Apollo 15 Part 2: Rover Deployment
Apollo 15 was the ninth crewed Apollo mission and the fourth to land on the Moon. It was also the first of the J-missions designed for a longer stay on the moon and was the first flight with the lunar rover.
Crew:
David Scott (CDR): 3rd and last spaceflight (Gemini 8, Apollo 9)
Alfred Worden (CMP): only spaceflight
James Irwin (LMP): only spaceflight
Dates:
Launch: Kennedy Space Center Pad LC-39A July 26, 1971
Lunar Landing: Hadley-Apennine July 30, 1971
Lunar Launch: August 4, 1971
Recovered: North Pacific Ocean August 7, 1971
Extravehicular Activity (EVA):
Stand up EVA: Dave Scott stood on top of lunar module ascent engine cover, opened the top hatch and took pictures: 33 minutes
Lunar Surface EVA 1: 6 hours, 32 minutes
Lunar Surface EVA 2: 7 hours, 12 minutes
Lunar Surface EVA 3: 4 hours, 49 minutes
Cislunar spacewalk by Al Worden to retrieve film cassettes from side of Service Module: 39 minutes
Apollo Lunar Module Descent Stage Quadrants:
Quad 1: folded lunar Rover (LRV)
Quad 2: ALSEP (Apollo Lunar Surface Experiments Package)
Quad 3: Rover aft tool pallet and payload pallet
Quad 4: MESA (Modularized Equipment Stowage Assembly)
Lunar Module “Falcon”
-Only LM that landed on the moon piloted by an Air Force pilot (all others piloted by Navy Pilots).
-Landing hit hard but within limits and landing in most challenging terrain (local terrain slope was 11 degrees). Landing gear designed to land on slopes up to 12 degrees.
-Final rest angle was 6.9 deg pitch up & 8.6 deg right roll.
-Longer descent engine nozzle buckled on landing but not due to impact but due to a buildup pressure in the nozzle due to thrusting in close proximity the the lunar surface.
-All lunar modules have gear legs that only stroke once with no rebound. Falcon gear legs stroked 1 inch on landing except for the front gear which stroked 3 inches. But in the final rest position, the front gear was not touching the ground.
Lunar Rover:
Manufacturer: Boeing/General Motors
Electric Motor: 0.25 HP DC motor on each wheel - Transmission: 80:1 harmonic drives
Range: 57 miles
Weight: 460 lbs Earth, 76 lbs Moon
A15 total time driven: 3h 2 min
MESA: deployed from a D-Ring near the porch. MESA contained, extra PLSS batteries, LiOH cartridges, TV camera, still cameras, geology tools, food, film, and sample containers.
J-Mission Modifications Most of the modifications involved making more room in Quad 1 for the LRV and Quad 4 for the enlarged MESA and additional water and GOX tanks. Modification to Lunar Module for J-Missions include:
S-band erectable antenna moved from Quad 1 to Quad 4
relocated Explosive Device relay box and pyro battery to provide Quad 4 clearance for additional water and GOX tanks
modified MESA support in Quad 4.
batteries and electrical control assemblies relocated from Quad 1 and 4 to -Z bulkhead (aft gear leg)
modified RCS plume deflectors (shortened) to provide protection to enlarged MESA and LRV addition.
modified ascent stage support structure for increased provisions.
cleared all previous equipment from Quad 1 for LRV
insulated docking tunnel to reduce cabin heat leakage
added controlled bleed vent for descent super critical Helium
added 10 inch fixed nozzle extension for descent engine to provide additional efficiency at full thrust
removed descent propellant tank balance lines
saved 25 lbs by removing thruster isolation valves - added additional battery to -Z bulkhead (along with the 3 other relocated batteries). This gave a total of 5 batteries
added capability to recharge PLSS
added 1208 lbs of usable descent propellant (18,697 lbs total propellant)
added 3rd sample return container
Acronyms:
-LCRU: lunar communications relay unit
-LiOH: lithium hydroxide
-MESA: modularized equipment stowage assembly
-PLSS: portable life support system
-SRC: sample return container
-TV: television