shuttle of ISS structural components and research modules if the shuttle does not complete this task by 2010.
A robust logistics capability not only will maintain the basic functioning of the ISS facility but also will be paramount in accomplishing ISS exploration mission objectives. Logistics flights to the ISS will deploy crew supplies; maintenance equipment, including replacement spares; specific research experiments and associated equipment and samples; and, finally, technology demonstration hardware and associated provisions.
Logistics requirements can be categorized as either pressurized logistics for internal use or unpressurized logistics for external use. The size and shape of unpressurized logistics are such as to prevent them from being handled internally. NASA suggested that logistics requirements after 2010 over and above those provided by the current baseline Progress flights, the European Space Agency’s automated transfer vehicle (ATV) flights, and the Japanese H-II transfer vehicle (HTV) flights will be provided by a combination of a yet-to-be-procured U.S. commercial cargo vehicle, the crew exploration vehicle (CEV) pressurized cargo system, the cargo delivery vehicle (an unpressurized CEV derivative), and additional Progress, HTV, and ATV flights. The capabilities of each element in the combination, the acquisition schedules, and the funding requirements have not been specified in enough detail to give the panel confidence that ISS exploration mission objectives have a high likelihood of being fulfilled. This suggests that there would be significant value in developing a detailed plan to provide the post-shuttle logistics system.
Although no clear data were provided on the amount of crew time required to accomplish the planned ISS research, technology demonstrations, and operations demonstrations, it is unlikely that a team of three will be sufficient. Nor were plans for increasing the crew size to six discussed in detail. A discussion and review of other NASA materials suggested several options for crew deployment. NASA described Notional Scenario 1,1 which provided for a crew of six in 2015. Notional Scenario 2 provided for a crew of six in 2009. In response to questions, NASA indicated that the ISS might be capable of sustaining a crew of six in 2008 at the earliest, depending on deployment of the advanced environmental control and life support systems. The panel believes that in order to accomplish ISS exploration mission objectives, the crew complement has to be increased as soon as practicable.
The following steps are needed to make possible the research, technology demonstrations, and operations demonstrations required to enable plans for human exploration of the Moon and Mars:
NASA should plan options and decision points for obtaining a post-shuttle logistics capability for maintaining the ISS facility, for supporting the flight crew and research, and for demonstrating the technology and operations that will enable exploration missions.
NASA should establish priorities and develop back-up plans to enable the post-2010 deployment of large ISS structural components and the research facilities required to accomplish exploration mission objectives.
NASA should develop plans to deploy six persons to the ISS as soon as practicable, preferably in 2008.