The International Space Station is an orbiting science laboratory, not some kind of exotic hotel. Yet late next year or in early 2022, two private companies plan to send three tourists on a 10-day trip to the distant station. The mission is a partnership between SpaceX, a California aerospace business founded by Tesla carmaker Elon Musk, and a Houston newcomer named Axiom. "It's real, and it’s happening," says Michael Suffredini, the head of Axiom. Paying guests will ride in a Crew Dragon capsule, which SpaceX has been developing for NASA, thrust into orbit atop a reusable Falcon 9 rocket that has worked well in past launches.

It'll be far from an ordinary vacation, obviously. For starters, it'll cost $10 million to $20 million. After training on Earth for 15 weeks, travelers will spend eight weightless days floating aboard the station after a day of flight to reach it. The trio will be accompanied by an Axiom "commander" to assist them and assure they don't interfere with the six crew members. One unidentified person is booked already, according to Axiom. Though seven tourists visited the ISS from 2001-09 aboard a Russian Soyuz rocket, the Texas company calls this "the first-ever fully private" trip. It's led by a former NASA executive who managed the agency's space station program from 2005-15.

SpaceX developed the Crew Dragon capsule to fly U.S. astronauts to the space station, starting this spring. An in-flight escape system was tested successfully in January. NASA has paid Russia, Japan and the European Space Agency during the past decade to bring Americans there to conduct experiments in biology, physics, astronomy, meteorology and other fields. Next year's planned excursion for wealthy customers will signal "a new era of human exploration," says SpaceX president and chief operating officer Gwynne Shotwell. NASA last year said that it would open the ISS to "private astronaut missions of up to 30 days." The space agency gets $35,000 a night for each guestr to cover service a tourist needs on board.

Axiom leader says: "This history-making flight will represent a watershed moment in the march toward universal and routine access to space." -- Michael Suffredini, chief executive

Different company says: "I'm hopeful it [space tourism] will be something cool and positive in the world." – Eric C. Anderson, chairman of Space Adventures in Virginia, which offers short-hop flights on its space plane

Other players: Virgin Galactic, a British company owned by Richard Branson, plans to offer a few minutes of weightlessness in its massive space plane for a few hundred thousand dollars. Blue Origin, a spaceflight company run by Amazon founder Jeff Bezo, is developing a similarly brief experience on its New Shepard rocket.