Taber MacCallum

Feasibility analysis for a manned mars free-return mission in 2018

In 1998 Patel et al searched for Earth-Mars free-return trajectories that leave Earth, fly by Mars, and return to Earth without any deterministic maneuvers after Trans-Mars Injection. They found fast trajectory opportunities occurring two times every 15 years with a 1.4-year duration, significantly less than most Mars free return trajectories, which take up to 3.5 years. This paper investigates these fast trajectories. It also determines the launch and life support feasibility of flying such a mission using hardware expected to be available in time for an optimized fast trajectory opportunity in January, 2018.

Demonstration of Metabolic Heat Regenerated Temperature Swing Adsorption Technology

Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is currently being investigated for removal and rejection of CO2 and heat from a Portable Life Support System (PLSS) to a Martian environment. The metabolically-produced CO2 present in the vent loop gas is collected using a CO2 selective adsorbent that has been cooled via a heat exchanger to near CO2 sublimation temperatures (approx.195K) with liquid CO2 obtained from Martian resources. Once the adsorbent is fully loaded, fresh warm, moist vent loop (approx.300K) is used to heat the adsorbent via another heat exchanger. The adsorbent will then reject the collected CO2 to the Martian ambient. Two beds are used to achieve continuous CO2 removal by cycling between the cold and warm conditions for adsorbent loading and regeneration, respectively. Small experiments have already been completed to show that an adsorbent can be cycled between these PLSS operating conditions to provide adequate conditions for CO2 removal from a simulated vent loop. One of the remaining technical challenges is extracting enough heat from the vent loop to warm the adsorbent in an appreciable time frame to meet the required adsorb/desorb cycle. The other key technical aspect of the technology is employing liquid CO2 to achieve the appropriate cooling. A technology demonstrator has been designed, built and tested to investigate the feasibility of 1) warming the adsorbent using the moist vent loop, 2) cooling the adsorbent using liquid CO2, and 3) using these two methods in conjunction to successfully remove CO2 from a vent loop and reject it to Mars ambient. Both analytical and numerical methods were used to perform design calculations and trades. The demonstrator was built and tested. The design analysis and testing results are presented along with recommendations for future development required to increase the maturity of the technology.

The ABS (Autonomous Biological System): Spaceflight Results from a Bioregenerative Closed Life Support System

Materially-closed aquatic life support systems containing vascular plants, invertebrate animals, algae and microbes were tested in three space flight experiments with ground controls. Termed Autonomous Biological Systems (ABS), the 0.9 liter systems were completely isolated from spacecraft life support systems and cabin atmosphere contaminants, and needed minimal intervention from astronauts. The first experiment, aboard the Space Shuttle in 1996 for 10 days, was the first time that aquatic angiosperms were successfully grown in space. The second and third experiments aboard the Mir space station had 4-month durations, in 1996-97 and 1997-98, and were the first time that higher organisms (aquatic invertebrate animals) completed their life cycles in space. Compared to the ground control ABS, the flight units showed clearer water and slightly higher total organic carbon and soluble free amino acids. ABS units from all 3 flights returned as diverse and complex ecosystems. The ABS are the first completely bioregenerative, closed ecological life support systems to thrive in space, demonstrating their efficacy for research in space biology and gravitational ecology.

Employing ionomer-based membrane pair technology to extract water from brine

Closing the water loop on long duration spaceflight missions is a key aspect of reducing mission mass and logistics support for orbiting facilities and interplanetary spacecraft. At present, no single practical process exists that is capable of extracting purified water from the wastewater stream in a single step. Recently, the use of synthetic membranes has shown promise in simplifying water purification systems. To build on this work, Paragon Space Development Corporation® (Paragon) researched the use of a microporous-ionomer membrane pair, or ionomer water processor (IWP), under a Phase I NASA SBIR to improve the robustness and effectiveness of membrane-based water/brine separation processes. The microporous membrane prevents liquid wastewater from direct contact with the ionomer, a condition that would reduce the effectiveness of the ionomer. A test rig was built and used to test the brine dewatering capabilities of the ionomer-microporous membrane pair. The hydrophobic side of an ionomer-microporous membrane pair was exposed to both liquid and vapor pretreated urine ersatz brine. The water vapor that transported across the membrane was collected as condensate and sent to a lab for analyses. While still not a singlestep solution to water recovery, prominent findings suggest that a brine dewatering system based on ionomer-microporous membrane pair technology shows great potential to reduce the complexity of water recovery systems. Of note: (1) the membrane pair can function in both liquid-contact and vapor-contact modes, which is important for zero-gravity operation, (2) the membrane pair was shown to prevent 98%-99% of brine stock TOCs and up to 99.8% of ammonium from entering the product stream (permeate), (3) near-complete drying of the brine can be accomplished with this technology, (4) temperatures to drive permeation are consistent with ECLSS waste heat, and (5) permeation rates suggest reasonable unit size can be designed.

