zlacker

TL;DR:

1. Voyager 2 has been pointing 2 degrees off from Earth

2. Been that way for a while and nobody noticed because very old computers.

3. Meaning that the probe has gone dark (ingress and egress comms are not possible)

4. However, both Voyager probes have software that tells them to routinely calibrate themselves every few months

5. Meaning that it should point at Earth in the next few months (most likely).

>>samhuk+(OP)
Can we also regain contact through the yearly movement of Earth on its orbit? Like the planet just walking into the new beam position?

>>Qem+91
Wouldn't work if the 2 degrees is not in the orbital plane of Earth. Right?

>>samhuk+(OP)
I don’t think the article or the news release from NASA actually says #2. They could have known for a week but took a week to release the news.

>>Qem+91
The Earth is only about 150 million km (1 AU) from the sun, so nope the Earth can't move far enough to make up for a 2 degree miss from 32 billion km away, even if it's in the right direction.

>>Qem+91
No. 2 degrees error at such a large distance equals huge distance error.

Also, empty space is huge and matter-things like Earth and the Sun are tiny compared to it.

>>Qem+91
I think we can answer this exactly. To visualize this think about the plane shared by the satellite and Earth. We'll imagine this as a 2D unit circle. In this graph Earth is at (1,0) and the satellite is at (0,0). So we end up with a scale where the radius is the same as the distance from the Earth to the satellite. But instead of pointing at (1,0), the satellite is now pointing at (cos(2), sin(2)) or (0.9994, 0.0349).

The distance from Earth (1,0) to the new location (0.9994, 0.0349) is about 0.0349. We need to scale that back up to "real" units so multiplying it by 15 billion miles. And we get about 520 million miles. The earth is about 93 million miles from the Sun, so its max positional shift (under extremely improbable absolutely perfect conditions) would be ~180 million miles.

So there's no way we could regain contact with just yearly movement, even before we account for the fact that it's getting further and further away. 2 degrees intuitively sounds small, but on an astronomical scale it's huge and this sounds like a pretty major flub by NASA.

>>somena+Am
Great explanation. Thank you!

>>samhuk+(OP)
> 5. Meaning that it should point at Earth in the next few months (most likely).

Provided that V2 still has enough propellent to make this adjustment.