Patent Description:
Planetary and orbital space vehicles require an environment or habitat controlled and configured for breathing by the occupants of such vehicles. For example, the partial pressure levels of oxygen and nitrogen in the various compartments or modules of such vehicles may be controlled to emulate the levels typically found at sea level on Earth. Further, discreet compartments or modules within such vehicles - e.g., unoccupied compartments or modules - may require lower levels of oxygen or nitrogen depending on the intended use or nonuse of the compartment or module at any particular time. For example, the environment within an airlock chamber or a crew lock chamber typically requires a deviation from sea level conditions when an astronaut is preparing for a spacewalk. Localized pressure control panels positioned within discreet compartments or modules are beneficial in providing a localized and convenient means of controlling the partial pressure levels of oxygen and nitrogen and the ambient pressure within such discreet compartments or modules.

<CIT> describes a method of circulating an air supply in a vacuum environment. <CIT> describes a reusable orbital vehicle with interchangeable modules.

<NPL> XP000178210 describes cooling in a space shuttle.

An environmental control system for a space vehicle is disclosed and defined in claim <NUM>.

In various embodiments, the environmental control system further includes an oxygen high-pressure regulator disposed between the oxygen supply and the first oxygen control board, the oxygen high-pressure regulator configured to reduce a high-pressure oxygen gas to a low-pressure oxygen gas. In various embodiments, the environmental control system further includes a nitrogen high-pressure regulator disposed between the nitrogen supply and the first nitrogen control board, the nitrogen high-pressure regulator configured to reduce a high-pressure nitrogen gas to a low-pressure nitrogen gas.

In various embodiments, the environmental control system further includes an oxygen sensor configured to measure the partial pressure of oxygen within the first module. In various embodiments, the first oxygen control board is configured to release the oxygen gas into the first module when the partial pressure of oxygen within the first module is below an oxygen pressure threshold value. In various embodiments, the first oxygen control board is configured to stop release of the oxygen gas into the first module when the partial pressure of oxygen within the first module is above the oxygen pressure threshold value.

In various embodiments, the environmental control system further includes an ambient pressure sensor configured to measure the ambient pressure within the first module. In various embodiments, the first nitrogen control board is configured to release the nitrogen gas into the first module when the ambient pressure is below an ambient pressure threshold value and the partial pressure of oxygen within the first module is above the oxygen pressure threshold value. In various embodiments, the first nitrogen control board is configured to stop release of the nitrogen gas into the first module when the ambient pressure is above the ambient pressure threshold value and the partial pressure of oxygen within the first module is above the oxygen pressure threshold value. In various embodiments, the first pressure control panel includes a pressure relief solenoid valve configured to exhaust at least a portion of the oxygen/nitrogen gas mixture from the first module if the ambient pressure exceeds the ambient pressure threshold value.

In various embodiments, the environmental control system further includes a second pressure control panel having a second oxygen control board configured to receive the oxygen gas from the oxygen supply and a second nitrogen control board configured to receive the nitrogen gas from the nitrogen supply. In various embodiments, the supervisory controller is configured to control the second pressure control panel and thereby to adjust the partial pressure of oxygen and the ambient pressure of the oxygen/nitrogen gas mixture within a second module. In various embodiments, the second pressure control panel can provide environmental control redundancy to the first pressure control panel when the modules are not isolated from one another.

A space vehicle is disclosed. In various embodiments, the space vehicle includes a first module; a second module; an oxygen supply; a nitrogen supply; a first pressure control panel within the first module, the first pressure control panel having a first oxygen control board configured to receive an oxygen gas from the oxygen supply and a first nitrogen control board configured to receive a nitrogen gas from the nitrogen supply; a second pressure control panel within the second module, the second pressure control panel having a second oxygen control board configured to receive the oxygen gas from the oxygen supply and a second nitrogen control board configured to receive the nitrogen gas from the nitrogen supply; and a supervisory controller configured to control the first pressure control panel and thereby to adjust a first partial pressure of oxygen and a first ambient pressure of a first oxygen/nitrogen gas mixture within the first module and to control the second pressure control panel and thereby to adjust a second partial pressure of oxygen and a second ambient pressure of a second oxygen/nitrogen gas mixture within the second module.

