Long-term operation of "Orlan" space suits in the "Mir" orbiting station: experience obtained and its application

The started assembly of the International Space Station (ISS) and its further operation will call for a great number of extravehicular activity sorties (EVA) to be performed by ISS crews. Therefore, of great importance is to make use of the EVA experience gained by cosmonauts in the process of 15-year operation of the Mir orbiting station (OS). Over the 15-year period, Mir crewmembers wearing Orlan type semi-rigid space suits have accumulated 158 man/sorties from the orbiting station. Crewmembers used 15 suits in orbit and some of the suits were in operation for more than 3 years. The paper presents principal design features, which provide effective and safe operation of orbit-based suits, and briefly describes procedures for preparation and maintenance of suit systems, which ensure long-term operation of space suit in orbit. The paper gives results of the space suit modifications, presents suit performance characteristics and lists novel or upgraded components of the space suit and its systems. The paper also summarizes improvements in the Orlan type suits described in some earlier publications. They refer, in the first run, to the improvement of space suit operations characteristics and reliability, and the utilization of the Orlan type space suit in the ISS program. The paper analyses the experience gained and drawbacks detected and observations made, and gives statistical data on long-term space suit operations aboard the Mir station. The paper reviews certain problems in the process of EVAs performed from the station, and describes the ways of their solution as applied to the further utilization of the suit within the ISS program.     

The experience in operation and improving the Orlan-type space suits

Nowadays significant experience has been gained in Russia concerning extravehicular activity (EVA) with cosmonauts wearing a semi-rigid space suit of the "Orlan" type. The conditions for the cosmonauts' vital activities, the operational and ergonomic features of the space suit and its reliability are the most critical factors defining the efficiency of the scheduled operation to be performed by the astronaut and his safety. As the missions performed by the cosmonauts during EVA become more and more elaborate, the requirements for EVA space suits and their systems become more and more demanding, resulting in their consistent advancement. This paper provides certain results of the space suit's operation and analysis of its major problems as applied to the Salyut and MIR orbiting stations. The modification steps of the space suit in the course of operation (Orlan-D, Orlan-DM, Orlan-DMA) and its specific features are presented. The concept of the suited cosmonauts' safety is described as well as trends for future space suit improvements.     

EVA Suit 2000: a joint European/Russian space suit design

A feasibility study in 1992 showed the benefits of a common European Russian space suit development, EVA Suit 2000, replacing the Russian space suit Orlan-DMA and the planned European Hermes EVA space suit at the turn of the century. This EVA Suit 2000 is a joint development initiated by the European Space Agency (ESA) and the Russian Space Agency (RKA). The main objectives of this development program are: first utilization aboard the Russian Space Station MIR-2; performance improvement with respect to current operational suits; development cost reduction. Russian experience gained with the present extravehicular activity (EVA) suit on the MIR Space Station and extensive application of European Technologies will be needed to achieve these ambitious goals. This paper presents the current status of the development activities, the space suit system design and concentrates in more detail on life support aspects. Specific subjects addressed will include the overall life support conceptual architecture, design features, crew comfort and operational considerations.     

Ensuring of long operation life of the orbiting station EVA space suit

Russia has gained a lot of experience in operating the space suits (SS) during the extravehicular activities (EVA) by the crews of SALYUT-6, SALYUT-7 and MIR orbiting stations. A total of 21 Orlan-type space suits of various models were operated onboard the orbiting stations (OS) during almost 20 years period. Some of these space suits served up to 3 years in orbit. The paper reviews special features of long SS operation (without return to the Earth) onboard an orbiting station as well as the problems associated with SS repeated use by several crews. An analysis of measures to support solving of the problems of SS long stay and reliable operation onboard the orbiting station is made: selection of a corresponding SS type and separate elements design; selection of the materials; routine and preventive maintenance; development tests. The advantages of the space suit of a semi-rigid type for solving the above problems are shown. The paper includes a short analysis of space suits' operation onboard the Russian orbiting station MIR, and some restuts of inspection of the Orlan-DMA space suit returned to the Earth from orbit by STS-79 alter long operation in orbit. Recommendations on further improvement of the space suits for EVA operations in the International Space Station (ISS) are given.     

The main results of EVA medical support on the Mir Space Station

The aim of this paper is to review the main results of medical support of 78 two-person extravehicular activities (EVAs) which have been conducted in the Mir Space Program. Thirty-six male crewmembers participated in these EVAs. Maximum length of a space walk was equal to 7 h 14 min. The total duration of all space walks reached 717.1 man-hours. The maximum frequency of EVA's execution was 10 per year. Most of the EVAs (67) have been performed at mission elapsed time ranging from 31 to 180 days. The oxygen atmosphere of the Orlan space suit with a pressure of 40 kPa in combination with the normobaric cabin environment and a short (30 min) oxygen prebreathe protocol have minimized the risk of decompression sickness (DCS). There has been no incidence of DCS during performed EVAs. At the peak activity, metabolic rates and heart rates increased up to 9.9-13 kcal/min and 150-174 min-1, respectively. The medical problems have centred on feeling of moderate overcooling during a rest period in a shadow after the high physical loads, episodes with tachycardia accompanied by cardiac rhythm disorders at the moments of emotional stress, pains in the muscles and general fatigue after the end of a hard EVA. All of the EVAs have been completed safely.     

