What SadPandaa said.
To use your limpets, you need to bind them to a fire key in the fire groups menu.
Collector limpets have two modes:
- If you have a fragment/cannister targetted when you fire a limpet, the limpet will collect this object and expire. This is useful if you want to quickly get a couple of items from a cloud of debris.
- If you have nothing targetted when you fire a limpet, the limpet will collect everything within range. This mode won't pick up cargo that you have dropped.
If you fly out of range of a limpet, it will expire.
If you are moving too fast, the cargo the limpet is bringing you will be destroyed.
Limpets will sometimes smash into debris or asteroids and expire.