Ordinal names are a modified base-26 encoding of ordinal numbers. To avoid locking short names inside the unspendable genesis block coinbase reward, ordinal names get shorter as the ordinal number gets longer. The name of sat 0, the first sat to be mined is "nvtdijuwxlp" and the name of sat 2,099,999,997,689,999, the last sat to be mined, is "a"