On Tuesday, OP Labs, the main development firm behind the Optimism blockchain, will begin testing fault proofs on Ethereum’s Sepolia test network. The new deployment comes a few months after Optimism launched an initial version of fault proofs on Goerli, another Ethereum test network, in October. Karl Floersch, co-founder of Optimism and CEO of OP Labs, told CoinDesk he expects the proofs to reach Ethereum’s main network later this year, with the Sepolia deployment bringing the team closer than ever to this goal.