New Analysis Video of the STS-75 Tether Incident

Originally posted by secretnasaman
reply to JimOberg........

Jim,you don't have this info report by NASA & so you ask me for it & mock me for no link! You give no link as my ATS friend says...

You're the one making the claim the quote is supposed to support. But you're the one finding excuses now not to show the world the link you claim you are quoting correctly but won't allow anyone to check. And you're blaming ME for your own refusal. Priceless.

just as you said originally here, at ATS, that my "clunker" reused tether report was a fantasy, & false. So I had to educate you with a post of NASAs admission of this totally strange decision! Now you admit it & say it doesn't matter which tether they used! The one they reused BROKE!

As I understand it, the original tether jammed at a deploy distance of about 1000 feet. The tether was reeled back in. When returned to Earth, NASA removed the deployed 1000-ft length and reused the rest of the 12-km undeployed tether for the reflight. Seems reasonable to me. What does this have to do with the subsequent failure, or with your videos and your claims about interpreting them?

So it was a bad decision & one that you did not even know about for 13 years. You are supposed to be a space historian & Space Journalist...my learning curve started in the 1990s.

Actually, I was an operator in Mission Control during those years specializing in orbital maneuvering and formation flying, rendezvous, and -- drumroll -- tether dynamics.

reply to post by JimOberg


Look if you are going to get technical, use the right terms, it is direction and Magnitude, which is mainly duration when it comes to rocket burns.

Are you saying that once an orbit is established, it never has to be maintained?

Is it your claim that once the space shuttle establishes it's orbit at 150 mile altitude, it will stay there forever, and never have to worry about orbital decay?

Or is it true that for anything to maintain such an orbit it will have to boost itself on a consistent basis, constantly finding a way to boost it's speed at fairly consistent intervals over the duration of its orbit if it is to maintain any long term orbit?

I just grabbed the first source that described what I was looking for. The shuttle motors establish its circular orbit. Maybe the shuttle never stays on orbit long enough to fire thrusters to sustain orbit, but I am sure if it did stay on the same orbit without maneuvering to different orbits, eventually it would have to do something to counter orbit decay.

I don't need to read more about the subject to recognize obfuscation when I see it.

Of course they never give those certificates out to clueless bureaucrats.

I love you too.

reply to post by Arbitrageur


At an amusement park near here we have a ride called the orbiter which provides an experience of what you are describing, spinning around and tilting up almost ninety degrees, so that just as you get to the top, and start down, you have a moment of weightlessness.

It is a balance of speed to create circumferential force that balances with the force of gravity in order to establish an orbit, in a nutshell, and that is as specific as we need to address the issue here.

What you continue to ignore is that all these UFOs clustered in the area viewed by the camera, which is very small for a considerable distance from the shuttle, are heading in different directions.

If the changes in direction are due to the pull of gravity, then what forces propelled these UFOs in their defiance of gravity, in all these different directions, in the first place?

If they all suddenly popped up out of the shuttle, they should all still be going in relatively the same direction, especially since they would have to be in a very tiny cluster if they are only a few meters from the shuttle, which means that they can NOT be particles just a few meters away from the shuttle.

Tiny cluster of particles heading in different directions that just happen to converge in front of the tiny area through which the camera was focusing on the tether almost a 100 miles away, extremely unlikely. The chances of this happening are so extremely unlikely to be that this simply is not a plausible explanation of what we are seeing in the video.

Originally posted by poet1b
reply to post by JimOberg

 

Are you saying that once an orbit is established, it never has to be maintained?

Is it your claim that once the space shuttle establishes it's orbit at 150 mile altitude, it will stay there forever, and never have to worry about orbital decay?

Jim Oberg is the expert on orbital topics, but from my limited knowledge I suspect you answered your own question here:

Maybe the shuttle never stays on orbit long enough to fire thrusters to sustain orbit, but I am sure if it did stay on the same orbit without maneuvering to different orbits, eventually it would have to do something to counter orbit decay.

Jim already mentioned the ISS fires its thrusters every month or two to maintain orbit. So yes if the shuttle was in orbit longer I expect it would have to make corrections just like the ISS does, but your answer to your question I suspect is correct, is that the Shuttle is probably not normally in orbit long enough to have to make many orbital corrections.

