Balloon System for Reflecting Solar Radiation

The present disclosure provides a balloon system for mitigating solar radiation. The balloon system reflects solar radiation away from the earth. The balloon system includes at least one balloon having an outer surface for reflecting solar radiation. An orbital launching system launches the balloon to a set orbital location at which the balloon can orbit around earth in a path of solar radiation from the sun toward earth. At the set orbital location, the earth's gravitational force and solar pressure imparted on the balloon counterbalance the sun's gravitational force on the balloon. The set orbital location is spaced apart from a Lagrange stability point L1 in a direction toward the sun and away from the earth.

FIELD

The present disclosure generally relates to stopgap solutions for negating effects of climate change, and more specifically, to a balloon system for managing solar radiation.

BACKGROUND

Recently, earth has set new records in worldwide heat index, and at the same time, the amount of carbon dioxide in the earth's atmosphere has reached unprecedented levels. Most proposed solutions for climate change either aim to mitigate carbon dioxide by either reducing rates of carbon dioxide production or by removing carbon dioxide from the atmosphere after it has been produced. Current efforts to address climate change require a long time horizon to have effect, and they are too costly to employ as stopgap measures to address short-term risks of acute warming conditions. Therefore, there is a need for a feasible, cost-effective, short-term solution to mitigate global warming.

BRIEF SUMMARY

In one aspect, a balloon system for mitigating solar radiation comprises at least one high-altitude balloon having an outer surface at least partially defined by material configured to reflect solar radiation. The balloon is configured to orbit around earth at a set orbital location in a path of solar radiation from the sun toward earth. An orbital launching system is configured for launching the balloon to the set orbital location.

In another aspect, a method for mitigating solar radiation on earth comprises launching at least one high-altitude balloon to a set orbital location via an orbital launching system. The set orbital location is in a path of solar radiation from the sun toward earth and the ball. Solar radiation is reflected away from earth via an outer surface of the balloon.

Other aspects and features will be apparent hereinafter.

DETAILED DESCRIPTION

The inventors believe that there is opportunity to address global warming by directly mitigating solar radiation. For example, 30% of solar radiation imparted on earth is reflected to space by white surfaces, in particular polar ice. The inventors believe that man-made systems for reflecting solar radiation could also be employed in an effort to reduce warming. As explained in further detail below, the inventors have devised a system for reflecting solar radiation that they believe can be selectively employed on an as-needed basis. Such a system may have utility in addressing long-term warming trends, as well as addressing acute solar radiation events.

Referring toFIGS. 1-3, the present disclosure provides a balloon system10for reflecting solar radiation away from earth. The balloon system10of the present disclosure can provide short-term negation of warming effects by preventing some solar radiation from impinging on the earth's surface. Although the total output of radiation from the sun cannot be changed, the amount of solar radiation that reaches the Earth may be changed in accordance with the present disclosure. The balloon system10broadly includes an orbital launching system12that is configured to launch at least one balloon16to a set orbital location14.

The at least one balloon16is illustrated as a single, high-altitude balloon. Alternatively, a plurality of high-altitude balloons may be used in accordance with the present disclosure. The high-altitude balloon16is intended to be located at the set orbital location14for a period of time of at least decades.

The high-altitude balloon16has an outer surface18formed in part from polyethylene, and in part from a reflective coating. The reflective coating is configured to reflect solar radiation and may comprise a multilayer coating including a bottom layer of mylar or a polyimide and a top layer of reflective metallic material. Mylar, also known as biaxially-oriented polyethylene terephthalate (BoPET) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its properties, such as, but not limiting to, reflectivity, gas and aroma barrier properties, high tensile strength, electrical insulation, and chemical and dimensional stability. Similarly, polyimide provides a tough aromatic film exhibiting an excellent balance of physical, chemical, and electrical properties over a wide temperature range. The set orbital location14may be subject to extreme temperature fluctuations. But because the balloon16is formed, at least in part, from material that is able to withstand a wide range of temperatures, capable of withstanding the conditions for relatively long periods of time. Hence, the high-altitude balloon16can provide a cost-effective solution for mitigating the amount of solar radiation to reach earth that is sustainable for decades. As one with ordinary skill in the art would understand, alternative materials with similar properties can be used in accordance with the present disclosure.

