This book provides a snapshot of how well NASA is planning and executing its major acquisitions -- an area that been on the Government Accountability Office's (GAO's) high risk list since 1990. Over the past 4 years, a range of projects such as robotic probes designed to explore the Martian surface and telescopes intended to explore the universe have been reviewed. NASA has launched many of the projects and most of the projects are returning science results as intended. For example, the Dawn spacecraft reached the solar system's second largest asteroid, Vesta, in July 2011 and is beaming back images and data to scientists about how the solar system formed. Another project called GRAIL, launched in September 2011, and its twin spacecraft recently entered orbit around the moon to begin its measurements of lunar gravity.