Lessons Learned from Biosphere 2: When Viewed as a Ground Simulation/Analog for Long Duration Human Space Exploration and Settlement

President Bushs recent announcement of the Exploration Initiative dictates manned bases on the Moon and eventually Mars. A ground swell of credible privately funded space projects is also reaffirming the notion that was for a time taken for granted but in recent years has seemed further and further from being realized - that humans will live permanently in space. A human mission to Mars, or a base on the Moon or Mars is a lengthier more complex mission than any space endeavor undertaken to date. Simulation Based Acquisition is a fundamental part of preparing for such a mission. Ground simulations provide a relevant, analogous environment for testing technologies and learning how to manage complex, long duration missions, while addressing inherent mission risks. Multiphase human missions and settlements with limited opportunities for immediate return to Earth should a problem occur, require high fidelity, end-to-end, full mission duration tests in order to evaluate a systems ability to sustain the crew for the entire mission and return them safely to Earth. Moreover, abort scenarios are essentially precluded in many mission scenarios though certain risks may only become evident late in the mission. Aging and compounding effects cannot be simulated through accelerated tests for all aspects of the mission. Until such high fidelity long duration simulations are available, and in order to help prepare those simulations and mission designs, it is important to extract as many lessons as possible from analogous environments. Biosphere 2 is a three-acre materially closed ecological system that supported eight crewmembers with food, air and water in a sunlight driven bioregenerative system for two years. It was designed for research applicable to environmental management on Earth and the development of human life support for space. Although the two-year mission of Biosphere 2 was completed ten years ago, it is quite possibly the best analog for a long duration space mission that has been conducted and warrants reexamination in light of NASAs new direction. A brief overview of the two-year Biosphere 2 mission is presented, followed by select data and lessons learned that are applicable to the design and operation of a long duration human space mission, settlement or test bed. These lessons include technical, programmatic, and psychological issues.

Martian Liquid CO2 and Metabolic Heat Regenerated Temperature Swing Adsorption for Portable Life Support Systems

Two of the fundamental problems facing the development of a Portable Life Support System (PLSS) for use on Mars, are (i) heat rejection (because traditional technologies use sublimation of water, which wastes a scarce resource and contaminates the premises), and (ii) rejection of CO2 in an environment with a ppCO2 of 0.4–0.9 kPa. This paper presents a conceptual system for CO2 collection, compression, and cooling to produce sub‐critical (liquid) CO2. A first order estimate of the system mass and energy to condense and store liquid CO2 outside at Mars ambient temperature at 600 kPa is discussed. No serious technical hurdles were identified and it is likely that better overall performance would be achieved if the system were part of an integrated ISRU strategy rather than a standalone system. Patent‐pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology for CO2 removal from a PLSS vent loop, where the Martian liquid CO2 is used as the heat sink is developed to utilize the readily ...

Environmental Psychology and Biosphere 2

This chapter deals with two categories of research in environmental psychology, the ecological psychology of the Biosphere 2 environment and the selection process related to that environment.

The Next Generation of ECLSS: Life Support Outside the Earth-Moon System

To date humans have travelled distances of up to roughly 350,000 km to the moon and stayed alive in the Mir Space Station for a record single mission length of 438 days. These numbers are compelling and encouraging because the technologies used to achieve those feats could be used to help achieve missions to further destinations. While missions to near Earth objects (NEO) and beyond may have durations shorter than or similar to some of our stays at ISS and Mir, they will span distances up to hundreds of millions of miles from Earth; this represents lengths tens to hundreds of times farther than current records with the important distinction of exponentially longer abort times and diminishing opportunities for resupply. Because of many technology attributes based on abort time, resupply opportunities and total distances, long missions to NEO or to Mars can draw on our experience at Station and in LEO, but we will need to dig deeper. Taking humans further into space will require new architectures and potentially disruptive changes to our mentality regarding system engineering and risk. This could mean new architectures, development cycles focused on a unified end goal, and spacecraft holding systemic margins of safety instead of relying on Earth for support. This paper is a top-down look at the requirements that have traditionally driven ECLSS architectures over the past two decades and the life support technologies that have been developed to meet those requirements. From a historical investigation, ideas for the next generation of ECLSS can be derived to bring us closer to humankind’s aspirations to travel beyond the Earth-Moon system.

World view stratospheric ballooning capabilities, research, and commercial applications

We are developing and deploying the capability to fly payloads, and later people, on high altitude balloon flights at altitudes up to 150 Kft, with flight times ranging from hours to weeks. Applications include research and education payloads for atmospheric science, astronomy, education, and other scientific pursuits, and commercial applications ranging from communications to remote sensing to defense, and near-space tourism. Over 50 flights have been conducted to date with payloads up to 1,000 pounds; flights with payloads up to 10,000 pounds are planned. We have introduced a new class of stratospheric vehicle known as a Stratollite, which enables long-duration (days, weeks, and months) uncrewed, persistent high-altitude flight with altitude control. Here we summarize capabilities, activities, and applications for these flight systems in what follows.

Autonomous biological system—an unique method of conducting long duration space flight experiments for pharmaceutical and gravitational biology research

Paragon Space Development Corporation (SDC) has developed an Autonomous Biological System (ABS) that can be flown in space to provide for long term growth and breeding of aquatic plants, animals, microbes and algae. The system functions autonomously and in isolation from the spacecraft life support systems and with no mandatory crew time required for function or observation. The ABS can also be used for long term plant and animal life support and breeding on a free flyer space craft. The ABS units are a research tool for both pharmaceutical and basic space biological sciences. Development flights in May of 1996 and September, 1996 through January, 1997 were largely successful, showing both that the hardware and life systems are performing with beneficial results, though some surprises were still found. The two space flights, plus the current flight now on Mir, are expected to result in both a scientific and commercially usable system for breeding and propagation of animals and plants in space.