T00:30:00,0     0,0000    -0,0000    20,0000   0,000038   0,000000   0,000323

Now planned for:
27/7 00:20 GMT

CODE

58296,013888 2018/06/27T00:20:00,0     0,0009     0,0000    20,0156  -0,001530  -0,000025  -0,025922
58296,020833 2018/06/27T00:30:00,0     0,0000    -0,0000    20,0000   0,000038   0,000000   0,000323

Size in ONC-T: 463
Size in ONC-W1: 44

My gut feeling then is that we will begin to see something on ONC-W1 after 24 hours from now, we will have to,
because even the wide angle camera must be able to see Ryugu from a distance of less than 50km!

Resolution calculator:
http://win98.altervista.org/telescopio.html

[Guest_mcmcmc_*]

I am pleased to report that the display window for OCN-W1 on the Haya 2 control panell has been switched on.

There is nothing yet to be seen, but this display area has been totally dark until now. It is now bright, as you can
see below.

P

Instructions say it will be just a schematic, not an image:

When Hayabusa2 is approaching Ryugu, the position and size of Ryugu from the onboard wide angle optical navigation camera (ONC-W1) will be displayed as a schematic drawing.

From 80 km, ONC-W1 still can just see 11 pixel.

[Guest_mcmcmc_*]

Added in post 342 foreseen resolutions at each TCM

[pandaneko]

schematic, not an image, yes, it has been nagging in me.

However, this statement is no longer there and I only noticed it when I reported the power-on of the ONC-W1.
It now only says, effectively, display window will show " asteroid position and size, Hayabusa will approach
Ryugu while capturing its image in view".

This is ridiculous, because we know the position of Ryugu, it is right in the middle of the display window, and
the size, we already know and we also know that it looks like a puff fish.

Creating scehmatics should cost time and to my mind it should be a lot easier to simply place a real image
downsized to suit the window size. Oh, I would be rambling on...

We will see anyway, one way or the other very shortly.

P