The electro-mechanical actuator, a new electronics technology, is an electronic system that provides the force needed to move valves that control the flow of propellant to the engine. It is proving to be advantageous for the main propulsion system plarned for a second generation reusable launch vehicle. Hydraulic actuators have been used successfully in rocket propulsion systems. However, they can leak when high pressure is exerted on such a fluid-filled hydraulic system. Also, hydraulic systems require significant maintenance and support equipment. The electro-mechanical actuator is proving to be low maintenance and the system weighs less than a hydraulic system. The electronic controller is a separate unit powering the actuator. Each actuator has its own control box. If a problem is detected, it can be replaced by simply removing one defective unit. The hydraulic systems must sustain significant hydraulic pressures in a rocket engine regardless of demand. The electro-mechanical actuator utilizes power only when needed. A goal of the Second Generation Reusable Launch Vehicle Program is to substantially improve safety and reliability while reducing the high cost of space travel. The electro-mechanical actuator was developed by the Propulsion Projects Office of the Second Generation Reusable Launch Vehicle Program at the Marshall Space Flight Center.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, an actuator is set up on a table for a 3D digital scan. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Dan Clark, with KSC Boeing, operates the camera for a 3D digital scan of the actuator on the table. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Boeing worker Alden Pitard looks at a 3D digital scan of an actuator. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - John Macke (standing, center), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, check results after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - Boeing workers get ready to perform a 3D digital scan of the actuator on the table. At left is John Macke, from Boeing, St. Louis. At right is Dan Clark.. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

KENNEDY SPACE CENTER, FLA. - John Macke (standing, left), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, look at a monitor after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

The development of the electric space actuator represents an unusual case of space technology transfer wherein the product was commercialized before it was used for the intended space purpose. MOOG, which supplies the thrust vector control hydraulic actuators for the Space Shuttle and brake actuators for the Space Orbiter, initiated development of electric actuators for aerospace and industrial use in the early 1980s. NASA used the technology to develop an electric replacement for the Space Shuttle main engine TVC actuator. An electric actuator is used to take passengers on a realistic flight to Jupiter at the US Space and Rocket Center, Huntsville, Alabama.

Ray Sadler adjusts hydraulic actuators with pads to the wing of the X-57 distributed electric aircraft wing at NASA's Armstrong Flight Research Center in California. Tests increased confidence in the wing's durability and calibrated installed strain gauges for inflight load monitoring of the wing.

– Hydraulic actuators are pinned to horizontal tail test fixture for testing a F/A-18E from the Naval Air Systems Command (NAVAIR) in Patuxent River, Maryland. The aircraft is in NASA’s Armstrong Flight Research Center Flight Loads Laboratory in Edwards, California, for the center’s biggest load calibrations tests. This testing is needed before the aircraft can serve as a test vehicle for determining if it can safely manage maneuvers and proposed upgrades.

Assembled test structures called whiffle trees, which are needed to distribute prescribed hydraulic actuator loads, are attached to load pads to test the F/A-18E from the Naval Air Systems Command (NAVAIR) in Patuxent River, Maryland. The aircraft is in NASA’s Armstrong Flight Research Center Flight Loads Laboratory in Edwards, California, for the center’s biggest load calibrations tests. This testing is needed before the aircraft can serve as a test vehicle for determining if it can safely manage maneuvers and proposed upgrades.

CAPE CANAVERAL, Fla. -- Inside the Operations and Checkout Building high bay at NASA’s Kennedy Space Center in Florida, technicians place a hydraulic actuator in the test stand for the Orion crew module. Lockheed Martin Space Systems and NASA engineers are preparing Orion for a series of static load tests that simulate the massive loads the spacecraft would experience during its mission. Orion is the exploration spacecraft designed to carry crews to space beyond low Earth orbit. It will provide emergency abort capability, sustain the crew during the space travel and provide safe re-entry from deep space return velocities. Orion’s first unpiloted test flight, Exploration Flight Test 1, is scheduled to launch in 2014 atop a Delta IV rocket. A second uncrewed flight test is scheduled for 2017 on NASA’s Space Launch System rocket. For more information, visit http://www.nasa.gov/orion. Photo credit: NASA/Gary Thompson

KENNEDY SPACE CENTER, FLA. -- From vantage points on the Fixed Service Structure (left) on Launch Pad 39A, workers and the media look down upon the Mobile Launcher Platform (MLP) waiting for the start of a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. Because of the unusual event, media and workers watch from nearby vantage points on the Fixed Service Structure (left). This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released for launch just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are being released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. Because of the unusual event, media and workers watch from nearby vantage points on the Fixed Service Structure (left). This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are being released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. Because of the unusual event, media and workers watch from nearby vantage points on the Fixed Service Structure (left). This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- A crimson and gold sunrise over the Central Florida coast begins illuminating Launch Pad 39A, where a water sound suppression test is to take place. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter’s three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- Water is released onto the Mobile Launcher Platform (MLP) on Launch Pad 39A at the start of a water sound suppression test. Workers and the media (left) are on hand to witness the rare event. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- Water recedes from the Mobile Launcher Platform (MLP) on Launch Pad 39A after the water sound suppression test. Workers and the media (left) were on hand to witness the rare event. This test was conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are being released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. Because of the unusual event, media and workers watch from nearby vantage points on the Fixed Service Structure (left). This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- Some water remains on the surface of the Mobile Launcher Platform (MLP) on Launch Pad 39A after a water sound suppression test. Workers and the media (left) were on hand to witness the rare event. This test was conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- Water is released onto the Mobile Launcher Platform (MLP) on Launch Pad 39A at the start of a water sound suppression test. Workers and the media (left) are on hand to witness the rare event. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- From vantage points on the Fixed Service Structure (left) on Launch Pad 39A, workers and the media look down upon the Mobile Launcher Platform (MLP) waiting for the start of a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- For the fourth time in Space Shuttle Program history, 350,000 gallons of water are released on a Mobile Launcher Platform (MLP) at Launch Pad 39A during a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.

KENNEDY SPACE CENTER, FLA. -- From vantage points on the Fixed Service Structure (bottom right and left) on Launch Pad 39A, workers and the media look down upon the Mobile Launcher Platform (MLP) at the start of a water sound suppression test. This test is being conducted following the replacement of the six main system valves, which had been in place since the beginning of the Shuttle Program and had reached the end of their service life. Also, the hydraulic portion of the valve actuators has been redesigned and simplified to reduce maintenance costs. The sound suppression water system is installed on the launch pads to protect the orbiter and its payloads from damage by acoustical energy reflected from the MLP during launch. The system includes an elevated water tank with a capacity of 300,000 gallons. The tank is 290 feet high and stands on the northeast side of the Pad. The water is released just before the ignition of the orbiter's three main engines and twin solid rocket boosters, and flows through parallel 7-foot-diameter pipes to the Pad area.