Multiple Space Suits are provided by the Ad Astra mod, with some being more powerful than others. You won’t be able to go into Space without one equipped, and some planets, such as Venus and Mercury, require a special suit due to how hot they are.
The first suit you will craft in Ad Astra is the standard Space Suit. This suit provides the bare minimum, allowing you to travel to less dangerous locations, like the Moon. Crafting an entire Space Suit requires 16 Steel Ingots, 5 White Wool, 1 Glass Pane, 2 Oxygen Tanks, and 1 Oxygen Gear.
Once a Space Suit has been created and equipped, it must be provided with Oxygen. Otherwise, you will die when leaving the Earth (Overworld). Oxygen can be added directly to a Space Suit using the Oxygen Loader. When supplies are low, filled Oxygen Tanks can be consumed to replenish Oxygen levels.
To obtain Steel Ingots provided by Ad Astra, you must place Iron Ingots inside a Blast Furnace at a rate of 1:1.. In contrast, Oxygen can easily be created by converting Buckets of Water inside the Oxygen Loader. This Space Suit can hold 1000 Oxygen.
Netherite Space Suit
When going deeper into Space, to planets like Venus and Mercury, you must upgrade your Space Suit into a Netherite Space Suit. Planets like Mercury are hot, and you will continually take fire damage in a standard Space Suit.
Crafting the Netherite Space Suit requires a complete set of Netherite Armor, 1 Glass Pane, 2 Oxygen Tanks, 1 Oxygen Gear, 14 Ostrum Plates, and 4 Desh Plates. Desh Ore can be mined on the Moon, whereas Ostrum can be found on Mars, with them most commonly spawning around Y level 0 and below.
Another reason to equip the Netherite Space Suit is that they provide more defenses than the regular Space Suit. If you try to visit Venus or Mercury without the Netherite Space Suit, you will die. Netherite Space Suits can hold 2000 Oxygen.
The final upgrade is the Jet Suit. Compared to the Netherite Space Suit, it provides additional protection, more Oxygen storage, and the ability to fly, which should help navigate hostile worlds like Venus or Mercury, where lava pools are common.
Crafting the Jet Suit requires a full set of the Netherite Space Suit, 14 Calorite Plates, 2 Calorite Tanks, 4 Calorite Blocks, 1 Calorite Engine, and 1 Glass Block. To obtain Calorite, which you’ll need a lot of, you will need to go mining in the caves of Venus.
Jet Suits can also be used to fly, provided they have Energy. Powering them requires an Energizer, which should be connected to energy-generating machines such as Coal Generators or Solar Panels.
When the Jet Suit is placed inside, it will begin to charge. In the top-right corner, you can see the remaining energy as a percentage value when it’s equipped. The Jet Suit can hold 4000 Oxygen and 1,000,000 Energy.