The Space Launch Initiative (SLI) is a NASA plan, also known as the Second Generation Reusable Launch Vehicle (RLV) Program, the goal of which is to develop a successor to the Space Shuttle that would lower the cost of delivering payloads to low Earth orbit to less than $1,000 per pound ($2,200 per kilogram) and would also reduce the risk of crew loss to approximately 1 in 10,000 missions. The SLI is seen by NASA as the key to opening the space frontier for continued civil exploration and commercial development. It is the centerpiece of NASA's long-range Integrated Space Transportation Plan, which also includes near-term Space Shuttle safety upgrades and long-term research and development toward third and fourth generation RLVs.