• MMU

““It may have been one small step for Neil, but it’s a It may have been one small step for Neil, but it’s a heck of a big leap for me!”heck of a big leap for me!”Astronaut Bruce McCandlessAstronaut Bruce McCandless

Manned Maneuvering Unit (MMU)

Space Shuttle MMU

Skylab Heritage

Installation & Checkout

3 Shuttle Missions

Reference Information

Astronaut Training

SelectImage

ISS Rescue

Skylab - NASA’s First Space StationSkylab Heritage

M509 Astronaut Maneuvering Equipment

Artist’s drawing of the MMU and its Flight Support Station (FSS) including donning configuration and egress. FSS is mounted to the orbiter supporting the MMU backpack during launch and landing.

Weightless Environment Training Facility (WETF)

Space Operations Simulator (SOS)Space Operations Simulator (SOS)

Installation in Challenger for STS 41B MMU Test Flight

FSS Mounting Bolt (5 Places)

FSS/Challenger Mounting Bolt

MMU/FSS in Challenger

Astronaut Bruce McCandless Supports MMU Checkout

STS 41B MMU Test Flight

STS 41B MMU Test Flight

STS 41B MMU Test Flight

STS 41B MMU Test Flight -Challenger from MMU

STS 41 C - Solar Maximum Mission Observatory RepairSTS 41 C - Solar Maximum Mission Observatory Repair

STS 51A – Westar VI Satellite RetrievalSTS 51A – Westar VI Satellite Retrieval

STS 51A – Westar VI Satellite RetrievalSTS 51A – Westar VI Satellite Retrieval

Simplified Aid for Extravehicular Activity Rescue (SAFER)

Hand Controller

Deployed

Stowed

MMU - Reference Information Text:Text:• “ “Manned Maneuvering Unit,” Martin Marietta, March 1985 - public relations publication Manned Maneuvering Unit,” Martin Marietta, March 1985 - public relations publication briefly describing the MMU including characteristics and flight history.briefly describing the MMU including characteristics and flight history.• “ “Manned Maneuvering Unit Post Mission Summary Report for STS 41B,” Martin Marietta, Manned Maneuvering Unit Post Mission Summary Report for STS 41B,” Martin Marietta, April 1984 - technical report summarizing the MMU STS 41B mission. April 1984 - technical report summarizing the MMU STS 41B mission. • “ “Manned Maneuvering Unit Post Mission Summary Report STS 51A,” Martin Marietta, Manned Maneuvering Unit Post Mission Summary Report STS 51A,” Martin Marietta, February 1985 - technical report summarizing the MMU STS 51A mission.February 1985 - technical report summarizing the MMU STS 51A mission.• “ “Manned Maneuvering Unit Users Guide,” MMU-SE-17-46, Martin Marietta, June 1985 - Manned Maneuvering Unit Users Guide,” MMU-SE-17-46, Martin Marietta, June 1985 - provides potential MMU users guidance information.provides potential MMU users guidance information.• “ “Manned Maneuvering Unit Operational Data Book,” MMU-SE-17-73, Martin Marietta, Manned Maneuvering Unit Operational Data Book,” MMU-SE-17-73, Martin Marietta, July 1985 - provides detailed MMU information.July 1985 - provides detailed MMU information.• “ “Space: the First 50 Years,” Patrick Moore, Sterling Publishing, New York, NY, 2007 -Space: the First 50 Years,” Patrick Moore, Sterling Publishing, New York, NY, 2007 -illustrated history of space.illustrated history of space.

Text and Images:Text and Images: http://grin.hq.nasa.gov/index.html http://images.jsc.nasa.gov/ http://quest.arc.nasa.gov/space/teachers/suited/6work.html http://www.astronautix.com/craft/skylab.htm

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MMU Space Shuttle Missions-STS 41B - Challenger, February, 1984 Bruce McCandless becomes the first human to fly untethered in space during the MMU test flight.-STS 41C - Challenger, April, 1984George Nelson successfully maneuvers into position to dock with the Solar Maximum Mission Observatory satellite but the docking device fails to lock. Later, the crew retrieved, repaired, and returned it to orbit. -STS 51A - Discovery, November, 1984Joseph Allen and Dale Gardner retrieve Palapa B-2 and Westar VI satellites, respectively. The satellites that failed to achieve proper orbits in February, 1984 were successfully secured in the orbiter and returned to Earth.

