SpaceX has successfully performed many resupply missions for the crew of the International Space Station, sending vital supplies to the orbiting laboratory using its Falcon 9 rocket and Dragon cargo spacecraft. Unfortunately, sometimes Mother Nature doesn’t feel like cooperating, and one of those times was Wednesday evening.

Poised and ready to fly skyward from its Cape Canaveral launch pad, the Falcon 9 never got the chance to do its job thanks to scattered thunderstorms that spread across Central Florida. The threat of lightning pushed SpaceX to scrub the launch less than a minute before its scheduled departure.

As Spaceflight Now reports, SpaceX had to clear two serious weather-related hurdles in the final minute before launch. A pair of rules — one regarding anvil clouds and another related to electrical fields — both returned “no go” responses in that last minute, leading SpaceX to push the launch to a later date.

That date happens to be today, and SpaceX will attempt the launch again tonight at 6:01:56 p.m. EDT. The launch opportunity is instantaneous, meaning that if everything isn’t exactly perfect at the moment the launch is slated to take place it will have to be pushed back again. A wider launch window affords the opportunity to wait for conditions to be right, but that’s not the case this time around.

The forecast doesn’t look particularly favorable for a Thursday evening launch, so there’s a strong possibility the mission could see another delay.

When the launch happens — either today or in the coming days — it will be the 18th resupply mission SpaceX has conducted for NASA to the International Space Station. These regular missions are needed to ensure the travelers aboard the orbiting laboratory have all the supplies they need to stay alive and conduct various scientific experiments and studies in space.