FIGURE S.1 Two possible configurations of the Ares V shroud—the current baseline shroud and a proposed extended shroud. Shown inside the shrouds are two possible Centaur upper-stage configurations: the Titan IV Centaur (left) and the Atlas V Centaur III Dual Engine Configuration (right). Any spacecraft carried atop an upper stage would have severely restricted volume constraints. Neither shroud option takes advantage of the width of the Ares V shroud. SOURCE: Adapted courtesy of NASA.

could be expensive. In order for Ares V to be attractive for future science missions, vehicle designers will have to consider the requirements of potential science missions.

Recommendation: If NASA wishes to use the Constellation System for science missions, it should preserve the capability for Orion to carry small scientific payloads and should ensure that the Ares V development team considers the needs of scientific payloads in system design.

The Constellation System offers great potential for space science missions, but the costs of the types of missions evaluated in this report may be unaffordable. Many of these missions have such large costs that they might require that funds be taken from numerous other, smaller science missions, which could create imbalances in the science programs in the individual disciplines. These missions will have to be evaluated carefully within the NRC’s decadal survey process. NASA will have to proceed with caution as it develops these new capabilities.