Reusable resupply systems and methods

A multi-use resupply system for a space-based platform may include a multi-use tug to swap old and new cargo containers on a launch vehicle upper stage. The system can rely on the launch vehicle upper stage to provide the function of cargo de-orbit and disposal. The launch vehicle upper stage may be provided with sufficient propellant and propulsion functionality to operate for a long enough period in space to maneuver a new cargo container to a rendezvous trajectory, support the swapping of cargo containers, and then perform a de-orbit burn with the old cargo container.

Not applicable.

FIELD

The disclosure relates in general to sustaining of space operations, and in particular to, for example, without limitation, a reusable space platform resupply system such as an international space station cargo resupply service.

BACKGROUND

The description provided in the background section, including without limitation, any problems, features, solutions or information, should not be assumed to be prior art merely because it is mentioned in or associated with the background section. The background section may include information that describes one or more aspects of the subject technology.

To sustain operations at the International Space Station (ISS), it is necessary to deliver cargo from the ground on a regular basis and dispose of waste cargo with each mission. Systems currently in use today, to provide cargo services to and from the ISS, are single use solutions that are destroyed by reentry at the end of a single cargo delivery mission. Alternatively, such systems utilize a reentry capsule that is recovered and must be refurbished after each mission.

SUMMARY

The description in this summary section may provide some illustrative examples of the disclosure. This section is not intended to be a broad overview or to identify essential elements of the disclosure.

In accordance with an aspect of some embodiments disclosed herein, it has been realized that the current systems used to deliver cargo to the ISS and dispose of cargo from the ISS do not recover or reuse the propulsion system and the structure used to maneuver cargo to and from the ISS. Further, in the case of a single use system, avionics and rendezvous and proximity operations (RPO) sensors are also destroyed at the end of each mission. The present disclosure relates to a more cost-effective and efficient solution for delivering or carrying cargo to or from an orbiting platform such as the ISS.

For example, in some embodiments, a tug is provided with mechanical, electrical, communications, and propulsion components for self-attachment to a cargo container that is delivered to orbit by a launch vehicle. While attached to the cargo container, the tug transfers the cargo container from the launch vehicle to the ISS. Following off-loading of cargo from the container to the ISS, the container can be filled with items that are no longer needed at the ISS (sometimes described herein as “waste cargo” or “trash”) and the tug then maneuvers the cargo container away from the ISS.

In some embodiments, the tug may perform a de-orbit burn to dispose of the trash. Further, in order to support more than one mission, the tug of these embodiments may re-orbit itself after performing the de-orbit burn. A tug capable of performing multiple round-trip maneuvers between the launch vehicle rendezvous point and the ISS and executing multiple de-orbit/re-orbit maneuvers may require an undesirably complex, expensive, and heavy propulsion system and sufficient propellant for these de-orbit/re-orbit maneuvers.

Therefore, in accordance with some embodiments, a system is provided for multi-use resupply of an orbiting or other space-based platform without requiring de-orbit and re-orbit of the tug, thereby reducing the maneuver and propellant demands on the tug. The system may include a multi-use tug that cooperates with an upper stage of a launch vehicle to perform resupply and waste removal operations.

In one or more implementations, a multi-use tug may be provided that includes first attachment features configured for coupling a first cargo container at a first attachment location; second attachment features configured for coupling a second cargo container at a second attachment location; and a grappling arm configured to capture the second cargo container and an attached launch vehicle upper stage, position the second cargo container for coupling to the second attachment features, and move the launch vehicle upper stage from the second cargo container to the first cargo container while the first cargo container is coupled to the first attachment features and the second cargo container is coupled to the second attachment features during space-based operations of the multi-use tug.

In one or more implementations, a method may be provided that includes maneuvering, with a multi-use tug, a first cargo container from a space-based platform to a delivery orbit; maneuvering, with a launch vehicle upper stage, a second cargo container to the delivery orbit; swapping, with a grappling arm of the multi-use tug, the launch vehicle upper stage from the second cargo container to the first cargo container; de-orbiting the first cargo container with the launch vehicle upper stage; and maneuvering, with the multi-use tug, the second cargo container from the delivery orbit to the space-based platform.

In one or more implementations, a multi-use resupply system for a space-based platform may be provided, the multi-use resupply system including a multi-use tug; and at least one upper stage vehicle of a launch vehicle, where the multi-use tug is configured to maneuver a first cargo container to a delivery orbit, where the at least one upper stage vehicle is configured to move a second cargo container to the delivery orbit, where the multi-use tug is configured to maneuver the second cargo container to the space-based platform, and where the at least one upper stage vehicle is configured to de-orbit the first cargo container.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the subject technology as claimed. It is also to be understood that other aspects may be utilized and changes may be made without departing from the scope of the subject technology.

