The key to Space Chain is to deploy all blockchain nodes on satellites so as to bring blockchain technology into space, adding a new dimension to blockchain’s core concept of distributed ledger by making use of space technology and advantages of space resources. As a space blockchain platform featuring data collecting, computing, application and storage, Space Chain uses satellites as its blockchain nodes for realizing direct on-satellite data processing and secure in-space data storage through cryptographic technologies such as quantum communications. Different from ground-network-based blockchain technology, Space chain provides a broader coverage and is based on a network of LEO satellites for achieving broad-based connectivity so that anyone and anything could become the user of blockchain technology anywhere and anytime.