EVA 2000: a European/Russian space suit concept

For the European manned space activities an EVA space suit system was being developed in the frame of the Hermes Space Vehicle Programme of the European Space Agency (ESA). The space suit was to serve the needs for all relevant extravehicular activities for the Hermes Columbus operations planned to begin in 2004. For the present Russian manned space programme the relevant EVAs are performed by the Orlan-DMA semi-rigid space suit. The origin of its development reaches back to the 1970s and has since been adapted to cover the needs for extravehicular activities on Salyut and MIR until today. The latest modification of the space suit, which guaranteed its completely self-contained operation, was made in 1988. However, Russian specialists considered it necessary to start developing an EVA space suit of a new generation, which would have improved performance and would cover the needs by the turn of the century and into the beginning of the next century. Potentially these two suit developments could have a lot in common based on similarities in present concepts. As future manned space activities become more and more an international effort, a safe and reliable interoperability of the different space suit systems is required. Based on the results of the Munich Minister Conference in 1991, the European Space Agency and the Russian Space Agency agreed to initiate a requirements analysis and conceptual design study to determine the feasibility of a joint space suit development, EVA 2000. The design philosophy for the EVA 2000 study was oriented on a space suit system design of: space suit commonality and interoperability; increased crew productivity and safety; increase in useful life and reduced maintainability; reduced development and production cost. The EVA 2000 feasibility study was performed in 1992, and with the positive conclusions for EVA 2000, this approach became the new joint European Russian EVA Suit 2000 Development Programme. This paper gives an overview of the results of the feasibility study and presents the joint requirements and the proposed design concept of a jointly developed European Russian space suit.     

Main problems of the Russian Orlan-M space suit utilization for EVAs on the ISS

In the recent years the Russian Orlan-M space suits have been improved as applied to their operational requirements for the ISS. A special attention is paid to enhancement of EVA crew efficiency and safety. The paper considers the main problems regarding specific features of the Russian space suit operation in the ISS, and analyses measures on their solution. In particular, the problems associated with the following are considered: enhancement of the anthropometric range for the EVA crewmembers; use of some US EMU elements and unified NASA equipment elements; Orlan-M operation support in the wide range of the ISS thermal conditions; use of Simplified Aid For Extravehicular activity Rescue (SAFER) designed as a self-rescue device, which will be used for an EVA crewmember return in the event that he (she) breaks away inadvertently from the ISS surface. The paper states the main space suit differences with reference to solution of the above problems. The paper presents briefly the design of space suit arms developed for crewmembers with small anthropometric parameters, as well as peculiarities and test results for the gloves with enhanced thermal protection. Measures on further space suit development with the purpose to improve its performances are considered.     

The feasibility of Doppler monitoring during EVA

During extravehicular activities (EVA) outside the spacecraft, astronauts have to work under reduced pressure in a space suit. This pressure reduction induces the risk of decompression sickness (DCS) by the formation of gas bubbles from excess nitrogen dissolved in the organism by breathing air at normal pressure. Under laboratory conditions the gas bubbles moving in the blood stream can be detected by the non-invasive ultrasonic Doppler method. By early detection of excessive bubble formation the development of DCS symptoms may be prevented by early application of preventative measures. The method could also be useful when applied in the space suit in order to compare the results of laboratory tests with operational results, because there is a discrepancy according to the DCS risk of laboratory experiments and actual EVA missions, where no symptoms have been reported yet. A prototype Doppler sensor has been developed and implemented in the Russian Orlan suit. To investigate the feasibility of this method under simulated space conditions, the equipment has been used in a series of 12 thermovacuum chamber tests with suited subjects, where intravenous bubble formation was compared to unsuited control experiments. In more than 50% of the suited tests good Doppler recordings could be achieved. In some cases with unsatisfying results the signal could be improved by breathholding. Although the results do not yet allow any conclusion about a possible difference between suited and unsuited subjects due to the small number of tests performed, the method proved its feasibility for use in EVA suits and should be further developed to enhance the safety of EVA procedures.     

