A method for deploying a control surface from an exterior surface of a spinning projectile during flight is provided. The method including: at least partially retracting the control surface into an interior of the projectile for a portion of a full revolution of the spinning projectile and extending the control surface from the interior of the projectile for another portion of the full revolution of the spinning projectile; and maintaining the control surface in a same plane during the full revolution of the spinning projectile.

A method for deploying a control surface from an exterior surface of a spinning projectile during flight is provided. The method including: at least partially retracting the control surface into an interior of the projectile for a portion of a full revolution of the spinning projectile and extending the control surface from the interior of the projectile for another portion of the full revolution of the spinning projectile; and maintaining the control surface in a same plane during the full revolution of the spinning projectile.

According to a first aspect of the invention, there is provided an object for moving through a fluid, the object comprising: an outer housing, arranged to be exposed to a hydrostatic pressure exerted by the fluid; a strain gauge, arranged to obtain an indication of the hydrostatic pressure, wherein a first part of the strain gauge is arranged to be in contact with the outer housing, such that the strain gauge is arranged to obtain an indication of the hydrostatic pressure by obtaining an indication of the strain on the housing.

Provided in some embodiments is a method of deploying a payload in a subterranean well. The method including advancing a torpedo in a first portion of a wellbore of a subterranean well (the torpedo including a body, a fiber-optic (FO) umbilical that is physically coupled to a surface component, and adapted to unspool from the torpedo as the torpedo advances in the wellbore, and an engine adapted to generate thrust to propel the torpedo), and activating the engine to generate thrust to propel advancement of the torpedo within a second portion of the wellbore such that the FO umbilical is disposed in the second portion of the wellbore.

A rocket motor ignitor assembly that may be used in a shoulder-fired rocket system. The rocket motor ignitor assembly may include a delay ignitor operable to ignite a rocket motor propellant, a stab firing pin operable to activate the delay ignitor by contacting the delay ignitor, and a biasing element coupled with the stab firing pin. The stab firing pin may have a length to diameter ratio greater than two, as well as relief grooves allowing air to vent past the stab firing pin as it travels toward the delay ignitor to activate it. The rocket motor ignitor assembly may also include a guide stop to limit penetration of the stab firing pin into the delay ignitor.

Projectile launch apparatus (20) for use in a fluid environment. The apparatus (20) comprises a launch tube (21) having a supercavitating projectile (24) with cavitator (29) received within the launch tube (21). A means for generating expulsion gas (not visible) is arranged to provide expulsion gas to propel the projectile (24) from the launch tube (21), with means for bleeding expulsion gas (31, 32) being provided to bleed a portion of expulsion gas around the projectile (24). This allows expulsion gases to contribute to the formation of the gas cavity around the supercavitating projectile (24) as the projectile (24) is launched from the launch tube (21). Particularly suited to the deployment of supercavitating projectiles underwater, such as in underwater mine disposal applications.

Projectile launch apparatus (20) for use in a fluid environment. The apparatus (20) comprises a launch tube (21) having a supercavitating projectile (24) with cavitator (29) received within the launch tube (21). A means for generating expulsion gas (not visible) is arranged to provide expulsion gas to propel the projectile (24) from the launch tube (21), with means for bleeding expulsion gas (31, 32) being provided to bleed a portion of expulsion gas around the projectile (24). This allows expulsion gases to contribute to the formation of the gas cavity around the supercavitating projectile (24) as the projectile (24) is launched from the launch tube (21). Particularly suited to the deployment of supercavitating projectiles underwater, such as in underwater mine disposal applications.

Provided in some embodiments is a method of deploying a payload in a subterranean well. The method including advancing a torpedo in a first portion of a wellbore of a subterranean well (the torpedo including a body, a fiber-optic (FO) umbilical that is physically coupled to a surface component, and adapted to unspool from the torpedo as the torpedo advances in the wellbore, and an engine adapted to generate thrust to propel the torpedo), and activating the engine to generate thrust to propel advancement of the torpedo within a second portion of the wellbore such that the FO umbilical is disposed in the second portion of the wellbore.

A method for deploying a control surface from an exterior surface of a spinning projectile during flight is provided. The method including: at least partially retracting the control surface into an interior of the projectile for a portion of a full revolution of the spinning projectile and extending the control surface from the interior of the projectile for another portion of the full revolution of the spinning projectile; and maintaining the control surface in a same plane during the full revolution of the spinning projectile.

A method for deploying a control surface from an exterior surface of a spinning projectile during flight is provided. The method including: at least partially retracting the control surface into an interior of the projectile for a portion of a full revolution of the spinning projectile and extending the control surface from the interior of the projectile for another portion of the full revolution of the spinning projectile; and maintaining the control surface in a same plane during the full revolution of the spinning projectile.