The US military has launched a robotic spacecraft for its seventh mission.

The US military's secret X-37B robotic spacecraft has lifted off from Florida for its seventh mission.

This mission is the first launch using SpaceX's Falcon Heavy rocket, which can carry aircraft into higher orbits than ever before. The Falcon Heavy made up of three interconnected rocket cores, blasted off the launch pad at NASA's Kennedy Space Center in Florida in a spectacular nighttime launch broadcast live Thursday night.

The US launch comes two weeks after China's robotic spacecraft, called the Shenlong, or God Dragon, was launched into orbit for its third mission in 2020. The Pentagon has released few details about the X-37B mission, which is expected to last several years and will be led by the US Space Force as part of the military's National Security Space Launch Program.

The drone, which resembles a small spaceship and is about 9 meters long, manufactured by Boeing is conducting various experiments. The first mission was in 2010, and the most recent was in May 2020. These flights are limited to low Earth orbit at an altitude of less than 2,000 km (1,200 miles).

The Pentagon did not say how high the plane would fly during the mission, but the Air Force Rapid Capability Office said in a statement last month that the tests would include "experiments with new orbital modes and future space awareness technologies." The X-37B also conducts experiments to study how long-term exposure to the harsh environment of space radiation affects plant seeds.

China's equally secretive Shenlong missile was launched on December 14 with a Long March 2F rocket. Space Force Gen. B. Chance Saltzman told reporters at an industry conference earlier this month that it was "no coincidence" that the launch was so close.

"It is not surprising that the Chinese are particularly interested in our spacecraft. We're very interested in them," Saltzman said, according to an opinion piece published in Air & Space Forces Magazine, an American aerospace magazine.

“These two objects are most visible in orbit while they are in orbit. "It's probably not a coincidence that we're trying to line up in terms of time and order," he said.

The planned duration of the X-37B's final mission has not been announced, but given the general pattern of longer and longer flights, it could be June 2026 or later. The last and longest flight lasted two and a half years before landing on the Kennedy Space Center runway last November.