MMU Characteristics -Size: 49 in high x 33 in wide x 48 in deep-Weight: About 782 lbs including astronaut, 338 lbs MMU backpack and 258 lbs Extravehicular Mobility Unit (EMU) spacesuit-Propulsion: Total of 24 thrusters with 1.7 lbs thrust each and 2 tanks pressurized with 3000 psi nitrogen-Maneuverability: astronaut right hand controller - pitch, yaw and roll; left hand controller - x, y & z translation-Operational Speed: 1/3-1 mph (top speed approximately 40 mph)

SkylabSkylab-NASA’s first space station was launched in May 1973. Skylab with a total -NASA’s first space station was launched in May 1973. Skylab with a total length of 118.5 ft and a weight of 168,201 lbs consisted of (from bottom length of 118.5 ft and a weight of 168,201 lbs consisted of (from bottom to top): the Orbital Workshop (OWS), Instrument Unit, Airlock Module, to top): the Orbital Workshop (OWS), Instrument Unit, Airlock Module, Apollo Telescope Mount and Multiple Docking Adapter. Apollo Telescope Mount and Multiple Docking Adapter. -In-orbit, instrumentation revealed that a shield, designed to protect -In-orbit, instrumentation revealed that a shield, designed to protect against meteoroids and control temperatures, along with one of two against meteoroids and control temperatures, along with one of two solar arrays, was missing; and the second array had been damaged. solar arrays, was missing; and the second array had been damaged. -The first of three manned missions to the station was delayed in order to -The first of three manned missions to the station was delayed in order to determine how to repair the spacecraft. The first three-man crew traveled determine how to repair the spacecraft. The first three-man crew traveled to the station; released the jammed solar array during a spacewalk; to the station; released the jammed solar array during a spacewalk; deployed a parasol through a OWS scientific airlock bringing the inside deployed a parasol through a OWS scientific airlock bringing the inside temperature down. temperature down. -Between May 1973 and February 1974, three crews spent 28, 59 and 84 -Between May 1973 and February 1974, three crews spent 28, 59 and 84 days aboard Skylab performing scientific experiments. days aboard Skylab performing scientific experiments.

M509 Astronaut Maneuvering EquipmentM509 Astronaut Maneuvering Equipment - MMU Predecessor - MMU Predecessor-Alan L. Bean, third mission commander, is shown flying the M509 in the -Alan L. Bean, third mission commander, is shown flying the M509 in the forward dome area of the OWS. forward dome area of the OWS. The dome area, where the experiment The dome area, where the experiment was conducted, is about 22 ft in diameter and 19 ft from top to bottomwas conducted, is about 22 ft in diameter and 19 ft from top to bottom .. -Bean is strapped into the back-mounted, hand-controlled Automatically -Bean is strapped into the back-mounted, hand-controlled Automatically Stabilized Maneuvering Unit (ASMU). This ASMU experiment is being Stabilized Maneuvering Unit (ASMU). This ASMU experiment is being done in shirt sleeves. Experiments were also conducted in a spacesuit. done in shirt sleeves. Experiments were also conducted in a spacesuit.

-Astronaut Bruce McCandless during an underwater test of the MMU Flight Support Station (FSS) in the Weightless Environment Training Facility (WETF) at Building 29, Johnson Space Center. -The WETF is a large 30 ft x 100 ft x 25 ft deep neutral buoyancy water tank utilized for procedures development and task training for manned space missions simulating the micro-gravity environment.

-McCandless is training to return to the FSS where he will doff the MMU and eventually return to the orbiter crew compartment. The hatch to the crew compartment airlock is located behind the right diver’s leg. Yellow handholds and the FSS foot restraint aid the astronaut during the extravehicular activity (EVA).

-SOS at the Martin Marietta plant in Denver, CO is used to familiarize astronauts with the flying characteristics of the MMU and procedures development.

-The pilot controls are identical to those of the MMU and provides realistic space training for astronauts.

-The pilot is positioned in a platform at the head of a carriage.

-Computer controlled motors drive the platform in translation along three sets of rails and in rotation about three gimbal axes.

- The two MMUs are installed in Challenger in the Orbiter The two MMUs are installed in Challenger in the Orbiter Processing Facility (OPF), Kennedy Space Center, FL.Processing Facility (OPF), Kennedy Space Center, FL.

- Challenger’s thermal protection blankets are removed prior to Challenger’s thermal protection blankets are removed prior to the MMU installation. the MMU installation.

- The FSS is positioned by an overhead crane and then mounted The FSS is positioned by an overhead crane and then mounted to Challenger with five bolts. to Challenger with five bolts.

- The MMU is lowered into Challenger by an overhead crane, The MMU is lowered into Challenger by an overhead crane, aligned and bolted to the FSS using 4 launch/landing bolts. Two aligned and bolted to the FSS using 4 launch/landing bolts. Two latches are used to capture/secure/release the MMU during orbital latches are used to capture/secure/release the MMU during orbital operations.operations.

