In space MMORPGs, there is a higher percentage of players who enjoy exploration than in fantasy MMORPGs, but they are also more disconnected from the regular MMORPG gamers. To cater to these players, we have specifically designed the Warrant NFT system for exploration gameplay in Space Nation Online. Unlike other persistent NFTs such as spaceships and crews, Warrant is a one-time use NFT that can be minted by players during their exploration. As players discover various findings in their exploration, such as star maps, special events in a wormhole, or treasures in a space-time rift, they can mint these discoveries into a Warrant NFT and list it on the marketplace. Upon purchasing the Warrant NFT, other players can gain access to the event, explore dungeons, embark on adventures, and potentially obtain loot from the event to test their luck. It is a small system, but we hope to show how NFT design can improve game design and enhance the overall game experience.