DETAILED DESCRIPTION

Some embodiments disclosed herein provide a multi-use supply system for a space-based platform such as a space station (e.g., a manned space station such as the ISS), a satellite, or other spacecraft as described herein. The multi-use supply system may include a multi-use tug configured to receive a cargo container from a launch vehicle, transport the cargo container to the space-based platform, and transport a waste container to a subsequently launched launch vehicle. For example, the multi-use supply system may be implemented as an ISS cargo resupply architecture, in some embodiments.

It has been discovered that, in some implementations, the design of a reusable tug can become undesirably large and expensive if too many functions are included for the tug to perform (e.g., shuttling cargo containers between a launch vehicle rendezvous point in low earth orbit (LEO) and the ISS in addition to providing propulsion for de-orbiting cargo containers).

In accordance with some embodiments, the multi-use supply system can be configured such that the only function performed by the tug is to shuttle cargo containers between a launch vehicle (e.g., at an LEO rendezvous point) and the space-based platform (e.g., the ISS or another spacecraft) and to swap cargo and waste containers as needed. Such embodiments can greatly reduce the size, complexity and cost of the tug.

In some embodiments, an upper stage of a launch vehicle is used to provide the function of waste cargo de-orbit and disposal. In some implementations, a multi-use tug can swap old cargo containers (e.g., waste containers loaded at the space-based platform with items no longer needed at the space-based platform) and new cargo containers on the launch vehicle upper stage. Further, the upper stage may be provided with sufficient propellant and propulsion systems to allow the upper stage to operate for a long enough period in space to maneuver to the rendezvous point, support the swapping of cargo containers and then perform a de-orbit burn with the old cargo container.

Accordingly, some embodiments disclosed herein can reduce the maneuvering requirements on the tug and therefore, reduce associated costs. In contrast, the current approach to an ISS cargo resupply service consumes expensive space hardware with each mission, requires refurbishment of space hardware with each mission, or requires a tug that is capable of many very large maneuvers, and is consequently driven to be very large and expensive. Further details and disclosure related to the present disclosure are included hereinafter.

FIG. 1shows a block diagram of an example of a system including a multi-use supply system and a space-based platform. As shown inFIG. 1, system100includes a space-based platform112and a launch vehicle102. Launch vehicle102may be provided with a multi-use resupply system103for repeatedly providing and removing items and materials to and from space-based platform112.

Space-based platform112may be a space station (e.g., the ISS), a satellite, or other spacecraft in a low-Earth orbit (LEO), a high-Earth orbit (HEO), a geosynchronous orbit, an orbit of another planet, moon, or other Solar System body (e.g., an asteroid, a dwarf planet, or a comet) or otherwise maintained at a space-based location (as examples). Launch vehicle102may, for example, be a rocket-based launch vehicle for delivering multi-use resupply system103into space (e.g., into a delivery orbit). Launch vehicle102may include other components110such as one or more rocket motors, telemetry and other communications systems, stabilization systems, monitoring systems, guidance systems, tracking systems, a payload fairing, and/or other suitable systems and components for launching a multi-use resupply system and/or other payloads into space. For example, in one implementation, launch vehicle102may be implemented as an Atlas V rocket as manufactured by United Launch Alliance.

As shown inFIG. 1, multi-use resupply system103may include a multi-use space tug such as multi-use tug104, one or more cargo containers such as cargo container106and one or more components of launch vehicle102such as upper stage vehicle108. Launch vehicle102may be an expendable launch vehicle that delivers multi-use resupply system103into space. Once in orbit, multi-use tug104and cargo container106may separate from upper stage vehicle108while multi-use tug104and cargo container106are attached together. Upper stage vehicle108may then perform a de-orbit burn to return to Earth. Multi-use tug104may perform various on-orbit safekeeping operations such as solar panel deployment and housekeeping operations. Once initial operations are completed, multi-use tug104may be operated to maneuver cargo container106to space-based platform112(e.g., by moving cargo container106into a common orbit with space-based platform112for attachment of cargo container106to space-based platform112).

Once attached, cargo from within cargo container106may be removed from the cargo container into and/or onto space-based platform112while the multi-use tug104remains attached to the container. For example, supplies for the ISS may be unloaded from cargo container106into the ISS. Waste items and materials can then be loaded into the same cargo container106and the cargo container106containing the waste items can be detached from space-based platform112and maneuvered by multi-use tug104to a loiter orbit (e.g., an orbit higher than the orbit of space-based platform112) until a subsequent supply mission (e.g., until a launch time of a launch of the subsequent supply mission).

As shown inFIG. 1, another launch vehicle113may include another cargo container114, upper stage vehicle116, and other components118for launching cargo container114to the delivery orbit for a subsequent delivery (e.g., a resupply delivery) to space-based platform112. Other components118may include as one or more rocket motors, telemetry and other communications systems, stabilization systems, monitoring systems, guidance systems, tracking systems, a payload fairing, and/or other suitable systems and components for launching a multi-use resupply system and/or other payloads into space. For example, in one implementation, launch vehicle113may be implemented as an Atlas V rocket as manufactured by United Launch Alliance.