Originally posted by poet1b
If the changes in direction are due to the pull of gravity, then what forces propelled these UFOs in their defiance of gravity, in all these different directions, in the first place?
If they all suddenly popped up out of the shuttle, they should all still be going in relatively the same direction, especially since they would have to be in a very tiny cluster if they are only a few meters from the shuttle, which means that they can NOT be particles just a few meters away from the shuttle.
Tiny cluster of particles heading in different directions that just happen to converge in front of the tiny area through which the camera was focusing on the tether almost a 100 miles away, extremely unlikely. The chances of this happening are so extremely unlikely to be that this simply is not a plausible explanation of what we are seeing in the video.

It's a fair question to wonder about objects criss-crossing the feidl of view, and why they might not all fly in the same direction. Let me list a few of the factors that I've observed influencing such motions when i watched them on our MCC display screens.

First, particles can come off many different locations on the shuttle (in technical terms, we call the spaceplane the 'orbiter', and when the tank and SRBs are added, that makes a 'shuttle' -- but it's not an issue here) from the nose to the tail, along the side (mostly the right side where most vents are located), and anywhere in the payload bay. So a camera at one of the corners of the bay (and these are the sources of the overwhelming majority of 'shuttle UFO videos, along with the 'docking camera' pointing straight up out of the docking unit -- you can recognize this camera by the three-pronged 'Y'-shaped sighting guide) can see particles moving across the FOV from practically any direction.

They also see particles moving away from the camera.

Large particle-generating events -- water dumps, thruster leaks, flash evaporator or hydraulic unit operation, early mission main engine flushing, etc etc) -- also add randomness to the motion because the flow is thick enough that particle-particle collisions occur and many particles are thrown back at different directions.

Add in illumination effects -- the camera line of sight backlit by the rising sun, with the still-dark Earth horizon in center of the FOV, and with the orbiter's shadow casting over nearby particles until they drift into sunlight (the particular condition when the most spectacular famous 'shuttle UFO videos' occur) -- and you have a "Faux-UFO Generator" operating at full force.

Curving of motion (I don't refer to sharp turns that occur during thruster firings) looks weird too. The wide FOV is slightly distorted along its edges, but not badly so, as far as I recall. The main influence on particle motion near the shuttle seems to be air drag, but only over a period of tens of minutes -- particles will 'decay' into lower orbits that have greater orbital velocities (they are falling 'downhill') and then they pull ahead of the orbiter. There are spectacular videos of clusters of scintillating dots, the ice generated by a water dump an hour earlier, leading the orbiter into shadow. These are the same kinds of effects that have been seen since John Glenn's "fireflies" in 1962.

I've heard speculation that solar heating can case small sublimation off the surfaces of ice particles that, if the particle is light enough and reasonably steady, could push it along a noticeably curved path. I've never confirmed the math of such an effect but it seems plausible -- but unproven. Perhaps this would be a worthy exercise for all of us to attempt.

The difference in orbital velocity at different ranges from the orbiter can be easy to approximate using an old 'rule of thumb' from Mission Control -- the "Ten-to-One Rule". Two objects in quasi-circular orbits with a vertical separation of X feet will separate along the velocity vector -- horizontally, essentialy -- by 10X every orbit.

So an object orbiting 50 feet lower than the shuttle will move 500 feet aheasd of it in 90 minutes -- an absolute rate of about 5 ft/minute, which comes out to about 6 degrees per minute at closest point.

The differential air drag pulls small light objects into lower, faster orbits relatively quickly. Whether that accounts for all the observed curves, I haven't determined. To claim the curves are genuinely anomalous, howver, it seems to me the burden of proof is on claimants, to show it could NOT be accounted for by ordinary (in space terms!) effects.

This could be discussed further. Some of the motion genuinely looks weird if you haven't gotten used to seeing it mission after mission, duty shift after duty shift, on the big screen. It is, after all, by definition, unearthly.

reply to post by JimOberg

Jim thank you, I've been hoping you would write a post like that addressing the motions, it gave me some good insights.

Since you listed multiple potential sources for the objects or particles we might see, does that infer that the source for the particles in the clip in the OP is unknown? (It's unknown to me, I don't know the source). But regardless of the source, while the motions are interesting, I don't see anything that looks like it's defying the laws of physics or intelligently controlled.

Regarding the sublimation propulsion effect, one thing that might kill that is rapid rotation of the ice particle. But if it's not rotating much, I would almost certainly expect there to be some sublimation, but I would also expect the propulsion effect from that to be relatively small in the context of a video like the one in the OP. It's an interesting question though.

