I noticed this too, and another thing even if you didn't want to reclaim your old ship, is you can finish grabbing any items that you did not have room for. I took the crashed ship, used up a bunch of items repairing, then went back to my old ship and grabbed all remaining items I had left on board. i noticed the option to take the original ship back but declined since I am trying to slowly upgrade mine.

Walk up to it and interact with it as you would a crashed ship.

Yes, you can go back to it as long as you don`t quit the game. From what I saw if you quit then come back, your old ship is gone, even if you saved.