In various embodiments, the first oxygen control board includes an oxygen pressure transducer configured to determine an oxygen pressure within the first oxygen control board and an oxygen solenoid valve configured to regulate and to release the oxygen gas into the first module. In various embodiments, the first nitrogen control board includes a nitrogen pressure transducer configured to determine a nitrogen pressure within the first nitrogen control board and a nitrogen solenoid valve configured to regulate and to release the nitrogen gas into the first module.

In various embodiments, the space vehicle further includes a first oxygen sensor configured to measure the first partial pressure of oxygen within the first module and the first oxygen control board is configured to release the oxygen gas into the first module when the first partial pressure of oxygen within the first module is below an oxygen pressure threshold value and to stop release of the oxygen gas into the first module when the first partial pressure of oxygen within the first module is above the oxygen pressure threshold value.

In various embodiments, the space vehicle further includes an ambient pressure sensor configured to measure the first ambient pressure within the first module. In various embodiments, the first nitrogen control board is configured to release the nitrogen gas into the first module when the first ambient pressure is below an ambient pressure threshold value and the first partial pressure of oxygen within the first module is above the oxygen pressure threshold value. In various embodiments, the first nitrogen control board is configured to stop release of the nitrogen gas into the first module when the first ambient pressure is above the ambient pressure threshold value and the first partial pressure of oxygen within the first module is above the oxygen pressure threshold value. In various embodiments, the first pressure control panel includes a pressure relief solenoid valve configured to exhaust at least a portion of the first oxygen/nitrogen gas mixture from the first module if the first ambient pressure exceeds the ambient pressure threshold value.

Referring now to the drawings, <FIG> schematically illustrates a space vehicle <NUM> (e.g., a planetary or orbital space vehicle) having a first module <NUM> and a second module <NUM>. The space vehicle <NUM> includes an oxygen supply <NUM> and a nitrogen supply <NUM>, each of which may comprise a high-pressure tank or a gas generator configured to generate oxygen or nitrogen at high-pressure (e.g., on the order of about <NUM> psi (≈ <NUM>,<NUM> KPa) to about <NUM>,<NUM> psi (≈ <NUM>,600KPa)). The oxygen supply <NUM> may be configured to provide the oxygen gas (O<NUM>) to an oxygen high-pressure regulator <NUM>, which may be configured to reduce the pressure of the oxygen gas to a low-pressure (e.g., on the order of thirty pounds per square inch (<NUM> psi or ≈ <NUM> KPa)). The low-pressure oxygen gas is then delivered to a first pressure control panel <NUM>, which is configured to control the partial pressure of oxygen within the habitat or environment of the first module <NUM>, and to a second pressure control panel <NUM>, which is configured to control the partial pressure of oxygen within the habitat or environment of the second module <NUM>. Similarly, the nitrogen supply <NUM> may be configured to provide the nitrogen gas (N<NUM>) to a nitrogen high-pressure regulator <NUM>, which may be configured to reduce the pressure of the nitrogen gas to a low-pressure. The low-pressure nitrogen gas is then delivered to the first pressure control panel <NUM>, which is configured to control the partial pressure of nitrogen within the habitat or environment of the first module <NUM>, and to the second pressure control panel <NUM>, which is configured to control the partial pressure of nitrogen within the habitat or environment of the second module <NUM>. In various embodiments, the first pressure control panel <NUM> and the second pressure control panel <NUM> are configured to control the partial pressure of oxygen from about twenty percent (<NUM>%) to about twenty-one percent (<NUM>%) and the partial pressure of nitrogen from about seventy-nine (<NUM>%) to about eighty percent (<NUM>%) of the oxygen/nitrogen gas mixture at an absolute pressure of about <NUM> psi (≈ <NUM> KPa), which emulates the oxygen/nitrogen partial pressure levels at sea-level on Earth.

