Back to the space age

39,693 km/hYesterday, Artemis II launched four people on a flyby of the Moon, the first such crewed mission in 56 years. I have dim memories of the Apollo program, not so much the missions themselves -- I don't remember whether I heard Neil Armstrong's "One small step" live or later, for example -- but I do remember details like drinking Tang, because astronauts drank it (and still do), and a print on the back of a cereal box (I think?) that you could cut out and fold up into a model of the lunar lander.

The original Apollo program was a truly remarkable engineering feat, particularly considering how much progress there has been since then in fields like materials science and, of course computing. Today, we build massively powerful datacenters (at least, they seem massive now). At the start of the Apollo program in 1961, computers were much, much smaller and the field was so new that the word software had only been coined three years before.

It would be tempting to say that Artemis is just a retread of 50-year-old technology. In the years since the Apollo missions, space flight has become routine. There were 330 orbital launches in 2025, 317 of them successful. The ISS has been in continuous operation for 25 years. A dozen countries have launched satellites into orbit. Spacecraft have gone to all eight planets, Pluto, the Kuiper Belt object Arrokoth and to within about 6 million kilometers of the Sun (harder than it might sound). There were even two lunar landings last year, not to mention ongoing missions on Mars.

Except ...

The vast bulk of space activity has been launches to Low Earth Orbit (LEO for short). An orbital launch is not nothing. It means accelerating whatever you're launching to about 8 kilometers per second (17,500 mph) and handling all the details of tracking exactly where the launch vehicle is at all times, deploying the actual satellite and plenty of stuff I'm leaving out because I don't know any better. Nonetheless, as far as space travel is concerned, LEO is easy mode.

Everything else in the last 50+ years has been uncrewed. No human has been past LEO since Apollo 17 splashed down in 1972.

There are several reasons for this, not all of them technical, but the technical obstacles are considerable. For one thing, crewed missions are much heavier. Besides the mass of the people themselves, you need a life support system, food and water, equipment for a cabin and so on. More mass means a bigger rocket. 

Missions beyond LEO need a significantly higher delta-v budget, which is the total of all speed changes for the maneuvers the mission needs to do. LEO needs about 8 km/s of delta-v. Artemis II will use around 13km/s, about 1.6 times as much. Since it takes more fuel to lift more fuel, that means significantly more than 1.6 times as much fuel. The Space Launch System (SLS) that launched Artemis II was the most powerful rocket that NASA has every launched. The Saturn V rockets used in Apollo are not too far behind.

The stakes are also higher. 13 of the 330 launches in 2025, or about 4%, failed. If you leave out LEO launches (crewed or uncrewed), that number is much higher. There were two successful lunar landings last year, but also at least three failures. Of the two successes, one landed on its side. This sort of thing is OK if it's just expensive equipment getting destroyed, so you can afford to take more risks. For a crewed mission, nothing major can go wrong, and even minor problems like toilet malfunctions require serious attention.

Even with the need to reduce risk, Artemis II is still pushing the envelope a bit, and not only in the power of the SLS. When Artemis II splashes down (assuming everything goes well up to then), it will be traveling at around 11,000 m/s, breaking the previous record held by Apollo 10  [As it turned out, Apollo 10 still holds the record at 11,082 m/s (24,791 mph) vs. 11,026 m/s (24,664 mph) for Artemis II  -- D.H 6 Jul 2026]. It will also go a bit further from Earth than the Apollo missions, so the Artemis crew will be further from Earth than anyone has ever been before [That one panned out. Artemis II reached 406,773 km (252,757 miles) from Earth, vs. 400,171 km (248,655 miles) for Apollo 13].

From a strictly economic perspective, crewed missions make very little sense. The real reason to send people around to the Moon is that we want to send people to the Moon, either for its own sake, or so that we can establish a presence there and eventually send people to Mars and beyond. Whether that's a worthwhile goal is a matter for debate and I'm not going to take a position on it here.

My point here is that a crewed mission to the Moon, or anywhere beyond LEO, wasn't just a major engineering feat 50 years ago. It's still a major engineering feat now. Practically all of the progress in the past 50 years ago has been aimed at solving different problems: Getting equipment and people to LEO, and getting equipment beyond LEO. Crewed missions like the ISS have told us a lot about what happens to people in space, and the Artemis mission reflects that, but not much about how to get them there that we didn't already know.

Suborbital crewed missions like Virgin Galactic's and Blue Origin's are pretty much irrelevant to all this.

As I write this, Artemis has successfully executed all but the last major maneuver in its mission. Before long, if all goes well, it will do the trans-lunar injection burn that will put it on a path to swing by the Moon and return directly to Earth. At that point, the crew needs to survive a bit more than a week in space and splash down safely. They also have a long list of mission goals to accomplish, of course.

I'm a bit surprised by my feelings about this. I've studied enough about the Apollo missions and spaceflight in general to know how much can go wrong, even with the most careful planning. NASA itself has lost crew members on multiple occasions. So while I'm excited for the crew and the many people on the ground, I'm also more nervous about it than I expected to be.

