Mission: Hayabusa 2 |
Mission: Hayabusa 2 |
Jun 19 2018, 02:47 PM
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#331
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Senior Member Group: Members Posts: 2922 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
Great help as our team in the world cup is to start any moment now! Congratulation! -------------------- |
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Jun 19 2018, 03:27 PM
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#332
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Member Group: Members Posts: 129 Joined: 25-March 05 Member No.: 218 |
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Jun 19 2018, 08:33 PM
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#333
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Junior Member Group: Members Posts: 80 Joined: 18-October 15 From: Russia Member No.: 7822 |
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Jun 20 2018, 02:15 AM
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#334
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Amazing, the diversity that we see in small bodies.
This is what granular NaCl (table salt) looks like under a microscope. |
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Jun 20 2018, 03:35 AM
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#335
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Senior Member Group: Members Posts: 1452 Joined: 26-July 08 Member No.: 4270 |
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.
-------------------- -- Hungry4info (Sirius_Alpha)
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Jun 20 2018, 04:31 AM
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#336
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Forum Contributor Group: Members Posts: 1374 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
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Jun 20 2018, 04:50 AM
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#337
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
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 |
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Guest_mcmcmc_* |
Jun 20 2018, 06:46 AM
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#338
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Guests |
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) QUOTE 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". QUOTE 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. |
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Jun 20 2018, 08:34 AM
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#339
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
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 |
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Jun 20 2018, 09:11 AM
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#340
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
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Jun 20 2018, 09:55 AM
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#341
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
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 |
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Guest_mcmcmc_* |
Jun 20 2018, 12:40 PM
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#342
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Guests |
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 |
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Guest_mcmcmc_* |
Jun 20 2018, 09:04 PM
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#343
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Guests |
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: QUOTE 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. |
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Guest_mcmcmc_* |
Jun 20 2018, 09:07 PM
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#344
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Guests |
Added in post 342 foreseen resolutions at each TCM
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Jun 21 2018, 01:50 AM
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#345
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
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 |
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