NASA is seeking proposals for a further two private astronaut missions to the International Space Station

• NASA is seeking proposals for its next two private astronaut missions to the ISS.
• The news follows a previously announced agreement with Axiom Space.
• The missions are part of the agency's plan to democratize space travel and make it more accessible.

NASA is seeking proposals for the next two private astronaut missions to the International Space Station (ISS), the agency announced Friday.

One mission is expected to take place between the fall of 2022 and mid-2023, and the other between the middle and end of 2023.

The agency said it is seeking proposals from US commercial space companies in an effort to make space accessible to more people than ever before.

The news follows a previously announced private mission to the ISS. Earlier in May, NASA and Axiom Space agreed to fly the first private astronauts to the ISS as early as January 2022.

A deadline for the new mission proposals has been set for July 9, 2021, at 5 p.m. EDT.

NASA defines private astronaut missions as "privately funded, fully commercial spaceflights on a commercial launch vehicle for the purpose of enabling tourism, outreach, commercial research, and approved commercial and marketing activities on the space station."

Phil McAlister, director of commercial spaceflight development at NASA, said in a statement posted on its website: "This year is truly a renaissance for human spaceflight both as we fly NASA and international partner astronauts on US commercial crew spacecraft to the International Space Station and also as we see the expansion of private astronaut missions."

He said that as more people fly to space and do more things during their spaceflights, it attracts even more people to do more activities in Low-Earth orbit (LEO). "It reflects the growing market we envisioned when we began the Commercial Crew Program 10 years ago," he added.

LEO encompasses Earth-centered orbits with an altitude of 2,000 km (1,200 miles) or less, according to NASA.

NASA expects the two new missions to last a period of up to 14 days.