Keith Splawn

Desert Research and Technology Studies 2005 Report

During the first two weeks of September 2005, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2005 Research and Technology Studies (RATS). The Desert RATS field test activity is the culmination of the various individual science and advanced engineering discipline areas year-long technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The purpose of the RATS is to drive out preliminary exploration concept of operations EVA system requirements by providing hands-on experience with simulated planetary surface exploration extravehicular activity (EVA) hardware and procedures. The RATS activities also are of significant importance in helping to develop the necessary levels of technical skills and experience for the next generation of engineers, scientists, technicians, and astronauts who will be responsible for realizing the goals of the Constellation Program. The 2005 Desert RATS was the eighth RATS field test and was the most systems-oriented, integrated field test to date with participants from NASA field centers, the United States Geologic Survey (USGS), industry partners, and research institutes. Each week of the test, the 2005 RATS addressed specific sets of objectives. The first week focused on the performance of surface science astro-biological sampling operations, including planetary protection considerations and procedures. The second week supported evaluation of the Science, Crew, Operations, and Utility Testbed (SCOUT) proto-type rover and its sub-systems. Throughout the duration of the field test, the Communications, Avionics, and Infomatics pack (CAI-pack) was tested. This year the CAI-pack served to provide information on surface navigation, science sample collection procedures, and EVA timeline awareness. Additionally, 2005 was the first year since the Apollo program that two pressurized suited test subjects have worked together simultaneously. Another first was the demonstration of recharge of cryogenic life support systems while in-use by the suited test subjects. The recharge capability allowed the simulated EVA test duration to be doubled, facilitating SCOUT proto-type rover testing. This paper summarizes Desert RATS 2005 test hardware, detailed test objectives, test operations and test results.

Development of a Space Suit Soft Upper Torso Mobility/Sizing Actuation System

ILC Dover Inc. was awarded a three-year NRA grant for the development of innovative spacesuit pressure garment technology that will enable safer, more reliable, and effective manned exploration of the space frontier. Figure 1: Spacesuit Hammering Motion (NASA Artist Concept) The research is focusing on the development of a high performance mobility/sizing actuation system. This technology has application in two areas (1) a spacesuit soft upper torso (SUT) pressure garment for joint interface geometry repositioning to improve specific joint motion, hammering (Figure 1) vs. hand over hand translation (Figure 2), etc., and (2) as a suit sizing mechanism to allow easier suit entry and more accurate suit fit with few torso sizes than the existing EMU. This advanced soft upper torso will support NASAs Advanced EMU Evolutionary Concept of a two-size fit all upper torso for replacement of the current EMU hard upper torso (HUT). A diagram of the proposed project plan is shown in Figure 3. The research began with a system requirement analysis to identify and categorize actuation system requirements for a multitude of applications (International Space Station, Mars, etc.). An actuation study has also been conducted to identify potential actuators that provide acceptable force and response times, and have limited power requirements. Methods for force multiplication will be researched for application to improve actuation range of motion with reduced power consumption. The actuators will be used to position the SUT shoulder joint interface angles in a designated location and remain Figure 2: Spacesuit Hand Over Hand there until task completion. The joint interface will then be held in this position until it is again activated. The control mechanism will also be modeled and developed. Attention will be given to developing a fail-safe design that provides redundant function in the event of a loss of power or function. The SUT development will include the creation of an algorithm for the conversion of scan or manual human anthropometric data into optimal SUT shape including optimal interface ring positions. The SUT will incorporate the mobility/sizing actuation technology in the form of a system of rapidly sizable structural tendons and softgoods that govern interface angles and allow for compact packaging of the upper torso.

Micrometeoroid and Orbital Debris Enhancements of Shuttle Extravehicular Mobility Unit Thermal Micrometeoroid Garment

it is expected that astronauts will be required to spend more and more time exposed to the hazards of performing Extra-Vehicular Activity (EVA). One of these hazards includes the risk of the space suit bladder being penetrated by hypervelocity micrometeoroid and orbital debris (MMOD) particles. Therefore, it has become increasingly important to investigate new ways to improve the protectiveness of the current Extravehicular Mobility Unit (EMU) against MMOD penetration. identifying methods of improving the current EMU protection. The first part of this evaluation focused on identifying how to increase the EMU shielding, selecting materials to accomplish this, and testing these materials to determine the best lay-up combinations to integrate into the current thermal micrometeoroid garment (TMG) design. Part of this study included using extensive hypervelocity testing to identify potential candidate materials. The last part of this study expanded on the previous results by conducting a more thorough investigation into the performance of the top three candidate lay-ups for micrometeor protection. The ability to manufacture the candidates into the current TMG and their effects on the torque of a mobility joint were the main focus points. This paper summarizes the findings of this study.

