During the early shuttle studies, there was a debate over the optimal shuttle design that best balanced capability, development cost, and operational cost. Initially a fully reusable design was preferred. This involved a very large winged manned booster which would carry a smaller winged manned orbiter. The booster vehicle would lift the orbiter to a certain altitude and speed, then separate. The booster would return and land horizontally, while the orbiter continued into low earth orbit. After completing its mission, the winged orbiter would reenter and land horizontally on a runway. The idea was that full reusability would promote lower operating costs.