Suitably, the outer surface18of the high-altitude balloon16has similar properties to a solar sail. Solar radiation exerts a force Fs (FIG. 3) onto the outer surface18of the balloon16as it is reflected. This force Fs of solar radiation can be used for propulsion. As explained in further detail below, the high-altitude balloon16may further include an active adjustment system to counteract solar radiation forces, Fs, exerted onto the high-altitude balloon once the high-altitude balloon is deployed.

As shown inFIGS. 1 and 2, the orbital launching system12is configured to launch the high-altitude balloon16into space and deploy the high-altitude balloon such that the high-altitude balloon's location is at the set orbital location14. In accordance with the present embodiment, the orbital launching system12is a rocket. As known to one in the art, any suitable system, process, structure, or combination thereof that is sufficiently capable of reaching the set orbital location14and deploying the high-altitude balloon16is within the scope of the present disclosure. In an exemplary embodiment, the high-altitude balloon16is partially inflated with carbon dioxide and stored in a payload system of a rocket, as seen inFIG. 1. The high-altitude balloon16, partially filled with carbon dioxide, is then released once the rocket reaches the set orbital location14. In an alternative embodiment, the high-altitude balloon16may be partially inflated once it is deployed when the rocket reaches the set orbital location14. As one with ordinary skill in the art would understand, an acid and base reaction could be used to produce carbon dioxide that will inflate the high-altitude balloon16. However, any method for storing or producing carbon dioxide can be used in the scope of the present disclosure.

As seen inFIGS. 2 and 3, the set orbital location14can be at a point in space such that the high-altitude balloon16is orbiting in a path of solar radiation from the Sun towards the Earth. More specifically, the set orbital location14can be near a Lagrange L1 point20between the Earth and the Sun. The Lagrange L1 point20affords an uninterrupted view of the Sun and is therefore a suitable location for the high-altitude balloon16to block out a portion of the Sun's solar radiation. Additionally, the Lagrange L1 point20defines a special point where a small mass can orbit in a constant pattern with two larger masses. Further, the Lagrange L1 point20is a position where the gravitational pull of two large masses precisely equals the centripetal force Fc required for a small object to move along and between them. At the Lagrange L1 point20in the Sun-Earth system, gravitational forces Fg of the Sun and the Earth cancel out in such a way that the high-altitude balloon16can be placed in orbit in equilibrium relative to a center of mass of the large bodies. As known to one in the art, the Lagrange L1 point20, described as meta unstable, has a precarious equilibrium. Therefore, set orbital location14of the high-altitude balloon16should be slightly closer to the sun than the Lagrange L1 point20because of the force equation of the earth's gravitational force Fg and the solar pressure Fs (due to the high-altitude balloon's reflective material) added together would have to be in equal and opposite magnitude to that of the Sun's gravitational force Fg. As known to one in the art, a general location of the set orbital location14can be calculated using mathematical and computational methods using software such as NASA's GMAT platform to perform analysis. The software required to run the computational and mathematical analysis is inexpensive and can be run on most hardware and offers a more simplified method of analysis than that of most geoengineering analysis.

Generally, the Lagrange L1 point20represents a region that is 1/100th distance towards the Sun away from the Earth. The Lagrange L1 point20is at a position of constant stream of particles from the Sun, such as solar wind, which reaches the Lagrange L1 point. Generally, the region of the Lagrange L1 point20can house a plurality of objects such as, but not limiting to, satellites, telescopes, asteroids, and in accordance with the present disclosure high-altitude balloons. Collectively, as one with skill in the art would understand, the objects within the region of the Lagrange L1 point20must have a relatively small mass in comparison to the Earth and the Sun. Further, as one with ordinary skill in the art would understand, since the Lagrange L1 point20is a meta unstable point, an object placed within the Lagrange L1 point will remain in the Lagrange L1 point until an external force nudges the object out of alignment.

