NEW YORK (CNNMoney) — The space agency said it will hold a news conference at Kennedy Space Center in Florida at 4 p.m. ET to discuss “the return of human spaceflight launches to the United States,” according to a brief statement on its website.
NASA ended its Space Shuttle program in 2011 amid funding concerns and a shift in priorities to exploring deep space.
The agency is expected to award a contract to one or more private aerospace companies to shuttle astronauts back and forth to the space station.
Since the shuttle program was retired, NASA crewmembers have been hitching rides on Russian Soyuz spacecraft, at a cost of $70 million per seat, according to a NASA spokeswoman. The agency typically purchases six seats per year.
Related: Elon Musk’s SpaceX will sue U.S. over rocket contract
The contract to be announced Tuesday will be difficult to compare with the current arrangement, since it will involve “additional capabilities,” such as development and certification programs, as well as shuttle services, the spokeswoman said.
The spokeswoman could not comment on which companies might be awarded the potentially lucrative contract.
The leading contender is Boeing (BA), according to the Wall Street Journal. Other bidders include SpaceX, which is backed by Tesla (TSLA) CEO Elon Musk, and Sierra Nevada Corp.
NASA could award contracts to multiple companies, the spokesperson said.
Representatives for Boeing, SpaceX and Sierra Nevada did not immediately respond to requests for comment.