Star for your post.

Originally posted by poet1b
What you continue to ignore is that all these UFOs clustered in the area viewed by the camera, which is very small for a considerable distance from the shuttle, are heading in different directions.
[]
Tiny cluster of particles heading in different directions that just happen to converge in front of the tiny area through which the camera was focusing on the tether almost a 100 miles away, extremely unlikely. The chances of this happening are so extremely unlikely to be that this simply is not a plausible explanation of what we are seeing in the video.

You are assuming wrong. No big attention needed, everybody can see that the bright moving objects are also filling the entire frame even when the camera is NOT ZOOMED. Look for one example, in STS75 videos there are many times when camera is not-zoomed:

[atsimg]http://files.abovetopsecret.com/images/member/e9355cacaf7c.jpg[/atsimg]

And when camera is not zoomed, it has an wide angle. Not small as you may want people to comprehend.

Let's make an estimate, taking tether as a ruler:

Tether has about 20 km. The distance from the shuttle to the tether is about 100 km.
But the tether in this un-zoomed image have just a little less than a third of the entire frame's height, let's say exactly one third for the sake of calculations.
It means the entire height of the frame is able to see 3 x 20 = 60 km at the distance (100km) where the tether is.
Therefore, basic geometrics, we could calculate the angle:

tan (angle) = 30/100
it results the angle:

Vertical Angle = 33 degree.
This value so represents the vertical angle of the lens when un-zoomed.

The horizontal angle it is bigger, let's assume a 4:3 aspect ratio of the frame, therefore

Horizontal angle = 44 degree

if you imagine the full circle 360 degree, a panorama if you wish, where camera could look if desired (ignoring the real posibilites in that circumstance), then NASA camera sees about 1 / 8 from a full panorama. Do you label this as "tiny"?


This values are pretty nominal for a normal angle (not-zoomed) lens, they represents a wide angle, just like your own photocamera or videocamera is able to have when UNZOOMED. Who says about "tiny"?

So, Poet1b, don't assume things about "tiny areas".

More, and this you ignore (why?), so, who is telling that those particles of debris are just in front of the camera? Have you any over video from STS75 looking to other areas in the same time, and no debris recorded to be sure when making this claim? Damn debris, are going just and only in one particular camera's angle of view...

It is like somebody film the sky with stars, no matter zoom or un-zoom, seeing and recording some stars in the frame, and then somebody else which later see the movie, wondering "why those tiny bright dots are only in the frame, the chances of this happening are so extremely unlikely to be .." This assuming of yours is hilarious when judgeing in it's full naked objectivity.

The shuttle could be very well surrounded by the cloud of debris generated by itself, so they are almost everywhere, not only in your "tiny area where lens it is seeing the very distant tether".

what you say? "unlikely chances"? maybe this is your biased wish, but the mundane reality, you know, the very probable one, don't care about everybody's wishes.





[edit on 1/10/09 by depthoffield]

Originally posted by JimOberg
It's a fair question to wonder about objects criss-crossing the feidl of view, and why they might not all fly in the same direction. Let me list a few of the factors that I've observed influencing such motions when i watched them on our MCC display screens.

one related short example, with debris having curved trajectories, appearing to go up and then down in image, some going to the left, some going to the right, criss-crossing the field of view and not going in the same direction:



let's say these are "crazy debris"

[edit on 1/10/09 by depthoffield]

reply to post by depthoffield
Nice work on that video DOF!

More curved trajectories!

Starred!

Also a good explanation about the field of view based on the tether's length.

Another star.

reply to post by depthoffield

I don't think we can use the length of the tether in calculations like those you posted because we cannot know what is the angle of the tether.

As far as I remember, the tether was not parallel with the shuttle's orbit, so it was seen in its full length, and not knowing what was that angle we cannot know how long did it looked when seen from the shuttle.

Maybe there is some study or report about that, but I don't remember seeing any.

Originally posted by ArMaP
reply to post by depthoffield

 

I don't think we can use the length of the tether in calculations like those you posted because we cannot know what is the angle of the tether.

As far as I remember, the tether was not parallel with the shuttle's orbit, so it was seen in its full length, and not knowing what was that angle we cannot know how long did it looked when seen from the shuttle.

