ALBERT

Description: NASA is continuing to investigate mission and transportation system alternatives to support human exploration of Mars. Several publications over the last few years have outlined, in detail, the baseline reference architectures under consideration. These alternatives include SEP-Chemical Hybrid Propulsion Systems, oxygen/methane propulsion stages, and nuclear thermal propulsion systems. Studies to date have focused on identifying mission architectures that leverage these different transportation options to best support a Mars mission within the context of overarching guidelines and constraints. The focus on identifying "closed" reference mission architectures for these transportation options is a key first step in comparing alternatives and supporting the development of technology investment strategies. Architecture closure implies that the architecture identified provides a viable solution which meets all constraints and closely aligns with guidelines. If a viable architecture cannot be identified for a given transportation option, there is no need to continue investigating that option. However, at this early stage of architecture development, metrics of comparison should look beyond how these architectures perform relative to the baseline reference mission. Architectural robustness, or an insensitivity to requirements drift, should also be considered in any comparison of architectures. At this early stage of design, mission requirements have the potential to change as more definition is provided and more analyses are completed. Particularly in relation to the mass of transported elements, including Mars landers and crew habitat, it is recognized that as designs for these elements mature there exists the potential for mass growth. Selection of an architecture alternative carries with it programmatic risks and relative sensitivity to mass growth can provide insight into a particular architecture option's risk of being unable to complete its mission without significant redesign as more element definition is provided. This paper outlines the current understanding of the sensitivity

Description: In FY 2002 a team of engineers and scientists at MSFC conducted a preliminary investigation of the options for deflecting a Near Earth Object (NEO) fiom a collision course with the earth. A general discussion of the current threat facing the earth from NEO s is outlined. A suite of tools were developed to model inbound and outbound trajectories, propulsive options, and assessment of threat. Propulsive options considered included; staged chemical, nuclear ablation and deflagration, mass driver and solar sail concepts. Trajectory tools plotted the outbound course to intercept the NE0 and the deflection requirements to cause the inbound NE0 to miss the earth. Threat assessment tools estimated the number of lives saved over a given time frame by deploying a system capable of deflecting an NE0 of a certain size and velocity. All of these tools were integrated into a routine to find the most effective vehicle for a given mission mass and mission time. Discussion of desired future efforts is given. This work was funded under the Revolutionary Aerospace Systems Concepts activity from NASA HQ.

Description: Throughout the human space flight program there have been instances where smoke, fire, and pressure loss have occurred onboard space vehicles, putting crews at risk for loss of mission and loss of life. In every instance the mission has been in Low-Earth-Orbit (LEO) with access to multiple volumes that could be used to quickly seal off the damaged module or escape vehicles for a quick return to Earth. For long duration space missions beyond LEO, including Mars transit missions of about 1000 days, the mass penalty for multiple volumes has been a concern as has operating in an environment where a quick return will not be possible. In 2016 a study was done to investigate a variety of dual pressure vessel configurations for habitats that could protect the crew from these hazards. It was found that for a modest increase in total mass it should be possible to provide significant protection for the crew. Several configurations were developed that either had a small safe haven to provide 30-days to recover, or a full duration safe haven using two equal size pressure vessel volumes. The 30-day safe haven was found to be the simplest, yielding the least total mass impact but still with some risk if recovery is not possible during that timeframe. The full duration safe haven was the most massive option but provided the most robust solution. This paper provides information on the various layouts considered in the study and provides a discussion of the findings for implementing a safe haven in future habitat designs.

Description: As we venture back to the Moon with a longer term goal of future Mars missions, lunar missions can provide an important testbed for technologies, systems and operations that directly feed forward to future Mars needs. Gateway missions can provide good in-space transportation feed forward to human Mars missions. Modest operations on the Moon such as the GER (Global Exploration Roadmap)-class missions, can provide key Mars human performance and surface mission capability development and risk reduction. A human return to the Moon can, if done correctly, serve as an excellent down payment to Mars.

Description: Several technology investments are required to develop Mars human scale Entry, Descent, and Landing (EDL) systems. Studies play the critical role of identifying the most feasible technical paths and high payoff investments. The goal of NASA's Entry, Descent and Landing Architecture Study is to inform those technology investments. In Phase 1 of the study, a point design for one lifting-body-like rigid decelerator vehicle, was developed. In Phase 2, a capsule concept was also considered to determine how it accommodated the human mission requirements. This paper summarizes the concept of operations for both rigid vehicles to deliver a 20-metric ton (t) payload to the surface of Mars. Details of the vehicle designs and flight performance are presented along with a packaging, mass sizing, and a launch vehicle fairing assessment. Finally, recommended technology investments based on the analysis of the rigid vehicles are provided.

Description: No abstract available

Description: Throughout the human space flight program there have been instances where systems failures resulting in smoke, fire, and pressure loss have occurred onboard space vehicles, putting crews at risk for loss of mission and loss of life. In most instances the missions have been in Low-Earth-Orbit (LEO) or Earth-Moon vicinity, with access to multiple volumes that could be used to quickly seal off the damaged module or access escape vehicles for return to Earth. For long duration missions beyond LEO, including Mars transit missions of about 1100 days, the mass penalty for multiple volumes and operating in an environment where a quick return will not be possible have been concerns. In 2016, a study was done to investigate a variety of dual pressure vessel configurations for habitats that could protect the crew from these hazards. It was found that with a modest increase in total mass it should be possible to provide significant protection for the crew. Several configurations were considered that either had a small safe haven to provide 30-days to recover, or a full duration safe haven using two equal size pressure vessel volumes. The 30-day safe haven was found to be the simplest, yielding the least total mass impact but still with some risk if recovery is not possible during that timeframe. The full duration safe haven was the most massive option but provided the most robust solution. This paper provides information on the various layouts developed during the study and provides a discussion of the findings for implementing a safe haven in future habitat designs.

Description: No abstract available