Fun with Satellites

[+Damenace]

I would imagine that clockwise would be the best revolution pattern for this simulation. I've tried running them counter clockwise, but even when they're close to the earth, the moon grabs them and pulls them farther and farther away. The ones I have in clockwise orbit move between more circular patterns and more elliptical patterns.

 

I've got 10 out that have been going for a few hours now. The ones I released last night around 11 scorched some peasants sometime in the overnight hours.

 

I would be curious to know why the satellites that are traveling in a clockwise rotation last long than the counter clockwise ones.

 

Is there a scientific reason reason behind this. In real life is this the direction that satellites rotate?

[Mushtang]

I would imagine that clockwise would be the best revolution pattern for this simulation. I've tried running them counter clockwise, but even when they're close to the earth, the moon grabs them and pulls them farther and farther away. The ones I have in clockwise orbit move between more circular patterns and more elliptical patterns.

 

I've got 10 out that have been going for a few hours now. The ones I released last night around 11 scorched some peasants sometime in the overnight hours.

 

I would be curious to know why the satellites that are traveling in a clockwise rotation last long than the counter clockwise ones.

 

Is there a scientific reason reason behind this. In real life is this the direction that satellites rotate?

My guess is that clockwise orbits pass the moon faster than counterclockwise orbits, and therefore the moon has less time to mess up the satellite.

 

In real life most satellites orbit in the same direction as the moon (counterclockwise as seen from above the North pole) because it's cheaper to get them that way since the earth spins that way too. For satellites that need a retrograde orbit for whatever reason, it's still possible.

 

This simulation has very little resemblance to the real interaction between the earth, the moon, and satellites. It's fun to play with, but it's not accurate at all. Primarily because of the distance between the earth and moon, and the gravitational fields. Also, in this simulation, the moon isn't in orbit around the earth, it's following a timed path. The difference is, if it were orbiting according to the same rules as the satellites then you could put one in orbit at the same distance as the moon is, and it would orbit at the same speed.

 

Objects that orbit closer to the earth go around in less time than object that are in orbit way out. The space shuttle normally orbits fairly close to the earth, and only takes 90 minutes to go all the way around. Geosynchronous satellites orbit much further out, and go around exactly once a day. The moon orbits much further away still, and takes a whole month to go around. In this simulation, you can put a satellite in orbit outside of the moon that will pass by it a couple of times before it goes all the way around.

 

A possible reason that some satellites are staying in orbit for 20+ hours and then crashing, is that in this program whenever you do something on your computer that takes a lot of CPU time (like downloading a massive web page, or starting up a large program), the program will pause momentarily a few times, and this will mess it up. The moon resumes it's orbit where it would have been with no pause, but the satellites start from where they were.

 

Launch a satellite near the moon's orbit and wait until it's about to crash into the moon. Right before it does, click the mouse button somewhere on the screen and hold it for about 10 seconds. When you let go the moon will shift way far away, but the satellite will be saved. If you got a satellite to stay in orbit for more than an hour, you could probably go on vacation and come back to see it still going, assuming your computer didn't do anything to cause the program to pause (auto virus checking, program updates, screen saver, whatever).

 

It's still a really fun toy to play with.

[+mudsneaker]

that explains why the one I had going from yesterday crashed then. It looked fine when I woke up, but then I fired up Explorer and was checking websites, news, ect. and when i looked again shortly after it was gone.

Good explainations

[+nickzeke]

I have 4 that have been orbiting for 25 hours. They are still in stable orbit. I expect them to go for at least another day.

[+Damenace]

I would imagine that clockwise would be the best revolution pattern for this simulation. I've tried running them counter clockwise, but even when they're close to the earth, the moon grabs them and pulls them farther and farther away. The ones I have in clockwise orbit move between more circular patterns and more elliptical patterns.

 

I've got 10 out that have been going for a few hours now. The ones I released last night around 11 scorched some peasants sometime in the overnight hours.

 

I would be curious to know why the satellites that are traveling in a clockwise rotation last long than the counter clockwise ones.

 

Is there a scientific reason reason behind this. In real life is this the direction that satellites rotate?

My guess is that clockwise orbits pass the moon faster than counterclockwise orbits, and therefore the moon has less time to mess up the satellite.

 

In real life most satellites orbit in the same direction as the moon (counterclockwise as seen from above the North pole) because it's cheaper to get them that way since the earth spins that way too. For satellites that need a retrograde orbit for whatever reason, it's still possible.

 

This simulation has very little resemblance to the real interaction between the earth, the moon, and satellites. It's fun to play with, but it's not accurate at all. Primarily because of the distance between the earth and moon, and the gravitational fields. Also, in this simulation, the moon isn't in orbit around the earth, it's following a timed path. The difference is, if it were orbiting according to the same rules as the satellites then you could put one in orbit at the same distance as the moon is, and it would orbit at the same speed.