As shown inFIG. 1, launch vehicle113does not include a multi-use tug. Multi-use tug104may be used to provide cargo container106, now a waste container containing waste items from space-based platform112, to upper stage vehicle116and to accept cargo container114from upper stage vehicle116. Upper stage vehicle116can then de-orbit cargo container106for disposal and multi-use tug104may perform propulsion operations to maneuver cargo container114to space-based platform112so that supplies from cargo container114can be loaded to space-based platform112and additional waste items can be loaded into cargo container114for disposal during a further subsequent resupply mission.

FIG. 2is a block diagram of an example of a multi-use tug104. As shown in the example ofFIG. 2, multi-use tug104may include a grappling arm200, an alignment system210such as one or more components of a berthing alignment system, propulsion system212and propellant storage202for storing propellant to be used by propulsion system212and guidance system216. Guidance and propulsion systems212and216may be operated for maneuvering tug104between various orbits and positions and for maintaining various orbits and positions in space for various resupply operations as described herein.

Multi-use tug may include other components and devices such as communications system204, electrical power components such as solar panels214and electrical power storage206(e.g., one or more batteries coupled to the solar panels), and coupling components208(e.g., latches, grappling features, alignment marks, alignment structures, or the like).

FIG. 3shows an exploded perspective view of an implementation of launch vehicle102ofFIG. 1. As shown inFIG. 3, launch vehicle102(and similarly launch vehicle113) may include components such as engine300, a primary booster304, one or more solid rocket boosters302, one or more adapters such as adapter306, and an upper stage vehicle108with an upper stage vehicle engine308. Upper stage vehicle108may be at least partially disposed within a payload fairing310when vehicle102is configured for launch. Upper stage vehicle108may include coupling features312for attachment to a cargo container such as cargo containers106and/or114(see, e.g.,FIG. 1).

FIG. 4shows a side view of multi-use resupply system103disposed within payload fairing310with a portion of payload fairing310cutaway in the figure for clarity. Payload fairing310may have a height H which may be between, for example, 68 inches and 87 inches (e.g., height H may, in one implementation be approximately 77 inches).

In the example ofFIG. 4, a cargo container is provided that includes cargo components400,402, and404attached between upper stage vehicle108and multi-use tug104which is shown in an undeployed configuration (e.g., with solar arrays and grappling arm(s) in a stowed position for launch). One or more of cargo components400,402, and404may be provided in combination to form cargo container106.

An enlarged view of system103in the configuration ofFIG. 4is shown inFIG. 5. Cargo component400may be a pressurized cargo carrier (PCC) configured to carry cargo in a pressurized environment. PCC400may, in one exemplary implementation, have an axial length of approximately 4.2 meters, a diameter of approximately 4.4 meters, a volume of approximately 42 cubic meters (e.g., the volume within an interior cavity of the container defined by an outer or inner housing structure and/or port or door that surround the interior cavity) and may be configured to hold approximately 5000 kg of cargo. First attachment features506may be used to attach PCC400to upper stage vehicle108during launch operations. Attachment features506may include a structural interface (e.g., an expanding tube separation joint ring), and an electrical interface (e.g., a separation electrical connector at the separation plane). Second attachment features508may be used to attach a different PCC400(e.g., a prior-launched PCC holding waste cargo) to upper stage vehicle108for de-orbit operations. Attachment features508may include a structural interface (e.g., one or more latches on the PCC such as three latches spaced 120° apart that capture and latch one or more corresponding clamp bars on upper stage vehicle108), and may be free of electrical interface components.

Cargo component402may be an unpressurized cargo container (UCC) configured to carry cargo that does not require a pressurized environment for storage and transport. UCC402may, in one exemplary implementation, have an axial length of approximately 1.7 meters, a diameter of approximately 4.4 meters, a volume of approximately 17 cubic meters (e.g., the volume within an interior cavity of the container defined by an outer or inner housing structure and/or port or door that surround the interior cavity) and may be configured to hold approximately 1500 kg of cargo. Attachment features504may be used to attach UCC402to PCC400. Attachment features504may include a structural interface (e.g., a bolted joint UCC ring to PCC ring flange interface) and an electrical interface (e.g., a harness-to-harness electrical connector).

Cargo component404may be a mission support module (MSM) configured to carry mission support materials such as hydrazine (N2H4) and Helium (He) for propulsion operations. Propulsion materials such as hydrazine and Helium that are stored in MSM404may be used by multi-use tug104during maneuvering of cargo components400,402, and404by tug104or may be used to refuel tug104for subsequent propulsion operations of tug104. MSM404may, in one exemplary implementation, have an axial length of approximately 1.4 meters, a diameter of approximately 4.4 meters, and may be configured to hold approximately 2050 kg of hydrazine and 16 kg of Helium at approximately 4000 psi. Attachment features502may be used to attach MSM404to UCC402. Attachment features502may include a structural interface (e.g., a bolted joint coupling a top plate of the UCC to the MSM at multiple locations) and an electrical interface (e.g., a harness-to-harness electrical connector).

