pioneer acceleration question

Can we determine precisely the direction pioneer is taking, with
respect to the sun? If it is engaged in a direction change ultimately
to return to SS orbit, what would the first indication be to our
measurement devices? ...
Thanks, johnreed

"johnreed" wrote in message
...
Can we determine precisely the direction pioneer is taking, with
respect to the sun?

It is moving at roughly a 10 degree angle to the
radial direction on a hyperbolic orbit.

If it is engaged in a direction change ultimately
to return to SS orbit, what would the first indication be to our
measurement devices? ...

The anomalous acceleration appears to be directed
towards the Sun or Earth (those directions are
separated by less than 2 degrees seen from the
craft so cannot be distinguished at the resolution
of the data). To change direction, there would need
to be a transverse component which does not appear
to exist.

The craft will never return, they are well above
escape velocity. Dividing the present speed by the
anomalous acceleration gives about 500 million years
for the craft to stop.

George

George Dishman wrote:
"johnreed" wrote in message
...
Can we determine precisely the direction pioneer is taking, with
respect to the sun?

It is moving at roughly a 10 degree angle to the
radial direction on a hyperbolic orbit.

jr writes Was the hyperbolic expected and the anomaly one of degree?

If it is engaged in a direction change ultimately
to return to SS orbit, what would the first indication be to our
measurement devices? ...

The anomalous acceleration appears to be directed
towards the Sun or Earth (those directions are
separated by less than 2 degrees seen from the
craft so cannot be distinguished at the resolution
of the data). To change direction, there would need
to be a transverse component which does not appear
to exist.

The craft will never return, they are well above
escape velocity. Dividing the present speed by the
anomalous acceleration gives about 500 million years
for the craft to stop.

George

jr writes
Thanks George.

johnreed wrote:
George Dishman wrote:
"johnreed" wrote in message
...
Can we determine precisely the direction pioneer is taking, with
respect to the sun?

It is moving at roughly a 10 degree angle to the
radial direction on a hyperbolic orbit.

jr writes
Was the hyperbolic expected and the anomaly one of degree?

Yes, the trajectory is almost exactly what was planned.
The anomaly is tiny by comparison, an acceleration
that has added up to only 0.2m/s error in over twenty
years compared to a planned speed of about 12000m/s

George

wrote:
johnreed wrote:
George Dishman wrote:
"johnreed" wrote in message
...
Can we determine precisely the direction pioneer is taking, with
respect to the sun?

It is moving at roughly a 10 degree angle to the
radial direction on a hyperbolic orbit.

jr writes
Was the hyperbolic expected and the anomaly one of degree?

Yes, the trajectory is almost exactly what was planned.
The anomaly is tiny by comparison, an acceleration
that has added up to only 0.2m/s error in over twenty
years compared to a planned speed of about 12000m/s

George

jr writes
Thank you George. Good information here. Have a good time.
johnreed