Identification and status of design improvements to the NASA Shuttle EMU for International Space Station application

To meet the significant increase in EVA demand to support assembly and operations of the International Space Station (ISS), NASA and industry have improved the current Shuttle Extravehicular Mobility Unit (EMU), or "space suit", configuration to meet the unique and specific requirements of an orbital-based system. The current Shuttle EMU was designed to be maintained and serviced on the ground between frequent Shuttle flights. ISS will require the EMUs to meet increased EVAs out of the Shuttle Orbiter and to remain on orbit for up to 180 days without need for regular return to Earth for scheduled maintenance or refurbishment. Ongoing Shuttle EMU improvements have increased reliability, operational life and performance while minimizing ground and on-orbit maintenance cost and expendable inventory. Modifications to both the anthropomorphic mobility elements of the Space Suit Assembly (SSA) as well as to the Primary Life Support System (PLSS) are identified and discussed. This paper also addresses the status of on-going Shuttle EMU improvements and summarizes the approach for increasing interoperability of the U.S. and Russian space suits to be utilized aboard the ISS.     

One hundred US EVAs: a perspective on spacewalks

In the 36 years between June 1965 and February 2001, the US human space flight program has conducted 100 spacewalks, or extravehicular activities (EVAs), as NASA officially calls them. EVA occurs when astronauts wearing spacesuits travel outside their protective spacecraft to perform tasks in the space vacuum environment. US EVA started with pioneering feasibility tests during the Gemini Program. The Apollo Program required sending astronauts to the moon and performing EVA to explore the lunar surface. EVA supported scientific mission objectives of the Skylab program, but may be best remembered for repairing launch damage to the vehicle and thus saving the program. EVA capability on Shuttle was initially planned to be a kit that could be flown at will, and was primarily intended for coping with vehicle return emergencies. The Skylab emergency and the pivotal role of EVA in salvaging that program quickly promoted Shuttle EVA to an essential element for achieving mission objectives, including retrieving satellites and developing techniques to assemble and maintain the International Space Station (ISS). Now, EVA is supporting assembly of ISS. This paper highlights development of US EVA capability within the context of the overarching mission objectives of the US human space flight program.     

Biomedical problems of EVA support during manned space flight to Mars

Current projects of manned missions to Mars are aimed to their realization in the second-third decades of this century. The purpose of this paper is to determine and review the main biomedical problems, that require a first and foremost decision for safety support of extravehicular activity (EVA) carried out by crewmembers of the Mars expedition. To a number of such problems the authors of the paper attribute a creation of adequate EVA equipment intended, first, for assembly of interplanetary spacecraft on the Earth orbit, performance of maintenance operations and scientific researches on the external surface of spacecraft during interplanetary flight and, secondly, for work on the Mars surface. New generation of space suits with low weight, high mobility and acceptable risk of decompression sickness must be as a central component of EVA equipment. The program for preparation to a Mars expedition also has to include special investigations in order to design the means and methods for a reliable protection of crew against space radiation, to elaborate the approach to medical monitoring and primary medical care during autonomous space mission, to maintain good health condition of crewmembers during EVA under the Mars gravity (0.38 g) after super long-term flight in weightlessness.     

The Soviet-Russian space suits a historical overview of the 1960's

The development of protective suits for space use started with the Vostok-suit SK-1, first used by Yu. Gagarin on April 12, 1961, and then used on all subsequent Vostok-flights. The technical background for the design of these suits was the work on full pressure protective suits for military pilots and stratospheric flights in the 1930's through 50's. The Soviet-Russian space programme contains a large number of 'firsts', and one of the most well known is the first EVA by Leonov in 1965. This event is also the starting point for a long series of space suit development for Extravehicular Activities over the last 35 years. The next step to come was the transfer in void space of crew members between the two spacecraft Soyuz 4 and 5 in 1969. As has later become known this was an essential element in the planned Soviet lunar exploration programme, which in itself required a new space suit. After the termination of the lunar programme in 1972, the space suit development concentrated on suits applicable to zero-gravity work around the manned space stations Salyut 6, Salyut 7 and MIR. These suits have become known as the ORLAN-family of suits, and an advanced version of this suit (ORLAN-M) will be used on the International Space Station together with the American EMU. This paper covers the space suit development in the Soviet Union in the 1960's and the experience used from the pre-space era.     

Suited crewmember productivity

Analysis of the extravehicular activity (EVA) sortie experience gained in the former Soviet Union and physiologic hygienic aspect of space suit design and development shows that crewmember productivity is related to the following main factors: -space suit microclimate (gas composition, pressure and temperature); -limitation of motion activity and perception, imposed by the space suit; -good crewmember training in the ground training program; -level of crewmember general physical performance capabilities in connection with mission duration and intervals between sorties; -individual EVA experience (with accumulation) at which workmanship improves, while metabolism, physical and emotional stress decreases; -concrete EVA duration and work rate; -EVA bioengineering, including selection of tools, work station, EVA technology and mechanization.     

