Welcome, Guest. Please Login.
Gravity Simulator
11/18/17 at 22:38:00
News: Registration for new users has been disabled to discourage spam. If you would like to join the forum please send me an email with your desired screen name to tony at gravitysimulator dot com.
Home Help Search Login


Pages: 1
Send Topic Print
NASA's Stereo Mission (Read 4790 times)
Tony
YaBB Administrator
*****




Posts: 1051
Gender: male
NASA's Stereo Mission
11/03/07 at 20:53:31
 
On October 26, 2006, NASA launched a pair of spacecraft to observe the Sun in stereo.  On December 15, 2006, the pair of spacecraft swung by the Moon for a gravity assist.  Stereo A was ejected into solar orbit.  Stereo B remained in Earth orbit to receive another gravity boost from the Moon on January 21, 2007.


 
The simulation http://orbitsimulator.com/gravity/simulations/stereo10272006.gsim shows a trio of spacecraft: Stereo A, Stereo B, and their booster rocket, in Earth orbit following launch.  If you run this simulation, you'll notice that all three spacecraft crash to Earth at perigee.  While this was the fate of the booster rocket, Stereo A and Stereo B performed a burn while near apogee, raising their perigees above Earth's surface.



 
The simulation http://orbitsimulator.com/gravity/simulations/stereo11022006.gsim shows these twin spacecraft as they continue to orbit the Earth in highly eccentric orbits that carry them from just above Earth's surface to slightly beyond the orbit of the Moon.
 


 
The simulation http://orbitsimulator.com/gravity/simulations/stereo12152006.gsim shows the spacecraft swing by the Moon for a gravity assist on December 15, 2006.  Watch as Stereo A is ejected from the Earth / Moon system, while Stereo B is boosted into a wider orbit around the Earth.



 
On January 21, 2007, Stereo B returns to the Moon for another gravity boost that will eject it from the Earth / Moon system.  The simulation http://orbitsimulator.com/gravity/simulations/stereo01212007.gsim shows Stereo B just prior to the gravity boost.  Watch as it is ejected into solar orbit.



 
Switch the Focus Object to the Sun and zoom out to watch the twin spacecraft in their solar orbits.



 
The simulation http://orbitsimulator.com/gravity/simulations/stereoRF.gsim shows the spacecraft in a rotating frame with its period set to Earth's orbital period.  Year after year the spacecraft become more distant.  Soon stereo images will not be possible because the seperation between the two spacecraft will be too great.

Back to top
 
 
Email View Profile WWW   IP Logged
frankuitaalst
Ultimate Member
*****


Great site

Posts: 1507
Gender: male
Re: NASA's Stereo Mission
Reply #1 - 11/04/07 at 02:11:14
 
The simulation http://orbitsimulator.com/gravity/simulations/stereoRF.gsim shows the spacecraft in a rotating frame with its period set to Earth's orbital period.  Year after year the spacecraft become more distant.  Soon stereo images will not be possible because the seperation between the two spacecraft will be too great.
Was is the intention to let the two spaccraft drift away ? Or don't they have any fuel or means to change their orbit anymore ? BTW : where does NASA provide the orbit data for this spacecrafts ?
Back to top
 
 
Email View Profile   IP Logged
Tony
YaBB Administrator
*****




Posts: 1051
Gender: male
Re: NASA's Stereo Mission
Reply #2 - 11/04/07 at 11:34:01
 
The data is available on the Horizons system.  Their IDs are -234 and -235.
 
Wikipedia's article states that they drift about 21 degrees a year in opposite directions.  They probably don't have enough fuel to halt their drift.
Back to top
 
 
Email View Profile WWW   IP Logged
Pages: 1
Send Topic Print