(CNN) The first mission to return samples from another planet will touch down on Earth in 2033, according to NASA and European Space Agency officials. The Perseverance rover is currently collecting the samples on Mars.
As Perseverance investigates the site of an ancient lake that existed billions of years ago, it's collecting rocks and soil. This material is of interest because it could contain evidence of past microscopic organisms that would reveal whether life ever existed on Mars. Scientists will have the chance to use some of the most sophisticated instruments around the world to study these precious samples.
The ambitious Mars Sample Return program involves collaboration between the two agencies to retrieve 30 samples from the red planet. Multiple missions will launch to Mars later this decade to safely pick up and bring the samples back.
The program is nearing the end of its conceptual design phase, and NASA has completed its system requirements review. The review has led to changes that will reduce the complexity of future missions and increase probability of success, according to NASA officials.
"The conceptual design phase is when every facet of a mission plan gets put under a microscope," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, in a statement. "There are some significant and advantageous changes to the plan, which can be directly attributed to Perseverance's recent successes at Jezero and the amazing performance of our Mars helicopter."
Initially, the plan was to launch a fetch rover along with a Sample Retrieval Lander in the mid-2020s. Once released on the Martian surface, the fetch rover would have retrieved samples from where Perseverance has stashed them on the Martian surface.
Now, Perseverance will be the primary transport vehicle to carry samples to the lander. The rover's latest health and life expectancy assessment shows that it should still be in prime condition to deliver the samples itself in 2030. Perseverance will back up to the lander, and the lander's robotic arm will transfer the samples.
The Sample Retrieval Lander will carry two sample recovery helicopters, similar in style to the Ingenuity helicopter currently on Mars -- rather than a fetch rover.
"Recent operations of the Ingenuity helicopter on Mars, which has completed 29 flights -- 24 more than originally planned -- have shown us the usefulness of potential rotorcraft of Mars," said Jeff Gramling, director of the Mars Sample Return Program.
Engineers have been impressed with Ingenuity's performance. The helicopter has survived more than a year beyond its expected life span. In the event that Perseverance can't return the samples to the lander, the little choppers will be able to fly away from the lander, use arms to retrieve the samples and bring them back.
The two sample return helicopters will be similar in size to Ingenuity but will be a little bit heavier. The landing legs will come equipped with small mobility wheels to allow it to travel on the ground as well as fly, and each chopper will have a little arm that can grab sample tubes, said Richard Cook, Mars Sample Return program manager at NASA's Jet Propulsion Laboratory in Pasadena, California.
If Perseverance's health remains the same over the next eight years and it doesn't need any help in returning samples to the lander, the choppers could observe and capture images of the process.
The Sample Retrieval Lander also carries the Mars Ascent Vehicle -- the first rocket that will ever launch from the Martian surface, with the samples tucked safely inside. The spacecraft is currently set to launch from Mars in 2031.
A separate mission will launch from Earth in the mid-2020s, called the Earth Return Orbiter, to rendezvous with the Mars Ascent Vehicle.
Onboard the Earth Return Orbiter is the Capture/Containment and Return System, which will collect the container of samples from the Mars Ascent Vehicle while both vehicles are in orbit around Mars.
The Earth Return Orbiter will then head back to our world. Once the spacecraft is close to Earth, it will release the Earth Entry Vehicle that contains the cache of samples, and that spacecraft will touchdown on Earth in 2033.
Previously, the agency said the samples could return to Earth by 2031, but the planned launch dates for the orbiter in fall 2027 and the lander in summer 2028 have created the new arrival date.
Engineers are currently testing robotic components for the campaign at NASA and ESA centers. The Mars Sample Return program will move into the preliminary design phase in October, which will last for about a year. The design phase will result in technology development as well as engineering prototypes for the main components.
"ESA is continuing at full speed the development of both the Earth Return Orbiter that will make the historic round-trip from Earth to Mars and back again; and the Sample Transfer Arm that will robotically place the sample tubes aboard the Orbiting Sample Container before its launch from the surface of the Red Planet," said David Parker, ESA director of human and robotic exploration, in a statement.
The Perseverance rover has collected 11 rock core samples so far. The samples represent "an amazing suite of materials," said Meenakshi Wadhwa, principal scientist for Mars Sample Return and director of Arizona State University's School of Earth and Space Exploration.
"The latest one, in fact, is a fine-grained sedimentary rock that has the greatest potential for preserving biosignatures, potentially, and so we have a diversity of materials already in the bag, so to speak, and really excited about the potential for bringing these back," Wadhwa said.
"Working together on historic endeavors like Mars Sample Return not only provides invaluable data about our place in the universe but brings us closer together right here on Earth," Zurbuchen said.