Tag Archives: David Randolph Scott

7 August 1971, 20:45:53 UTC, T plus 295:11:53.0

Apollo 15 descends to the Pacific Ocean with two functional parachutes. (NASA)

7 August 1971: At 6:45 a.m., local time, 287 nautical miles (531 kilometers) north of Honolulu, Hawaii, the Apollo 15 command module Endeavour “splashed down” after twelve days in space. On board were Colonel David Randolph Scott, Mission Commander; Major Alfred Merrill Worden, Command Module Pilot; and Lieutenant Colonel James Benson Irwin, Lunar Module Pilot. All three were United States Air Force officers and NASA astronauts.

During the descent following reentry, one of the three main parachutes fouled. This did not cause any problems, though, as only two were necessary.

The spacecraft landed approximately 5.3 nautical miles (9.8 kilometers) from the primary recovery ship, the amphibious assault ship USS Okinawa (LPH-3).

The Apollo 15 flight crew disembarks the Sikorsky SH-3G recovery helicopter (Bu. No. 149930) aboard USS Okinawa (LPH-3), 21:25 UTC, 7 August 1971. Left to right, Scott, Worden, Irwin. (NASA)

Apollo 15 was the ninth manned mission of the Apollo Program, and the fourth to land on The Moon. The total duration of the flight was 12 days, 7 hours, 11 minutes, 53.0 seconds.

This was the first mission that the crew were not quarantined after returning to Earth.

The Apollo 15 command module is displayed at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

Apollo 15 command module (CSM-112) at the National Museum of the United States Air Force. (U.S. Air Force)

© 2017, Bryan R. Swopes

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31 July 1971

Apollo 15: Jim Irwin loads the LRV for EVA-1, 31 July 1971. The mountain behind the Lunar Module is Hadley Delta. (David Scott/NASA)

At 13:52:31 UTC, 31 July 1971, (T + 120:18:31) the Lunar Roving Vehicle was deployed from Apollo 15’s Lunar Module, Falcon. This was the first time that an LRV had been used on the surface of the moon.

The LRV was a four-wheeled, electrically-powered, surface transportation vehicle designed to carry two astronauts and their equipment to explore areas farther away from the landing site than they would be able to by walking.

The LRV was built by Boeing at Kent, Washington. prime contractor. The wheels, electric motors and suspension system were built by a General Motors subsidiary in Santa Barbara, California.


Three-view drawing of Lunar Roving Vehicle with dimensions (Lunar Roving Vehicle Operations Handbook LS006-002-2H, Page 1 – 3, Fig. 1 – 1, The Boeing Company LRV Systems Engineering, Huntsville, AL)

The lunar rover was constructed of welded aluminum tubing and hinged to allow folding to store aboard the lunar module. It had two folding seats for the astonauts. The four tires were ingeniously constructed of woven steel strands (0.083 cm). about 122 inches (3.10 meters) long. The wheelbase was 90 inches (2.29 meters) and the track was 72 inches (1.83 meters). It was 44.8 inches (1.14 meters) high.

Jim Irwin with LRV at Hadley Rille, 31 July 1971. (Dave Scott/NASA)
Jim Irwin with LRV at Hadley Rille, 30 July 1972. Detail from image above. (Dave Scott/NASA)

The mass of the empty LRV was 210 kilograms (463 pounds on Earth, but only about 77 pounds on the surface of the Moon), and it was capable of transporting a payload of 490 kilograms (about 81 “moon-pounds”).

The four tires were ingeniously constructed of woven steel strands (0.083 centimeters diameter). The tire was 81.8 centimeters (32.2 inches) in diameter, and 23 centimeters (9.1 inches) wide. The aluminum wheels were 80 centimeters (31.5 inches) in diameter and 24 centimeters (9.4 inches) wide. The tires’ traction was enhanced by “chevrons” made of titanium.