 

Objects that orbit closer to the earth go around in less time than object that are in orbit way out. The space shuttle normally orbits fairly close to the earth, and only takes 90 minutes to go all the way around. Geosynchronous satellites orbit much further out, and go around exactly once a day. The moon orbits much further away still, and takes a whole month to go around. In this simulation, you can put a satellite in orbit outside of the moon that will pass by it a couple of times before it goes all the way around.

 

A possible reason that some satellites are staying in orbit for 20+ hours and then crashing, is that in this program whenever you do something on your computer that takes a lot of CPU time (like downloading a massive web page, or starting up a large program), the program will pause momentarily a few times, and this will mess it up. The moon resumes it's orbit where it would have been with no pause, but the satellites start from where they were.

 

Launch a satellite near the moon's orbit and wait until it's about to crash into the moon. Right before it does, click the mouse button somewhere on the screen and hold it for about 10 seconds. When you let go the moon will shift way far away, but the satellite will be saved. If you got a satellite to stay in orbit for more than an hour, you could probably go on vacation and come back to see it still going, assuming your computer didn't do anything to cause the program to pause (auto virus checking, program updates, screen saver, whatever).

 

It's still a really fun toy to play with.

 

Thank you for the very detailed scientific explanation

 

I have 4 that have been orbiting for 25 hours. They are still in stable orbit. I expect them to go for at least another day.

 

I have one that has now gone over 24 hours, I added another one earlier today and it is just as stable as the first one. In fact it is rotating is the same "orbit" as the first one.

[+Iowa Tom]

Just discovered this topic. I've been Googling "Earth to Moon Experiment" for years. I challenge my students by telling them to try to get a satellite to do a figure-8 around the earth and the moon. This applet works real well when showing the acceleration of gravity.

 

-it

[peachs]

How do NASA make it look so easy?

[peachs]

Mine's been up for over 24 hours.

 

[+Retcon]

How do NASA make it look so easy?

 

I'm guessing they have slightly more sensitive equipment than a mouse and a 300x300 window.

[+Iowa Tom]

A friend of mine once said he had a satellite orbiting the earth and the moon for two days, at least.

 

-it

[+nameless301]

This is a pretty cool game, haha, crash and burn.

[+Iowa Tom]

Here's a link with all the successful real SATS now in orbit.

 

http://science.nasa.gov/RealTime/jtrack/3d/JTrack3D.html

J-Track 3D does not show all the operational satellites in orbit. It is selective. Here's an image I made showing a lot more of the stuff that's up there. The green haze close to the earth are low earth satellites.

 

I'm currently writing curriculum about satellites and their orbits and do find J-Track 3D to be very useful! Just today I discovered a fun trick that I didn’t realize that a person can do with it. Try this, click on this URL then under “Satellite” and “Select” highlight the top satellite in the list. Then press and hold down the down arrow on your keyboard. A fast computer will produce quite a show. I find it especially informative when the GPS and COSMOS satellite orbital planes are displayed one after the other. The Iridiums occupy many planes as well. I especially like watching for the highly eccentric orbits like the one for DOUBLESTAR (TC-1).

 

Tonight at my location I will see a magnitude -4 flare from the Iridium 57 satellite. Flares from these satellites are not uncommon but the really bright ones, e.g. up to magnitude -8 or -9, don’t occur often at any one location, aside from the poles that is, and then only at certain times of the year. Here's a picture I took of a -8 Iridium flare that occurred over my place the other day.

 

What I’m going to do at the time of this flare is, not only will I observe the satellite directly, but I will have J-Track 3D up on my laptop using wireless outside. I’ll have Iridium 57 “selected” and “centered” and as the flare occurs and I will see where it is with respect to my location. I have planetarium software that will do a lot better job but I would like to see how J-Track 3D works live in this situation. Secondly I will also go to this website to see where it’s at. Lastly I will click on this URL as well.

 

-it

Edited February 19, 2007 by Iowa Tom

[+Iowa Tom]

What I’m going to do at the time of this flare is, not only will I observe the satellite directly, but I will have J-Track 3D up on my laptop using wireless outside. I’ll have Iridium 57 “selected” and “centered” and as the flare occurs and I will see where it is with respect to my location. I have planetarium software that will do a lot better job but I would like to see how J-Track 3D works live in this situation. Secondly I will also go to this website to see where it’s at. Lastly I will click on this URL as well.

I saw the flare and observed the satellite's position using this this website. It's position compared to my position, the house, at the time of the flare, is shown below. I forgot to use J-Track!

 

Edited February 20, 2007 by Iowa Tom

[+Iowa Tom]

I just started this topic that is an offshoot of this one.

 

-it