Axiom Space - founded in 2016 Houston-based startup, is shaping its plans to build the International Space Station's privately owned successor. Founders of Axiom are Michael Suffredini - retired NASA's program manager for the ISS, and Kam Ghaffarian, CEO of SGT, the company that operates the ISS for NASA and also trains America’s astronauts.
The goal is to build and fly the world's first private space station, on the first stage using the ISS as a springboard. Axiom wants to launch its first module in 2021. It will be installed on the ISS's docking port and then in 2022 two other modules (Habitatiom Module and Research and Manufacturing Module) will be added. With these modules Axiom segment will become fully operational.
Image: Axiom Space - artist's impression: Axiom Node 1 and Habitation Module docked to the ISS
After ISS's retirement, which is now planned on 2024, the station will be detached and continue autonomous flight.
With delivery of Node 2 in 2025, station will be completed.
Image: Axiom Space - Fully assembled Axiom Station on Earth's orbit
As written on their website, whole construction will be one to two orders of magnitude less costly than ISS
Axiom comes not on the empty market: Bigelow Aerospace is now occupying ISS docking port with its BEAM module, built with proprietary inflatable technology. Testing of the BEAM started one year ago and will last one year more. Bigelow also has plans for private orbital and cislunar station, based ot its magor project - inflatable module Bigelow B330 which also is scheduled for the ISS in 2020. Both companies will compete for the sole free docking port.
Image: Bigelow Aerospace - Bigelow B330 Module
In an inteview with Scientifical American Journal Suffredini said:
The sooner ISS gets out of orbit, the sooner NASA saves three and a half or even four billion dollars per year, depending on when exactly they deorbit. That’s NASA’s yearly operating cost. And then you look at all the other government partners, and between all of them they’re in it probably close to a billion dollars more in terms of yearly costs. That’s money that could instead be spent on exploration work, which makes 2024 seem desirable.
Answering to the question about competition with Bigelow, he said:
Bigelow has been very overt about their desire to fly, but I don’t know enough about what they’re doing to say how viable they are. What I do know is they are planning on using inflatable technology. Inflatable modules are pretty cool but they have their challenges. How the material itself works is being tested on orbit today, but there’s a very big trick in figuring out how you’re going to outfit inflatables—where all the plumbing and other systems will go, and how you’re going to ensure stale pockets of air don’t form inside, since that’s something that could asphyxiate a crew. There are all kinds of things that need to be done—and I’m sure they will be—but in the near term I think that’s much further away than the time frame we need to fly
Axioms says that they want to launch as soon as possible, so we might expect interesting race. But neither of them would be first station, built after ISS: with probability close to 100% it will Chinese station, with its core module is scheduled for launch in 2019.
Sources:
[2] https://www.space.com/35488-private-space-station-2020-axiom-space.html