Normally shielded in secrecy, the USAF is revealing some of the missions to be carried out by the X-37B space plane. Credit: Boeing.

Its lengthy missions in space are usually cloaked in secrecy. It’s reusable and has faithfully completed five missions, spending a total of 2,865 days in orbit, on its own.

Doing exactly what, we don’t know … until now.

For the first time ever, the US Air Force is revealing some of the missions that will be carried out by the X-37B Orbital Test Vehicle, which will be launched for its sixth mission on May 16 from Cape Canaveral Air Force Station, Mandy Mayfield of National Defense reported.

“This important mission will host more experiments than any prior X-37B flight,” including two NASA experiments, Barbara Barrett said during a webinar hosted by the Space Foundation, a Colorado Spring, Colorado-based non-profit.

The Boeing-made space vehicle will deploy the FalconSat-8, a small satellite developed by the Air Force Academy and sponsored by the Air Force Research Laboratory, to conduct several experiments in orbit, National Defense reported.

“The Air Force’s Rapid Capabilities Office has combined forces with the Air Force Research Lab and now the US Space Force to execute a mission that maximizes the X-37B’s unique capabilities,” Barrett said.

One example of an experiment the vehicle will support is the study of the effects of ambient space radiation on seeds, Barrett said.

Another experiment, which was designed by the Naval Research Laboratory, “transforms solar power into radio frequency microwave energy, then studies transmitting that energy to Earth,” she said.

The vehicle is managed by the Air Force, while the Space Force is responsible for the launch, on-orbit operations, and landing, National Defense reported.

“This launch is a prime example of integrated operations between the Air Force, Space Force and government-industry partnerships,” Air Force Chief of Staff Gen. David Goldfein said in the release.

“The X-37B continues to break barriers in advancing reusable space vehicle technologies and is a significant investment in advancing future space capabilities.”

This mission is the first for the X-37B where it will utilize a service module to host experiments, National Defense reported. The module attaches to the vehicle and allows additional experimental payload capability to be carried to orbit.

The vehicle completed its fifth mission in October 2019, landing after 780 days spent on orbit, according to the press release.

According to CNN Business, the current mission has no specified end date, according to Air Force spokesman Major William Russell.

The spacecraft will return to Earth only after its completed all its objectives, he said.

According to Science Alert, the X-37B space plane haas been spotted at relatively low altitudes – less than 200 miles, according to some, lower than the International Space Station. Credit: Boeing.

The details of those objectives remain a closely guarded secret. The X-37B program tends to attract public interest because of that secrecy: The Air Force does not share the locations of the X-37B planes while they’re in orbit, although amateur astronomers have made a sport out of spotting the spacecraft with telescopes.

The X-37B is also popular among space fans because of its unique design.

The planes, which look like miniature space shuttles, launch into orbit atop powerful rockets and then break away to carry out their mission, CNN reported.

When their duties are complete, they swoop back toward Earth and touch down horizontally on a runway, like a commercial airplane.

The spacecraft are also designed to carry out “experiments” that “can be returned to, and examined, on Earth” after the mission is over, according to Russell, the Air Force spokesman. The nature of those experiments are — you guessed it — also top secret.

Experts say the planes could be involved in spying activities or testing out a space weapon. There’s plenty of precedent — in the US and abroad — for both types of projects.

According to Science Alert, it’s been spotted at relatively low altitudes – less than 200 miles, according to some, lower than the International Space Station – which experts have said may mean the US is looking at moving spy satellites to lower orbits, where they could take sharper photos but would need more fuel to manoeuvre.

Barrett’s predecessor, Heather Wilson, last year called the X-37B “fascinating” because “when it’s close to the Earth, it’s close enough to the atmosphere to turn where it is.”

That means “adversaries don’t know … where it’s going to come up next. And we know that that drives them nuts. And I’m really glad about that,” Wilson said, according to Military.com.

Artist’s concept of the NASA X-37B spacecraft in orbit, showing payload bay and solar panels. Credit: Handout.