- Five bolts, fitting through FSS slider blocks, attach the FSS to Five bolts, fitting through FSS slider blocks, attach the FSS to the Challenger structure. The attachment allows the FSS to slide the Challenger structure. The attachment allows the FSS to slide compensating for thermal and structural distortions.compensating for thermal and structural distortions.

- The stainless steel FSS mounting bolt tapers from a diameter of The stainless steel FSS mounting bolt tapers from a diameter of 1.0 inch to 0.72 inch and has an overall length of 9.94 inches. The 1.0 inch to 0.72 inch and has an overall length of 9.94 inches. The bolt weighs 1.8 lbs. bolt weighs 1.8 lbs.

- After the MMU is installed, ground protective covers are added After the MMU is installed, ground protective covers are added to the twenty-four propulsion thrusters. The covers are identified to the twenty-four propulsion thrusters. The covers are identified by remove-before-flight ribbons. by remove-before-flight ribbons.

- Two MMU arms support the rotational and translational hand Two MMU arms support the rotational and translational hand controllers. The arms can be pivoted and extended during flight controllers. The arms can be pivoted and extended during flight or locked in the stowed position.or locked in the stowed position.

- The MMU lap belt retains the astronaut if one of the two latches The MMU lap belt retains the astronaut if one of the two latches fail. The latches are located above the lap belt.fail. The latches are located above the lap belt.

- Bruce McCandless, shown in the blue flight suit, supports the Bruce McCandless, shown in the blue flight suit, supports the final MMU tests and checkout in the Challenger cargo bay. Tests final MMU tests and checkout in the Challenger cargo bay. Tests and checkout include verification of the operation of the two hand and checkout include verification of the operation of the two hand controllers and the twenty-four propulsion thrusters. controllers and the twenty-four propulsion thrusters.

- The FSS foot restraint platform is installed after all testing and The FSS foot restraint platform is installed after all testing and checkout is completed. The adjustable foot restraint provides the checkout is completed. The adjustable foot restraint provides the astronaut with stability and leverage to move and work in the astronaut with stability and leverage to move and work in the FSS.FSS.

- After the OPF ground operations are completed, Challenger was After the OPF ground operations are completed, Challenger was moved to the Vehicle Assembly Building (VAB) where it was moved to the Vehicle Assembly Building (VAB) where it was stacked on the Crawler Transporter and moved to the launch pad. stacked on the Crawler Transporter and moved to the launch pad.

- The two MMU batteries are located in the center above the The two MMU batteries are located in the center above the latches and behind a protective cover. After Challenger was latches and behind a protective cover. After Challenger was moved to the launch pad, the batteries were installed as close to moved to the launch pad, the batteries were installed as close to launch as possible, before the cargo doors were closed.launch as possible, before the cargo doors were closed.

-A fixed camera in the Space Shuttle Challenger recorded this A fixed camera in the Space Shuttle Challenger recorded this view in space during STS 41B in February, 1984. view in space during STS 41B in February, 1984.

-Astronaut Robert Stewart is working on Serial Number 3 MMU Astronaut Robert Stewart is working on Serial Number 3 MMU using the Flight Support Station foot restraint.using the Flight Support Station foot restraint.

-Astronaut Bruce McCandless is flying Serial Number 2 MMU out Astronaut Bruce McCandless is flying Serial Number 2 MMU out of the photograph.of the photograph.

-The Shuttle pallet satellite is configured mid cargo bay as SPAS-The Shuttle pallet satellite is configured mid cargo bay as SPAS-01A. 01A.

-A fixed camera in the Space Shuttle Challenger recorded this view in A fixed camera in the Space Shuttle Challenger recorded this view in space during STS 41B in February, 1984. Challenger was flying with its space during STS 41B in February, 1984. Challenger was flying with its aft end aimed toward the Earth. aft end aimed toward the Earth.

-Astronaut Bruce McCandless is shown flying Serial Number 2 MMU Astronaut Bruce McCandless is shown flying Serial Number 2 MMU during a test involving the trunnion pin attachment device (TPAD) and during a test involving the trunnion pin attachment device (TPAD) and the shuttle pallet satellite (SPAS-01A), partially visible at the bottom of the shuttle pallet satellite (SPAS-01A), partially visible at the bottom of the frame. The TPAD is mounted to the MMU arms. the frame. The TPAD is mounted to the MMU arms.

-Bruce McCandless approaches the maximum distance of about 300 -Bruce McCandless approaches the maximum distance of about 300 feet from Challenger during STS 41B. feet from Challenger during STS 41B.

-The astronaut is performing this Extra Vehicular Activity without -The astronaut is performing this Extra Vehicular Activity without being tethered to the shuttle. being tethered to the shuttle.

-He is framed by the blackness of space and below him a cloudy -He is framed by the blackness of space and below him a cloudy earth.earth.

-A fixed camera on the MMU is pointed toward Challenger.-A fixed camera on the MMU is pointed toward Challenger.