Referring now to <FIG>, a schematic view of an environmental control system <NUM> for a planetary or orbital space vehicle is provided, in accordance with various embodiments. The environmental control system <NUM> includes an oxygen supply <NUM> and a nitrogen supply <NUM>, each of which may comprise a high-pressure tank or a gas generator configured to generate oxygen or nitrogen at high-pressure. The oxygen supply <NUM> may be configured to provide the oxygen gas to an oxygen high-pressure regulator <NUM>, which may be configured to reduce the pressure of the oxygen gas to a low-pressure; the nitrogen supply <NUM> may be configured to provide the nitrogen gas to a nitrogen high-pressure regulator, which, in various embodiments, has components identical or nearly identical to those of the oxygen high-pressure regulator <NUM>. The low-pressure oxygen gas and the low-pressure nitrogen gas are then delivered to a pressure control panel <NUM>, similar to the first pressure control panel <NUM> and the second pressure control panel <NUM> described above with reference to <FIG>, which is configured to control the partial pressure of oxygen and the partial pressure of nitrogen within a module or compartment, such as, for example, the first module <NUM> or the second module <NUM> described above with reference to <FIG>. In various embodiments, the pressure control panel <NUM> is configured to control the partial pressure of oxygen from about twenty percent (<NUM>%) to about twenty-one percent (<NUM>%) and the partial pressure of nitrogen from about seventy-nine (<NUM>%) to about eighty percent (<NUM>%) of the oxygen/nitrogen gas mixture at an absolute pressure of about <NUM> psi (≈ <NUM> KPa), which emulates the oxygen/nitrogen partial pressure levels at sea-level on Earth.

Still referring to <FIG>, and in various embodiments, the oxygen high-pressure regulator <NUM> includes a high-pressure input <NUM>, a first pressure transducer <NUM>, a manual shutoff valve <NUM>, an electronic control valve <NUM> (e.g., a stepper motor or solenoid), a second pressure transducer <NUM>, a low-pressure regulator <NUM> and a low-pressure oxygen output <NUM>. During operation, high-pressure oxygen gas from the oxygen supply <NUM> is provided to the high-pressure input <NUM> and subsequently provided to the electronic control valve <NUM> and the low-pressure regulator <NUM>, which regulates the pressure and flow rate of the oxygen gas provided by the oxygen supply <NUM>. In various embodiments, the electronic control valve <NUM> is responsive to the pressure of the oxygen gas provided by the oxygen supply <NUM> as determined by the first pressure transducer <NUM>. The oxygen gas is then provided to the low-pressure regulator <NUM>, which reduces the pressure of the oxygen gas downstream of the electronic control valve <NUM> to a lower pressure. The low-pressure oxygen gas is then provided to the pressure control panel <NUM> via the low-pressure oxygen output <NUM>. In the event the low-pressure regulator <NUM> fails to regulate the pressure of the oxygen gas to a target low pressure or below, a relief valve <NUM> is disposed between the low-pressure regulator <NUM> and the low-pressure oxygen output <NUM> and configured to exhaust such an overpressure to an exterior of the space vehicle via a vacuum relief port <NUM>. Further, in the event of an emergency or required maintenance, the manual shutoff valve <NUM> is configured to shutoff the supply of oxygen gas from the oxygen supply <NUM>. Note that as used in this disclosure, a pressure regulator is a system or device configured to reduce pressure of a gas from a high-pressure value to a low-pressure value, with the low-pressure value being less than the high-pressure value. For example, in various embodiments, the high-pressure regulators described herein are configured to reduce the pressure of the oxygen or nitrogen gas streams from a high-pressure value (e.g., <NUM>,<NUM> psi (≈ <NUM>,<NUM> KPa)) to a low-pressure value (e.g., <NUM> psi (≈ <NUM> KPa)), while the low-pressure oxygen and nitrogen solenoids are controlled to maintain the pressure of the oxygen or nitrogen gas streams from the low-pressure value (e.g., <NUM> psi (≈ <NUM> KPa)) to an habitable-pressure value (e.g., <NUM> psi (≈ <NUM> KPa) with <NUM>% Oxygen and <NUM>% Nitrogen. Further, as described, the pressure regulators typically comprise a valve that is biased by a spring or the like or open and closed by a servomotor or the like. Finally, as mentioned above, the nitrogen high-pressure regulator includes components identical or nearly identical to the components comprised within the oxygen high-pressure regulator <NUM>, so such components within the nitrogen high-pressure regulator are not described in further detail.