Maybe there is some study or report about that, but I don't remember seeing any.

Excellent point. I watched the tether passing nearly overhead a few days after this video was taken, and recognizing the growing foreshortening effect -- the realization that it was a large object in 3_D -- raised the hair on the back of my neck in weirdness.

However, it is reasonable to assume the shuttle was seeing the tether at nearly full perpendicular line of sight, because of their relative motion. At the break moment, it was thrown into a higher orbit, with a longer orbital period, and the shuttle quickly pulled ahead of it until it vanished behind. It wasn't until days later, when the shuttle had 'lapped' the tether and was approaching from behind, that it was seen again. By then it was stable in a nearly vertical alignment, and at a range of 70 to 100 miles -- the range that happened to occur when the solar illumination was most convenient for these observations -- it would have been viewed more-or-less 'from the side', from the point of view of the shuttle.

I think this also explains why some folks like Martyn believe there are lots more videos of the tether that were never broadcast -- Martyn, please clarify, if you'd like. They assume that the tether should have been in constant view for days as it drifted farther and farther away. Not so -- it quickly went out of sight and only days later did it briefly fall within range before the shuttle's faster motion pulled it too far ahead again.

[edit on 1-10-2009 by JimOberg]

If you would indulge a stupid question, what happened to the errant tether? Did it re-enter or is it still up there?

Originally posted by draknoir2
If you would indulge a stupid question, what happened to the errant tether? Did it re-enter or is it still up there?

It burned up within a few weeks -- its drag was a lot higher than normal metallic satellites.

but there are a number of other tether satellites in higher orbits, under observation.



[edit on 1-10-2009 by JimOberg]

Originally posted by ArMaP
I don't think we can use the length of the tether in calculations like those you posted because we cannot know what is the angle of the tether.

As far as I remember, the tether was not parallel with the shuttle's orbit, so it was seen in its full length, and not knowing what was that angle we cannot know how long did it looked when seen from the shuttle.

of course, my calculus is just to give an idea. If the angle between the shuttle-to-tether line of sight and the tether was let's say 30 degree (and this is very forced!) then the projected lentgh as seen from the shuttle were 20 km x cos (30) = 10 km. Therefore, my calculated angles will have half of the values. But as J Oberg said, and if i remember corectly what i read, free tethers have automatically the vertical position due to diferential gravity (tidal stabilisation)
But this precission of calculations here is not necessary...the principle is that the un-zoomed lens have not a small angle, but a suficienty large one. No need to say "tiny area".
anyway the point of my post was that it was wrong to assume "there are low chances that debris appear exactly in the field of view of the camera", see the sky with stars example.




[edit on 1/10/09 by depthoffield]


[edit on 2/10/09 by depthoffield]

Originally posted by depthoffield

Originally posted by JimOberg
It's a fair question to wonder about objects criss-crossing the feidl of view, and why they might not all fly in the same direction. Let me list a few of the factors that I've observed influencing such motions when i watched them on our MCC display screens.

one related short example, with debris having curved trajectories, appearing to go up and then down in image, some going to the left, some going to the right, criss-crossing the field of view and not going in the same direction:

snipped

let's say these are "crazy debris"

[edit on 1/10/09 by depthoffield]

Nice try, but no cigar. Your video example is a nice attempt but those ice particles are near the shuttle, not 100 miles away in which case the lens would have focused past them and even if they were seen they would be ghostly images, not detailed as these ice particles are.

reply to post by Skeptical Ed

not detailed as these ice particles are.

haha that's hilarious

you offer no proof of nothing and make claims you know for a fact what the objects are

reply to post by JimOberg


Jim: for the third time: please comment about whether the shuttle is a capable vehicle to send astronauts to the moon including landers in its vast storage space, or not.

Originally posted by easynow
reply to post by Skeptical Ed

 

not detailed as these ice particles are.

haha that's hilarious

you offer no proof of nothing and make claims you know for a fact what the objects are

He tends to do that a lot doesn't he?

reply to post by nightmare_david


seems that way doesn't it

maybe since i gave him some instructions on how to upload pictures he will redeem himself ? we will see

Originally posted by easynow
reply to post by nightmare_david

 

seems that way doesn't it

maybe since i gave him some instructions on how to upload pictures he will redeem himself ? we will see

Doubt it. He's been trying to figure that out for a year I believe he said?

I figured it out the first time I ever posted an image on here.