A disclosed fan section of a gas turbine engine includes a fan rotor having a plurality of fan blades and a duct defining a passageway aft of the fan rotor. A fan exit guide vane is disposed within the duct downstream of the fan blades. The fan exit guide vane includes a plurality of exit guide vanes positioned downstream of the fan rotor with at least two of the plurality of exit guide vanes including different aft geometries for guiding airflow through the passage to reduce pressure distortions at the fan blades.

Seals for gimbaling and/or fixed rocket engine nozzles, and associated systems and methods are disclosed. A representative rocket propulsion system includes a rocket engine having an exhaust nozzle, a seal plate carried by the exhaust nozzle, and a seal engaged with the seal plate. The seal includes at least one support, multiple pivotable first flaps, carried by the at least one support and positioned to contact the seal plate, and multiple pivotable second flaps, with an individual second flap positioned to shield a corresponding individual first flap. At least one forcing element is operatively coupled to at least one of the individual first flap or the individual second flap, to apply a pivoting force to the at least one of the individual first flap or the individual second flap.

Seals for gimbaling and/or fixed rocket engine nozzles, and associated systems and methods are disclosed. A representative rocket propulsion system includes a rocket engine having an exhaust nozzle, a seal plate carried by the exhaust nozzle, and a seal engaged with the seal plate. The seal includes at least one support, multiple pivotable first flaps, carried by the at least one support and positioned to contact the seal plate, and multiple pivotable second flaps, with an individual second flap positioned to shield a corresponding individual first flap. At least one forcing element is operatively coupled to at least one of the individual first flap or the individual second flap, to apply a pivoting force to the at least one of the individual first flap or the individual second flap.

An atmospheric re-entry vehicle includes a main body defining a forward end of the vehicle, a base defining an aft end of the vehicle, and a heat shield at the base. The heat shield includes a heat shield outer surface. The main body and the heat shield are configured such that a centerline of the heat shield is offset relative to a centerline of the main body. At least a portion of the heat shield outer surface is at least substantially axisymmetric relative to the centerline of the heat shield.