Posted:

**Jan 21, 2022 12:35 pm**So the L2 insertion burn is scheduled for next Monday, 24th Jan.

It's nearly a million miles away. How do they measure its position and velocity accurately enough to get the burn - duration and direction - exactly right?

I can think of a variety of ways, including integrating telemetry data from onboard accelerometers (once for the velocity, again for the distance), but I have no feel for whether that could be precise or accurate enough.

Anyone with actual knowledge? I mean it can't be rocket science, surely ... ah wait

It's nearly a million miles away. How do they measure its position and velocity accurately enough to get the burn - duration and direction - exactly right?

I can think of a variety of ways, including integrating telemetry data from onboard accelerometers (once for the velocity, again for the distance), but I have no feel for whether that could be precise or accurate enough.

Anyone with actual knowledge? I mean it can't be rocket science, surely ... ah wait