To correct misalignment with the Lagrange L1 point20, the object may include a thruster or a plurality of thrusters. For example, if the high-altitude balloon16was originally at the Lagrange L1 point20, the high-altitude balloon's outer surface18, which acts as a solar sail, would experience the force Fs from solar radiation that would push the high-altitude balloon too far from the Lagrange L1 point, resulting in a non-zero net force due to Earth's gravitational pull Fg. Therefore, the high-altitude balloon16is placed at a location slightly closer to the Sun than Earth at the Lagrange L1 point20as described above. The high-altitude balloon16may correct misalignments by having the active stability system that includes the plurality of thrusters to allow equivalent sustainability at the set orbital location. Merely rotating the high-altitude balloon16along a roll axis, or using active controls involving exhaust (e.g., gas or liquid) from thrusters, can align the object or change its direction. The most common kinds of active controls used in space are attitude-control that can be controlled from a location on Earth. Further, the active adjustment system can comprise small clusters of thrusters mounted all around the balloon16that can be selectively fired to correct misalignments. This allows the object such as the high-altitude balloon16to be turned in any direction by changing its orientation or inclination to a desired specification.

As schematically illustrated inFIG. 4, a method for mitigating solar radiation on Earth can be separated into three distinct and separate phases. Phase 1 represents preparing a launch for launching a single or plurality of high-altitude balloons16into a sun-earth system. First, a set orbital location14is calculated such that the high-altitude balloon16would be positioned in a path of solar radiation from the sun towards the earth. Additionally, an outer material of the high-altitude balloon16can be selected such that the outer material reflects solar radiation. Further, the set orbital location14is set such that the high-altitude balloon16can remain in orbit for decades. Prior to launching the high-altitude balloon16, the balloon may be partially filled with carbon dioxide. Either before or after the high-altitude balloon16is partially filled with carbon dioxide, the high-altitude balloon is loaded into an orbital launching system12for launching to the set orbital location.

As shown in Phase 2, the illustrated method for mitigating solar radiation further comprises positioning the balloon16at the set orbital location where it will continuously remain in the path of solar radiation for as long as the balloon remains in service. The orbital launching system12launches the high-altitude balloon16to the set orbital location via, for example, a rocket. The high-altitude balloon16may be deployed at the set orbital location, such as a near Lagrange L1 point in the sun-earth system. Once deployed, the carbon dioxide expands within the high-altitude balloon, making a greater surface area for reflecting solar radiation. As the high-altitude balloon16reflects solar radiation, the balloon is propelled by the force or radiation. In addition, thrusters can be utilized to propel the high-altitude balloon16during misalignments.

Phase 3 begins when the high-altitude balloon16is actively reflecting solar radiation. The reflection is intended to generate a climate response, e.g., an anti-warming response. The climate response can at least partially be measured in terms of a globally resolved energy balanced climate model (GREB), calculated based on the amount of solar radiation reflected away from earth by the high-altitude balloon16. For example, the GREB may be used to assess the high-altitude balloon's effect on a number of environmental indications such as but not limiting to, solar radiation, thermal radiation, the earth's hydrologic cycle, and sea ice. Further, data from one or more sensors onboard the high-altitude balloon16may be used to further understanding of the global warming crisis. In accordance with the present disclosure, the balloon system10provides a way to mitigate solar radiation. The system10can be rapidly deployed to address acute radiation threats and is capable of long-term (e.g., decades long) deployment for sustained climate change mitigation. At the end of the useful life of a balloon16, it can be decommissioned (e.g., dismantled and brought back to earth) and replaced by another balloon. In addition, the balloon system10can be deactivated on essentially a moment's notice should a need arise.

The foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in view of this disclosure. Indeed, while certain features of this disclosure have been shown, described and/or claimed, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the apparatuses, forms, method, steps and system illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present disclosure.

Furthermore, the foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the disclosure. Thus, the foregoing descriptions of specific embodiments of the present disclosure are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed, many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosed system and method, and various embodiments with various modifications as are suited to the particular use contemplated.