Lunar Roving Vehicle wheel and tire assembly. (NASM-A197508300000_PS02)

Each wheel was driven by a DC electric motor, capable of 0.25 horsepower at 10,000 r.p.m. There was a 80:1 speed reduction.

Electric power for the vehicle was provided by two 36-volt (+5/-3 volts) silver-zinc potassium hydroxide batteries with a total capacity of 121 amperes/hour. The batteries were not rechargeable.

The Apollo 15 landing crew made three excursions with the LRV, traveling a total distance of 27.8 kilometers (17.3 statute miles) in 3 hours, 26 minutes driving time. The maximum speed reached was 12 km/h (7.5 mph). NASA reported that “the longest single traverse was 12.5 km [7.8 miles] and the maximum range from the LM was 5.0 km. [3.1 miles]

Apollo 15’s three LRV traverses. Image from the Lunar Reconnaissance Orbiter. (NASA/GSFC/Arizona State University)

© 2018 Bryan R. Swopes

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26 July 1971, 13:34:00.6 UTC, T plus 00:00:00.6

Apollo 15 (AS-510) lifts off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida, at 13:34:00.6 UTC, 26 July 1971. (NASA)

26 July 1971: At 9:34:00.6 a.m., Eastern Daylight Time (13:34:00.6 UTC), the Apollo 15/Saturn V (AS-510) lifted off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida. The three-man flight crew were Colonel David Randolph Scott, United States Air Force, Mission Commander, on his third space flight; Major Alfred Merrill Worden, USAF, Command Module Pilot, on his first mission; and Lieutenant Colonel James Benson Irwin, USAF, Lunar Module Pilot, also on his first space mission.

Their destination was was Hadley Rille, Mare Imbrium, The Moon.

The flight crew of Apollo 15, left to right, Colonel David R. Scott, Major Alfred M. Worden and Lieutenant Colonel James B. Irwin. (NASA)

At first stage ignition, the Apollo 15/Saturn V launch vehicle (AS-510) had a total weight of 6,494,415 pounds (2,945,817 kilograms). The five Rocketdyne F-1 engines of the S-IC first stage produced 7,558,000 pounds of thrust (33,619.66 kilonewtons).

After the first stage engines shut down, the S-IC stage was jettisoned. The five Rocketdyne J-2 engines of the S-II second stage received the Engine Start Command at T + 161.95 seconds. They produced 1,169,662 pounds of thrust (5,202.92 kilonewtons), and were themselves shut down at T + 549.06 seconds. The second stage was jettisoned and the single J-2 of the S-IVB third stage started at T + 553.2 and shut down at T + 694.7 seconds. The S-IVB engine produced 202,965 pounds of thrust (902.83 kilonewtons) during its First Burn.

Apollo 15 entered a parking orbit 11 minutes, 44 seconds after launch. The nearly-circular 105.3 × 106.4 miles (169.5 × 171.3 kilometers) orbit had a period of 1 hour, 27.84 minutes.

This 1966 illustration depicts the J-2 engine of the S-IVB third stage firing to send the Apollo spacecraft to the Moon. (NASA)

The Trans Lunar Injection maneuver (TLI) began at mission elapsed time 02:50:03. The total vehicle mass at the S-IVB’s Second Burn ignition was 307,661 pounds (139,552 kilograms). The J-2 engine produced 203,111 pounds of thrust (903.48 kilonewtons. The engine shut down at T + 02:55:53.7.

Endeavour docked with Falcon to extrack from S-IVB adapter fairing. (NASA)

Once on the way to The Moon, the Command and Service Module Endeavour separated from the S-IVB third stage, reversed its relative position and then extracted the Lunar Module Falcon from the stage adaptor fairing. The S-IVB third stage was then released, continuing its own journey. It impacted the lunar surface at mission elapsed time 79:24:41.55, traveling 5,764 miles per hour (9,277 kilometers per hour).

This was the fifth manned lunar landing mission (though Apollo 13 did not land).