System Considerations for an Exploration Spacesuit Upper Torso Architecture

NASA’s Exploration Architecture announced in September 2005, calls for development and flight of a Crew Exploration Vehicle (CEV) no later than 2014 and return to the moon by 2020 with a goal to reach and explore Mars. Intra-Vehicular Activity (IVA) suit systems will need to comfortably protect the crew during launch entry and abort scenarios. Extra-Vehicular Activity (EVA) suit systems will need to provide the capability to perform contingency zero-gravity EVA from the CEV as well as surface EVA to explore the moon and Mars. Studies currently underway to begin definition of the IVA and EVA suits point to a two suit architecture, the first being a launch, re-entry, and contingency EVA system used from CEV, the second and later being a lunar surface mobility suit only. An important consideration, yet to be determined, is the level of commonality between the early CEV and late Lunar suits. One concept is to have maximum commonality beginning with the architecture of the spacesuit upper torso. The upper torso is the foundation of the spacesuit. The upper torso supports the life support system, displays and controls, the opening for entry and closure, the helmet, and the shoulder and waist mobility joints. Upper torso architecture therefore, has a great affect on life support configuration, don/doff capability, mass and volume, suit sizing, and suit performance particularly in terms of visibility, mobility and comfort. Of prime consideration, is the upper torso material. Historically, hard upper torsos (HUTs) have been made of aluminum or composite, and soft upper torsos (SUTs) have been made of dual layer coated and noncoated fabrics. Architecture concepts have included waist entry, rear entry, and zipper closures. Upper Torso architecture is a key driver for the early CEV and late Lunar exploration spacesuit systems definition. This paper provides a review of probable Constellation Program requirements, existing upper torso architectures, and material candidates. Recent developments in the ILC Dover I-Suit fabric upper torso are discussed in relation to meeting program goals. Trade assessments suggest that fabric upper torsos, common to both Constellation Program spacesuits, provide the best advantage to meet the goals of the program.

Human and Robotic Enabling Performance System Development and Testing

With a renewed focus on manned exploration, NASA is beginning to prepare for the challenges that lie ahead. Future manned missions will require a symbiosis of human and robotic infrastructure. As a step towards understanding the roles of humans and robots in future planetary exploration, NASA headquarters funded ILC Dover and the University of Maryland to perform research in the area of human and robotic interfaces. The research focused on development and testing of communication components, robotic command and control interfaces, electronic displays, EVA navigation software and hardware, and EVA lighting. The funded research was a 12-month effort culminating in a field test with NASA personnel.

Evaluation of a Rear Entry System for an Advanced Spacesuit

The success of astronauts in performing Extra-Vehicular Activity (EVA) is highly dependent on the performance of the spacesuit they are wearing. The Space Shuttle Extravehicular Mobility Unit (EMU) is a waist entry suit consisting of a hard upper torso (HUT) and soft fabric mobility joints. The EMU was designed specifically for zero gravity operations. With a new emphasis on planetary exploration, a new EVA spacesuit design is required. One of the key features of any space suit is the entry method. Historical examples of different entry types include waist entry, rear entry, bi-planar entry, and soft zipper type entry. Suit entry type plays a critical role in defining the overall suit architecture. Some of the critical suit features affected by entry type are suit don/doff capability, suit sizing, suit mass, suit volume, and suit comfort. In general, rear entry designs provide better don/doff capabilities. However, mass and limitations to vertical torso length may be disadvantages of the rear entry design. Entry type is also affected by the vehicle and habitat interfaces such as air locks, hatches, and manned rovers. One concept for planetary exploration is to have an unpressurized vestibule attached to the habitat and have the spacesuit attached to the habitat wall acting as an air lock. This scenario is best supported by a rear entry design minimizing the amount of dust and dirt entering the habitat. ILC has designed a rear entry prototype upper torso for the I-Suit advanced spacesuit. The design facilitates don/doff while minimizing mass and the negative effects on vertical sizing. This paper discusses research performed at ILC Dover to develop the rear entry design and initial evaluations of the prototype.

Enhancing Capability in Launch, Entry, and Abort Style Spacesuits For ISS and Commercial Use

As the pending retirement of the Space Shuttle Transportation System draws closer and the focus on a replacement vehicle to ferry crews to and from the International Space Station increases, requirements for the suit that will be worn by the crew members that will fly this vehicle are also currently being written. These requirements will focus on the suits ability to operate in a variety of nominal and contingency environments which will likely require a high degree of functionality in both pressurized and unpressurized modes of operation. While many of these requirements have yet to be finalized several Launch, Entry, and Abort (LEA) type suits have been designed and fabricated by ILC Dover using requirement sets that focused on different specific suit designs and their accompanying technologies. These design elements serve to minimize suit mass, enhance both pressurized and unpressurized mobility, increase safety, and identify potential operational risks. The purpose of this paper is to introduce several of these design elements and some of their preliminary test and operational results.

Phase VI Glove TMG Evolution

As Extra-Vehicular Activity (EVA) is becoming more challenging and a renewed interest into planetary exploration is being pursued, having a spacesuit glove that is able to perform more complex and dexterous tasks with less hand fatigue is critical. In an effort to build upon an already proven foundation a new investigation has been made into reducing the torque of the Phase VI Glove Thermal Micrometeoroid Garment (TMG) along with improving dexterity and tactility. This paper addresses the makeup of the Phase VI Glove TMG and details the investigation into improving the current design. An investigation into alternative heating methods was also pursued.