President Obama has set his sights on Mars – again.

“We have set a clear goal vital to the next chapter of America’s story in space: sending humans to Mars by the 2030s and returning them safely to Earth, with the ultimate ambition to one day remain there for an extended time,” Obama wrote Tuesday in an opinion piece for CNN.

The voyage to the Red Planet will require collaboration between NASA and private companies like SpaceX.

“Within the next two years, private companies will for the first time send astronauts to the International Space Station,” he added in the piece, which echoed his words from his 2015 State of the Union address and from a 2010 speech.

“This week, we’ll convene some of America’s leading scientists, engineers, innovators and students in Pittsburgh to dream up ways to build on our progress and find the next frontiers,” he wrote.

“Just five years ago, US companies were shut out of the global commercial launch market. Today, thanks to groundwork laid by the men and women of NASA, they own more than a third of it. More than 1,000 companies across nearly all 50 states are working on private space initiatives.”

The first step in achieving the ambitious interplanetary goal is leaving our planet’s orbit, Obama said.

‘We have set a clear goal vital to the next chapter of America’s story in space: sending humans to Mars by the 2030s and returning them safely to Earth, with the ultimate ambition to one day remain there for an extended time.’ - President Obama

He announced that the US is working with its commercial partners “to build new habitats that can sustain and transport astronauts on long-duration missions in deep space.

“These missions will teach us how humans can live far from Earth — something we’ll need for the long journey to Mars,” he said about the roughly 34 million-mile trip.

NASA Administrator Charles Bolden said the attendees at Pittsburgh’s White House Frontiers Conference will explore how US investments in science and technology will help the US settle “the final frontier” – space.

In his NASA blog, Bolden addressed public-private initiatives by the space agency.

“By reaching out further into the solar system and expanding the frontiers of exploration, the president outlined a vision for pushing the bounds of human discovery, while also revitalizing the space industry and creating jobs here at home,” he wrote about Obama’s 2010 challenge.

In the next decade, NASA will embark on a “Proving Ground” stage – testing technologies in cis-lunar space around the moon, he said.

In the mid-2020s, a robotic spacecraft will be sent to a nearby asteroid to test exploration gear such as solar-electric propulsion and return a rock for astronauts to study around the moon, Bolden said.

Meanwhile, six companies have been granted awards to begin developing habitation systems as part of the Next Space Technologies for Exploration Partnerships, or “NextSTEP” program.

NASA, which also is expanding partnerships with commercial space companies, has asked the private sector how it could use a docking port on the International Space Station.

“As a result of the responses, this fall, NASA will start the process of providing companies with a potential opportunity to add their own modules and other capabilities to the International Space Station,” he wrote.

Obama described his childhood memories about the Apollo lunar program.

“One of my earliest memories is sitting on my grandfather’s shoulders, waving a flag as our astronauts returned to Hawaii,” he wrote. “This was years before we’d set foot on the moon. Decades before we’d land a rover on Mars. A generation before photos from the International Space Station would show up in our social media feeds.”