RE: ACE elements

Philip Chien (
Sun, 7 Sep 1997 23:42:19 -0400

Jeff Hunt <> said:

>I found two nice web sites related to ACE
>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.