Designing e-infrastructure is work conducted today with an eye toward long-term sustainability. Participants in such development projects find themselves caught with one foot in the demands of the present and the other in a desired future. In this paper we seek to capture participants' formulation of problems as they go about developing long-term information infrastructure.Drawing from cross-case ethnographic studies of four US e-infrastructure projects for the earth and environmental sciences (cyberinfrastructure), we trace nine tensions as they are framed and articulated by participants. To assist in understanding participants' orientations we abstract three concerns -motivating contribution, aligning end goals, and designing for use -which manifest themselves uniquely at each of the 'scales of infrastructure': institutionalization, the organization of work, and enacting technology. The concept of "the long now" helps us understand that participants seek to simultaneously address all three concerns in long-term development endeavors.