SpaceX said Friday it will attempt to send a cargo-loaded spacecraft to the International Space Station on May 19 after a series of delays, the latest over software issues. \"SpaceX and NASA are nearing completion of the software assurance process, and SpaceX is submitting a request to the Cape Canaveral Air Force Station for a May 19th launch target with a backup on May 22nd,\" said spokeswoman Kirstin Grantham. \"Thus far, no issues have been uncovered during this process, but with a mission of this complexity we want to be extremely diligent.\" SpaceX aims to be the first private company to send its own spacecraft to the orbiting research lab on a cargo mission. The launch attempt has been repeatedly delayed, most recently from a planned April 30 launch date, and again on May 7. Japan, Europe and Russia\'s space agencies all operate supply ships that can bring cargo to the ISS, but never before has a private company launched its own craft capable of toting both cargo and humans. SpaceX made history with its Dragon launch in December 2010, becoming the first commercial outfit to send a spacecraft into orbit and back. The Dragon spacecraft has also been built to carry humans to space, and the company, owned by Internet entrepreneur and PayPal co-founder Elon Musk, hopes that a successful cargo trip to the ISS will soon lead to a manned mission. The end of the 30-year US space shuttle program last year left Russia as the sole nation capable of sending astronauts to the ISS. SpaceX and several other companies are competing to be the first to operate a private capsule that could tote astronauts and cargo to the ISS. In addition to SpaceX, Orbital Sciences also has a NASA contract to deliver freight to the space station. Other companies in the private space race include aerospace giant Boeing, the Nevada-based Sierra Nevada Corporation, and Washington state-based BlueOrigin LLC. The main goals of SpaceX\'s cargo flight include a fly-by of the ISS and a berthing operation in which the company\'s reusable spacecraft, the Dragon, will approach the ISS and the crew aboard the orbiting outpost will use the ISS robotic arm to help it latch on. The gumdrop-shaped Dragon capsule will carry 521 kilograms (1,148 pounds) of cargo for the space lab and will also aim to return a 660 kg (1,455 lb) load to Earth.