Dana Brewer

The Living with a Star Program NASA's role in assuring performance in space and atmospheric environments

NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user a~dication communities. This will enable future . . science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation andlor mitigation of the effects of solar variability on technological systems. A pre-formulation study determined the optimum combination of science missions, modeling, and technology infusion elements to accomplish this goal. The results of the study are described below.

A simulation model for the analysis of Space Station gas-phase trace contaminants

A simulation model for the analysis of gas-phase trace contaminants in the cabin air of the NASA Space Station Reference Configuration was developed at the NASA Langley Research Center. The model predicts changes in trace contaminant concentrations from both physical and chemical sources an sinks as a function of time. Simulations were performed in which values for relative humidity, temperature radiation intensity, pressure, and initial species concentrations were constrained to values for the parameters measured and modeled in the continental tropics at the Earths surface. Species concentrations simulated using the model compared favorable with concentrations in the continental tropics which demonstrated that the chemical mechanism in the trace contaminant model approximates changes atmospheric species concentrations. The sensitivity of initial species concentrations to producing change in additional species concentrations was also assessed. Results from the model indicated that chemical reactions will be important in determining the composition of cabin air in the Space Station. It is anticipated that the trace contaminant model will be useful in assessing the impact of experiments a commercial operations on the composition of the cabin air in the Space Station.

Carrier Plus: a sensor payload for Living With a Star space environment testbed (LWS/SET)

The Defense Threat Reduction Agency (DTRA) and National Aeronautics and Space Administration (NASA) Goddard Space Flight Center are collaborating to develop the Carrier Plus sensor experiment platform as a capability of the Space Environment Testbed (SET). The Space Environment Testbed (SET) provides flight opportunities for technology experiments as part of NASAs Living With a Star (LWS) program. The Carrier Plus will provide new capability to characterize sensor technologies such as state-of-the-art visible focal plane arrays (FPAs) in a natural space radiation environment. The technical objectives include on-orbit validation of recently developed FPA technologies and sensor performance prediction methodologies, as well as characterization of the FPA radiation response to total ionizing dose damage, displacement damage and transients. It is expected that the sensor experiment will carry 4-6 FPAs and associated radiation correlative environment monitors (CEMs) for a 2008 launch. Sensor technology candidates may include n- and p-charge coupled devices (CCDs), active pixel sensors (APS), and hybrid CMOS arrays. This paper will describe the Carrier Plus goals and objectives, as well as provide details about the architecture and design. More information on the LWS program can be found at http://lws.gsfc.nasa.gov/ gov/. Business announcements for LWS/SET and program briefings are posted at http://lws-set.gsfc.nasa.gov.

NASA's Living with a Star Program: Science with relevance

Abstract NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user application communities by addressing scientific questions that pertain to human radiation exposure, climate change, and technological systems. This will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on these systems. The formulation of the LWS Program architecture and implementation plan is currently in progress with inputs from the science and engineering communities. There are plans for two groups of science spacecraft: (a) solar dynamics elements that observe the Sun and track disturbances originating there and (b) geospace elements located between the Sun and the Earth and around the Earth to measure downstream effects the geospace response to changes in solar activity. Plans also include a data analysis component to improve scientific understanding, and a series of Space Environment Testbeds to provide infusion of the improved understanding to the design and operations of future missions. The LWS Program is developing partnerships with other US and International agencies and industry to augment existing capabilities. The full paper will give an overview of the program architecture and the implementation and partnering plan for LWS.

The effects of solar variability on technology: objectives of NASA's Space Environment Testbed

The Space Environment Testbed (SET) is a complementary element of NASAs new Living With a Star (LWS) Program. This program is designed to help humankind understand and successfully exist with the Sun and its variability throughout the solar cycle. The SET element is a series of flight testbeds focused on this variability and its effects on space system technology, as well as crew safety. In particular, the SET aims to improve the engineering approach and/or mitigate the effects of solar variability on spacecraft design and operations. The SET encompasses a series of flight testbeds with collateral environment measurements. The SET supports incorporation of the results from experiments and environment measurements (both on SET flight testbeds and elsewhere) into improved application models.