In configurations in which an MSM is provided with the cargo container, MSM404may be detachably coupled to multi-use tug104using attachment features500. In other configurations, attachment features500may be used to attach multi-use tug104directly to UCC402or directly to PCC400. For example, an MSM may be included in cargo container106only for missions in which refueling of multi-use tug104is desired (e.g., every mission, every other mission, every third mission, every fourth mission, or as needed depending on mission and/or cargo demands).

Attachment features500may operate differently during a first mission (e.g., a delivery mission for tug104in which tug104and cargo container106are coupled during launch) and subsequent missions (e.g., resupply missions during which cargo container106is not attached to tug104during the launch). For example, in a first mission, attachment features500may include a structural interface (e.g., two mating rings with pin-puller shear pins that are activated at the beginning of a first swap operation for tug104), an electrical interface (e.g., an electrical connector on a bracket that takes the place of an electrical grapple fixture, the connection actuated by an end effector), and a fluid interface (e.g., one or more mechanisms on tug104configured to actuate a quick disconnect connection). In a subsequent mission, attachment features500may include, for example, a structural interface (e.g., two mating rings and an end effector and grapple fixture, berthing features, docking features, and/or other structural interface structures), an electrical interface (e.g., an end effector electrical mate to the grapple fixture, the connection actuated by an end effector), and a fluid interface (e.g., one or more mechanisms on tug104configured to actuate a quick disconnect connection)

Grappling arm200may have an end effector542configured to interface with grappling features of container106(e.g., one or more of grappling features512disposed on PCC400and/or one or more grappling features513disposed on upper stage vehicle108) for various mating, un-mating, repositioning, and maneuvering operations. Multi-use tug104may also include mating features540(e.g., berthing structures) configured to form an additional attachment point for attaching a cargo container with or without an attached upper stage vehicle.

Multi-use tug104may, in one exemplary implementation, include storage for approximately 2195 kg of hydrazine and 4 kg of Helium at approximately 4000 psi for propulsion operations. In this implementation, multi-use tug104may have an axial length (including attachment features540) of approximately 2.4 meters and may have electrical power storage and generation capable of providing approximately 6500 watts of power.

FIGS. 6-13show various aspects of cargo supply and resupply operations using a multi-use resupply system as described herein, in accordance with various embodiments. In particular,FIGS. 6, 7, and 8show various aspects of a first supply mission in which a multi-use tug is launched into orbit with a cargo container andFIGS. 9, 10, 11, 12, and 13show various aspects of a subsequent (e.g., second or later) resupply mission in which a multi-use tug is used to swap an old cargo container containing waste items with a new cargo container containing supply items for the space-based platform.

Illustrative operations that may be performed for a first supply mission with a multi-use resupply system are shown inFIG. 6.

At block600, a payload may be launched (e.g., using a launch vehicle such as launch vehicle102ofFIG. 1) into a delivery orbit. The payload may include a multi-use tug, a cargo container, and a launch vehicle upper stage as described herein. For the first launch, from liftoff through spacecraft/launch vehicle separation, multi-use tug104may use a telemetry and data relay satellite system (TDRSS) band such as a TDRSS S-band to communicate with ground-based monitors and controllers. For all launches, the launch vehicle may transmit telemetry data to a ground-based spacecraft operations center (SOC) through range ground stations from liftoff through early ascent. Range ground stations (e.g., TEL-4, Jonathan Dickenson Missile Tracking Annex (JDMTA), and Antigua ground stations) may be used to provide launch vehicle telemetry support during early launch ascent phases. During ascent, the launch vehicle may reduce the telemetry data rate for compatibility with TDRSS and perform a roll to orient an antenna along a TDRSS line of sight, which remains the primary launch vehicle telemetry collection asset for the remainder of the flight. Supplemental support may be provided via other communications networks such as the Air Force Satellite Control Network (AFSCN) ground stations based on visibility and a predicted radio-frequency (RF) link. Both TDRSS and AFSCN data may be available real-time.

At block602, the multi-use tug and cargo container (e.g., the cargo container attached to the multi-use tug) may be separated from the launch vehicle upper stage.

At block604, the launch vehicle upper stage may be de-orbited (e.g., by performing a de-orbit burn with the launch vehicle upper stage).

At block606, multi-use tug on-orbit safekeeping operations may be performed. On-orbit safekeeping functions may include solar array deployments and vehicle housekeeping operations.

At block608, the multi-use tug may be maneuvered (e.g., using its own propulsion systems) to a platform orbit at which a space-based platform such as the ISS is orbiting.

At block610, tug coupling and unloading operations may be performed at the space-based platform. For example, the cargo container and the attached multi-use tug may be berthed or docked (e.g., using a grappling arm and/or other mounting or berthing features of the space-based platform) to the space-based platform such that the cargo in the cargo container may be accessed and loaded onto and/or into the space-based platform. For example, while the multi-use tug is attached to a first end of the cargo container, an opposing second end of the cargo container may be berthed to the space station and opened so that the cargo therein can be unloaded by the space station astronauts.