-A fixed camera on the MMU recorded this scene of the Space A fixed camera on the MMU recorded this scene of the Space Shuttle Challenger during STS 41B in February 1984. Shuttle Challenger during STS 41B in February 1984.

-The two Flight Support Stations (FSS) for the two MMU The two Flight Support Stations (FSS) for the two MMU backpacks are located in the forward end of the cargo bay. backpacks are located in the forward end of the cargo bay.

-Astronaut Robert Stewart is standing beneath the remote Astronaut Robert Stewart is standing beneath the remote manipulator system (RMS) arm. manipulator system (RMS) arm.

-The Shuttle pallet satellite is configured mid cargo bay as SPAS-The Shuttle pallet satellite is configured mid cargo bay as SPAS-01A. 01A.

-Also visible in the cargo bay are the sunshields for the Palapa B-Also visible in the cargo bay are the sunshields for the Palapa B-2 and Westar VI satellites, Ku-band antenna, and a number of 2 and Westar VI satellites, Ku-band antenna, and a number of Getaway Special (GAS) canisters including an IMAX camera.Getaway Special (GAS) canisters including an IMAX camera.

STS 41C Astronaut George Nelson maneuvers between solar panels and STS 41C Astronaut George Nelson maneuvers between solar panels and prepares to dock to the 5000 lb Solar Maximum Mission Observatory satellite prepares to dock to the 5000 lb Solar Maximum Mission Observatory satellite and use the MMU thrusters to stop its spin. A protruding insulation fastener and use the MMU thrusters to stop its spin. A protruding insulation fastener near the satellite’s capture pin prevented Nelson from completing docking.near the satellite’s capture pin prevented Nelson from completing docking.

-STS 51A Astronaut Dale Gardner approaches Westar VI and prepares to -STS 51A Astronaut Dale Gardner approaches Westar VI and prepares to capture the 1200 lb satellite using a “stinger” docking device.capture the 1200 lb satellite using a “stinger” docking device.

-Astronaut Joe Allen retrieved Palapa B-2 two days earlier.-Astronaut Joe Allen retrieved Palapa B-2 two days earlier.

-The Westar VI and Palapa B-2 satellites failed to achieve proper orbits -The Westar VI and Palapa B-2 satellites failed to achieve proper orbits during the STS 41B mission in February, 1984. during the STS 41B mission in February, 1984.

-The orbiter remote manipulator arm end effector, controlled by -The orbiter remote manipulator arm end effector, controlled by astronaut Anna Fisher, is to the right of Gardner.astronaut Anna Fisher, is to the right of Gardner.

-STS 51A Astronaut Dale Gardner approaches Westar VI preparing to soft -STS 51A Astronaut Dale Gardner approaches Westar VI preparing to soft dock by inserting the “stinger” into the satellite’s motor nozzle. Gardner dock by inserting the “stinger” into the satellite’s motor nozzle. Gardner released three spring-loaded toggles at the end of the “stinger” to hold it in released three spring-loaded toggles at the end of the “stinger” to hold it in place and manually retracted the “stinger” to hard dock the satellite. He then place and manually retracted the “stinger” to hard dock the satellite. He then stopped its spin with the MMU thrusters. stopped its spin with the MMU thrusters.

-The orbiter remote manipulator arm, controlled by astronaut Anna Fisher, -The orbiter remote manipulator arm, controlled by astronaut Anna Fisher, grasped the “stinger” and located the satellite in the orbiter payload bay grasped the “stinger” and located the satellite in the orbiter payload bay where it was secured for return to Earth. where it was secured for return to Earth.

-After Palapa B-2 and Westar VI were returned to Earth, they were -After Palapa B-2 and Westar VI were returned to Earth, they were refurbished, relaunched and successfully operated as communications refurbished, relaunched and successfully operated as communications satellites.satellites.

Hand Controller

Deployed

Stowed

-SAFER is a self-rescue device used on the International Space Station -SAFER is a self-rescue device used on the International Space Station (ISS). If an astronaut becomes separated from the station and a space (ISS). If an astronaut becomes separated from the station and a space shuttle is not available to retrieve the astronaut, the crew member would shuttle is not available to retrieve the astronaut, the crew member would use SAFER to return to the station. use SAFER to return to the station.

-SAFER fits over the Extravehicular Mobility Unit’s (spacesuit) primary -SAFER fits over the Extravehicular Mobility Unit’s (spacesuit) primary life support system. It is always worn when an astronaut goes for a life support system. It is always worn when an astronaut goes for a spacewalk on the ISS. spacewalk on the ISS.

-Astronaut Mark Lee is shown test flying SAFER in September 1994.-Astronaut Mark Lee is shown test flying SAFER in September 1994.