Patent Publication Number: US-2022212236-A1

Title: Multi-stage cleaning of space suit

Description:
BACKGROUND 
     Exemplary embodiments pertain to the art of space exploration and, in particular, to multi-stage cleaning of a space suit. 
     Extravehicular activity on the surface of a planet refers to activity outside of a space vehicle, habitat, or other facilities that provide a habitable environment without the need for each astronaut to wear an individual space suit with life support capability. When entering such a facility, the astronauts must ensure that dust or any other planetary material are not introduced into the facility. Such foreign material may negatively affect both the vehicle components and the crew members. For example, lunar dust has been found to cause scar tissue in lungs and may be linked with brain cancer, and Martian dust has been found to be toxic. 
     BRIEF DESCRIPTION 
     In one embodiment, a system to perform multi-stage cleaning of material from a space suit worn by an astronaut in a deep space environment includes one or more discharge units installed external to an interior volume of a facility in the deep space environment. Each of the one or more discharge units releases one or more substances. The one or more substances includes water or air and the interior volume of the facility is defined by an interior hatch that is separated from an exterior hatch leading to the deep space environment by an airlock. The system also includes one or more collection units installed external to the interior volume. Each collection unit traps released material that is released from a space suit based on the multi-stage cleaning to prevent the released material from entering the interior volume. 
     Additionally or alternatively, in this or other embodiments, the one or more discharge units releases air to blow off the material from the space suit in a first stage of the multi-stage cleaning, releases water to clean off remaining material from the space suit in a second stage of the multi-stage cleaning, releases air to dry off the space suit in a third stage of the multi-stage cleaning, and releases wax to coat the space suit in a fourth stage of the multi-stage cleaning. 
     Additionally or alternatively, in this or other embodiments, the one or more discharge units releases positively and negatively charged ions to neutralize the material on the space suit in a first stage of the multi-stage cleaning, releases water to clean off remaining material from the space suit in a second stage of the multi-stage cleaning, releases air to dry off the space suit in a third stage of the multi-stage cleaning, and releases wax to coat the space suit in a fourth stage of the multi-stage cleaning. 
     Additionally or alternatively, in this or other embodiments, the material is planetary or lunar dust. 
     Additionally or alternatively, in this or other embodiments, the system is located in the airlock between the interior hatch and the exterior hatch of the facility and the facility is a space vehicle or a habitat. 
     Additionally or alternatively, in this or other embodiments, the system also includes a filter in a space between a raised platform with openings on which the astronaut stands and the floor of the airlock. 
     Additionally or alternatively, in this or other embodiments, one of the discharge units is installed in a ring-shaped support whose opening is sized to encircle the astronaut. 
     Additionally or alternatively, in this or other embodiments, the ring-shaped support moves up and down. 
     Additionally or alternatively, in this or other embodiments, one of the discharge units is installed on a swing arm or robotic arm to move around the space suit. 
     Additionally or alternatively, in this or other embodiments, the system is located external to the exterior hatch of the facility, and one of the discharge units releases carbon dioxide waste that is reclaimed from the interior volume. 
     Additionally or alternatively, in this or other embodiments, one of the one or more discharge units is a hand-held unit that is located in the airlock or outside the facility. 
     Additionally or alternatively, in this or other embodiments, the system also includes an additional set of one or more discharge units arranged in the airlock adjacent to the interior hatch. The additional set of one or more discharge units releases air when the interior hatch is open so that the released material in the airlock does not enter the interior volume. 
     Additionally or alternatively, in this or other embodiments, the system also includes a controller controls a duration of the release of the one or more substances. 
     Additionally or alternatively, in this or other embodiments, the controller controls the duration based on a manual input or based on an automated determination of an amount of the material on the space suit. 
     In another embodiment, a method of assembling a system to perform multi-stage cleaning of material from a space suit worn by an astronaut in a deep space environment includes installing one or more discharge units external to an interior volume of a facility in the deep space environment. Each of the one or more discharge units releases one or more substances. The one or more substances includes water or air and the interior volume of the facility is defined by an interior hatch that is separated from an exterior hatch leading to the deep space environment by an airlock. The method also includes installing one or more collection units external to the interior volume. Each collection unit traps released material that is released from a space suit based on the multi-stage cleaning to prevent the released material from entering the interior volume. 