On this flight, NASA was sending a powered wheeled transport vehicle, the Lunar Roving Vehicle, or LRV. This would allow the astronauts on the moon’s surface to travel farther from the landing point, spend less time getting where they were going, and with less physical exertion. They would also be able to return to their space craft with more geologic samples. The emphasis on this flight was to conduct a meaningful scientific examination of the surface. The astronauts had received extensive training in this regard.

© 2018, Bryan R. Swopes

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3 March 1969, 16:00:00 UTC, T Plus 000:00:00.26

Apollo 9 launches from Pad 39A, at 11:00:00 a.m., EST, 3 March 1969. (NASA)
Apollo 9 Saturn V (AS-504) launches from Pad 39A, at 11:00:00 a.m., EST, 3 March 1969. (NASA)

3 March 1969: At 11:00:00 a.m. Eastern Standard Time (16:00:00 UTC), Apollo 9 Saturn V (AS-504), the second manned Saturn V rocket, is launched from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. Aboard are astronauts Colonel James Alton McDivitt, U.S. Air Force, the Spacecraft Commander; Colonel David Randolph Scott, U.S. Air Force, Command Module Pilot; and Mr. Russell Louis Schweickart (formerly an Air Force pilot), Lunar Module Pilot. McDivitt and Scott were on their second space flight. Rusty Schweickert was on his first.

The 10-day Earth orbital mission is used to test docking-undocking with the lunar module, and to certify the LM as flight-worthy. This was necessary before the program could proceed to the next phase: The Moon.

The flight crew of Apollo 9, James A. McDivitt, David R. Scott and Russell L. Schweickart. SA-504 is in the background. (NASA)
The flight crew of Apollo 9, James A. McDivitt, David R. Scott and Russell L. Schweickart. AS-504 is in the background. (NASA)

The Apollo Command/Service Module was built by the Space and Information Systems Division of North American Aviation, Inc., at Downey, California.

The SPS engine was an AJ10-137, built by Aerojet General Corporation of Azusa, California. It burned a hypergolic fuel combination of Aerozine 50 and nitrogen tetraoxide, producing 20,500 pounds of thrust (91.19 kilonewtons). It was designed for a 750 second burn, or 50 restarts during a flight.

Astronaut David R. Scott stands in the open hatch of the Apollo Command Module “Gumdrop” in Earth Orbit, 6 March 1969. (Russell L. Schweickart/NASA)

The Apollo Lunar Module was built by Grumman Aerospace Corporation to carry two astronauts from lunar orbit to the surface, and return. There was a descent stage and ascent stage. The LM was intended only for operation in the vacuum of space, and was expended after use.

The LM was 23 feet, 1 inches (7.036 meters) high with a maximum landing gear spread of 31 feet (9.449 meters). It weighed 33,500 pounds (15,195 kilograms). The spacecraft was designed to support the crew for 48 hours, though in later missions, this was extended to 75 hours.

The Descent Stage was powered by a single TRW LM Descent Engine. The LMDE used hypergoloc fuel and was throttleable. It produced from 1,050 pounds of thrust (4.67 kilonewtons) to 10,125 pounds (45.04 kilonewtons). The Ascent Stage was powered by a Bell Aerospace Lunar Module Ascent Engine. This also used hypergolic fuels. It produced 3,500 pounds of thrust (15.57 kilonewtons).

Apollo 9 Lunar Module “Spider” (Apollo LM-3) in Earth orbit, 7 March 1969. (Dave Scott/NASA)

The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet (110.642 meters) tall. The first and second stages were 33 feet (10.058 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,948,350 kilograms). It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.

The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust (6770.19 kilonewtons), each, for a total of 7,610,000 pounds of thrust at Sea Level (33,850.97 kilonewtons). These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.

The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust (1,022.01 kilonewtons), and combined, 1,161,250 pounds of thrust (717.28 kilonewtons).

The Saturn V third stage was designated S-IVB. It was built by Douglas Aircraft Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant. The S-IVB would place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.

Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.

© 2017, Bryan R. Swopes

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