It is 50 years since the first trip of Americans on the moon.
Half a century ago, during the Apollo 15 mission on the Moon, Americans for the first time rode around the satellite in a “lunar buggy” – a driver-driven car. Some details related to implementing this project, difficulties, and curiosities that happened during the Apollo expeditions, Free News remembers.
There are many glorious things connected with the Apollo 15 mission – the ninth crewed expedition under the Apollo program and the fourth landing on the Moon itself: it is recognized as “one of the most brilliant from a scientific point of view” (and at the same time one of the most scandalous). For the first time, the so-called scientific Instrument module SIM (Scientific Instrument Module) was used in the service compartment of the ship – equipment and cameras for studying the Moon from orbit; a small artificial satellite was delivered and launched into lunar orbit.
On the way back to Earth, the first spacewalk into interplanetary space was made (for dismantling and subsequent delivery of the captured photographic cassettes to Earth). For the first time, the ALSD (Apollo Lunar Surface Drill) drilling rig was used directly on the Moon, although not quite successfully. In general, as in all subsequent missions, the main emphasis was no longer on the purely technical achievements of the “lunar race” but the scientific component.
The lunar module, which this time received the name “Falcon,” was modified so that it turned out to be significantly heavier than all its predecessors. The steepest trajectory was chosen for landing, as a result of which this landing turned out to be the toughest of all six Apollo landings — even with a dented landing stage engine nozzle.
But, of course, the most remarkable innovation was the vehicle delivered and tested for the first time on July 31, 1971, which allowed astronauts to dramatically increase the range of their trips on the surface of the satellite – up to 28 km – and collect 77 kg of lunar soil samples (almost twice as large as Apollo 14). The two remaining missions – “Apollo-16” and “-17 “— also successfully used the same “lunar carts,” or, as they were officially called, LRV (Lunar Roving Vehicle), and colloquially – “lunar buggies.”
The launch of the Apollo 15 spacecraft took place on July 6, 1971, from the Cape Canaveral cosmodrome in Florida with the help of a superheavy Saturn-5 launch vehicle by Werner von Braun (modifications allowed to increase the total payload slightly). The landing site on the Moon was chosen in the Rotting Swamp (Palus Putredinis) on the south-eastern edge of the Sea of Rains (Mare Imbrium), at the foot of the lunar Apennines, the highest ridge of the lunar mountains, with a height of more than 4500 m. The return to Earth and landing took place in the Pacific Ocean on August 7, 530 km from Pearl Harbor-also not without adventures — on two parachutes out of three. The crew consists of David Scott (commander), Alfred Worden (pilot of the command module who did not land on the moon), and James Irwin (pilot of the lunar module). All the crew members were active officers of the US Air Force. Three trips to the surface were made with a total duration of 18.5 hours.
By this time, the Soviet Lunokhod-1 was working hard on the surface of the Moon; its journey lasted from November 17, 1970, to September 14, 1971.
So the “lunar cart” was not destined to become the world’s first planetary rover. However, the fundamental difference was that our “Lunokhods” — and the second one would be delivered to the Moon on January 15, 1973, having traveled 42 km before the mission was terminated on June 4, 1973 — were controlled remotely and automatically, while the crew commander sat directly at the wheel of the LRV.
It is interesting how the designers approached the design of all-terrain vehicles in different ways: the undercarriage of the Soviet 900-kilogram “Lunokhods,” created under the leadership of Georgy Babakin in the design bureau of the Lavochkin Machine-Building Plant, contained an eight-wheeled engine with an elastic suspension for each wheel, and the wheels were chosen trellised non-pneumatic. The rotation was carried out by changing the speed and direction of rotation of the left and right sides.
The Americans (the developer and general contractor here was Boeing) managed with a more traditional four-wheeled structure made of aluminum pipes with inflatable wheels and the absence of a sealed cabin. The mass of this device was a more modest 210 kg; the load capacity in conditions of reduced lunar gravity was 490 kg.
Each wheel of the “moon buggies” was driven by a separate traction electric motor with a power of 190 watts. The movement was controlled by two steering electric motors (one for the front and rear wheels). Moreover, during the first trip of Scott and Irwin from Apollo 15, the turn of the front wheels did not work, which, however, did not significantly affect the performance of the design because the rover remained controllable when either of the two steering engines was turned off, it only had a turning radius increased from three meters to six (and before further trips, this was also fixed).
The power supply of the “Lunokhods” (later reproduced in American rovers) was based on solar panels with an area of 3.5 m2 with a capacity of 180 watts and buffer batteries (silver-cadmium with a capacity of 200 ampere-hours). Two non-rechargeable silver-zinc batteries with a capacity of 121 ampere-hours each were installed on the LRV.
The wheels of the American Rover (developed by General Motors) were also wrapped with zinc-coated steel wire over the tires and contained a special titanium tread for reliable contact with the ground. Wings — dust shields – were attached above the wheels, but they were not very reliable. During the Apollo 17 expedition, Eugene Cernan accidentally touched the rear right wing extension with a hammer sticking out of his pocket and tore it off. The attempt to fix it with tape was only partially successful, and the astronauts on that expedition were greatly annoyed by the moon dust flying from under the wheels, besides sticking to the adhesive tape, which after that did not stick to anything. Later, on the advice of the Earth, it was possible to build and attach a paper extension cord to the wing, which is still stored in the National Air and Space Museum of the Smithsonian Institution in Washington.
With the help of the rover, Apollo 15 managed to collect a valuable collection of stones, which included the first sample of the original crust of the Moon (4.5 billion years old), often called the “Stone of Being” (15415) and an amazing “Loose Green Lump” (15425) containing the first water found on the Moon.
In this expedition, for the first time, constant video surveillance of astronauts from Earth was actively used, but on their own initiative and quite often, the crew departed from the flight task, doing it surreptitiously and playing along with each other. Perhaps science should be grateful to them for this. Back on the first trip, Scott made an unauthorized stop to pick up an interesting piece of dark-colored basalt while informing the Ground that he was stopping to adjust his seat belts. Now this stone is known as The Seatbelt Basalt.
Also, on their own initiative and hiding it from the Earth, the astronauts held a memorial ceremony, leaving a small plaque with the names of fourteen dead Soviet and American space explorers and an 8.5-centimeter aluminum figure representing the fallen astronaut.
Later, a scandal broke out when, contrary to the agreement, the creator of “the first and so far the only work of art delivered to the Moon,” the Belgian sculptor Paul Van Hoeydonck decided to sell copies of this figure.
In addition, by agreement with a businessman and without the permission of NASA, the astronauts took on a flight. They brought back 398 envelopes with stamps, on which special cancellations and autographs were affixed. It was supposed to make money on this after the end of the Apollo program, but the businessman violated the agreements, began selling envelopes in Europe in September 1971, and the investigation of the incident reached the level of the US Congress; the envelopes were confiscated, and the astronauts were suspended from preparing for further flights and soon were even forced to leave NASA.