Pioneer H was a proposed space probe for the US Pioneer program. If it had been approved, it would have been launched in 1974 and have been designated Pioneer 12; that designation was later applied to the Pioneer Venus Orbiter.
Pioneer H was a proposed space probe for the US Pioneer program. If it had been approved, it would have been launched in 1974 and have been designated Pioneer 12; that designation was later applied to the Pioneer Venus Orbiter.