NASA's goal to send people to Mars has reached its next phase with the announcement of the top 3 designs for its 3D-Printed Habitat Challenge.

The multimillion-dollar contest, which was launched in 2015, challenged architectural teams to come up with various designs suitable for Mars. The goal is to provide future Red Planet inhabitants with permanent homes and other structures.

The American space agency hopes that these designs could be also used in explorations to other points in the universe.

"What might a human habitat on Mars look like?" NASA wrote on Twitter.

"We challenged citizen inventors to imagine life-supporting environments on the Red Planet by creating a full-scale habitat design using modeling software."

NASA's 3D-Printed Habitat Challenge

When the competition started four years ago, NASA asked contestants to develop architectural renderings of their intended space structures and crafts. They also had to come up with technologies that would be needed to produce the components of their designs.

In the contest's most recent stage, participants were instructed to produce full-scale renderings of their concepts through the help of modeling software. They were also asked to include a short video to explain why they chose their specific designs.

Judges from NASA evaluated the teams' ideas based on their architectural layout and design aesthetics. They also looked at other important traits such as feasibility and scalability of the concepts.

Team SEArch+/Apis Cor from New York won the top spot for its design of a twisted structure that makes use of small holes dotted along its sides to allow natural light to enter.

Meanwhile, Arkansas-based Team Zoperhous came in as a runner-up with their idea for modular buildings. Components for these structures will be printed using an autonomous robotic rover.

The engineers and artists of the Mars Incubator team came up with a modular design made up of four distinct spaces, one of which is meant for growing various plants. They also finished as runners-up.

All three design teams will split the $100,000 prize between them

NASA will conduct the next stage of the competition in May, where the finalists will be asked to produce 3D-printed scale models of their concepts. The winner will receive $800,000.

Sending Space Explorers To Other Planets

The space agency's 3D-Printed Habitat Challenge is the latest phase in its goal to send colonizers into space. The first destination will be to the moon, followed by Mars, and then hopefully to other galaxies.

In 2018, NASA selected nine American companies to bid on $2.6 billion worth of government contracts. The winner will be tasked with delivering services to the moon over the next 10 years.

In 2017, U.S. President Donald Trump signed the Space Policy Directive 1, which is designed to refocus the country's space program on projects such as discovering planets and exploring them.

Trump explained that the directive marks the first step in sending American astronauts back to the moon. These space explorers will help lay down the foundation for future missions to Mars and other worlds.

"This time, we will not only plant our flag and leave our footprints," the president said.