At block612, waste loading and decoupling operations may be performed at the space-based platform. For example, while the multi-use tug is attached to the first end of the cargo container and the second opposing second end of the cargo container is attached to the space station and open, waste cargo can be loaded into the cargo container by the space station astronauts, the cargo container can be closed, and the cargo container can be detached from the space station while the multi-use tug is attached to the cargo container at the first end. The operations of blocks610and612may be controlled automatically and/or by human operators at the space-based platform and/or at a ground station mission control center for the space-based platform. In various embodiments, operations of the multi-use tug other than berthing and loading operations may be controlled by the same or a different ground station control center.

At block614, the multi-use tug may maneuver the multi-use tug and its attached waste cargo container to a loiter orbit (e.g., an orbit that is higher than the platform orbit).

At block616, the multi-use tug may maintain cargo container106(and tug104itself) at the loiter orbit until the time of a subsequent resupply mission.

FIG. 7is a diagram showing the configuration of various components of a multi-use resupply system at various stages of the first mission as described above in connection withFIG. 6in an implementation for supplying and resupplying the international space station (as an example). As shown inFIG. 7, launch operations700may be performed with a launch vehicle102leading to ascent702of an integrated stack that includes multi-use tug104, cargo container106and upper stage vehicle108.

Following ascent, upper stage vehicle108may be separated from cargo container106and attached multi-use tug104. Disposal operations710may be performed for upper stage vehicle108(e.g., by performing a de-orbit burn with upper stage vehicle108). For example, after performing maneuvers to safely back away from upper stage vehicle108, multi-use tug104may perform a departure trajectory maneuver that raises apogee a minimum of 1.4 km above upper stage vehicle108. With this trajectory, multi-use tug104initially drifts in front, then above and then starts to fall behind the upper stage vehicle108. Once multi-use tug104reaches a safe distance, upper stage vehicle108starts disposal operations.

Before, during, or after disposal operations710, phasing operations703may be performed with multi-use tug104to orient, position, and maneuver tug104and container106to meet space-based platform112(e.g., the ISS) at a platform orbit. Rendezvous operations704may be performed to position cargo container106for berthing with platform112while multi-use tug is fully deployed and attached to cargo container106. Phasing and maneuvering of tug104and container106may be performed using the propulsion systems of tug104.

ISS operations706(e.g., docking and/or berthing operations, loading operations, and unloading operations) may be performed at space-based platform112. Following loading of unwanted cargo into cargo container106, cargo container106and tug104may be detached from platform112and tug104may maneuver tug104and container106to a loiter orbit and perform loiter operations708to maintain the loiter orbit until the time of a subsequent resupply mission.

As shown inFIG. 8, for the first mission, an injection altitude may be tailored such that, after separation from upper stage vehicle108, tug104and container106will be in a delivery orbit800in which a worst case 360° phasing with the ISS can be accommodated and still meet the cargo delivery requirement for the mission (e.g., a 96 hour cargo delivery time limit). The delivery orbit800may be a 254.5 km altitude, 51.6° inclination orbit. With this strategy, the launch vehicle may be provided with the performance to launch on any day.

After injection, multi-use tug104and container106separate from upper stage vehicle108and, after reaching a safe distance from upper stage vehicle108, multi-use tug may begin initial on-orbit safekeeping functions such as solar array deployments and vehicle housekeeping. Risk reduction testing operations for the first mission may also be performed. Time and propellant may be reserved to allow for optional testing of the rendezvous, proximity-operations and capture operations with an upper stage launch vehicle for later recurring missions.

In the example, ofFIG. 8, line822shows the trajectory of the launch vehicle to delivery orbit800during launch opportunities and injection orbits portion820of the first mission. Line826shows the trajectory of multi-use resupply system103leading to separation operations824from upper stage vehicle108. Following separation operations824, disposal operation828for upper stage vehicle108are indicated by line830and line834indicates various ISS phasing operations832and ISS rendezvous proximity operations838for multi-use tug104and attached cargo container106during which multi-use tug104may maneuver container106between a phasing orbit802, a first co-elliptic orbit804, a second co-elliptic orbit806, and the platform orbit (e.g., the ISS orbit)808. Phasing operations832and rendezvous proximity operations838may be performed to properly align, position, and phase container106for berthing with space-based platform112. Portion836of the diagram ofFIG. 8shows maneuvering of cargo container106(with waste items therein) by multi-use tug104to a loiter orbit810. In the example, ofFIG. 8, the loiter orbit810is approximately 10 km above the platform orbit808.

Illustrative operations that may be performed for a resupply (or recurring) mission with a multi-use resupply system are shown inFIG. 9.