Still referring to <FIG>, the low-pressure oxygen output <NUM> is coupled to and provides the oxygen gas to a low-pressure oxygen input <NUM> of the pressure control panel <NUM>. The oxygen gas is then provided to an oxygen control board <NUM> within the pressure control panel <NUM>. An oxygen pressure transducer <NUM> is configured to sense the pressure of the oxygen gas (or an oxygen pressure) entering the oxygen control board <NUM>. A first oxygen solenoid valve <NUM> is then configured to open or close at a rate based on the pressure of the oxygen gas and the partial pressure of oxygen within the compartment of module. More particularly, an oxygen sensor <NUM> is configured to measure the partial pressure of oxygen within the compartment or module. If the partial pressure of oxygen within the compartment or module is lower than an oxygen pressure threshold value, the first oxygen solenoid valve <NUM> is opened, allowing the oxygen gas to flow to the compartment or module via a vent <NUM> until the oxygen pressure threshold value is reached; note the vent <NUM> may also act as a diffuser configured to mix the oxygen and nitrogen gas streams exiting the vent <NUM>. On the other hand, if the partial pressure of oxygen within the compartment or module is equal to or higher than the oxygen pressure threshold value, the first oxygen solenoid valve <NUM> is closed, preventing the oxygen gas from flowing to the compartment or module via the vent <NUM>. In various embodiments, the oxygen control board <NUM> further includes a second oxygen solenoid valve <NUM> configured to vent the oxygen gas via a vacuum exhaust <NUM> in the event of an overpressure within the oxygen control board <NUM>, with the vacuum exhaust typically opening to an exterior area of the space vehicle.

Similarly, the low-pressure nitrogen output is coupled to and provides the nitrogen gas to a low-pressure nitrogen input <NUM> of the pressure control panel <NUM>. The nitrogen gas is then provided to a nitrogen control board <NUM> within the pressure control panel <NUM>. A nitrogen pressure transducer <NUM> is configured to sense the pressure of the nitrogen gas (or a nitrogen pressure) entering the nitrogen control board <NUM>. A first nitrogen solenoid valve <NUM> is then configured to open or close at a rate based on the pressure of the nitrogen gas and the partial pressure of oxygen within the compartment of module. More particularly, the oxygen sensor <NUM> is configured to measure the partial pressure of oxygen within the compartment or module. If the partial pressure of oxygen within the compartment or module is higher than the oxygen pressure threshold value and the ambient pressure is below the ambient pressure threshold (or the partial pressure of nitrogen is below a nitrogen pressure threshold value), the first nitrogen solenoid valve <NUM> is opened, allowing the nitrogen gas to flow to the compartment or module via the vent <NUM> until the ambient pressure threshold value is reached. On the other hand, if the ambient pressure of the compartment or module is equal to or higher than the ambient pressure threshold value, the first nitrogen solenoid valve <NUM> is closed, preventing the nitrogen gas from flowing to the compartment or module via the vent <NUM>. In various embodiments, the nitrogen control board <NUM> further includes a second nitrogen solenoid valve <NUM> configured to vent the nitrogen gas via the vacuum exhaust <NUM> in the event of an overpressure within the nitrogen control board <NUM>. Note that in various embodiments, the pressure control panel <NUM> includes an ambient pressure sensor <NUM> configured to sense the ambient pressure within the compartment or module. If the ambient pressure exceeds the ambient pressure threshold value (e.g., <NUM> psi or ≈ <NUM> KPa), a pressure relief solenoid valve <NUM> is opened, allowing the oxygen/nitrogen gas mixture within the compartment or module to be exhausted from an exhaust intake <NUM> and through the vacuum exhaust <NUM>.

