Abstract: A disclosed method may include (1) receiving, at a node within a network, an MPLS echo request from an additional node adjacent to the node, (2) determining that a FEC query is included in a FEC stack of the MPLS echo request and then, in response to determining that the FEC query is included in the FEC stack of the MPLS echo request, (3) determining at least one FEC that corresponds to a label included in a label stack of the MPLS echo request, and then (4) notifying the additional node of the FEC that corresponds to the label included in the label stack by sending, to the additional node, an MPLS echo reply that identifies the FEC that corresponds to the label. Various other systems, methods, and computer-readable media are also disclosed.

Abstract: A label switch router (LSR) in a label-switched path (LSP) may receive, from an ingress edge LSR, a Multi-Protocol Label Switching (MPLS) echo request, where the LSP includes a tunnel having details that are hidden by a Nil Forward Equivalency Class (FEC). The LSR may determine whether the LSR is an egress node for the tunnel in the LSP based at least in part on one or more labels in the MPLS echo request. The LSR may, in response to determining that the LSR is the egress node for the tunnel in the LSP, send an MPLS echo reply that indicates the LSR as being the egress node for the tunnel in the LSP.

Abstract: A disclosed method may include (1) receiving, at a node within a network, an MPLS echo request from an additional node adjacent to the node, (2) determining that a FEC query is included in a FEC stack of the MPLS echo request and then, in response to determining that the FEC query is included in the FEC stack of the MPLS echo request, (3) determining at least one FEC that corresponds to a label included in a label stack of the MPLS echo request, and then (4) notifying the additional node of the FEC that corresponds to the label included in the label stack by sending, to the additional node, an MPLS echo reply that identifies the FEC that corresponds to the label. Various other systems, methods, and computer-readable media are also disclosed.

Abstract: A static label-switched path (LSP) over which packets belonging to a forwarding equivalency class (FEC) are forwarded may be tested by (a) generating a multi-protocol label switching (MPLS) echo request message including a target FEC stack type-length-value (TLV), the target FEC stack TLV having a Nil FEC sub-TLV; and (b) sending the MPLS echo request message with a label stack corresponding to the FEC for forwarding over the static LSP. A static segment routed traffic engineered (SRTE) path, including at least two segments, over which packets belonging to a forwarding equivalency class (FEC) are forwarded, may be tested by (a) generating a multi-protocol label switching (MPLS) echo request message including, for each of the at least two segments, a target FEC stack type-length-value (TLV), each target FEC stack TLV having a Nil FEC sub-TLV; and (b) sending the MPLS echo request message with a label stack corresponding to the FEC for forwarding over the static SRTE path.

Abstract: A static label-switched path (LSP) over which packets belonging to a forwarding equivalency class (FEC) are forwarded may be tested by (a) generating a multi-protocol label switching (MPLS) echo request message including a target FEC stack type-length-value (TLV), the target FEC stack TLV having a Nil FEC sub-TLV; and (b) sending the MPLS echo request message with a label stack corresponding to the FEC for forwarding over the static LSP. A static segment routed traffic engineered (SRTE) path, including at least two segments, over which packets belonging to a forwarding equivalency class (FEC) are forwarded, may be tested by (a) generating a multi-protocol label switching (MPLS) echo request message including, for each of the at least two segments, a target FEC stack type-length-value (TLV), each target FEC stack TLV having a Nil FEC sub-TLV; and (b) sending the MPLS echo request message with a label stack corresponding to the FEC for forwarding over the static SRTE path.

Abstract: Methods, systems, and computer-readable media are described herein for using a modified Kalman filter to generate attitude error corrections. Attitude measurements are received from primary and secondary attitude sensors of a satellite or other spacecraft. Attitude error correction values for the attitude measurements from the primary attitude sensors are calculated based on the attitude measurements from the secondary attitude sensors using expanded equations derived for a subset of a plurality of block sub-matrices partitioned from the matrices of a Kalman filter, with the remaining of the plurality of block sub-matrices being pre-calculated and programmed into a flight computer of the spacecraft. The propagation of covariance is accomplished via a single step execution of the method irrespective of the secondary attitude sensor measurement period.

Abstract: Methods, systems, and computer-readable media are described herein for using a modified Kalman filter to generate attitude error corrections. Attitude measurements are received from primary and secondary attitude sensors of a satellite or other spacecraft. Attitude error correction values for the attitude measurements from the primary attitude sensors are calculated based on the attitude measurements from the secondary attitude sensors using expanded equations derived for a subset of a plurality of block sub-matrices partitioned from the matrices of a Kalman filter, with the remaining of the plurality of block sub-matrices being pre-calculated and programmed into a flight computer of the spacecraft. The propagation of covariance is accomplished via a single step execution of the method irrespective of the secondary attitude sensor measurement period.

Abstract: A system and method for performing in-orbit alignment calibration using on-board attitude sensors to improve reflector alignment after deployment to improve spacecraft pointing.

Abstract: A star tracker coupled to the spacecraft having a star catalog associated therewith. A sun sensor is coupled to the spacecraft. A control processor is coupled to the star tracker and the sun sensor. The processor obtains star data using a star tracker and an on-board star catalog. The processor generates a coarse attitude of the spacecraft as a function of the star data, and establishes a track on at least one star in the on-board star catalog. The processor calculates a sun tracking rate, and obtains a normal phase attitude as a function of the star data and the coarse attitude. The information is used to slew the spacecraft to a desired attitude.