Eth2 Beacon Chain Launches on Ropsten Testnet, Paving Way for Merge

The Ethereum Foundation launched the Eth2 Beacon Chain on a public testnet yesterday, marking one of the final tests before Ethereum transitions to Proof-of-Stake later this year.

The Beacon Chain, Eth2’s Proof-of-Stake consensus layer, went live on the longstanding public testnet, Ropsten. 

The launch is a major milestone toward Ethereum’s highly anticipated ‘chain-merge’, which developers expect to go live on mainnet during the third quarter of this year. 

The event, also known as The Merge, will unify the Eth2 Beacon Chain with the Ethereum mainnet, transitioning the network from Proof-of-Work consensus to Proof-of-Stake. 

The upgrade, several years in the making, is tipped to usher in a more than 99% reduction in Ethereum’s energy consumption on mainnet, alongside a 90% reduction in Ether issuance. 

Combined with the base fee of Ethereum’s transaction fees being burnt, analysts predict that The Merge will burn more ETH than is created through validator rewards, making the cryptocurrency deflationary.

After five shadow forks — deployments to closed testnets — the Merge must first launch on three public Ethereum testnets, starting with Ropsten. 

The launch of Beacon Chain on Ropsten paves the way for The Merge to deploy on Ropsten. Analysts expect the Ropsten merge will take place in about nine days.

The Ethereum Foundation will publish an update confirming the Terminal Total Difficulty (TTD) for Ropsten on June 3. TTD, also known as the difficulty bomb, refers to the block height at which the devs will hardcode The Merge to take place.

Once The Merge is live on Ropsten, it will soon launch on the Goerli and Sepolia testnets. Provided they discover no major issues on the testnets, Ethereum developers will deploy The Merge on the mainnet.

The foundation urges teams running dapps on Ethereum to ensure that their code works as intended on Ropsten, and to report any issues they experience to the Foundation. ETH holders don’t have to do anything to prepare for The Merge. 

The Foundation also scheduled a merge community call for June 3. Client developers and researchers will answer questions from the community concerning The Merge during the call. The Foundation added that it intends to deprecate Ropsten after The Merge.

The road to Eth2 has been long and winding. Ethereum chief scientist Vitalik Buterin first articulated a roadmap for the network’s transition to Proof-of-Stake in 2015 –  two days before launching Ethereum’s mainnet. 

Buterin expressed regret for “wasted time” on the Hashing It Out podcast in mid-2020. “Had we known that it would end up taking us years, we probably would have designed the roadmap differently and thought about what the different teams would be working on differently, and ma[de] a lot of decisions in that regard in a very different way from how we are now,” Buterin said.”

The Eth2 Beacon Chain finally launched in December 2020, allowing ETH holders to deposit and stake their ETH on the new chain. Withdrawals and smart contracts functionality will go live on the Beacon Chain sometime after The Merge.

Last week, a miner sought to stress-test The Merge’s deployment on Ropsten by directing significant hashing power towards the network

They were responsible for a 100x increase in the testnet’s hashrate, speeding up block production and temporarily hastening the difficulty bomb by 13 days – even though the Beacon Chain hadn’t been deployed to Ropsten yet.

While Ethereum’s devs easily mitigated the issue by delaying the bomb, the changes required node operators to upgrade their software again to prepare for The Merge on Ropsten.