Skip to comments.Chinese Space Station Crash: Why It's So Hard to Predict Where Space Debris Will Land
Posted on 03/29/2018 12:57:17 PM PDT by BenLurkin
Newtons laws tell us that satellites orbit the Earth in perfectly circular or elliptical orbits, repeating their path again and again (assuming that gravity is the only force acting on them). However, this is not true at low altitudes, say below 1,000km, because the satellite is then moving through the Earths atmosphere. This causes aerodynamic drag (air resistance) a force that opposes the satellites velocity, which effectively turns the orbit into a downward spiral towards the Earths surface.
In theory, we can calculate drag perfectly to predict the path of a satellite. This can be done using an equation that depends on the velocity of the satellite (v²), the density of the atmosphere (ρ), a numerical coefficient that depends on the shape of the satellite and its orientation with respect to the airflow (C), and the objects area (A). For those who are interested, the equation is: D = ½ × C × ρ × A × v². But you dont have to understand the equation to grasp why it is so hard to calculate drag.
The spacecrafts velocity is easy to measure fairly accurately using observations. However, the other parameters are highly uncertain making it difficult to determine Tiangong-1s path. For vehicles such as cars and aircraft, C can be estimated theoretically or with computational fluid dynamics and measured experimentally in a wind tunnel. The main problem here is that Tiangong-1s shape is complex, and the object is uncontrolled and tumbling chaotically, resulting in a constantly changing C.
The other unknown is the density of the atmosphere, which decreases with altitude. However, particularly at high altitudes, this varies due to a number of unpredictable factors the most important of which is solar activity.
(Excerpt) Read more at space.com ...
I predict it will land on my house!............................................[I’m always wrong!]......................
I was hoping on Hoggs house with him in it.
Hamtramk MI, molenbeek belgium, Malmo Sweden.
The odds-makers in Vegas should be working on this one....
“Hamtramk MI, molenbeek belgium, Malmo Sweden.”
Right on Rick’s butt in Cicely Alaska! (Maggie sad!)
Call me crazy but I suspect it might hit the earth.
Its at least as hard as trying to predict when Hillary will stop blaming everyone else for her election loss.
I predict she will blame the space station for her loss.
I don’t think Alaska is in the danger zone...................
Laboratories crashing out of the sky, diplomats being ejected in Russia — did I freaking wake up in the 70s?
I had live through carter once, GOD please not again!
I give it about 3 chances in 4 of hitting water.
So you are saying that earth’s atmosphere is rotating at up to 1000mph, even though this cannot be demonstrated in a laboratory.
And still, just as the same way we have no actual real photos of the earth from space (only fake composites), we have no actual photos of the over 250,000 pieces of broken satelites and space debris in the sky.
Only photoshopped composites.
It’s all so weird.
But then again, we are relying not on our own eyes and our own senses and our own common sense in these matters, but State-run agencies for evidence and proof.
It’s like trusting the DMV about science.
I need a new roof!..........................
Don’t know about you but I’m wearing a hard hat until this thing has fallen
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