At block900, the multi-use tug and attached waste container may be maneuvered, using the propulsion system of the multi-use tug, from the loiter orbit to a staging orbit (e.g., a two-day phase repeating staging orbit) in preparation for the arrival of a new cargo container and upper stage vehicle. The staging orbit may, for example, be a 351.4 km altitude, 51.6° inclination orbit. The multi-use tug may maneuver the waste container to the staging orbit at or near the launch time (e.g., within approximately two days) of the resupply mission.

At block902, a new payload may be launched (e.g., using a launch vehicle such as launch vehicle113ofFIG. 1) into a delivery orbit. The payload may include a new cargo container, and a new launch vehicle upper stage attached thereto. The new payload may be launched once the tug104and container106is in position at the staging orbit, and the new upper stage vehicle (e.g., upper stage vehicle116) may deliver the new arrival container (e.g., cargo container114) to a precision target (e.g., 1.4 km below tug104and container106) where a near field rendezvous operation can commence immediately after on-orbit checkouts complete. The staging orbit may be a two-day phase repeating staging orbit that may be used to provide launch opportunities every other day that will not require significant amounts of time or propellant. In the case of a short (e.g., 2 day) launch delay, multi-use tug104may have propellant reserves to correct for the drift in the ISS-relative planar alignment. If longer delays are expected, an alternate long-term repositioning operation may be performed in which multi-use tug104returns to an altitude slightly above the space-based platform (e.g., the ISS) to counteract any additional planar drift. At an appropriate time before the next launch attempt, multi-use tug104and the waste container106return to the 2-day phase-repeating staging orbit.

At block904, the multi-use tug and waste container may be maneuvered by tug104from the staging orbit to the delivery orbit to rendezvous with the new cargo container and upper stage vehicle. During launch operations for resupply launches, cargo container114will not have access to power from the multi-use tug until rendezvous therewith. The PCC of the cargo container114may include a battery that provides power to the new cargo container from launch until rendezvous with multi-use tug104. Multi-use tug104may provide power to the new cargo container once berthed thereto. Propellant for multi-use tug104may be managed to ensure sufficient reserves to accommodate repositioning for several launch delays.

At block906, the new cargo container and the waste container can be swapped by the multi-use tug. Swapping the new cargo container and the waste container may include attaching the new upper stage vehicle to the waste container and attaching the new cargo container to the multi-use tug with the grappling arm of the multi-use tug. In this way, the grappling arm of the multi-use tug may be used to swap the launch vehicle upper stage from the new cargo container to the waste cargo container. Further details of cargo container swapping operations and described hereinafter in connection with, for example,FIGS. 10 and 13.

At block908, refueling operations may optionally be performed for the multi-use tug (e.g., by transferring propellant or other materials from a mission support module of the new cargo container to the multi-use tug).

At block910, the new launch vehicle upper stage and its attached waste cargo container released from multi-use tug104may be de-orbited (e.g., by performing a de-orbit burn with the new launch vehicle upper stage while the waste cargo container is attached to the new launch vehicle upper stage).

At block912, the multi-use tug may be maneuvered (e.g., using its own propulsion systems) to the platform orbit at which the space-based platform such as the ISS is orbiting.

At block914, tug coupling and unloading operations may be performed at the space-based platform. For example, the new cargo container and the attached multi-use tug may be berthed or docked to the space-based platform such that the new cargo in the new cargo container may be accessed and loaded onto and/or into the space-based platform. For example, while the multi-use tug is attached to a first end of the new cargo container, an opposing second end of the new cargo container may be berthed to the space station and opened so that the new cargo therein can be unloaded by the space station astronauts.

At block916, waste loading and decoupling operations may be performed at the space-based platform. For example, while the multi-use tug is attached to the first end of the new cargo container and the opposing second end of the new cargo container is attached to the space station and open, waste cargo can be loaded into the cargo container by the space station astronauts, the new cargo container can be closed, and the new cargo container can be detached from the space station while the multi-use tug is attached to the new cargo container at the first end. The operations of blocks914and916may be controlled automatically and/or by human operators at the space-based platform and/or at a ground station mission control center for the space-based platform. In various embodiments, operations of the multi-use tug other than berthing and loading operations may be controlled by the same or a different ground station control center.

At block918, the multi-use tug may maneuver the multi-use tug and its attached new waste cargo container to a loiter orbit (e.g., an orbit that is higher than the platform orbit).

At block920, the multi-use tug may maintain the loiter orbit with the new waste cargo container until the time of a further subsequent resupply mission.

Illustrative operations that may be performed for swapping a cargo container and a waste container with a multi-use tug, as described above in connection with block906ofFIG. 9, are shown inFIG. 10, according to an embodiment.

At block1000, the new launch vehicle upper stage and cargo container may be captured with a tug grappling arm (see, e.g., tug grappling arm200ofFIGS. 2 and 5). The new launch vehicle upper stage and cargo container may be captured with the tug grappling arm while the waste container is attached, at a first attachment location on the tug.

At block1002, the new cargo container with the attached new upper stage vehicle may be attached to the multi-use tug at a second attachment location (e.g., using berthing features and/or an end effector of the tug and corresponding features on the new cargo container).

