Lyle Kelly greets a visitor to his home in this Cincinnati suburb with a button proclaiming “Mars or Bust” pinned to his tan cardigan. As chairman of the Ohio chapter of the Mars Society, Kelly helps lead a drive to persuade the U.S. government to commit to human exploration and settlement of the red planet. The society, founded in 1998, boasts 3,000 to 4,000 members who this month launched a lobbying effort to visit or provide materials to every lawmaker in Congress. Robert Zubrin, president of the Mars Society, said the United States could have humans on Mars in 10 years at a cost of $20 billion. He said his group’s offensive has begun now, in part, to grab the attention of the incoming Bush administration.