SpaceX is set to launch their eighteenth International Space Station resupply mission from Cape Canaveral Air Force Station this evening. The Dragon cargo spacecraft will be launched aboard a Falcon 9 loaded with 2,300 kilograms of cargo including new science experiments and the International Docking Adapter-3.
The SpaceX CRS-18 mission to the ISS is set to liftoff at 22:24 UTC from Space Launch Complex 40 at Cape Canaveral in Florida. However, earlier today SpaceX revealed on Twitter that the weather forecast was only 30% favourable for a launch this evening. If the launch is delayed due to unfavourable weather, SpaceX will move to a backup launch window scheduled for 22:01 UTC tomorrow (July 25).
If the mission is successfully launched this evening, the CRS-18 Dragon spacecraft it is expected to arrive at the ISS for docking procedures on Friday, July 26. Unlike the Crew Dragon, the Dragon cargo spacecraft cannot dock itself to the station. As a result, the spacecraft is brought within reach of the Canadarm2 robotic arm, which is operated by a crew member aboard the station. The spacecraft is captured by the arm and installed onto its designated docking adapter.
The CRS-18 Dragon spacecraft is expected to remain docked to the ISS for approximately four weeks. Once its mission is complete, the spacecraft will return to Earth with 1,500 kilograms of cargo.