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Systems, methods, and apparatus of a space communication file transfer system

This application claims the benefit of U.S. Provisional Application Ser. No. 60/891,846, filed Feb. 27, 2007 under 35 U.S.C. 119(e).

The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore.

This invention relates generally to communications systems, and more particularly to space communication systems. BACKGROUND

Space missions transfer blocks of data to spacecraft. The data transfer blocks are called “loads.” For example, a mission may load a new version of onboard software, or a new version of a table to be used by onboard software. Space missions transfer large data blocks from spacecraft. Data block transfers from the spacecraft are called “dumps.” For example, a mission may dump images captured by an onboard detector.

Loads and dumps use fundamental communication capabilities provided by a space link. Most missions use the Consultative Committee for Space Data Systems (CCSDS) space link protocols, but not all use the CCSDS. Some space links are based on Internet protocols, and there is some support for migrating in that direction. To be widely reusable, a solution must be flexible with regard to the space link.

Space links are typically intermittent. For example, the link may be present for 15 minutes out of every 90 minutes of an orbit around the earth, with no communication during the other 75 minutes of the 90 minutes. Any practical solution must provide a way to suspend communication between contacts.

Loads and dumps interface with the on-board data storage system. Some missions have onboard file systems, while others do not—in which large data blocks are stored, but not in files. To be widely reusable, a solution must be flexible with regard to the data storage system.

Generally, each mission uses its own unique mechanisms to accomplish loads and dumps. The load mechanism is usually different than the dump mechanism. Reliable dumps typically require manual inputs in which no automatic feedback loop ensures retransmission of data.

One problem with conventional systems is that customized software development is required. Another problem with conventional systems is that manual inputs are not compatible with lights-out operations.

For at least the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a systems, methods and apparatus that can accomplish both loads and dumps, that further is suitable for both flight and ground environments, and is reusable from mission to mission.

The above-mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and studying the following specification.

In one aspect, a method to transfer outgoing-data in a space flight system includes receiving a user request into memory at a library that is compliant with the consultative committee for space data systems file delivery protocol (CFDP). The method also includes routing the user request withto the CFDP-compliant library apparatus by a shell. The method also includes starting a state machine in the memory of the CFDP-compliant library apparatus that prompts a core protocol to transfer a specified file to a specified destination. The method also includes initiating transfer of data blocks from the memory of the CFDP-compliant library. In some embodiments, the user request is one of two service classes, a first service class of which the CFDP-compliant library of which the CFDP-compliant library does not guarantee delivery of data blocks and a second service class of which the CFDP-compliant library guarantees delivery of the data blocks.

In another aspect, a file-transfer routine library includes one or more state machine(s) in a memory. Each of the one or more state machine(s) is operable to instruct a core protocol to transfer a specified file to a specified destination. Each of the one or more state machine(s) is operable to store a status of data at a given time. Each of the one or more state machine(s) is operable to change the status and/or cause an action or output to take place for any given change and one or more state table(s) in the memory. Each state table corresponds to one and not more than one of the one or more state machine(s). Each state table specifies one or more action(s) in response to specific events for each of a plurality of possible states, each state table implementing a core CFDP protocol.

In yet another aspect, a space communication system including a first entity having memory. The first entity and a second entity include memory. Each entity is operable to communicate in a CFDP communication protocol. Each entity includes a shell in the first memory that is operable to manage concurrent file transfers into and out of memory with one or more other entitie(s) in the CFDP protocol.

Apparatus, systems, and methods of varying scope are described herein. In addition to the aspects and advantages described in this summary, further aspects and advantages will become apparent by reference to the drawings and by reading the detailed description that follows.