Hey, my apologies if this has already been covered.

If collision detector has no charges and you boost/barrel roll and land on an asteroid. Do you have to land on the obstacle, does the action fail or do you get a choice?

Yes you can still boost and barrel roll onto Obstacles, you just can't spend a charge to ignore the effects. It's not a choice though, you cannot 'turn off' your collision detector to make an action fail.

34 minutes ago, Ubjub said:

Hey, my apologies if this has already been covered.

If collision detector has no charges and you boost/barrel roll and land on an asteroid. Do you have to land on the obstacle, does the action fail or do you get a choice?

I agree with what AramoroA said. You don't get a choice. If you have collision detector you can no longer "fail" your boosts or barrel rolls.

11 minutes ago, Frimmel said:

I agree with what AramoroA said. You don't get a choice. If you have collision detector you can no longer "fail" your boosts or barrel rolls.

You can still fail them due to other ships or board edges. Just not obstacles.