Referring now to <FIG>, a schematic view of an environmental control system <NUM> for a planetary or orbital space vehicle is provided, in accordance with various embodiments. The environmental control system <NUM>, which is similar to the environmental control system <NUM> described above, includes an oxygen supply <NUM> and a nitrogen supply <NUM>, each of which may comprise a high-pressure tank or a gas generator configured to generate oxygen or nitrogen at high-pressure. The oxygen supply <NUM> is configured to provide the oxygen gas to an oxygen high-pressure regulator <NUM>, which is configured to reduce the pressure of the oxygen gas to a low-pressure. Similarly, the nitrogen supply <NUM> is configured to provide the nitrogen gas to a nitrogen high-pressure regulator <NUM>, which, in various embodiments, has components identical or nearly identical to those of the oxygen high-pressure regulator <NUM> (and to the oxygen high-pressure regulator <NUM> described above). The low-pressure oxygen gas and the low-pressure nitrogen gas are then delivered to a first pressure control panel <NUM> and to an Nth pressure control panel <NUM> (e.g., a second pressure control panel, a third pressure control panel, etc.), with N equaling the number of control panels disposed throughout the various compartments or modules within the space vehicle. Similar to the pressure control panel <NUM> described above, the first pressure control panel <NUM> and the Nth pressure control panel <NUM> are configured to control the partial pressure of oxygen from about twenty percent (<NUM>%) to about twenty-one percent (<NUM>%) and the partial pressure of nitrogen from about seventy-nine (<NUM>%) to about eighty percent (<NUM>%) of the oxygen/nitrogen gas mixture at an absolute pressure of about <NUM> psi (≈ <NUM> KPa), which emulates the oxygen/nitrogen partial pressure levels at sea-level on Earth.

Similar to the environmental control system <NUM> described above, during operation, a high-pressure oxygen gas from the oxygen supply <NUM> is provided to the oxygen high-pressure regulator <NUM>, which reduces the pressure of the oxygen gas. The oxygen gas is then provided to a first oxygen control board <NUM> located within the first pressure control panel <NUM> and to an Nth oxygen control board <NUM> (e.g., a second oxygen control board, a third oxygen control board, etc.) located within the Nth pressure control panel <NUM>, as well as to any pressure control panels intermediate the first and the Nth pressure control panels. In similar fashion, a high-pressure nitrogen gas from the nitrogen supply <NUM> is provided to the nitrogen high-pressure regulator <NUM>, which reduces the pressure of the nitrogen gas. The nitrogen gas is then provided to a first nitrogen control board <NUM> located within the first pressure control panel <NUM> and to an Nth nitrogen control board <NUM> (e.g., a second nitrogen control board, a third nitrogen control board, etc.) located within the Nth pressure control panel <NUM> (as well as to any pressure control panels intermediate the first and the Nth pressure control panels). In various embodiments, each of the first oxygen control board <NUM> and the Nth oxygen control board <NUM> and the first nitrogen control board <NUM> and the Nth nitrogen control board <NUM> are coupled to an oxygen sensor (PPO<NUM>) configured to measure the partial pressure of oxygen and an ambient pressure sensor within a corresponding compartment or module. In various embodiments, each of the oxygen and nitrogen control boards also include a pressure transducer (PT) (e.g., the oxygen pressure transducer <NUM> or the nitrogen pressure transducer <NUM> described above) and a function selector (SEL) configured for inputting control functions (e.g., whether the control board is a nitrogen control board or an oxygen control board within the corresponding compartment or module). In various embodiments, the first pressure control panel <NUM> includes a first carbon dioxide sensor <NUM> and the Nth pressure control panel <NUM> an Nth carbon dioxide sensor <NUM>, each of which is configured to detect the level of carbon dioxide in the corresponding compartment or module.

