Orion Multi-Purpose Crew Vehicle Research Articles

Exercise countermeasure preferences of three male astronauts, a preliminary qualitative study

BackgroundA single flywheel exercise countermeasure has been chosen for use on-board the Orion Multi-Purpose Crew Vehicle for spaceflight missions of up to 30 days. As previous missions have typically involved the use of multiple exercise countermeasures there is a concern that the use of only flywheel may lead to boredom and reduce astronaut adherence to exercise prescriptions, presenting a risk to their health and the operational success of the mission. To determine if this will be a concern, this qualitative work identified astronaut-reported operational considerations for the implementation of an exercise countermeasure device for use during spaceflight, and if current plans for the implementation of a single flywheel exercise countermeasure device may affect astronaut adherence to exercise prescriptions. MethodsThe responses of three male astronauts to an open-ended qualitative survey were analysed using thematic analysis. All participants were required to currently be taking part in, or have previously taken part in, human spaceflight. ResultsAstronaut preferences for the use of an exercise device during spaceflight were categorised into three broad themes: exercise device ease of access, motivational and behavioural considerations, and operational and technical considerations. The three astronauts considered a single flywheel-based exercise device suitable for use as the sole exercise countermeasure on-board the Orion MPCV, and similar capsular spacecraft, so long as it met several conditions. The device should engage astronauts in a varied exercise prescription. The device should also meet the physiological expectations required of exercise countermeasures for spaceflight deconditioning. The device should be enjoyable to use, and measures should be put in place to reduce boredom (via variety in exercise prescription). The device should be easy to access in terms of both use and setup/takedown. Finally, the device should only be used without other exercise countermeasures for missions of 30 days or less. ConclusionIndividual crewmember preferences should be taken into consideration following crew selection to ensure the greatest adherence to exercise prescriptions. The data reported here should be used to supplement, not entirely inform, the development and use of future exercise countermeasures.

Our Future in the Stars

After years of hard physical and mental training, they take their first steps to the shuttle, waving goodbye to all the spectators and Earth. These astronauts, originally scientists, teachers, pilots, and engineers, each endured at least three years of rigorous professional training before even applying to an astronaut program. Earning a bachelor’s degree is the minimum requirement for NASA positions, and the astronauts train beyond the classroom by swimming laps in a space suit to experience zero-gravity. A day in an astronaut’s life might start by climbing aboard the “vomit comet,” an aircraft that flies a parabolic path to simulate microgravity conditions. Astronauts also accustom themselves to move and work in weightlessness at the Neutral Buoyancy Lab in NASA’s Johnson Space Center (JSC). Behind the walls of this facility in Houston, Texas, these astronauts-in-training submerge themselves in a massive swimming pool while in clunky space suits. They navigate in full-scale underwater mockups of their shuttle and familiarize themselves with the life-size replica of the International Space Station (ISS).
 After years of training, these space pioneers stand at the launch pad with 1000 jet aircraft pilot-in-command hours in their pockets, thoroughly acquainted with every module on the ISS. NASA statistics claim that the launch shuttle sends our astronauts hurling into space at 18,000 mph, a speed nine times faster than the average rifle bullet. In just six hours, they arrive at the actual ISS, which spans about the width of an American football field. The docking process is actually the most complicated component of their journey; the spacecraft cannot dock without entering the correct orbit at the correct time, and there is no room for a mistake that might send the spacecraft crashing into the ISS.
 
 
 
 When the astronauts finally do make it onboard the ISS, they’ll find themselves inside a leviathan weighing nearly one million pounds. The astronauts have more space than a six-bedroom house and are required to exercise in the station’s gymnasium. They might walk through the main central truss and look through the 360o bay window, and then visit laboratories where physicists attempt to detect dark matter and biologists study muscle atrophy in zebrafish. To prevent loss of muscle and bone mass, our astronauts engage in scheduled exercise and various spaceship repairs every day, leaving them only an hour or two of free time in the mornings. Control center staff back on Earth likewise cannot sit back and relax. Orbital debris presents a constant, imminent danger to the wellbeing of the ISS. Station-crew and on-ground staff must do all that they can to protect this $150 billion flying space station from large debris while simultaneously conducting research and repairing the ship.
 