At block1004, the waste container may be repositioned to a new orientation at the first attachment location on the multi-use tug using the tug grappling arm. In the new orientation, the waste cargo container may be attached on a sidewall thereof to the first attachment location on the tug in an orientation that is substantially parallel to the orientation of the new cargo container.

At block1006, the new launch vehicle upper stage may be detached from the new cargo container (e.g., by disengaging attachment features506ofFIG. 5) and removed from the new cargo container using the tug grappling arm.

At block1008, the new launch vehicle upper stage may be moved, with the grappling arm, to the waste cargo container and attached to the waste cargo container (e.g., using attachment features508ofFIG. 5).

At block1010, the waste container with the attached new upper stage vehicle may be detached from the multi-use tug.

At block1012, the new cargo container may be repositioned, using the tug grappling arm, to a cargo delivery orientation on the multi-use tug.

FIG. 11is a diagram showing the configuration of various components of a multi-use resupply system at various stages of a resupply mission as described above in connection withFIGS. 9 and 10in an implementation for supplying and resupplying the international space station (as an example). As shown inFIG. 11, launch operations1100may be performed with a launch vehicle113leading to ascent1102of an integrated stack that includes cargo container114and upper stage vehicle116.

For the recurring mission, multi-use tug104may be pre-positioned in the 2-day phase-repeating staging orbit 1.4 km above the delivery orbit of cargo container114and upper stage vehicle116. With the use of, for example, GPS navigation, upper stage vehicle116may deliver cargo container114to a designated target such that multi-use tug104can commence container rendezvous and proximity operations immediately after orbit insertion check-outs and minimal phasing are complete.

Following ascent, swap operations1104may be performed to swap waste container106with new cargo container114(e.g., as described above in connection with the operations ofFIG. 10).

Following the swap, disposal operations1112may be performed for upper stage vehicle116and waste container106(e.g., by performing a de-orbit burn with upper stage vehicle116while waste container106is attached thereto). Before, during, or after disposal operations1112, rendezvous operations1106to position cargo container114for berthing with platform112may be performed while multi-use tug is fully deployed and attached to cargo container114. Phasing and maneuvering of tug104and container114may be performed using the propulsion systems of tug104.

ISS operations1108(e.g., docking and/or berthing operations, loading operations, and unloading operations) may be performed at space-based platform112. Following loading of additional unwanted cargo into cargo container114, cargo container114and tug104may be detached from platform112and tug104may maneuver tug104and container114to the loiter orbit and perform loiter operations1110to maintain the loiter orbit until the time of a subsequent resupply mission.

The recurring mission container rendezvous and proximity operations trajectory design is illustrated inFIG. 12. The exemplary strategy ofFIG. 12uses a single co-elliptic approach with the waste container from above and in front. As indicated by line1220ofFIG. 12, for the resupply mission, multi-use tug104may be pre-positioned in the 2-day phase-repeating staging orbit1204. Staging orbit1204may, for example, be 1.4 km above the delivery orbit1202for the new container and upper stage vehicle. The delivery orbit1202may, for example, be a 254.5 km altitude, 51.6° inclination orbit.

In the example, ofFIG. 12, line1212shows the trajectory of the new launch vehicle to delivery orbit1202during launch opportunities and injection orbits portion1210of the first mission. As shown, the multi-use tug maneuvers the waste container from the staging orbit to the delivery orbit during rendezvous and proximity operations1214. Line1224shows the trajectory of multi-use tug104, waste container106, new upper stage vehicle116, and new cargo container114during swap operations1216at the delivery orbit. Following swap operations824, disposal operation1226for upper stage vehicle116and waste container106are indicated by line1228and line1230indicates various ISS phasing operations1229and ISS rendezvous proximity operations1231for multi-use tug104and attached cargo container114during which multi-use tug104may maneuver container114between, delivery orbit1202, staging orbit1204, a phasing orbit1200, first co-elliptic orbit804, second co-elliptic orbit806, and the platform orbit (e.g., the ISS orbit)808. Phasing operations1229and rendezvous proximity operations1231may be performed to properly align, position, and phase container114for berthing with space-based platform112. Portion1232of the diagram ofFIG. 12shows maneuvering of cargo container114(with waste items therein) by multi-use tug104to loiter orbit810. As shown inFIG. 12, the loiter orbit may be higher than the platform orbit, the platform orbit may be higher than the staging orbit, and the staging orbit may be higher than the delivery orbit.

FIG. 13is a diagram illustrating the configuration of various components of a multi-use resupply system at various stages of swap operations of a waste container and a new cargo container with a multi-use tug. As shown inFIG. 13, at stage1300, once tug104and the disposal container106rendezvous with upper stage vehicle116and the arrival container114after launch, multi-use tug104approaches and station-keeps in proximity with the upper stage vehicle116inside the tug arm berthing box (e.g., using similar proximity operations used for ISS approach, only from a negative Rbar direction).

