Accommodating Science and Technology Development Sortie Missions in the Post Space Shuttle Era
Sortie missions during the Space Shuttle era provided a unique opportunity for scientists to conduct experiments using standardized payload hardware. With the advent of a developing fleet of crewed and uncrewed space vehicles a new opportunity for sortie missions may be viable. These vehicles provide options for accommodating laboratory space for sortie science payloads, either in dedicated missions or as part of other activities like resupply. These missions would be analogous in a small way to earlier Space Shuttle Spacelab and Spacehab sortie missions and to previous biosatellites. Advantages of sortie missions include the ability to run multiple independent experiments or a series of related experiments. With multiple smaller spacecraft being developed for rendezvous with ISS, science payloads might have more frequent opportunities. If automated, reduced integration costs could be achieved and possibly some legacy payload equipment reused without extensive refurbishment. Uncrewed vehicles can provide capabilities for investigations not previously accommodated due to risk, cost, or schedule issues. One concept being considered for supporting sortie science missions is the Dream Chaser Cargo System. The Dream Chaser variant designed for CRS2 missions can remain in space for weeks or months and contains mechanical, electrical, and data interfaces to support standard middeck locker equivalent and custom payloads. The Dream Chaser could also dock or berth with habitat modules to act either as a temporary laboratory or to transport specimens and experiments between the habitat and Earth. As a lifting body vehicle, Dream Chaser's shuttle-like gentle entry deceleration results in minimal impacts to specimens and the pinpoint runway landings onto commercial runways <8000ft allow investigators immediate access to returned specimens, which minimizes confounding influences of the 1g environment.