 The ISS is anything but permanent. Our astronauts’ toil will amount to nothing if we cannot raise the funds necessary to keep the station in orbit. Boeing predicts that the ISS’s parts can hold up through 2028, but the bigger issue is finding funding to keep the station alive. NASA and its partners in Russia, Japan, Canada, and other countries have committed to funding the station through 2020, but what its fate afterwards is uncertain. These countries are debating the question if the structure should be kept in orbit, allowing further research and providing a market for space transport companies like SpaceX and Sierra Nevada. Alternatively, they could choose to give up the mammoth, perhaps by letting it spiral down into the South Pacific for a watery death.
 Fortunately for ardent ISS supporters, there is some solace for the immediate future; NASA and White House officials announced plans to keep the station running till at least 2024. Still, it is time to look beyond this station. As famous and celebrated as it may be, new avenues for exploration must be built after the ISS becomes dysfunctional. As our society has look into our future in space, we have expanded our ideas, including plans to construct space colonies –stations with Earth-like features that function as permanent settlements. If these colonies successfully sustain human life, there are plans to build a mega-station called ‘Elysium’ – based off the movie – which could house a large portion of the human population. Such stations might very well be essential to mankind’s future in the stars.
 There are also plans to construct a new NASA vehicle, the Orion Multi-Purpose Crew Vehicle (MPCV), specifically for deep space exploration. Expected to meet the constantly growing needs of human space exploration programs, Orion may eventually carry astronauts to worlds far beyond Earth’s orbit which no man has ever seen or set foot on. This century marks the dawn of a new era in exploration, and if we can muster the manpower and financial support, humankind will advance further than we’ve ever been from our home planet.
 
 
 

Characterization of Solar Energetic Particle Radiation Dose to Astronaut Crew on Deep‐Space Exploration Missions

AbstractHuman radiation exposure from solar energetic particle (SEP) events during deep‐space exploration missions has a greater impact on mission planning and operations compared to spaceflight missions to low Earth orbit. Deep‐space SEP radiation exposure may require in‐flight preventative actions in order to reduce the radiation risks to as low as reasonably achievable, to limit the onset and severity of acute biological responses, and to ensure that astronaut permissible exposure limits are not exceeded. In this paper, radiation dose to the blood forming organs (BFO) of astronaut crew is calculated from a set of historical SEP events, using the design of the Orion Multipurpose Crew Vehicle (MPCV). The BFO doses from the historical events are analyzed in several ways. The results show the range and upper limit of BFO doses expected in heavily shielded space vehicles such as the Orion MPCV, based on calculations from all the major SEP events encountered in the space age. The dose reduction properties of the MPCV storm shelter are characterized over the broad range of SEP events included in the historical database. Correlations are derived between the integral proton fluence and BFO dose in the vehicle, showing that integral fluence is a good proxy for predicting or forecasting vehicle BFO dose. The best correlation with MPCV BFO dose is from the >100 MeV integral fluence. These results will assist in the design of future space weather architectures by identifying models and measurements needed to expand and extend NASA's existing SEP radiation risk tools in the support and management of human space exploration missions.

NASA’s Plans for Development of a Standard for Additively Manufactured Components

The current version of NASA standards for manned spaceflight hardware do not contain sufficient detail for the certification of additively manufactured components. The development of additively manufactured standards is currently in work by several standards organizations. However, NASA cannot wait on these organizations to develop such standards. NASA and its program partners in manned spaceflight (Commercial Crew, Space Launch System and the Orion Multi-Purpose Crew Vehicle) are actively developing additively manufactured components for flight as early as 2019.

The Lunar Space Tug: A sustainable bridge between low Earth orbits and the Cislunar Habitat

The International Space Station is the first space human outpost and over the last 15 years, it has represented a peculiar environment where science, technology and human innovation converge together in a unique microgravity and space research laboratory. With the International Space Station entering the second part of its life and its operations running steadily at nominal pace, the global space community is starting planning how the human exploration could move further, beyond Low-Earth-Orbit. According to the Global Exploration Roadmap, the Moon represents the next feasible path-way for advances in human exploration towards the nal goal, Mars. Based on the experience of the ISS, one of the most widespread ideas is to develop a Cislunar Station in preparation of long duration missions in a deep space environment. Cislunar space is de ned as the area of deep space under the influence of Earth-Moon system, including a set of special orbits, e.g. Earth-Moon Libration points and Lunar Retrograde Orbit. This habitat represents a suitable environment for demonstrating and testing technologies and capabilities in deep space. In order to achieve this goal, there are several crucial systems and technologies, in particular related to transportation and launch systems. The Orion Multi-Purpose Crew Vehicle is a reusable transportation capsule designed to provide crew transportation in deep space missions, whereas NASA is developing the Space Launch System, the most powerful rocket ever built, which could provide the necessary heavy-lift launch capability to support the same kind of missions. These innovations would allow quite-fast transfers from Earth to the Cislunar Station and vice versa, both for manned and unmanned missions. However, taking into account the whole Concept of Operations for both the growth and sustainability of the Cislunar Space Station, the Lunar Space Tug can be considered as an additional, new and fundamental element for the mission architecture. The Lunar Space Tug represents an alternative to the SLS scenario, especially for what concerns all unmanned or logistic missions (e.g. cargo transfer, on orbit assembly, samples return), from Low Earth Orbit to Cislunar space. The paper focuses on the mission analysis and conceptual design of the Lunar Space Tug to support the growth and sustainment of the Cislunar Station. Particular attention is dedicated to the analysis of the propulsion subsystem effects of the Lunar Space Tug design. Main results are presented and discussed, and main conclusions are drawn.

