Not only are SETI scientists not discouraged, they are actually more optimistic than ever before. They do feel that in another 50 or 100 years, they will have succeeded in detecting alien signals. What is the reason for this confidence? Previous searches were limited by the shortcomings of available technology. For example, while there are hundreds of billions of stars in our galaxy, fewer than a thuousand have been monitored for alien signals.But technology is improving all the time. As technology improves, scientists are going to have a better chance of picking up alien signals. In the next few decades,hundreds of thousands of stars, maybe even millions, will have been monitored.