Abstract:
A fuel depot in space is provided. The fuel depot has a collapsible housing with a guidance, navigation, and control (GNC) system, a power management system, and a reaction control system (RNC). Connected to the housing are a plurality of fuel tanks that are connected via collapsible rods. The fuel tanks have pipe systems that are in communication with a plurality of pumps to transfer fuel from the tanks through a refueling arm and into a spacecraft during refueling.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/106,021 filed Jan. 21, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to the aerospace industry. More specifically, the invention advances the current capabilities of in space refueling procedures for long missions and expands the distance that spacecrafts can travel by allowing spacecrafts to refuel during their stages in orbit. 
         [0003]    There are currently no other platforms in orbit that can perform a refueling operation on this level, as current designs are too bulky and limited in size due to mass considerations. The invention is a fuel depot placed in orbit to allow for refueling. The fuel depot is able to collapse down to a manageable size for a single launch into orbit and then to fully expand autonomously to its full size once in orbit. This saves money and space associated with launching this craft. The station is also fully autonomous, making the need for personnel to run the platform non-existent. 
         [0004]    The invention includes ‘inflatable’ fuel tanks with telescoping rods allowing them to fully collapse into themselves reducing the overall size of the tanks at the time of launch. The skin of the tanks are made out of a lightweight material, such as Mylar, that is also durable enough to withstand the negative pressures of space while safely containing fuel. 
         [0005]    The fuel depot includes at least one fuel tank, a guidance, navigation, and control (GNC) system, hypergolic thrusters, a pump, and a plurality of solar panels. In one embodiment of the fuel depot includes five tanks to accommodate the potential need of the customer. Two of the tanks are used to store liquid oxygen (LOX), two are used to store rocket grade kerosene (RP 1 ), and the final tank is used as a reserve/fail safe in the event of a catastrophic failure of one of the aforementioned tanks. 
       BRIEF SUMMARY OF THE PRESENT INVENTION 
       [0006]    A fuel depot in space. The invention is configured to be implemented in space to fully facilitate the need for in-flight refueling operations. The fuel tanks are fully collapsible for a reduction in overall craft volume. The fuel tanks are inflatable to hold a greater amount of fuel over what is currently available. The fuel tanks are supported by, but not limited to, telescoping rods. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]      FIG. 1  is a perspective view of a fuel depot in space; 
           [0008]      FIG. 2  is a perspective view of a fuel depot in space; and 
           [0009]      FIG. 3  is a schematic view of a fuel depot in space. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0010]    Referring to the figures, a fuel depot  10  is disclosed and is comprised of a housing  12  that contains a GNC system  14  and all the parts integrated specifically to handle the computing tasks of keeping the fuel depot  10  in orbit and performing fueling operations autonomously. Within the housing  12  is a power management system  16  to collect power from a solar panel assembly  18  and store the power for later use. Surrounding the housing  12  are mounts  20  for a reaction control system (RCS)  22  to keep the orientation and orbit of the fuel depot  10  stable during fueling operations and idle operations. 
         [0011]    A pump housing  24  holds the necessary equipment to pump the components from the tanks  26  and out to a craft  28  during fueling. Each fuel tank  26  has a designated pump  30  to avoid the complications of contaminating a fuel component with oxidizer or vice versa, thus keeping the mixtures pure to be mixed later by the receiving craft  28 . The pumps  30  are connected to individual pipe systems  32  that are in communication with their perspective tanks  26 . There is also a pipe system  32  coming in from a refueling arm  34  that transports the fuel from the pump housing  24  to the craft  28 . In one embodiment there are two pumps  30  per fuel type. A joint  35  connects the two like fuel pumps  30  to a combined pipe  36 . In one embodiment, there are two combined pipes  36  that hold different fuels, such as LOX and one RP 1 . 
         [0012]    The solar panel assembly  18  serves as the main power generating system of the fuel depot  10 . There are two fully collapsible solar panels  38  that extend out to full length once the fuel depot  10  is in orbit to fully power the fuel depot  10  during idle operations and fueling operations. In an alternative embodiment, the two solar panels  38  are assembled into a multi-panel, dual-purpose solar panel assembly  18  that functions as both a solar array and a heat shield. In one embodiment of this alternative, the solar panels  38  are made out of triangular segments. 
         [0013]    The fuel tanks  26  are the main storage bodies of the fuel depot  10 . The fuel tanks  26  are inflatable and in one embodiment are made out of the lightweight material, such as Mylar. Connected to the fuel tanks  26  are telescoping rods  40  that are in a retracted position prior to orbit and in a protracted position once in orbit, thereby allowing the fuel tanks  26  and the housing  12  of the fuel depot  10  to be collapsed during launch and then expanded once orbit is entered. Additionally, the fuel tanks  26 , once in orbit, are inflated autonomously. Each fuel tank  26  holds only one of the two fuel components, LOX or RP 1 , except for the reserve tank  26 , which will be empty until use of it is required. In other embodiments the tanks  26  can hold a combination of fuels or the fuel tanks  26  may be partitioned to allow containment of multiple fuels. 
         [0014]    The pipe junction  42  is positioned at the intersection of the piping systems  32 , one per tank  26 , and makes a  90  degree bend with respect to each of the adjacent piping systems  32 . The only pipe system  32  that does not make this bend is the reserve tank  26  pipe system  32  which continues along the axis of the fuel depot  10  to the reserve tank  26 . 
         [0015]    The RCS  22  hypergolic tank system  44  is the storage system for the fuel of the RCS  22  thrusters. Since hypergolics are ignited by the two components being mixed, the hypergolic tank system  44  is similar to the fuel tank  26  arrangement that allows all the components for the fuel to remain separated until the fuel is mixed in the RCS thruster  22 . 
         [0016]    In operation, the fuel depot  10  is in a collapsed position prior to launch. While in the collapsed position the fuel tanks  26  and housing  12  are collapsed and the telescoping rods  40  are in the retracted position. The fuel depot  10  is launched and travels to the desired orbit, which can include low earth orbit, geosynchronous orbit, Earth-Moon L3 Lagrange Point, or any other orbit. Once in orbit the fuel depot  10  extends the telescoping rods  40  to the protracted position and the fuel tanks  26  and the housing  12  are transitioned to an expanded position. 
         [0017]    Once in the expanded position, the fuel tanks  26  are filled with the respective fuel, except for the reserve tank  26 , which remains empty. When a craft  28  arrives for refueling the RCS system  22  is activated by drawing fuel from the hypergolic tank system  44  to drive the RCS thrusters  22  to stabilize the fuel depot  10  during refueling. The craft  28  connects to the refueling arm  24 . Fuel is transferred from the fuel tanks  26  to the craft  28  by each fuel tanks  26  pump  30 , which transfers fuel from the tanks  26  through the pipe systems  32  to the pipe junction  42  and out to the craft  28  through the refueling arm  24 . 
         [0018]    The fuel depot  10  is continually powered using the solar panel system  18 , which includes a plurality of solar panels  38  that are in the collapsed position prior to launch by transition to the expanded position when orbit is entered. Unused energy is stored by the solar panel system  18  for later use by the fuel depot  10 . 
         [0019]    From the above discussion and the accompanying figures and claims it will be appreciated that the fuel depot  10  offers many advantages over the prior art. That is, the fuel depot  10  provides a compact and lightweight system for refueling crafts  28  as well as many other advantages and improvements over the prior art. It will be appreciated by those skilled in the art that other various modifications could be made to the device without parting from the spirit and scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered thereby. It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in the light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.