Comparison of novel active semiconductor pixel detectorwith passive radiation detectors during the NASA Orion Exploration Flight Test 1 (EFT-1)

The first unmanned flight of the Orion Multipurpose Crew Vehicle (MPCV) was successfully completed on December 5, 2014. The total mission duration was 4.5 h, and the EFT-1 trajectory consisted of a high apogee (∼6000 km, 28.6° inclination), high eccentricity orbit through the Van Allen belts. Radiation measurements on Orion included a novel Battery-operated Independent Radiation Detector (BIRD) based on Timepix hybrid pixel technology, luminescence dosimeters (LiF:Mg,Ti, 6LiF:Mg,Ti, 7LiF:Mg,Ti, CaF2:Tm and Al2O3:C) and plastic nuclear track detectors (CR-39). This paper will discuss the advantages of the BIRD instrument with respect to analysis of the environment changes along the flight trajectory using the time stamp tracking capability of the pixel detector. In addition, a dosimetry comparison between the active BIRD instrument and the passive radiation area monitor (RAM) detectors in terms of mission absorbed dose.

Heat-Shield Ablation Visualized Using Naphthalene Planar Laser-Induced Fluorescence

A combined experimental and computational study is conducted of heat-shield ablation from a scaled model of NASA’s Orion Multi-Purpose Crew Vehicle in a Mach 5 wind tunnel. The ablating heat shield is made of naphthalene, which sublimates at room temperature and below, and thus is suitable for ablation studies in low-enthalpy supersonic wind tunnels. Naphthalene has the added advantage that the dispersion of the ablation products can be visualized by planar laser-induced fluorescence. Planar laser-induced fluorescence imaging of the gas-phase naphthalene reveals the distribution of the ablation products as they are transported into the heat-shield boundary layer, over the capsule shoulder, and into the separated shear layer and backshell recirculation region. High concentrations of naphthalene in the capsule separated flow region, intermittent turbulent structures on the heat-shield surface, and interesting details of the capsule shear-layer structure are observed by using the naphthalene planar laser-induced fluorescence technique. Numerical simulations of the capsule flowfield temperature and pressure fields at 0, 12, and 24 deg angles of attack are then used to compute naphthalene mole fraction from the planar laser-induced fluorescence images.

Liftoff and time equivalent duration data evaluation of exploration flight test 1 Orion multi-purpose crew vehicle

The liftoff phase induces high acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. There arises the question about time equivalent (Teq) duration of the liftoff phase and similarity to other launch vehicles. Vibroacoustic engineers require the fatigue-weighted time duration values for qualification testing inputs. In order to determine the Teq for the Space Launch System, NASA’s newest launch vehicle, the external microphone data from the Exploration Flight Test 1 (EFT-1) flight of the Orion Multi-Purpose Crew Vehicle (MPCV) was evaluated. During that evaluation, a trend was observed in the data, and the origin of that trend is discussed in this paper. Finally, the Teq values for the EFT-1 Orion MPCV are presented.

Geometric Calibration of the Orion Optical Navigation Camera using Star Field Images

The Orion Multi Purpose Crew Vehicle will be capable of autonomously navigating in cislunar space using images of the Earth and Moon. Optical navigation systems, such as the one proposed for Orion, require the ability to precisely relate the observed location of an object in a 2D digital image with the true corresponding line-of-sight direction in the camera’s sensor frame. This relationship is governed by the camera’s geometric calibration parameters — typically described by a set of five intrinsic parameters and five lens distortion parameters. While pre-flight estimations of these parameters will exist, environmental conditions often necessitate on-orbit recalibration. This calibration will be performed for Orion using an ensemble of star field images. This manuscript provides a detailed treatment of the theory and mathematics that will form the foundation of Orion’s on-orbit camera calibration. Numerical results and examples are also presented.

