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Obsolete devices add to the rising levels of electronic waste, a major environmental concern, and a contributing factor to climate change. In recent years, device manufacturers have established environmental commitments and launched initiatives such as supporting the recycling of obsolete devices by making more ways available for consumers to safely dispose of their old devices. However, little support is available for individuals who want to continue using legacy or 'end-of-life' devices and few studies have explored the usefulness of these older devices, the barriers to their continued use and the associated user experiences. With a human-computer interaction lens, this paper reflects on device usefulness as a function of utility and usability, and on the barriers to continued device use and app installation. Additionally, the paper contributes insights from a sequel study that extends on prior work evaluating app functionality of a 'vintage' Apple device with new empirical data on app downloadability and functionality for the same device when newly classified as 'obsolete'. A total of 230 apps, comprising the top 10 free App Store apps for each of 23 categories, were assessed for downloadability and functionality on an Apple iPad Mini tablet. Although only 20 apps (8.7%) could be downloaded directly onto the newly obsolete device, 143 apps (62.2%) could be downloaded with the use of a different non-legacy device. Of these 163 downloadable apps, 131 apps (com-prising 57% of all 230 apps and 80.4% of the downloadable apps) successfully installed, opened, and functioned. This was a decrease of only 4.3% in functional apps (of the 230 total apps) compared to the performance of the device when previously classified as 'vintage'., Comment: 10 pages, 3 figures, 1 table

This analysis is organized by decades, 1950s-1990s. In each decade, a context is presented for summarizing general information on broad education events that also affected rural areas and schools. Next, policies are outlined that were directed at or had a significant impact on rural education at the federal and then the state level. State-level policies with national significance are included. Research that specifically focused on rural education is also described. Finally, other critical developments that significantly affected rural education in that decade are listed. Each milestone is followed by a brief statement of rationale for inclusion. Those interested in rural schools have much to celebrate when they review the milestones of the past 50 years, including the virtual demise of mandated school district reorganization; the development of many state policy strategies to address issues of funding adequacy and equity, as well as quality educational programs; the growing body of additive, policy-relevant research; the increasing professionalization of rural policymakers, educators, and researchers; the growth of rural special interest groups at the national and state levels; the resurgence of local citizens seeking to play an active role in their schools; and the slow, inexorable establishment of precedence favorable to rural schools in federal laws and policy. The continuing struggle of rural residents to provide a quality education for their children, despite obstacles, has helped make these milestones possible. (Contains 21 references.) (TD)

This paper explores the impact of human Mars mission architecture decisions on the design and performance of a lander using the HIAD entry system: (a) Earth departure options, (b) Mars arrival options, (c) Entry Descent and Landing options.

Landing humans on Mars is one of NASA's long term goals. The Evolvable Mars Campaign (EMC) is focused on evaluating architectural trade options to define the capabilities and elements needed for a sustainable human presence on the surface of Mars. The EMC study teams have considered a variety of in-space propulsion options and surface mission options. As we seek to better understand how these choices affect the performance of the lander, this work informs and influences requirements for transportation systems to deliver the landers to Mars and enable these missions. This paper presents the effects of mission and vehicle design options on lander mass and performance. Beginning with Earth launch, options include fairing size assumptions, co-manifesting other elements with the lander, and Earth-Moon vicinity operations. Capturing into Mars orbit using either aerocapture or propulsive capture is assessed. For entry, descent, and landing both storable as well as oxygen and methane propellant combinations are considered, engine thrust level is assessed, and sensitivity to landed payload mass is presented. This paper focuses on lander designs using the Hypersonic Inflatable Aerodynamic Decelerators (HIAD), one of several entry system technologies currently considered for human missions.

The total ascent vehicle mass drives performance requirements for the Mars descent systems and the Earth to Mars transportation elements. Minimizing Mars Ascent Vehicle (MAV) mass is a priority and minimizing the crew cabin size and mass is one way to do that. Human missions to Mars may utilize several small cabins where crew members could live for days up to a couple of weeks. A common crew cabin design that can perform in each of these applications is desired and could reduce the overall mission cost. However, for the MAV, the crew cabin size and mass can have a large impact on vehicle design and performance. This paper explores the sensitivities to trajectory, propulsion, crew cabin size and the benefits and impacts of using a common crew cabin design for the MAV. Results of these trades will be presented along with mass and performance estimates for the selected design.

Human missions to Mars, particularly to the Martian surface, are grand endeavors that place extensive demands on ground infrastructure, launch capabilities, and mission systems. The interplay of capabilities and limitations among these areas can have significant impacts on the costs and ability to conduct Mars missions and campaigns. From a mission and campaign perspective, decisions that affect element designs, including those based on launch vehicle and ground considerations, can create effects that ripple through all phases of the mission and have significant impact on the overall campaign. These effects result in impacts to element designs and performance, launch and surface manifesting, and mission operations. In current Evolvable Mars Campaign concepts, the NASA Space Launch System (SLS) is the primary launch vehicle for delivering crew and payloads to cis-lunar space. SLS is currently developing an 8.4m diameter cargo fairing, with a planned upgrade to a 10m diameter fairing in the future. Fairing diameter is a driving factor that impacts many aspects of system design, vehicle performance, and operational concepts. It creates a ripple effect that influences all aspects of a Mars mission, including: element designs, grounds operations, launch vehicle design, payload packaging on the lander, launch vehicle adapter design to meet structural launch requirements, control and thermal protection during entry and descent at Mars, landing stability, and surface operations. Analyses have been performed in each of these areas to assess and, where possible, quantify the impacts of fairing diameter selection on all aspects of a Mars mission. Several potential impacts of launch fairing diameter selection are identified in each of these areas, along with changes to system designs that result. Solutions for addressing these impacts generally result in increased systems mass and propellant needs, which can further exacerbate packaging and flight challenges. This paper presents the results of the analyses performed, the potential changes to mission architectures and campaigns that result, and the general trends that are more broadly applicable to any element design or mission planning for human exploration.

Human missions to Mars may utilize several small cabins where crew members could live for days up to a couple of weeks. At the end of a Mars surface mission the Mars Ascent Vehicle (MAV) crew cabin would carry the crew to their destination in orbit in a matter of hours or days. Other small cabins in support of a Mars mission would include pressurized rovers that allow crew members to travel great distances from their primary habitat on Mars while unconstrained by time limits of typical EVAs. An orbital crew taxi could allow for exploration of the moons of Mars with minimum impact to the primary Earth-Mars transportation systems. A common crew cabin design that can perform in each of these applications is desired and could reduce the overall mission cost. However, for the MAV, the crew cabin size and mass can have a large impact on vehicle design and performance. The total ascent vehicle mass drives performance requirements for the Mars descent systems and the Earth to Mars transportation elements. Minimizing MAV mass is a priority and minimizing the crew cabin size and mass is one way to do that. This paper explores the benefits and impacts of using a common crew cabin design for the MAV. Results of a MAV configuration trade study will be presented along with mass and performance estimates for the selected design.