Aerospace startup Rocket Lab is finally about to launch its first vehicle to space. Later this month, the California-based company will try to pull off the inaugural test flight of its Electron rocket — a new launch vehicle capable of sending small satellites into orbit.

The first Electron is slated to fly sometime during a 10-day launch window that will open on May 21st at 5PM ET. The test vehicle, aptly named “It’s a Test,” will take off from the company’s private launch facility on the Mahia Peninsula in New Zealand. If the rocket successfully gets off the ground during that window, it’ll be the first of three test launches Rocket Lab wants to do before the Electron is deemed operational.

a 10-day launch window will open on May 21st

Rocket Lab has been developing the Electron for the last four years and has been testing parts of the vehicle on the ground over the last year. In February, the first test vehicle was moved to the company’s New Zealand launch facility, Launch Complex 1, in preparation for this test. “We are all incredibly excited to get to this point,” Peter Beck, Rocket Lab’s CEO, said in a statement. “Our talented team has been preparing for years for this opportunity and we want to do our best to get it right. Our number one priority is to gather enough data and experience to prepare for a commercial phase. Only then can we can start delivering on our mission to make space more accessible.”

Standing just over 55 feet high, the Electron is a much smaller orbital rocket compared to other heavyweight commercial launchers like the Falcon 9 or the Atlas V, which can stand more than 200 feet tall. But the rocket isn’t designed to launch what those vehicles can lift. Rather than launch satellites weighing thousands of pounds, the Electron is only meant to launch satellites between 330 and 500 pounds into lower Earth orbit.

Rocket Lab’s goal is to capitalize on the small satellite revolution

That’s because Rocket Lab’s goal is to capitalize on the small satellite revolution. Typically, robust communications satellites are usually about the size of a car or small bus. But as technology advances, people are figuring out ways to make equally capable satellites at even smaller sizes. Rocket Lab is hoping to tap into that small satellite market by offering up a tantalizing price to get that cargo into space: just $4.9 million per flight. Compared to the $62 million SpaceX charges for each flight of the Falcon 9, Rocket Lab’s option sounds like a steal for small satellite operators who don’t want to pay to hitch a ride on larger rockets. And so far, Rocket Lab says it has a full manifest of customers hoping to fly on the Electron when it’s ready.

Of course, Rocket Lab still has a way to go before it can fulfill its obligations to customers, beginning with this month’s test launch. And the company is being cautiously optimistic about when the vehicle will take off — if at all. “During this first launch attempt it is possible we will scrub multiple attempts as we wait until we are ready and conditions are favorable,” Beck said. Rocket Lab says it will only launch during the window if conditions are just right for flight, and it’s possible launches could be postponed while the company makes “small, technical modifications.” But if the company does launch, it’ll be the first time a vehicle has achieved orbit after taking off from a private launch facility.

To follow along with the Electron’s test flight, Rocket Lab says it will provide updates on its Twitter account.