Jeff Hunt <firstname.lastname@example.org> said: >I found two nice web sites related to ACE > >http://www.gsfc.nasa.gov/ace/ace.html >http://sd-www.jhuapl.edu/ACE/ACE_FactSheet.html > >Unfortunately, there are no elements there either ACE is currently in cruise mode on its way to the L1 point. The Delta 2nd stage sent it on to a heliocentric trajectory so it's no longer in orbit around the Earth. When it arrives at L1 it technically won't be in 'orbit' since it will be in a halo path around the L1 point which is controlled by the interaction of both the Earth and Sun. Yes, it will travel around the sun once a year and no it doesn't obey the laws of physics. But the general assumption for orbits is one object orbiting around another. And the Lagrange points are gravitationally stable because they use the interation of three bodies.