     Additionally or alternatively, in this or other embodiments, the installing the one or more discharge units includes configuring the one or more discharge units to release air to blow off the material from the space suit in a first stage of the multi-stage cleaning, to release water to clean off remaining material from the space suit in a second stage of the multi-stage cleaning, to release air to dry off the space suit in a third stage of the multi-stage cleaning, and to release wax to coat the space suit in a fourth stage of the multi-stage cleaning. 
     Additionally or alternatively, in this or other embodiments, the installing the one or more discharge units includes configuring the one or more discharge units to release positively and negatively charged ions to neutralize the material on the space suit in a first stage of the multi-stage cleaning, to release water to clean off remaining material from the space suit in a second stage of the multi-stage cleaning, to release air to dry off the space suit in a third stage of the multi-stage cleaning, and to release wax to coat the space suit in a fourth stage of the multi-stage cleaning. 
     Additionally or alternatively, in this or other embodiments, the installing the one or more discharge units is in the airlock between the interior hatch and the exterior hatch of the facility or external to the exterior hatch of the facility, and the facility is a space vehicle or a habitat. 
     Additionally or alternatively, in this or other embodiments, the method also includes configuring a controller to control a duration of the release of the one or more substances. 
     Additionally or alternatively, in this or other embodiments, the configuring the controller includes configuring the controller to control the duration based on a manual input or based on an automated determination of an amount of the material on the space suit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  is a process flow of a method of performing multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; 
         FIG. 2  shows an exemplary system to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; 
         FIG. 3  is an exemplary embodiment of a system to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; 
         FIG. 4  is an exemplary embodiment of a system to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; 
         FIG. 5  is an exemplary embodiment of a system to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; 
         FIG. 6  shows relevant aspects of an exemplary facility including a system to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments; and 
         FIGS. 7A-7D  show exemplary embodiments of substances released to perform multi-stage cleaning of a space suit in a deep space environment according to one or more embodiments, in which: 
         FIG. 7A  shows the release of cations and anions; 
         FIG. 7B  shows the release of gas; 
         FIG. 7C  shows the release of water; and 
         FIG. 7D  shows the release of wax. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     In deep space exploration or habitation, an astronaut travels between a planetary environment that requires the astronaut to wear a space suit for life support and a habitable facility that includes life support systems and, thus, allows the astronaut to remove the space suit. Generally, the habitable facility incudes an airlock, which is a space between an exterior hatch leading outside to a planetary surface and an interior hatch leading into the habitable volume. Embodiments of the systems and methods detailed herein relate to multi-stage cleaning of a space suit (e.g., extravehicular mobility unit (EMU)). As previously noted, dust and other materials (e.g., pollen, alien life forms) present dangers for the equipment and personnel in the habitable facility. Thus, the cleaning of the space suit must be completed prior to the astronaut entering the habitable facility (e.g., space vehicle, habitat) via the interior hatch of the airlock. 
       FIG. 1  is a process flow of a method  10  of performing multi-stage cleaning of a space suit  120  ( FIG. 2 ) in a deep space environment according to one or more embodiments. Different substances  135  ( FIG. 2 ) are released at each of the stages to clear away material  110  ( FIG. 2 ) from the space suit. As shown more clearly in  FIG. 6 , the airlock  105  is a space between an exterior hatch  620  leading outside to a surface  605  of a celestial body (e.g., Moon, Mars) and an interior hatch  630  leading into the interior volume  610  of the facility  600  (e.g., space vehicle, habitat). All of the stages of the multi-stage cleaning may be performed in the airlock  105  or, alternately, one or more stages may be performed outside prior to the astronaut entering the airlock  105 . 
     For example, at block  20 , the release of gas  730  ( FIG. 7B ) may be performed outside the airlock  105 . In this case, the gas  730  may be waste CO 2  from the interior volume  610  that may be released at a flow rate that facilitates blowing off material  110  from the space suit  120 . Alternately, the release of gas  730 , at block  20 , may be performed in the airlock  105 . When the airlock  105  is first entered, it is essentially a vacuum which is then filled with gases (e.g., oxygen O 2 , nitrogen N 2 , carbon dioxide CO 2 ). According to one or more embodiments, this inflow of these gases may be used to perform the first stage (block  20 ). For example, air may be the gas  730  released in the airlock  105  via one or more discharge units  130  ( FIG. 2 ) to blow material  110  off the space suit  120 . Alternately or additionally, inflow of some or all of the gases  730  may be through an electric field to generate the ions (cations  710  and anions  720  ( FIG. 7A )) released via one or more discharge units  130  (at block  30 ). When the material  110  on the space suit  120  is charged (e.g., lunar dust), this release of ions  710 ,  720  (at block  30 ) neutralizes the charged material  110  so that it falls off the space suit  120  as released material  115  ( FIG. 2 ). 
