GUADALAJARA, Mexico — The United Nations plans to purchase a dedicated mission on a Sierra Nevada Corporation (SNC) Dream Chaser spacecraft in 2021 to give developing nations an opportunity to fly experiments in space.

At a press conference during the International Astronautical Congress here Sept. 27, the United Nations Office of Outer Space Affairs (UNOOSA) said the agreement to fly the dedicated Dream Chaser mission is part of a broader effort by the office to increase access to space to emerging nations.

“Our project is the first-ever United Nations space mission,” said Simonetta Di Pippo, director of UNOOSA. “The mission has one very important goal: to allow United Nations member states to conduct research that cannot be done on Earth.”

The mission, she said, will be open to all nations, but with a particular emphasis on those nations that don’t have the capabilities to fly their own experiments in space. UNOOSA will soon start the process of soliciting payload proposals, with a goal of selecting payloads by early 2018 so that the winning countries have time to build them for a 2021 launch.

Neither SNC nor UNOOSA disclosed the cost of the mission. Mark Sirangelo, corporate vice president of SNC’s Space Systems division, said that the mission will be financed by several ways, with the countries selected to fly experiments paying at least some of the cost of the flight.

“We believe this is an opportunity for companies and organizations to potentially be sponsors of this effort,” he said at the press conference. “We also believe that some of the existing space nations and companies will want to be part of this and provide either in-kind services or support to the program.”

SNC is developing Dream Chaser as a cargo spacecraft to service the International Space Station under a NASA contract, with the vehicle ready to begin those missions by the end of the decade. However, this mission is currently planned as a two-week free-flyer mission in low Earth orbit, with no plans to travel to the ISS.

“In order to provide as much opportunity to the global space community, it will be a free flyer,” Sirangelo said. “It’s not necessary for us to go to the ISS.” He added Dream Chaser is able to fly in orbit for extended periods of time, should the UN desire a longer mission.

The Dream Chaser mission, while billed as the UN’s first space mission, fits into a broader effort by UNOOSA called the Human Space Technology Initiative that started in 2010. “The main goal is to provide access to our member states to microgravity experiments,” said Di Pippo. “We wanted to offer, mainly to developing countries, the possibility to access space in microgravity conditions.”

Besides the Dream Chaser mission, the initiative includes two other major projects. The KiboCUBE program, in cooperation with the Japan Aerospace Exploration Agency, gives developing nations the opportunity to launch cubesats from the ISS. In August, UNOOSA selected a cubesat proposed by the University of Nairobi in Kenya as the first KiboCUBE satellite, and opened a second call for missions Sept. 27.

A third element of the initiative is cooperation with China’s space program. A memorandum of understanding signed in March is the first step in a process that could lead to UN access to China’s space station when it is completed in the early 2020s, Di Pippo said.