archive: Re: SETI FW: [ASTRO] Spacecraft distances from the Sun

Re: SETI FW: [ASTRO] Spacecraft distances from the Sun

David Woolley ( david@djwhome.demon.co.uk )
Wed, 16 Sep 1998 08:43:14 +0100 (BST)

>
[ sagan list deleted, it would just bounce; astro list not in headers
received. ]

> ----------
> From: Jega A. Arulpragasam

> Could someone please provide me with the current distances from the Sun
> of the Voyager and Pioneer spacecraft that are now winging their way out

The JPL web site certainly has orbital elements (sets of 6 numbers that
characterise, the for Voyager, hyperbolic orbit in time and space)
for Voyager, and probably the others. You ought to be able to manually
reconstruct the orbit to a reasonable accuracy with these, but JPL's
horizons system should be able to compute an orbit forwards including
planetary perturbations. These will give the theoretical orbits not
the reported anomalous ones, but I suspect the latter are out only by
a few meters. They won't account for any propulsion effects, either.