The SpaceX Dragon cargo launch to the International Space Station has been pushed back again — this time stopped with just seconds left on the countdown clock. SpaceX had aimed to send its CRS-34 resupply mission toward the orbiting lab on Wednesday evening, May 13, but called off the attempt with roughly 30 seconds remaining due to bad weather.

When the Next Launch Window Opens

With Wednesday’s try scrubbed, the next opportunity to get Dragon off the ground is Friday, May 15, at 6:05 p.m. EDT (2205 GMT). It’s the latest in a string of weather-related setbacks for this mission.

In fact, Wednesday’s attempt was already a one-day slip. NASA and SpaceX had originally planned to launch on Tuesday evening, May 12, before weather forced a delay to Wednesday — and then Wednesday’s window didn’t cooperate either.

What the CRS-34 Mission Is All About

The launch will kick off the CRS-34 mission, named because it marks the 34th flight SpaceX has flown for NASA’s Commercial Resupply Services program.

The robotic Dragon capsule is set to lift off atop a Falcon 9 rocket from Cape Canaveral Space Force Station in Florida. On board is about 6,500 pounds (2,950 kilograms) of supplies, hardware, and scientific experiments bound for the space station.

The Science Headed to Orbit

Beyond routine supplies, CRS-34 is carrying a notable set of research projects. According to NASA officials, the scientific cargo includes:

• A project designed to test how well Earth-based simulators actually mimic microgravity conditions
• A bone scaffold made from wood, which could lead to new treatments for fragile-bone conditions like osteoporosis
• Equipment to study how red blood cells and the spleen change in space, with the goal of protecting future astronauts

It’s a mix of experiments that could have real implications for both space travel and medicine back on Earth.

Arrival at the Space Station

Once Dragon does launch, the trip to the station is quick. The capsule is expected to reach the ISS the morning after liftoff, docking autonomously to the forward port of the orbiting lab’s Harmony module. NASA plans to stream the rendezvous live when the time comes.

Dragon will stay attached to the station for just about a month. It’s scheduled to return to Earth in mid-June, bringing back time-sensitive research and cargo before splashing down off the coast of California.

Why Dragon Is Unique Among Cargo Ships

That return trip is something only Dragon can do. It’s the only ISS resupply vehicle capable of hauling material back down to Earth.

The other three operational robotic freighters — Japan’s HTV-X, Russia’s Progress, and Northrop Grumman’s Cygnus — are all designed to burn up in Earth’s atmosphere once their time in orbit ends. Dragon’s ability to survive reentry makes it essential for returning experiments and equipment intact.

A Record-Setting Flight

CRS-34 is also noteworthy for the hardware itself. This will be the sixth spaceflight for this particular Dragon capsule — a new record for a SpaceX cargo craft. The only other Dragon to reach six missions is Endeavour, one of the company’s astronaut-carrying Crew Dragon capsules.

The Falcon 9 booster is a veteran too. If the launch goes as planned, the rocket’s first stage will return to Earth for a landing at Cape Canaveral less than eight minutes after liftoff — its sixth flight and sixth touchdown. Dragon is expected to separate from the rocket’s upper stage about 9.5 minutes after launch, at which point it will begin chasing down the space station.

The Bottom Line

Weather has proven to be the stubborn obstacle for this SpaceX Dragon cargo launch, scrubbing back-to-back attempts and now pointing toward a Friday try. But once CRS-34 finally lifts off, it will deliver thousands of pounds of supplies and a compelling slate of science to the ISS — all aboard a record-setting capsule and a well-traveled Falcon 9 booster. For now, it’s a waiting game until the skies over Cape Canaveral cooperate.