To move around Hardscape: Shipbreaker, your suit needs fuel to power the jets on your back. Without fuel, you're a slow block who won't be able to find a suitable surface to bounce on, and you can get stuck pretty quickly. It's easy to get distracted by a great ship and find yourself in the middle of it when the fuel runs out, or when you get out of it and can't come back to the terminal to buy more. Fortunately, you have a few tools to help you navigate without fuel.
The most effective, and possibly chaotic, tool available to you is your grappling hook. You can not only use it to direct the trajectory of the objects you collect, but yourself in space. Aim your grapple at an object, then curl up using the retraction beam. For those who play with mouse and keyboard, this is the right mouse button or the G key. If you are playing on a gamepad, it is the LT button, while you have your grappling hook attached. to an object. The retractable beam propels you forward and sends you places pretty quickly.
Unfortunately, without fuel, you can't stop. You don't want to be too fast, or you could throw yourself in the wrong direction, potentially off the job site and into space. You should slowly crawl towards the center hub using the retraction beam. Take your time and be patient.
Using the grapple and retraction beam is your primary method of returning to the hub. Alternatively, if you are stuck in the closed environment of a vessel with no fuel, you can use your hands. Use the X key for your right hand and the Z key for your left, which translates to RB and LB for those using a controller. Your magnetic hands can hold onto a ship, giving you time to stabilize and move forward. It doesn't move you fully around like your jet thrusters do, but it does help move around in enclosed environments.
Being stuck in space without fuel is difficult. Check your reserves before jumping into the belly of a ship and always keep an eye on how much you have and your oxygen levels.