Microgravity
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## Mathematical Model of Heat-Controlled Accumulator (HCA) for Microgravity Conditions

National Aerospace University Kharkov Aviation Institute, Ukraine-
• Journal Article
• 01-13-01-0001
Published 2020-01-09 by SAE International in United States
It is reasonable to use a two-phase heat transfer loop (TPL) in a thermal control system (TCS) of spacecraft with large heat dissipation. One of the key elements of TPL is a heat-controlled accumulator (HCA). The HCA represents a volume which is filled with vapor and liquid of a single working fluid without bellows. The pressure in a HCA is controlled by the heater. The heat and mass transfer processes in the HCA can proceed with a significant nonequilibrium. This has implications on the regulation of TPL. This article presents a mathematical model of nonequilibrium heat and mass transfer processes in an HCA for microgravity conditions. The model uses the equations of mass and energy conservation separately for the vapor and liquid phases. Interfacial heat and mass transfer is also taken into account. It proposes to use the convective component k for the level of nonequilibrium evaluation. The experiments were carried out in microgravity conditions for the estimation of the k value. The heating of the HCA was investigated in the flight experiments. The workingâ€¦

## Active Response Gravity Offload System

• Magazine Article
• TBMG-29696
Published 2018-07-01 by Tech Briefs Media Group in United States

NASA has used two systems to train astronauts for weightlessness. The first is the Reduced Gravity Simulator that suspended the astronaut at an angle of 80.5 so that only 1/6th of his or her weight was supported by the ground, while the rest was supported by a pulley system. The other system, designed during the Apollo era, is the Partial Gravity Simulator (POGO), which uses an air-controlled piston along with air bearings and gimbals to simulate reduced gravity. This pneumatic system is attached to an air-bearing rail to allow for maneuverability in two dimensions. POGO was used to train astronauts on how to use tools and other hardware in microgravity.

## Volumetric 3D Printing

• Magazine Article
• TBMG-29717
Published 2018-07-01 by Tech Briefs Media Group in United States

While additive manufacturing (AM), commonly known as 3D printing, is enabling engineers and scientists to build parts in configurations and designs never before possible, the impact of the technology has been limited by layer-based printing methods, which can take up to hours or days to build three-dimensional parts, depending on their complexity.

## Space-Based Bone Scanner Expands Medical Research

• Magazine Article
• TBMG-28319
Published 2018-02-01 by Tech Briefs Media Group in United States

Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.

## Additive Manufacturing Facility for Utilization Primarily in Microgravity Environments

• Magazine Article
• TBMG-28152
Published 2018-01-01 by Tech Briefs Media Group in United States

The purpose of this innovation is to create the ability to manufacture off Earth, primarily in a microgravity environment. This additive manufacturing facility (AMF) will have the capability to build tools, parts, experimental hardware, and upgrade hardware while primarily being utilized in microgravity environments.

## Sensor Assists NASA with Wearable CO2 Monitor

• Magazine Article
• TBMG-28027
Published 2017-12-01 by Tech Briefs Media Group in United States

SST Sensing Ltd.Coatbridge, UK

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## Group Combustion Excitation in Randomly Distributed Droplet Clouds Based on Flame-spread Characteristics with Two-droplet Interaction in Microgravity

Sebelas Maret University-
Yamaguchi University-
• Technical Paper
• 2017-32-0077
Published 2017-11-05 by Society of Automotive Engineers of Japan in Japan
Experiments of flame-spread of fuel droplets have been performed in microgravity actively. However, the experiment has limitation in the number of droplets due to relatively short microgravity durations in the ground based facilities. It is difficult to conduct flame spread experiments of large scale droplet clouds in microgravity. This study conducted simulation of flame-spread behavior in randomly distributed large-scale droplet clouds by using a percolation approach, in order to make a theoretical link the gap between droplet combustion experiments and spray combustion phenomenon with considering two-droplet interaction. Droplets are arranged at lattice points in 2D lattice. The occurrence probability of group combustion (OPGC) is calculated as a function of the mean droplet spacing (S/d0)m. The (S/d0)m for 0.5 OPGC is defined as the critical mean droplet spacing (S/d0)critical, which separates the droplet cloud into two groups if the lattice size becomes infinity; relatively dense droplet clouds in which the group combustion is excited through flame spread and dilute droplet clouds in which the group combustion in is never excited. The results show that in 2Dâ€¦
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## Robotic Gripper Cleans Up Space Debris

• Magazine Article
• TBMG-27731
Published 2017-10-01 by Tech Briefs Media Group in United States

Large amounts of existing space debris pose a threat to satellites, space vehicles, and astronauts aboard those vehicles. However, cleaning up the debris is problematic. For example, suction cups don't work in a vacuum, and traditional sticky substances like tape are largely useless because the chemicals they rely on can't withstand extreme temperature swings.

## Studies into Additive Manufacturing for In-Space Manufacturing

• White Paper
• WP-0001
Published 2017-06-26 by SAE International in United States
NASA has embarked on an ambitious program to integrate additive manufacturing techniques and to develop processes for the microgravity environment. The most recent example of this program is the successful launch and deployment of the first 3D printer on the International Space Station. In this one-year effort, students were required to meet a series of milestones to design, manufacture, and test their ideas in close cooperation with members of the NASA Exploration Augmentation Module (EAM) concept team.The participants in this project were tasked with thinking of new solutions using AM that would simultaneously be recyclable with minimal loss in mechanical properties but also have the capacity for high mechanical properties. Working in interdisciplinary teams, the participant teams investigated the use of recycled materials, characterization, testing, modeling, and tool development. The underlying philosophy adopted in these papers is the ability to use a strut-and-tie approach that integrates reusable carbon-fiber tension ties for tension zones.The results of this project encompass a series of nterconnected studies exploring the issues surrounding 3D printing in a space environment.

## Novel Threading Enables New Approach to Golf Clubs

• Magazine Article
• TBMG-26877
Published 2017-05-01 by Tech Briefs Media Group in United States

Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.