Supervised autonomy may be used during the free-flyer capture of the upper stage vehicle108by arm200due to the vehicle residual rates, latency and the time criticality of the operation. With the robotic arm200pre-positioned in a “ready for capture” stance, the robotic arm200may automatically align, track, and capture the upper stage vehicle116, once the upper stage vehicle grapple is authorized by the spacecraft management computer, based on pre-established go/no-go criteria. This operation may employ vision tracking technology and techniques. Scripted operations with user-configurable “authority-to-proceed” pause points may be used for all maneuvering and berthing within the known and fixed workspace of the multi-use tug spacecraft.

Robotic arm ground station software may also allow an operator of arm200to command arm motion by interacting with a virtual certified model of environment and creating scripts that can be pre-validated on the ground and uplinked for execution by the flight segment.

Following capture, at stage1302, multi-use tug104may be berthed to new cargo container114at attachment location1320(e.g., using berthing features and procedures, grappling features and procedures, and/or latching features and procedures at attachment location1320).

At stage1304, waste container106may be repositioned, using arm200, to an orientation parallel to the orientation of container114at attachment location1322on an opposing side of tug104from container114(e.g., from an orientation substantially perpendicular to the orientation of container114as shown in stage1302). In the new configuration, waste container106may be attached to attachment location1322(e.g., using berthing features and procedures, grappling features and procedures, and/or latching features and procedures at attachment location).

At stage1306, grappling arm200may be used to move upper stage vehicle116from cargo container114to waste container106to be berthed to the waste container. The disposal container may berthed onto the upper stage vehicle116using a motorized latch mating mechanism (e.g., a latch mating mechanism as used on the Hubble Space Telescope for attachment of the NASA soft capture system). In this way, the grappling arm may be configured to capture the cargo container and an attached launch vehicle upper stage, position the cargo container for coupling to second attachment features on the tug, and move the launch vehicle upper stage from the cargo container to the waste cargo container while the waste cargo container is coupled to first attachment features on the tug and the cargo container is coupled to second attachment features during space-based operations of the multi-use tug.

At stage1308, arm200may release upper stage vehicle116and waste container106. At stage1310, arm200may be used to reposition cargo container114from attachment location1320to a new orientation at attachment location1322such that container114is attached at an end to tug104for delivery to space-based platform112(e.g., by guidance and propulsion systems of tug104maneuvering the cargo container114to the space-based platform112). At stage1312, upper stage vehicle116may perform a controlled reentry with the disposal container106.

Examples of systems that may be used for the robotic exchange operations are shown inFIGS. 14-17.FIG. 14shows an exemplary end effector1400that may be used by multi-use tug for capturing, attaching, and/or releasing a container or upper stage vehicle.FIG. 15shows a berthing alignment system1500that includes visual systems1502for guidance during berthing operations. Exemplary motorized latches1600that may be used for berthing upper stage vehicle116to waste container106are shown inFIG. 16.FIG. 17shows grapple features1700and1702that may be captured and used to align and secure a cargo container and/or upper stage vehicle to one or more locations on multi-use tug104. As shown, grappling features1702may include mechanical fixtures1706and electrical fixtures1704shown in an enlarged inset inFIG. 17.

A reference to an element in the singular is not intended to mean one and only one unless specifically so stated, but rather one or more. For example, a clock signal may refer to one or more clock signals, a control signal may refer to one or more control signals, an input signal may refer to one or more input signals, an output signal may refer to one or more output signals, and a signal may refer to differential voltage signals.

Unless specifically stated otherwise, the term some refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the invention.

The word exemplary is used herein to mean serving as an example or illustration. Any aspect or design described herein as exemplary is not necessarily to be construed as preferred or advantageous over other aspects or designs. In one aspect, various alternative configurations and operations described herein may be considered to be at least equivalent.

In one or more aspects, the terms “substantially” and “approximately” may provide an industry-accepted tolerance for their corresponding terms and/or relativity between items. Such an industry-accepted tolerance may range from less than one percent to percent.

Various items may be arranged differently (e.g., arranged in a different order, or partitioned in a different way) all without departing from the scope of the subject technology. In one aspect of the disclosure, the elements recited in the accompanying claims may be performed by one or more modules or sub-modules.

It is understood that the specific order or hierarchy of steps, operations or processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps, operations or processes may be rearranged. Some of the steps, operations or processes may be performed simultaneously. Some or all of the steps, operations, or processes may be performed automatically, without the intervention of a user. The accompanying method claims, if any, present elements of the various steps, operations or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using a phrase means for or, in the case of a method claim, the element is recited using the phrase step for. Furthermore, to the extent that the term include, have, or the like is used, such term is intended to be inclusive in a manner similar to the term comprise as comprise is interpreted when employed as a transitional word in a claim.

The claims are not intended to be limited to the aspects described herein, but is to be accorded the full scope consistent with the language claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of 35 U.S.C. §101, 102, or 103, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.