In Returnal you can randomly find so-called Reconstructors in side rooms (behind blue gates on minimap). The Reconstructor costs 6 Ether to activate.
Here’s what a Reconstructor looks like:
What Reconstructor does in Returnal: The Reconstructor for 6 Ether is essentially a respawn station. If you die you respawn at the Reconstructor. You should always keep your Ether (a form of currency) for activating Reconstructors. However, you only respawn there if you happen to die in the same biome (region). If you travel to a different biome and die there, the Reconstructor won’t work and you respawn at the drop pod instead. Only activate a Reconstructor if it’s in the same region as your next boss fight, otherwise it’s not worth it. Don’t waste your ether on cleansing purple items/chests. Because Ether is relatively rare, 6 Ether is actually quite expensive so use it wisely. The most important Reconstructor in the game is at the start of the 5th biome (Fractured Wastes) which you should always activate when you get there.