China's Space Program News Thread
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AssassinsMace
Lieutenant General
Wow I have one unlocked CCTV English-language channel on my Direct TV and I'm watching the events live. I wasn't sure if this channel would show extensive coverage live. I missed the launch because it was too early in the morning to see.
danielchin
Junior Member
Here's a shot by the same person showing TG-10 and station transiting across the sun:
The exposure for the whole shot lasted about half a second, and the images are captured using high quality camera taking 36 shots a second. Can you figure out what is the approx speed that they are travelling at relative to camera?
Must be a pain to get the timing just right, wonder how many shots he took in total.
A safe return.
Unless my school boy maths have now fully deserted me, I think you would need to know the altitude of the Space Station and be able to measure the arc of the disk of the sun. With those and a precise measure of the time taken to transit the suns arc, you will be able to calculate the circumference of the Space Stations Orbit and divide it into the distances represented by hours, minutes and seconds of arc.
Once you have the distance of a second of arc plus the time to transit, the final calculation is simple.
Once you have the distance of a second of arc plus the time to transit, the final calculation is simple.
I was thinking maybe a rough and dirty estimation by finding out the length of the Tiangong +SZ10, then finding out the distance that they have moved during 1/36th of a second by measuring their subsequent locations on the exposed photo.
Dividing that distance by 1/36th second would give a good idea of speed. Of course the error margin would be quite large as the T+sz10 is just a smudge on the photo. But I think thir orbiting speed is public data anyway.
edit the details are here: Hydrogen-alpha solar transit of Shenzhou-10 module docked to Tiangong-1, taken from Southern France on June 17th 2013 at 12h34min24s UT.
Transit duration: 0.46s. Distance to observer: 368 km. Speed in orbit: 7.4km/s (26500 km/h or 16500 mph).
My own estimation via pic is low at 20700Km/h
The high resolution photos and info is here:
Dividing that distance by 1/36th second would give a good idea of speed. Of course the error margin would be quite large as the T+sz10 is just a smudge on the photo. But I think thir orbiting speed is public data anyway.
edit the details are here: Hydrogen-alpha solar transit of Shenzhou-10 module docked to Tiangong-1, taken from Southern France on June 17th 2013 at 12h34min24s UT.
Transit duration: 0.46s. Distance to observer: 368 km. Speed in orbit: 7.4km/s (26500 km/h or 16500 mph).
My own estimation via pic is low at 20700Km/h
The high resolution photos and info is here:
Last edited:
Engineer
Major
Assume the angular diameter of the sun to be around 32.0 arc-minutes. To find out how many degrees that is, we do:
32.0 arc-minutes × 1 degree / 60 arc-minutes = 0.533 degrees
A LEO orbit with an altitude of 300 km has a period of around 90 minutes. One complete orbit also means 360 degrees, and to find out the transit time we do:
0.533 degrees / 360 degrees × 90 minutes = 0.133 minutes
Which is about 8 seconds.
This does not factor in the rotation of the Earth though.
32.0 arc-minutes × 1 degree / 60 arc-minutes = 0.533 degrees
A LEO orbit with an altitude of 300 km has a period of around 90 minutes. One complete orbit also means 360 degrees, and to find out the transit time we do:
0.533 degrees / 360 degrees × 90 minutes = 0.133 minutes
Which is about 8 seconds.
This does not factor in the rotation of the Earth though.
thanks this is just what I was looking for, I've seen bits and pieces but here is the entire ''return to earth'' process. it's sad that 15 day mission is over. wang ya ping is the most popular female for all Chinese school kids now
i saw reports saying this is the last manned mission to tiangong-1 and that it's designed purpose has been fulfilled. what are they going to do with tiangong-1 now? it seems to be a waste. they should continue to sent astronauts to tiangong-1 for training. yang li wei must be dying to go up one more time.- Status