Manned five crew. Deployed Westar 6, Palapa B2; tested Manned Maneuvering Unit (MMU). Payloads: PALAPA-B2 (Indonesian communications satellite) with Payload Assist Module (PAM)-D and WESTAR (Western Union communications satellite)-Vl with PAM-D. Both satellites were deployed but the PAM-D in each satellite failed to ignite, leaving both satellites in earth orbit. Both satellites were retrieved and returned to earth for renovation on the STS-51-A mission. The manned maneuvering unit (MMU) was tested with extravehicular astronauts as free flyers without tethers as far as 98 m from the orbiter. Shuttle Pallet Satellite (SPAS)-01 experiments, Monodisperse Latex Reactor (MLR), Isoelectric Focusing Experiment (lEF), Acoustic Containerless Experiment System (ACES), Cinema 360 cameras, five getaway specials (GAS), Aerodynamic Coefficient Identification (ACIP)/High Resolution Accelerom-eter Package (HIRAP).

Orbits of Earth: 127. Distance traveled: 5,329,147 km. Orbiter Liftoff Mass: 113,527 kg. Orbiter Mass at Landing: 91,278 kg. Payload to Orbit: 15,362 kg. Payload Returned: 8,620 kg. Landed at: Runway 15 at Kennedy Space Center, Florida. Landing Speed: 363 kph. Touchdown miss distance: 585 m. Landing Rollout: 3,296 m. EVA: Bruce McCandless and Robert Stewart. EVA No. 1 duration 5 hours, 35 minutes, EVA No. 2 duration 6 hours, 2 minutes. First flight of the manned maneuvering unit (MMU). Bruce McCandless operating time one hour, 55 minutes; Robert Stewart, 44 minutes.

Mission Name: 41-B (10)
CHALLENGER (4)
Pad 39-A (22)
10th Shuttle mission
4th Flight OV-099
1st KSC landing

Crew:
Vance D. Brand (3), Commander
Robert L. Gibson (1), Pilot
Bruce McCandless II (1), Mission Specialist
Ronald E. McNair (1), Mission Specialist
Robert L. Stewart (1), Mission Specialist

Milestones:
OPF - Sept. 10, 1983
VAB - Jan.6, 1984
PAD - Jan. 12, 1984

Payload:
PALAPA-B2,WESTAR-6,ACES,IEF,RME,MLR(4),SSIP(x1),IRT,GAS(x5)
Mission Objectives:

Launch:
February 3, 1984, 8:00:00 a.m, EST. Launch set for Jan. 29 postponed five days while orbiter still in OPF to allow changeout of all three auxiliary power units (APUs), a precautionary measure in response to APU failures on previous STS-9 mission. Launch Weight: 250,452 lbs.
Orbit:
Altitude: 189nm
Inclination: 28.5 degrees
Orbits: 128
Duration: 7 days, 23 hours, 15 minutes, 55 seconds.
Distance: 3,311,380 miles

Hardware:
SRB: BI-010
SRM: 010MW(HPM)
ET : 10/LWT-3
MLP : 2
SSME-1: SN-2109
SSME-2: SN-2015
SSME-3: SN-2012

Landing:
February 11, 1984, 7:15:55 a.m, EST, Runway 15, Kennedy Space Center, Fla. Rollout distance: 10,815 feet. Rollout time: 67 seconds. First end-of-mission landing at KSC. Landing Weight: 201,238 lbs.

Mission Highlights:
First untethered space walks by McCandless and Stewart, using manned maneuvering unit. WESTAR-VI and PALAPA-B2 satellites deployed, but failure of Payload Assist Module-D (PAM-D) rocket motors left them in radical low-Earth orbits. German-built Shuttle Pallet Satellite (SPAS), first flown on STS-7, became first satellite refurbished and flown again. SPAS remained in payload bay due to electrical problem with Remote Manipulator System (RMS). RMS manipulator foot restraint first used, practice procedures performed for Solar Maximum satellite retrieval and repair planned for next mission. Integrated Rendezvous Target (IRT) failed due to internal failure. Five Get Away Special canisters flown in cargo bay and Cinema-360 camera used by crew. Other payloads: Acoustic Containerless Experiment System (ACES); Monodisperse Latex Reactor (MLR); and Radiation Monitoring Equipment (RME), and Isoelectric Focusing (IEF) payload. References: 1 , 2 , 5 , 6 , 7 , 33 .