ISS and Space-related discussion

[Loz]

 

[True Romance]

That was nail bitting with the low cloud and video dropouts. Still amazing how spacex can knock these things together and launch in just a few weeks.

 

[The Bear78]

I've worked out that at the stated 2400 rpm, the 48" diameter rotor on Ingenuity will have a tip speed of 343mph.
What sort of cameras are they using to achieve this apparently static image, ie no apparent movement-induced blur from root to tip? View attachment 113464

View attachment 113462

(48" diameter x pi is 151" circumference, multiplied by 2400 rotations per minute is 361911 inches per minute tip speed.
361911 / 12 is 30159 feet per minute, /60 is 503 fps, which is 343mph)

I thought I would try and tackle this one!
343 mph equates to 153 metres per second. The image appears to have been taken reasonably close if you consider the wheel tracks so we can probably ignore the effect of distance. Also, note that the tips do have marginal blur compared to the roots.

If we take the "sunny 16 rule" and juggle the figures we can produce ISO 12800, f8, 1/51200.
153m divided by 51200 is ~3mm which I would argue is in the ballpark of the motion blur visible at the tips in the image.
Mars itself is further from the Sun than Earth and due to the make up of its atmosphere it receives about half of the light at the surface. We can simply adjust the ISO or aperture by one stop to correct for this giving either:
ISO 25600, f8, 1/51200
or
ISO 12800, f5.6, 1/51200

Neither of these are particularly remarkable in terms of modern mirror less cameras.

Of course, I could be completely wrong...

Edited as I missed a stop on my calculations...

 

[Phil_G]

Of course, I could be completely wrong...

You sound convincing enough for me

 

[Skyliner33]

I've worked out that at the stated 2400 rpm, the 48" diameter rotor on Ingenuity will have a tip speed of 343mph.
What sort of cameras are they using to achieve this apparently static image, ie no apparent movement-induced blur from root to tip? View attachment 113464

View attachment 113462

(48" diameter x pi is 151" circumference, multiplied by 2400 rotations per minute is 361911 inches per minute tip speed.
361911 / 12 is 30159 feet per minute, /60 is 503 fps, which is 343mph)

I don't think it would take anything exotic in the world of cameras.
There are some that will film at 10 trillion frames per second.

 

[VanDamMan]

Should we worry…. 18ton Chinese junk falling back to earth ( ex main body ..Long March-5b rocket ).


it’s nice …they’ve shared the virus..now we can share there Junk

 

[Loz]

Their orbit doesn't overfly us, pacific more likely.

 

[JOG]

Have they calculated possible land zone yet? They’re waiting for it to enter atmosphere?

 

[VanDamMan]

Their orbit doesn't overfly us, pacific more likely.

Let’s hope it’s a splash and not a crash

 

[The Bear78]

By all accounts only a tiny fraction of the spent stage will survive the re-entry inferno. It still seems incredibly reckless to just leave it to chance that whatever is left will not harm anyone.

 

[Ghost]

live launch Starlink mission

 

[Ghost]

Looks like a nice clear night, for a incredibly bright ISS pass over the UK tonight ... 21:56 & 23:33

 

[Pete C]

Yes, very bright !

Pete

 

[Ghost]

Another incredibly bright ISS pass over the UK tonight..

21:57 & 23:35

 

[Loz]

Great pass, Venus low and bright on the NW horizon.

 

[Loz]

Full moon rises at 21:38 followed by the ISS at 22:00

 

[Pete C]

Very visible again In the current clear sky.

Pete

 

[JOG]

Great pass, Venus low and bright on the NW horizon.
View attachment 117291

Even I managed to see it on Monday!

 

[Ghost]

Jeff Bezos is set to launch into space today..

Jeff Bezos to blast into space aboard New Shepard rocket ship

 

[Loz]