Mach 6 Wake Flow Simulations Using a Large-Eddy Simulation/Reynolds-Averaged Navier–Stokes Model

A hybrid large-eddy simulation/Reynolds-averaged Navier–Stokes turbulence model is used to simulate the Mach 6 flow around a scaled model similar to NASA’s Orion multipurpose crew vehicle. The results for surface pressure and heat transfer are compared with experimental data from previous base flow experiments conducted at the Calspan—University at Buffalo Research Center. Using the highest Reynolds number test case ( based on capsule diameter), different numerical aspects of the hybrid approach are addressed, such as use of a low-dissipation scheme, a modification to the eddy-viscosity blending function, time-averaging results, filtering computational results, and sensitivity to grid resolution. In addition, results are compared with Reynolds-Averaged Navier–Stokes using Menter’s two-equation baseline model and to detached-eddy simulation predictions. By introducing a new modification to the blending from Reynolds-averaged Navier–Stokes to large-eddy simulation within boundary layers, very good agreement with the experiment is obtained in regions where the boundary-layer grid spacing is too coarse for large-eddy simulation. The findings show that the high-fidelity schemes produce results that agree much better with the experimental data than Reynolds-averaged Navier–Stokes methods, which tend to underpredict base pressures and overpredict heat fluxes. The overall accuracy of each scheme is evaluated using a normalized root mean square error in different regions of the flow, and the analysis shows that, in separated regions, the integrated error is over 120% using a Reynolds-averaged Navier–Stokes model, and 30–50% using the higher fidelity schemes. Additionally, the hybrid methodology presented is further validated by considering a lower Reynolds number (), where the flow is nominally transitional, and very accurate heat transfer predictions are also obtained.

Arcjet Testing and Thermal Model Development for Multilayer Felt Reusable Surface Insulation

Felt reusable surface insulation was used extensively on leeward external surfaces of the shuttle Orbiter, where the material is reusable for temperatures up to 670 K. For application on leeward surfaces of the Orion multipurpose crew vehicle, where predicted temperatures reach 1620 K, the material functions as a pyrolyzing conformable ablator. An arcjet test series was conducted to assess the performance of multilayer felt reusable surface insulation at high temperatures, and a thermal-response, pyrolysis, and ablation model was developed. Model predictions compare favorably with the arcjet test data.

Sand Impact Tests of a Half-Scale Crew Module Test Article

AbstractAlthough the Orion Multi-Purpose Crew Vehicle (MPCV) is being designed primarily for water landings, the possibility exists of an onshore landing at Kennedy Space Center (KSC) following a launch abort. To obtain data to evaluate the adequacy of sand material models used in beach landing simulations, sand impact tests were conducted at National Aeronautics and Space Administration (NASA) Langley Research Center (LRC). Both vertical drop tests and swing tests with combined vertical and horizontal velocity were performed onto beds of common construction-grade sand using a geometrically scaled crew module test article. The tests were simulated using the explicit, nonlinear, transient dynamic finite-element code LS-DYNA. The shape of the test article was similar to a scaled crew module, but the structure was much heavier and was sufficiently robust to survive multiple impacts without permanent deformation. The focus was the sand model, not the structural response of the test article. The sand material ...

Tough Financial Times Bring ESA Down to Earth

Europe will be going to Mars, but not to the moon, and it will have to wait for a decision on a next-generation Ariane 6 launcher.

A lunar L2-Farside exploration and science mission concept with the Orion Multi-Purpose Crew Vehicle and a teleoperated lander/rover

A novel concept is presented in this paper for a human mission to the lunar L2 (Lagrange) point that would be a proving ground for future exploration missions to deep space while also overseeing scientifically important investigations. In an L2 halo orbit above the lunar farside, the astronauts aboard the Orion Crew Vehicle would travel 15% farther from Earth than did the Apollo astronauts and spend almost three times longer in deep space. Such a mission would serve as a first step beyond low Earth orbit and prove out operational spaceflight capabilities such as life support, communication, high speed re-entry, and radiation protection prior to more difficult human exploration missions. On this proposed mission, the crew would teleoperate landers/rovers on the unexplored lunar farside, which would obtain samples from the geologically interesting farside and deploy a low radio frequency telescope. Sampling the South Pole-Aitken basin, one of the oldest impact basins in the solar system, is a key science objective of the 2011 Planetary Science Decadal Survey. Observations at low radio frequencies to track the effects of the Universe’s first stars/galaxies on the intergalactic medium are a priority of the 2010 Astronomy and Astrophysics Decadal Survey. Such telerobotic oversight would also demonstrate capability for human and robotic cooperation on future, more complex deep space missions such as exploring Mars.

Application of model based development to flexible code generation

This address will present the authors views and perspectives on the past, present and future use of model based development techniques to enable the automated generation of source code and other forms of programming. This address will discuss past and present use of model based development and automated code generation at Lockheed Martin, with special emphasis on NASA's Orion Multi-Purpose Crew Vehicle Program. This address will discuss the advantages and disadvantages, associated with the current state of the practice techniques and tools, used to automatically generate source code from general purpose and domain specific models. This address will discuss the obstacles and enablers, associated with achieving the desired future state of complete and efficient automated generation of programming through transformation of general purpose and domain specific models.