Still referring to <FIG>, the environmental control system <NUM> includes a supervisory controller <NUM> configured to control operation of the system. The supervisory controller <NUM>, as illustrated, is coupled to the first pressure control panel <NUM> and the Nth pressure control panel <NUM> and to the various components comprising the first pressure control panel <NUM> and the Nth pressure control panel <NUM>. The supervisory controller <NUM> is also coupled to the oxygen high-pressure regulator <NUM> and to the nitrogen high-pressure regulator <NUM>. During operation, the supervisory controller <NUM> receives inputs from the various sensors (e.g., the oxygen sensors, the ambient pressure sensors and the carbon dioxide sensors) and the function selectors. In response, the supervisory controller <NUM> controls operation of the high-pressure regulators and the pressure control panels. For example, the supervisory controller <NUM> controls the flow of oxygen gas and nitrogen gas out of a first vent <NUM> associated with the first pressure control panel <NUM> and the flow of oxygen gas and nitrogen gas out of an Nth vent <NUM> associated with the Nth pressure control panel <NUM> in response to signals received from the oxygen sensors, the ambient pressure sensors, and the carbon dioxide sensors corresponding to each of the control panels. Similarly, the supervisory controller <NUM> is configured to control the exhaust of ambient air from a first exhaust intake <NUM> and through a first vacuum exhaust <NUM> associated with the first pressure control panel <NUM> and from an Nth exhaust intake <NUM> and through an Nth vacuum exhaust <NUM> associated with the Nth pressure control panel <NUM>. The supervisory controller is also configured to control operation of the various oxygen, nitrogen and pressure relief solenoid valves comprised within the various control panels. The supervisory controller <NUM> may be connected to the pressure regulation systems and the pressure control panels by physical wire or by wireless communication. In addition to controlling operation of the environmental control system <NUM>, the supervisory controller <NUM> may be configured to broadcast status and warnings to a control console and to mission control. The supervisory controller <NUM> may also be responsible for running prognostic health maintenance on the high-pressure regulation systems, the pressure control panels and even itself, including when a new pressure control panel is added to the environmental control system <NUM>. In various embodiments, the supervisory controller <NUM> may include a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or some other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

Various benefits of the foregoing disclosure may be realized. For example, the environmental control systems described above may be deployed on different types of space vehicles using modular components. This allows design of custom, integrated, lightweight, and scalable environment or habitat pressure control systems to be designed into space vehicles without incurring design or redesign expenses associated with custom designs that are specific to each type of space vehicle. The use of modular components also minimizes the number and different types of spare parts required to be stored on the space vehicles. Redundancy is also readily built into the environmental control system (e.g., into the pressure control panels) that enables pressure control to continue operation until repairs may be made.

In various embodiments, system program instructions or controller instructions may be loaded onto a tangible, non-transitory, computer-readable medium (also referred to herein as a tangible, non-transitory, memory) having instructions stored thereon that, in response to execution by a controller, cause the controller to perform various operations. The term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se.

Numbers, percentages, or other values stated herein are intended to include that value, and also other values that are about or approximately equal to the stated value, as would be appreciated by one of ordinary skill in the art encompassed by various embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable industrial process, and may include values that are within <NUM>%, within <NUM>%, within <NUM>%, within <NUM>%, or within <NUM>% of a stated value. Additionally, the terms "substantially," "about" or "approximately" as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the term "substantially," "about" or "approximately" may refer to an amount that is within <NUM>% of, within <NUM>% of, within <NUM>% of, within <NUM>% of, and within <NUM>% of a stated amount or value.

Claim 1:
An environmental control system for a space vehicle, comprising:
an oxygen supply (<NUM>, <NUM>);
a nitrogen supply (<NUM>, <NUM>);
a supervisory controller (<NUM>) configured to control the first pressure nitrogen supply (<NUM>) and thereby to adjust a partial pressure of oxygen and an ambient pressure of an oxygen/nitrogen gas mixture within a first module (<NUM>),
characterized by
a first pressure control panel (<NUM>, <NUM>) including a first oxygen control board (<NUM>, <NUM>) configured to receive an oxygen gas from the oxygen supply (<NUM>, <NUM>) the first oxygen control board including an oxygen pressure transducer configured to determine an oxygen pressure within the first oxygen control board, and an oxygen solenoid valve configured to regulate and to release the oxygen gas into the first module (<NUM>),
and a first nitrogen control board (<NUM>, <NUM>) configured to receive a nitrogen gas from the nitrogen supply (<NUM>, <NUM>), the first nitrogen control board including a nitrogen pressure transducer configured to determine a nitrogen pressure within the first nitrogen control board, and a nitrogen solenoid valve configured to regulate and to release the nitrogen gas into the first module (<NUM>).