Virgin Galactic, which plans to use a rocket-powered plane to fly groups of tourists to the edge of space, announced Thursday that Under Armour will develop the suits that will be worn by pilots and passengers during flight.

"Working with Sir Richard [Branson] and Virgin Galactic is an opportunity of a lifetime, one that has the entire Under Armour team across the world excited," Under Armour CEO Kevin Plank said in a statement.

Hundreds of people are signed up to fly with Virgin Galactic, and the company expects to conduct its first trip with passengers sometime this year.

Virgin Group founder Richard Branson and Under Armour founder and CEO Kevin Plank announced a partnership between the apparel brand and Virgin Galactic.

In addition to developing bespoke flight suits,will design Virgin Galactic employee uniforms and prepare customized "physical preparation and recovery" programs for customers. The financial terms of the partnership were not disclosed.

Under Armour will unveil the designs later this year.

Virgin Galactic conducted its first test flight to reach more than 50 miles above Earth last month, high enough to earn commercial astronaut wings for the two pilots aboard the plane.

More than 600 people, who have reserved tickets priced between $200,000 and $250,000, are lined up to fly with Virgin Galactic.

A few more high-altitude test flights are planned before the company will allow passengers on board, and Branson plans to be on the first trip. He told CNN Business' Richard Quest on Thursday that he expects to be in space by July.

The company's space plane will travel up to three times the speed of sound to reach the edge of space, and passengers will experience a few minutes of weightlessness before the vehicle begins its descent.

The plane will be pressurized, so passengers won't necessarily need to have air-tight suits.

Plank said that his company will have safety in mind. He said he wants the suits to "help you keep your blood in the right places" as passengers endure breakneck speeds.

Plank didn't go into detail about how Under Armour might achieve that goal — but Margaret Frey, a professor of fiber science and apparel design at Cornell, said Plank is likely talking about using compression clothing. There's a long history of Air Force test pilots using compression to help their bodies function properly during high-speed and high-altitude flights.

Plank also said that Under Armour will take advantage of clothing the company has created for some of the top athletes it sponsors. The flight suits will be flame retardant, he said, and make use of the fabric technology Under Armour developed for football icon Tom Brady that is supposed to help control body temperature.

Branson said he wants Under Armour to deliver something that will make his customers feel like astronauts.

"Apart from maybe giving birth to your children and getting married — it's going to be a momentous day, the day that you remember the most," Branson said. "So if you're going to do that, you want to be able to look in the mirror before you go up and feel 'I am an astronaut.'"

Virgin Galactic has said that its customers will not need to be in pristine physical condition, but the company will offer optional training experiences. Under Armour will add to those options by developing personal health and fitness plans for passengers, and they will have the option to travel to Under Armour's performance facility in Portland, Oregon, Plank told CBS.