     At block  40 , releasing water  740  ( FIG. 7C ) from one or more discharge units  130  washes off the space suit  120  as a next stage in the multi-stage cleaning. The temperature of the water  740  may be high enough to wash off a coating of wax  750  ( FIG. 7 ) from the space suit  120 . At block  50 , releasing air (or another gas  730 ) from one or more discharge units  130  dries off the space suit  120  and also blows off any material  110  that remains on the space suit  120  mixed with the water  740 . At block  60 , releasing wax  750  to coat the space suit  120  ensures that any wax  750  removed by the wash at block  40  is replaced. The wax  750  may be a polymer-based wax, for example, and may prevent or reduce adhesion of the material  110  on the space suit  120 . 
     At block  70 , the processes include releasing air (or another gas  730 ) adjacent to the interior hatch  630  leading into the interior volume  610  from the air lock  105 . This release of air may be by different discharge units  130  than those used in other processes. This is illustrated in  FIG. 6 , for example. This release of air ensures that material  110  lingering in the air lock  105  does not make its way into the interior volume  610  when the interior hatch  630  is opened. As further discussed, the duration of each stage and other features of the multi-stage cleaning may be controlled. Different exemplary embodiments for the discharge units  130  and for collection of the released material  115  that results from the various stages of removing the material  110  from the space suit  120  are discussed with reference to  FIGS. 2-7 . 
       FIG. 2  shows an exemplary system  200  to perform multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. The exemplary system  200  may be in an airlock  105 , as indicated in the exemplary case of  FIG. 2 , or outside of a facility  600  ( FIG. 6 ). According to alternate embodiments, the facility  600  may be a space vehicle or habitat in a deep space environment. An astronaut wearing an exemplary space suit  120  is shown in the airlock  105 . An exemplary space suit  120  may be an EMU, an exploration EMU (xEMU), or a Mars EMU (mEMU). As indicated, the space suit  120  may include a pack  121  with oxygen tanks and power systems, boots, and a helmet in addition to a full body suit. Material  110  (e.g., dust) is indicated on and around the space suit  120 . For example, negatively and/or positively charged dust may have become attached to the space suit  120  during extravehicular activity on the surface  605  of the celestial body (e.g., Moon, Mars). The system  200  ensures that the dust and any other material  110  that adhered to the space suit  120  is removed and captured so that it does not make its way into the interior volume  610  of the facility  600  when the interior hatch  630  is opened to allow the astronaut to enter. 
     According to the exemplary embodiment shown in  FIG. 2 , a discharge unit  130  may be disposed in a ceiling of the airlock  105 , for example. As indicated, a discharge unit  130  may include multiple outlets. The number and placement of discharge units  130  is not intended to be limited by this exemplary illustration. Further, each discharge unit  130  may release a different substance  135  or each discharge unit  130  may release more than one type of substance  135  in turn. For example, discharge units  130  may be located on the sides above the collection units  140   a ,  140   b  (generally referred to as  140 ). Additional alternate exemplary embodiments are discussed with reference to  FIGS. 3-6 . 
     A controller  131  is shown coupled to the exemplary discharge unit  130  but the placement of the controller  131  is not limited by this exemplary arrangement. The controller  131  may control the duration of each of the stages in the multi-stage cleaning process. That is, the controller  131  may control the duration of release of each of the substances  135 . According to an exemplary embodiment, the basis for this control may be manual (i.e., based on an input from an astronaut). That is, the astronaut may assess the level of cleaning needed and either select a specific duration or select a cleaning level (e.g., light, medium, heavy) that maps to a duration for each stage of the multiple stages of cleaning. 
