A MASSIVE CRAFT. When Microsoft co-founder Paul Allen’s Stratolaunch aircraft finally leaves the ground, it’ll become the aircraft with the largest wingspan in history to do so. That maiden voyage could take place in the next few months, before the end of 2018. And now we know what the massive craft will carry once it’s fully operational.

On Monday, Stratolaunch Systems announced some details about its four launch vehicles that will (if everything goes according to plan) carry satellites into orbit. The Stratolaunch aircraft will ferry these vehicles high into the sky and then drop them, at which point they’ll launch and shoot into orbit to deliver their payloads.

This method of launching a rocket in mid-air, known as air launch to orbit, means you can launch something into space from pretty much anywhere, isn’t as dependent on the weather, and requires less rocket fuel (read: cheaper) than a standard rocket launch. However, the craft carrying today’s launch vehicles to altitude aren’t large enough to handle payloads as heavy as those the Stratolaunch will be able to support.

THE FOUR VEHICLES. The Stratolaunch aircraft won’t carry any of these launch vehicles on its maiden voyage later this year, but the company has already started developing them to be used in the coming years. Here’s what we know about each so far:

Pegasus: This one can only carry a payload of about 815 lbs ( 370 kg). However, it is dependable and proven; Stratolaunch Systems has already completed 35 successful launches of the vehicle using other carriers. The first launch via a Stratolaunch should take place in 2020.

This one can only carry a payload of about 815 lbs ( Stratolaunch Systems has already completed 35 successful launches of the vehicle using other carriers. The first launch via a Stratolaunch should take place in 2020. Medium Launch Vehicle (MLV): This one will have a much heavier payload capability than Pegasus: 7,500 lbs (3,400 kg). Its first flight should take place in 2022.

Medium Launch Vehicle – Heavy: This is a three-core version of the MLV variant, and it’ll be capable of delivering payloads of up to 13,200 lbs ( 6,000 kg). No word on when it’ll be ready for launch as it’s still in the e arly development stage.

Space Plane: Stratolaunch Systems also plans to develop a fully reusable space plane. Though still in the design stage, this one should be able to handle cargo launch, cargo return, and the transportation of crew.

EASY ACCESS. Stratolaunch Systems believes these vehicles could help democratize access to space by making it easier for others to send satellites into orbit.

“We are excited to share for the first time some details about the development of our own, proprietary Stratolaunch launch vehicles, with which we will offer a flexible launch capability unlike any other,” said Stratolaunch CEO Jean Floyd in a statement. “Whatever the payload, whatever the orbit, getting your satellite into space will soon be as easy as booking an airline flight.”

READ MORE: Finally, the Biggest Airplane in the World Has Some Rockets to Launch [Ars Technica]

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