Some problems of selection and evaluation of the Martian suit enclosure concept

One of the most important tasks for preparation of a future manned mission to Mars is to create a space suit, which ensures efficient and safe operation of the man on the planet surface.

The concept of space suit (SS) utilisation on the Mars surface will be determined mainly by the Mars mission scenario. Currently the preference is given to utilisation of robotics with the crew driving a Mars rover vehicle, whereby the suit will be used solely as an additional safety means.

However, one cannot exclude the necessity of a durable self-contained stay of the man outside a pressurised compartment, to pick up, for instance, soil samples or do certain repair work in case of an emergency.

The requirements to the Mars suit and especially to the personal self-contained life support system (LSS) will depend in many respects on the Mars environmental conditions, the space vehicle system concept and performance characteristics, the airlock and its interface design, the availability of expendable elements for the LSS, etc.

The paper reviews principal problems, which have to be solved during development of the Martian suit. A special attention is paid to the issue of suited man mobility during traversing on the planet surface.

The paper also reviews the arguments for application of a suit semi-rigid design concept and evaluates potentialities of using certain elements of the existing “Orlan” type suit.

The paper presents results of a number of studies on selection of the planetary SS enclosure concept and on experimental evaluation of mobility of the lower torso and leg enclosures in conjunction with a specially designed prototype model (tentative model) of the SS enclosure.     

EVA worksite analysis—Use of computer analysis for EVA operations development and execution

To sustain the rate of extravehicular activity (EVA) required to assemble and maintain the International Space Station, we must enhance our ability to plan, train for, and execute EVAs. An underlying analysis capability has been developed to ensure EVA access to all external worksites as a starting point for ground training, to generate information needed for on-orbit training, and to react quickly to develop contingency EVA plans, techniques, and procedures. This paper describes the use of computer-based EVA worksite analysis techniques for EVA worksite design. EVA worksite analysis has been used to design 80% of EVA worksites on the U.S. portion of the International Space Station. With the launch of the first U.S. element of the station, EVA worksite analysis is being developed further to support real-time analysis of unplanned EVA operations. This paper describes this development and deployment of EVA worksite analysis for International Space Station (ISS) mission support.     

Design to safety: experience and plans of the Russian space suit programme

The paper presents the analysis of the Russian experience gained in the operations of Salyut-6, 7 and Mir orbital stations. The main factors determining their effectiveness and safety are considered and the main requirements to the EVA suit, as the most important tool for the EVA, are formulated.     

EVA design: lessons learned

Extravehicular Activities (EVAs) are very demanding and specialized space flight activities. There are many aspects to consider in the design of hardware, tools, and procedures to be used on an EVA mission. To help minimize costs and optimize the EVA productivity, experience shows that astronauts should become involved early in the design process.     

Man in space.

Today, more than 20 years after the first in the world man's space walk, soviet cosmonautics gained large experience of extravehicular activity (EVA). Space suits of high reliability, onboard facilities for passing through the airlock, sets of special tools and technological rigging, as well as procedures for carrying out various EVA's were developed. In the course of the Salyut-7 space station orbital operation the EVA's have become regular. The author of the report as the participant of the EVA's considers the main steps of man activities in space and analyzes specific problems arised in performing such activities.     

Geologic field work on Mars: Distance and time issues during surface exploration

Based on field experience at Analogue stations MDRS and FMARS and additional theoretical computations, motorized field work traverses were planned for various surface feature types on Mars, with emphasis on their horizontal dimension, maximal slope angle and cumulative vertical surface undulation or roughness. The aim was to explore the possibilities and characteristics of field work for different terrain types. Those terrain types are reviewed in the present study that have already been analyzed based on remote sensing data, and that are described in the scientific literature.Dunes, gullies, slope streaks, cross sections of valley networks and of lava channels might be analyzed during only one extra vehicular activity (EVA, e.g., pedestrian and vehicular field work) with the objective of a first in-situ exploration along an optimized traverse, in order to provide the most valuable scientific information on their general characteristics and origin. Smaller tectonic faults, lava flows, lobate debris aprons and outcrops of polar layered deposits can be analyzed only by several EVAs together. Analysis of large landslides, calderas and interior layered deposits produce even more difficulties on Mars, and require specialized technology. In cases where several EVAs are necessary for detailed analysis along the best traverse, mobile pressurized vehicles (with pressurized cabin for astronauts without spacesuits) or other methods would be necessary.Many of the geologic structures that have been analyzed only with remotely sensed data could not be surveyed during one field campaign, and in some cases because of high slope angle and large cumulative topographic undulation, their in-situ exploration could not be accomplished with the technological capabilities available, and in-situ analysis requires more advanced technology than long distance rovers can provide now. Hence, the prior location of important sites and the usage of robotic help will be of high importance.