Beyond that, though, is a strange feeling of being in two timelines at once: a young kid in the late 1960s curious about all the moonshot stuff going on, and an adult watching nearly the same things happen 50 years later, almost as though for the first time.

Why don't we still use stone-age tools (or do we)?

While binge-watching a drama set a few hundred years ago in one of the world's empires, I realized that there was something intriguing about the mix of technology in use, which I think was a reasonably accurate rendition of what actually was in use at that time and place. This wasn't a meticulously-researched historical drama, so I'd expect some anachronisms, but the showrunners were constrained by using actual locations and a well-known and well-documented society, so I wouldn't expect to see the equivalent of a Roman senator on an e-bike.

On the one hand, there were ships at sail, intricately woven fabrics, expansive, multistory buildings with carefully crafted architectural details, and a highly-developed administrative state which, among other things, required people across a wide geographical range to carry personal ID. There was an extensive system of roads and detailed maps to show you how to get around them. There were cannon, rifles telescopes, steel farm implements and deadly-sharp swords.

On the other hand, buildings, including heavy-duty structures like jails and military fortifications, were built mainly of wood -- very well built, to be sure, but of wood just the same. Most people lived in small wood-and-stone huts. Some lived in very small dwellings made of sticks. Ladders were made from small logs bound together with rope. The roads were generally traveled on foot or horseback, or in wooden horse-drawn carts. Fighting was mostly hand-to-hand and the main projectile weapon was the bow and arrow.

In other words, while there was quite a bit of technology that would have been state-of-the-art at the time, many if not most of the objects most people dealt with day-to-day could have been made a thousand years before the time of the story, or even five thousand. Consider, for example, a clay cooking pot. While an archeologist could probably tell from the details roughly when and where a particular pot was made, from a purely technical point of view "clay cooking pot" narrows the time and place down to ... "probably not Antarctica" and "probably the last 20,000 years".

Impressive as the more modern-looking items were, few of them seemed essential. An elaborately-embroidered ceremonial robe is not purely decorative. It serves as a signal that the wearer has the resources, including human labor, at their disposal to make such things. Nonetheless, it's far from the only way to keep the wearer warm, and it's actively in the way of the wearer moving around easily (again a feature, not a bug, in context).

Relatively few technological developments are groundbreaking. An aluminum extension ladder is a better general-purpose ladder than a log-and-rope ladder. It's easier to carry. It's probably more weather-resistant and durable though, not knowing any better, I wouldn't want to underestimate how well a well-made wooden ladder would hold up. Likewise, it can probably bear more weight. Because it's easy to change the length of an extension ladder, it can be used in a wider variety of places.

Nonetheless, an aluminum extension ladder is still a ladder, and ladders have probably been around about as long as cooking pots. It's hard to tell for sure since a non-metal ladder is less likely to survive the millennia than a ceramic pot, but there is at least one surviving depiction of a ladder from 10,000 years ago. On a clay pot, of course.

An aluminum extension ladder is also a lot harder to make. While aluminum compounds, particularly alums, have been known for millennia, actually extracting aluminum requires electricity, and quite a bit of it. Aluminum has only been available in commercial quantities for a little more than a century. While we may think of aluminum foil and beverage cans, not so long ago aluminum was rare and expensive. It's probably not true that Napoleon III had a special set of aluminum silverware, but the aluminium statue of Anteros in Piccadilly circus, made in 1893 was the first of its kind, and so kind of a big deal.

Now that we can make aluminum ladders cheaply, they're everywhere. I have a couple in my garage. If someone gave me a carefully crafted wooden ladder, I'd keep it, because cool, and maybe even use it if it happened to come in handy. Like most of us, though, I have absolutely no reason to go out of my way to get one, particularly since it would almost certainly be much more expensive.

As far as technological developments go, I think aluminum ladders are more the rule than the exception. A modern freeway is in most respects a better road than the Via Appia, though not necessarily in durability. A modern car can go much farther and faster than a horse-drawn cart. A coat with a zipper is easier to get in and out of than one with buttons. It's somewhat easier to pay with a card or phone than it is to count coins and notes.

In general, a new development has to offer at least some advantage in order to catch on. That advantage doesn't have to be groundbreaking or even particularly great, however, and it doesn't even have to make sense on a larger scale. Plastic bags have their uses, but whether a new and cheaper way to make plastic bags catches on has little to do with whether we need more plastic bags, as long as we want some plastic bags.

Coming back to the title, in some sense we do still use stone-age tools every day. Ladders are still a thing. You can still buy rope at a hardware store and put it to the same kinds of uses it's been put to for as long as there's been rope. But in most cases, you'll be buying a stone-age tool made with modern technology. The rope you buy at a hardware store was almost certainly made by machine and very likely from a material that didn't exist a hundred years ago, much less several thousand.

I do keep thinking of getting a clay tagine pot, though.