     According to another exemplary embodiment, the basis for the control may be automatic. A determination of the amount of material  110  on the space suit  120  may be made. For example, this determination may be based on image processing of an image obtained of the space suit  120  or on the weight of the astronaut before and after the extravehicular activity (while accounting for oxygen use affecting the weight of the pack  121 ). The determination of the amount of material  110  may then be used to control the duration of each stage in the multi-stage cleaning. The assessment may also be between stages. Thus, for example, the release of water  740  (at block  40 ) may be for a longer duration than standard based on an assessment of remaining material  110  after the release of ions  710 ,  720  (at block  30 ). Other features of the multi-stage cleaning that may be controlled include the temperature of the water  740  released at block  40  and the flow rate of different substances  135 . 
     As more clearly shown in  FIG. 6 , the astronaut stands on a platform  150  that is raised above the floor  627  of the airlock  105 , thereby creating a space  625  below the platform  150  and the floor  627 . The platform  150  may be a grating or other surface with openings  155 . The released material  115  cleaned from the space suit  120  may fall through the openings  155  in the platform  150 . A filter  160  below the platform  150  (i.e., in the space  625 ) may catch the dust particles or other particles in the release materials  115 , as well as the substances  135  released for purposes of cleaning at the different stages. 
     Between stages, the filter  160  may be covered for protection based on the substance  135  being used in the next stage. For example, prior to releasing water  740  ( FIG. 7 ) or wax  750  ( FIG. 7 ), the filter  160  may be covered or moved. Alternately, the filter  160  may operate in both wet and dry conditions. Following a stage in which gas  730  (at block  20 ) or ions  710 ,  720  (at block  30 ) are released, the released material  115  that is blown off or neutralized on the space suit  120  and caught in the filter  160  may be released to be collected in storage  170 . Further, the filtered air  180  that is free of the released material  115  is recirculated. The particles in storage  170  may ultimately be disposed of or retained for analysis. Alternately, the particles may be routed through the waste management system so that water may be reclaimed. 
     In addition to falling through the platform  150 , released materials  115  may be trapped by one or more collection units  140 . While two collection units  140   a ,  140   b  are shown on opposite sides of the airlock  105  in  FIG. 2 , the exemplary number and arrangement of the collection units  140  is not intended to be limiting. One or more collection units  140  may be placed below the platform  150  along with the filter  160 , for example. Other embodiments are discussed with reference to  FIGS. 4-6 . 
       FIG. 3  is an exemplary embodiment of a system  300  to perform multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. As shown a ring-shaped support  310  includes one or more discharge units  130 . One discharge unit  130  may span the circumference of the ring-shaped support  310  or multiple discharge units  130  may be disposed around the ring-shaped support  310 . According to a further exemplary embodiment, the ring-shaped support  310  that holds one or more discharge units  130  may move up and down. As shown, the ring-shaped support  310  is sized such that an opening  315  accommodates the astronaut. The ring-shaped support  310  may be supported on opposite-side walls  320  of the airlock  105 , for example. The ring-shaped support  310  may be supported on tracks  325  such that it moves down the walls  320  along the length of the space suit  120  to emit the substances  135  along the length of the space suit  120 . While not shown, one or more collection units  140  and the filter  160  may be present, as shown in  FIG. 1 , for example. 
       FIG. 4  is an exemplary embodiment of a system  400  to perform multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. As shown in  FIG. 4 , a ring-shaped support  410  may be supported on opposite-side walls  320  of the airlock  105 , for example. The ring-shaped support  410  may include one or more collection units  140  and may be mounted on tracks  325  to move up and down along the walls  320 . The ring-shaped support  410  may be additional to the ring-shaped support  310  shown in  FIG. 3 . That is, both a stationary ring-shaped support  310  and a moveable ring-shaped support  410  may be mounted to release different substances  135  or the same substances  135  at the different stages. 
       FIG. 5  is an exemplary embodiment of a system  500  to perform multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. Two mechanical arms  510  (e.g., swing arm, robotic arm) are shown affixed to the walls  320  of the airlock  105 , for example. One mechanical arm  510  is shown supporting a discharge unit  130  and the other is shown supporting a collection unit  140 . A circular path  505  is shown for both the discharge unit  130  and the collection unit  140  based on movement of the mechanical arms  510 . According to additional embodiments, the mechanical arms  510  may move along tracks  325  mounted on the walls  320  to move the discharge unit  130  and the collection unit  140  up and down. While both the discharge unit  130  and the collection unit  140  are shown supported by mechanical arms  510 , only one mechanical arm  510  may support the discharge unit  130  or the collection unit  140 . Alternately, multiple mechanical arms  510  may support multiple discharge units  130  or multiple mechanical arms  510  may support multiple collection units  140 . 
