The Dragon is packed with nearly 6,000 pounds (2,700 kilograms) of science research, crew supplies and hardware. The company has successfully landed 10 of its Falcon 9 rockets since 2015, and one of these used boosters flew again for the first time in March - an important proof-of-concept in SpaceX's pursuit of reusability.
When the Dragon arrives at the space station, U.S. astronauts Peggy Whitson and Jack Fischer will grapple Dragon using the station's 57-foot-long robotic arm. Commands from the ground will then be relayed to the crew aboard the ISS to correctly position the Dragon space capsule into the station's Harmony module.
The mission labeled CRS-11 will launch with almost 6,000 pounds of supplies, science experiments and equipment to the ISS during the instantaneous launch window.
Reusing a spacecraft, however, is not a new concept given that Nasa space shuttles have made numerous trips into orbit. The cargo includes materials for over 250 science experiments and investigations covering topics as diverse as combustion in microgravity and seed cultivation. The company will attempt to return its first stage booster to a land-based site on the coast about nine minutes after the launch. It was also the first SpaceX launch of a Falcon 9 from NASA's historic pad 39A. Falcon Heavy was created to carry humans into space and make it feasible to fly humans to the Moon or Mars, said SpaceX.
The spaceflight company SpaceX is one of several firms building private space taxis and cargo ships to launch astronauts and supplies into space.
On the weather front, conditions were 70 percent "go" as of Wednesday morning, according to the Air Force's 45th Weather Squadron, with the forecast dropping to 60 percent "go" for a backup 5:07 p.m. launch on Saturday.
If the launch is scrubbed, the next launch opportunity is 5:07 p.m. on Saturday, with NASA TV coverage starting at 4:30 p.m.
Above: Static test firing of a SpaceX rocket, May 28, 2017 at the Kennedy Space Center.
SpaceX vice president of flight reliability Hans Koenigsmann did not specify how much money the firm saved by re-flying the spacecraft.
The spacecraft is also loaded with solar panels and equipment to study neutron stars.