10 Common Digestive Disorders. The spleen is part of the lymphatic system, which plays a role in immunity and maintenance of healthy blood cells. It is an important organ and is affected by disorders of the blood, liver, and immune system. An enlarged spleen is known as splenomegaly. Although hepatosplenomegaly often produces no symptoms, it is known to cause abdominal pain in the upper portion of your abdomen.
NASA is sending astronaut Scott Kelly to live on the International Space Station for a year. That's the longest any U.S. astronaut has spent in space and twice as long as crew members usually stay on the space station. A year is a long time to stay anyplace. But staying a year in space has some special challenges.
View Caption. SpaceX called off the planned launch of a commercial cargo ship bound for the International Space Station for NASA Monday (April 14) due to a helium leak on the company's Falcon 9 rocket that will keep the mission stuck on Earth until at least Friday (April 18).