       FIG. 6  shows relevant aspects of an exemplary facility  600  including multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. As previously noted, the facility  600  may be a space vehicle or habitat on another plant. An airlock  105  is shown between an interior hatch  630  leading into the interior volume  610  and an exterior hatch  620  leading outside the facility  600 . Discharge units  130  are shown adjacent to the interior hatch  630 . These discharge units  130  may be among those that form the air curtain used at block  70 . That is, the discharge units  130  may release air (or another gas  730 ) to ensure that material  110  does not enter the interior volume  610  from the airlock  105  when the interior hatch  630  is opened. As indicated by the arrows, the output from the discharge units  130  may be directed into the airlock  105  in order to ensure that any remaining material  110  or released material  115  is blown into the airlock  105  rather than being allowed into the interior volume  610 . 
     A ladder  640  is shown to provide access to the exterior hatch  620  from the surface  605 . The platform  150  and the space  625  between it and the floor  627  are indicated. According to the exemplary embodiment shown in  FIG. 6 , a discharge unit  130  and a collection unit  140  may be affixed to a track  650  affixed to the ladder  640 . According to alternate embodiments, any of the exemplary systems  300 ,  400 ,  500  may be implemented at the ladder  640  to remove material  110  prior to the astronaut reaching the exterior hatch  620 . That is, some or all of the processes discussed for blocks  20 ,  30 ,  40 ,  50 , and  60  may be performed outside the airlock  105 . In this case, the discharge units  130  shown in the airlock  105  are used only at block  70 . Alternately, additional discharge units  130  according to any of the previously discussed embodiments may be used in the airlock  105  to implement the processes at block  20 ,  30 ,  40 ,  50 , or  60 . 
     According to further embodiments, some of the stages of the cleaning (i.e., release of some of the substances  135 ) may be performed outside the facility  600  (i.e., outside the exterior hatch  620 ) while other stages of the cleaning (e.g., release of other substances  135 ) may be performed within the airlock  105 . For example, an initial stage described at block  20  or  30  may be performed outside. Once the astronaut enters the airlock  105 , the stage described at blocks  40 ,  50 ,  60 , and  70  may be performed in turn. Unlike the embodiments shown in the airlock  105 , any system affixed to the ladder  640  may be part of a temporary setup. For example, when the facility  600  is a space vehicle, the ladder  640  and any attachments must be removed prior to leaving the planetary surface  605 . When the facility  600  is a habitat, both the outside and inside cleaning setups may fixed. 
       FIGS. 7A-7D  show exemplary substances  135  released to perform multi-stage cleaning of a space suit  120  in a deep space environment according to one or more embodiments. In addition, the figures show an additional or alternate discharge unit  130  that is hand-held. One or more hand-held discharge units  130  may be located outside, inside, or both outside and inside the airlock  105 . When the same hand-held discharge unit  130  releases different substances  135  at different stages, the substance  135  being released by the hand-held discharge unit  130  (i.e., stage of cleaning) may be changed automatically or manually. The manual change of substances  135  facilitates manual control over the duration of each stage of the cleaning even without a controller  131  that obtains inputs. 
       FIG. 7A  shows release of cations  710  and anions  720  from a discharge unit  130  (at block  30 ) to neutralize charged dust or other charged material  110  on the space suit  120 .  FIG. 7B  shows release of gas  730  from a discharge unit  130  (at block  20 ) to blow off material  110  from the space suit  120 . As previously noted, this gas  730  may be air (e.g., block  20  in the airlock  105 , blocks  50  and  70 ) or CO 2  (e.g., block  20  outside the airlock  105 ).  FIG. 7C  shows the release of water  740  (at block  40 ) to wash off material  110  from the space suit  120 . As previously noted, the water  740  may be hot enough to melt and wash off a coating of wax  750  applied to the space suit  120  to mitigate the adhesion of materials  110 .  FIG. 7D  shows the release of wax  750  (at block  60 ). As previously noted, according to exemplary embodiments, all of the substances  135  may be released at different stages through the same one or more discharge units  130 . According to alternate embodiments, each of the substances  135  may be released by a different discharge unit  130 . Each discharge unit  130  may include nozzles or other flow control devices to disperse the released substances  135 . 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof. 
     While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.