NASA is seeking capability statements from potential contractors for structural modifications to a Gulfstream V aircraft (S/N 570) to install two nadir viewports and relocate systems for clearance. This is a sources sought notice for planning purposes, not a solicitation. The work will leverage existing technical data from a prior modification of a similar aircraft (GV S/N 672) with minimal design deviations. Capability statements must include anticipated subcontracting goals for various small business categories. Responses are due via email by 1:00 PM Pacific Time on January 20, 2026.