The Backpack is the main tool that the player has throughout Astroneer. It features a total of ten small attachment slots, with an additional three slots on the Terrain Tool, a printer, a handle to access the research catalog, a handle to access the mission log, a built-in oxygen canister, and a built-in battery for powering the printer or the Terrain Tool. Of the ten attachment slots, eight are normal slots and two are Widget Slots, with the Widget Slots being on the top left and right of the backpack.
The various features of the backpack can be accessed by "opening" it, which makes it larger and easier to interact with. To open the backpack, simply press Q on the keyboard, or on the controllers, or press or to select it directly using the cursor.
The backpack has 8 slots dedicated to resource and small item storage. Items can be placed into, removed from, and rearranged within these slots manually, but as long as there is an inventory slot available, resource nuggets collected with the deform tool or items created using the backpack's printer will be automatically placed there. If all inventory slots are full, newly created or collected items will drop to the ground nearby. To quickly put items into backpack slots, Shift and left click on the item; on gamepad, hover over the item with or and press or .
There are 2 additional slots on the top left and right of the backpack, which is meant for Widgets. These are commonly used to host items such as the Solar Panel, Worklight or Portable Oxygenator. Some widgets in these slots can be toggled on and off using the context keys (default C , , or and V , , or , left and right respectively), such as the Worklight, Portable Oxygenator or Small Generator. Like other attachment points, however, they can also be fitted with resource stacks or other small items for additional storage.
Pressing Tab, , or , or clicking the handle on the left side of the backpack will open the research catalog, where player can purchase Schematics using accumulated Bytes. The catalog is separated into 4 different size categories, corresponding to the four sizes of objects created by the corresponding printers. The context keys (default C , , or and V , , or ) can be used to move around those categories.
The catalog includes a pad with buttons that can be used to navigate around it, which also hints which controller buttons are used to navigate around the catalog.
The movement keys can be used to move around a category, and the Context Left/Right keys to change categories. Alternatively, the buttons and schematics can be clicked on to move to categories or different items.
Using the small printer on the Backpack, items can be crafted on the go at the cost of 3 Units of Power. Cycling through the available items will automatically move the appropriate resource to the printer's input slot if it is already in the backpack. This input slot can be used to deliberately store a specific extra resource, if so desired, but be forewarned that changing the item to be printed will eject the contents of the input slot from the backpack if the rest of its inventory slots are already full.
Oxygen and Power Storage
- Prominently displayed on the backpack are two gauges: the horizontal oxygen gauge in light blue, and the vertical power gauge in bright yellow.
- Enough oxygen is stored for 72.5 seconds of untethered field work. Running consumes a little more oxygen, making the tank empty in 50 seconds instead.
- You get a notification when the tank is 50% and then 25% full. When you run out of oxygen, you are suffocating. Within 5 seconds of starting to suffocate, you cannot run anymore. After 15 seconds of suffocation, you will die and be sent back to your ship or shelter.
- Each segment of the vertical yellow bar represents a single Unit of power, storing a total of 10 Units.
- Power is only drained when using an Augment on the Terrain Tool, or when using the printer.
- A small battery stores enough power to use a single augmented deform tool continuously for about 64 seconds, depending on whether power-generating widgets are being used.
- As an internal battery, the backpack will not transfer its charge to other batteries.
- Technically the backpack has a total of 14 available slots (8 backpack inventory slots, 2 attachment slots, 1 printer inventory slot, and 3 more slots on the terrain tool as of the latest update)
- Initially in the tutorial, the oxygen tank in the player's backpack is smashed open, presumably by the crash the player experienced at the start. This renders it impossible to survive for any length of time away from a oxygen source, as the moment the player leaves a tether's range, they will begin to suffocate. The moment the player interacts with the dead astroneer's backpack however, they replace the smashed oxygen tank with the discarded backpack's good one, enabling the player to travel away from tethers as they normally would be able to.
- A broken version of the Research Catalog can rarely be found, and was added to tease the working counterpart's addition in a later update.
- A total of 284,050 bytes are needed to research every Schematic in the game.