Anticipation was high for Starship’s first orbital launch attempt yesterday. Unfortunately, due to a frozen valve in Super Heavy’s first booster stage, the launch cleared just eight minutes before takeoff. SpaceX now has a new launch window and it will open on Thursday, April 20. SpaceX wrote in an updated mission statement that the 62-minute launch window will open at 09:28 ET (1:28 p.m. GMT) today.

The date—April 20—is important to cannabis lovers and SpaceX CEO Elon Musk, who in 2018 posted an extremely expensive joke referring to history, so it’s no surprise that memes proliferate.

Starship is designed to be completely reusable to significantly reduce the cost of successive launches. But during Thursday’s Orbital Flight Test (OFT), SpaceX will attempt to launch a massive rocket into orbit for the first time.

If it reaches orbit, the Super Heavy’s first stage, powered by 33 Raptor engines, will make a hard landing in the Gulf of Mexico about eight minutes after launch. Meanwhile, Starship’s upper stage will orbit almost completely around Earth before plunging into the Pacific Ocean off Hawaii about 90 minutes after launch.

However, Starship is not guaranteed to reach orbit on the first try. Last month, SpaceX CEO Elon Musk said the company’s next-generation rocket had a nearly 50 percent chance of reaching orbit in its first try. “I’m not saying it will go into orbit, but I guarantee the excitement,” Musk wrote on Twitter.

SpaceX wrote in its mission statement: “Success with a test like this is measured by how much we can learn, which will inform and increase the likelihood of future success as SpaceX rapidly advances Starship development.”

Last week, SpaceX released an impressive animated video showcasing its ambitious plans for the Starship program. The video shows the Starship flying to Mars. As soon as it arrives, it reaches a base on Mars and many other Starship spacecraft approach the Red Planet.

To make this sci-fi scenario possible, SpaceX designed Starship to be fully reusable and also the world’s most powerful rocket. If all goes according to plan, Starship will become the most powerful operational launch system, dethroning NASA’s disposable Space Launch System (SLS).