Space travel is not trivial. The historic mission of SpaceX to undertake the first private trip to the ISS is hampered by technical problems. On May 19 the 2nd attempt failed due to high pressure in the engine 5 combustion chamber. SpaceX engineers discovered a faulty check valve on the Merlin engine.
About this SpaceX Mission:
This SpaceX mission is a milestone in that transition, marking the first time in history that a commercial company will attempt to send a spacecraft to the International Space Station, something only a few governments have ever accomplished. This is a demonstration mission, a test flight primarily designed to provide NASA and SpaceX with valuable insight to ensure successful future missions.
Demonstration launches are conducted to determine potential issues so that they might be addressed and – by their very nature – carry a significant risk. All spaceflight is incredibly complicated, and this flight introduces a series of new challenges -- it is only the third flight of the Falcon 9 rocket, the second of the Dragon capsule, and the first for a number of all-new components necessary to berth with the International Space Station. If any aspect of the mission is not successful, SpaceX will learn from the experience and try again.
This is SpaceX's second demonstration flight under a 2006 Commercial Orbital Transportation Services (COTS) agreement with NASA to develop the capability to carry cargo to and from the International Space Station. To date, SpaceX has received $381 million for completing 37 out of 40 milestones worth a possible $396 million set in that agreement. Completed milestones include the first test flight in December 2010, during which SpaceX became the first commercial company to send a spacecraft to low-Earth orbit and recover it successfully, something that only three governments – the United States, Russia and China – have ever done.
Once SpaceX has successfully demonstrated Dragon’s ability to berth with the space station, it will begin to fulfill a 2008 contract signed with NASA for a minimum of 12 flights carrying supplies to and from the space station. Without the space shuttle, Dragon is the only spacecraft in the world capable of returning significant cargo from the space station. Falcon 9 and Dragon were designed to carry astronauts in the future; these cargo missions will yield valuable flight experience toward this goal.