Apollo, the Lunar Dust and NASA's Dirty Problem

At times, even the most minuscule entities can pose significant challenges. The Apollo missions of 1969-72 encountered a major issue with the tiny particles of lunar dust. This dust, described as being as fine as talc but as rough as sandpaper, possesses properties that may be hazardous for both humans and machines. Some scientists have even cited it as a greater problem for future astronauts than radiation. The lunar surface is covered in a thin layer of dust, which has been created by the bombardment of meteorites and micro meteorites over millions of years. These particles collide with the moon's surface at a speed of about 12 miles or 20 kilometers per second, heating up and pulverizing rocks and dirt that contain silica and metal such as iron. Some of the dust is melted in the extreme heat of the impact, creating tiny glass beads as the silicon melts and then cools and falls back to the surface. This continual smashing shatters the silica and other minerals to produce finer and finer grains of dust. However, because there is no weathering on the moon like there is on Earth, the edges of these tiny shards, which are not only very hard but also remain very sharp and jagged, make it incredibly abrasive and potentially damaging to anything it sticks to.

NASA had an idea about the dust before the manned missions from the previous survey Landers, but it quickly became apparent that once men were there, it was going to be far more of a problem than was first thought. In fact, before the mission started, some scientists thought that because the dust had not been in contact with oxygen, it may spontaneously combust if exposed to air. Before the departure of Apollo 11 from the moon, Buzz Aldrin and Neil Armstrong had to carry out a rather ad-hoc experiment to see if the dust was safe to bring back into the lunar lander in an air environment. They got a grab sample of dust and went back to the lander. They placed some of it on the engine cover of the ascent module, then closed the hatch, re-pressurized the cabin while looking out to see if the dust would smoke. Luckily, it did not, and they got on with the departure. Aldrin said later that if it had, they would have stopped the pressurization, opened the hatch, and thrown it out as quickly as possible.

Astronauts have been seen bouncing around on the moon's surface and getting covered in the dust, but they have also found that it sticks to anything it comes in contact with, from the sun visors on helmets to gauges, dials, and more importantly, things like seals on the spaces and containers for bringing back rock samples. The dust is electrically charged by the bombardment of charged particles from the sun, and this is what makes it stick to anything it lands on. During Apollo 17, crew members Harrison "Jack" Schmitt and Gene Cernan reported that the dust was making it difficult for them to move their arms around during the moonwalk because it had gotten into the joints of their spacesuits. It also scratched the gold visors on the helmets to such an extent that when they tried to wipe it off, it made it difficult to see, a bit like trying to clean glass with sandpaper. The same applied to cameras and other optical surfaces, which had to be cleaned with a small camera cleaning brush to avoid damage. It also damaged seals between the gloves and the spacesuit locking ring, so they started to slowly leak air in the vacuum on the moon's surface. Just how abrasive the dust is was revealed when it wore through almost three layers of a Kevlar-like material on Schmitt's moon boot as he made his way around the lunar surface.

The Apollo missions brought back 382 kilograms of rock samples, which were placed into sealed containers to keep the low-pressure atmosphere of the moon in with the samples. However, when they got back to Earth, it was found that every sample box leaked air from the cabin because the dust had damaged the seals on the containers. There was also no way to isolate the crew from the dust in the lander's cabin either. There were no airlocks and nowhere to change out of their suits other than in the cabin. When the crews returned to the lander and re-pressurized the cabin, on every mission, they noticed that some of the dust became airborne and floated around the cabin, not only coating the inside of the craft but also being breathed in as well. They said that it had the smell of spent gunpowder or wet ashes in a fire, and after the mission, Gene Cernan said that it took about three months for the embedded dust to grow out from under his fingernails. On Apollo 17, Schmitt said he felt congested and complained of "lunar dust hay fever," but the symptoms disappeared the next day