Putting footprints on Pluto isn’t that much harder than going to the moon.
Except that the ratio of fuel to useful mass actually increases exponentially with So the argument is locally invalid.
Feels weird to correct-vote and also give a missed the point react.
I'm aware of Tsiolkovsky's harsh equation, and I totally am treating my delta-v here as magical momentum applied from some kind of platonic spherical cow engine. I stand by my metaphor anyway. If you handwave the mass of the fuel, I think my numbers are roughly right. If you don't handwave the fuel, then all my numbers are wrong, yes in a way that makes Pluto take more effort, and handling the implications of how much more effort becomes closer to an engineering problem (e.g. "do multiple launches to bring fuel up before leaving LEO.")
Once we're treating it as engineering problems, if you've already gone to the moon I think you've already solved the hardest engineering problems involved in going to Pluto.
“If you can get your ship into orbit, you’re halfway to anywhere.” - Robert Heinlein
This generalizes.
Spaceflight is hard.
Putting a rocket on the moon is one of the most impressive feats humans have ever achieved. The International Space Station, an inhabited living space and research facility in Low Earth Orbit, has been continuously inhabited for over two decades now, and that’s awesome. It is a testament to the hard work and brilliance of a lot of people over a lot of time that this is possible.
And we’re not done yet. There are footprints on the moon today, but there are also robots leaving tracks on Mars and satellites have taken photos of the rings of Saturn and the craters of Pluto. Voyager has stood waaay back and taken a family picture of the solar system. Give us a rocket and a place to send it, and we’ll go anywhere we’re curious about.
There’s a funny property of space flight though, which is that half the work happens very close to home and is surprisingly similar no matter where you’re going.
When you boil spaceflight down into the very abstract basics, it takes a certain amount of force to get around. That movement is measured in Δv, or delta-v. In plain English, delta-v is the change in velocity; when I step on the gas pedal in my car, the engine and the tires conspire to increase my velocity and make me go forwards. When I’m in my kayak and dip my oar in the water to row, I’m applying delta-v to change my velocity and go faster or slow down or just change direction. In a rocket, delta-v comes from the engine. As anyone who has tried to get out and push a stalled car into movement, I need a certain amount of energy just to move at all. Just so with rockets.
It turns out that in order to get to the moon or Mars or basically anywhere else, you wind up going to Low Earth Orbit (LEO) first. You don’t really save much work trying to do what’s call a Direct Injection — drawing a line up out of atmosphere and to your target that doesn’t do a loop or two around the globe. It takes about 9,400 meters per second of delta-v to get to LEO, and you can save something like 300 meters per second (m/s) on the upper end. Sometimes you save more like 50 m/s. No matter where you’re going, hauling your rocket off the ground and through the air and into space is going to take you at least 9 kilometers per second (km/s.)
Keep that 9.4 km/s number in mind for a second.
Here’s a table of places you might want to go, along with their delta-v costs starting from LEO:
| Destination | delta-v |
| Moon orbit | 4.1 km/s |
| Mars orbit | 5.2 km/s |
| Jupiter orbit | 6.8 km/s |
| Pluto orbit | 9.4 km/s |
| Escape the solar system | 8.7 km/s |
Heck, if you’re willing to take a couple hundred thousand years, 9 km/s will get you to Alpha Centauri. Putting footprints on Pluto isn’t that much harder than going to the moon.
Once you've noticed that so much work happens during the early stages, you notice that this pattern shows up elsewhere.
The general principle here is that you spend most of your effort in surprisingly generic setup work.
Let's say you want to cook eggs for breakfast. You go to the grocery store and get eggs, you remember to pay your gas or electric bill so the stove works, then you make the eggs, then you clean the pan and your dish. Compare wanting to make sausage for breakfast. You go to the grocery store and get sausage, you remember to pay the gas or electric bill so the stove works, then you make the sausages, then you clean the pan and your dish. Most of the work isn’t the sausage or egg making!
Maybe you’re a shipping company and you want to deliver a piano from Tokyo to Boston. You need to wrap it in a box, you need to find a ship, you need to label the box and put it on the ship, you need someone to sail the ship across the world, you need someone to take the box off the ship at the other end, you need someone to read the label and figure out what address in Boston it’s going to, you need someone to load it on a truck and drive the truck to the address, you need someone to unload the truck and move the box to where it’s going in the building. You’ve recreated the global logistics network, involved at least three different people in at least two different countries, and you don’t save much effort if you decide to deliver the piano to Australia instead, or if you decide to get out of the piano business and get into wholesaling couches instead. “On a ship off the coast of Japan” is halfway to anywhere in the world.
Or, for a topic near and dear to my ACX Meetup Czar heart: If you want to run a conference on science fiction, you have to book a venue, you have to find some presenters, you need a schedule attendees can view, you need some way to sell tickets and take people’s money, you need to respond to emails where people can’t find the venue or where they have a complaint about another attendee, you probably want to send out a feedback form.
Notice how none of the steps in that science fiction conference go away if it’s, say, a bioengineering conference, or a trade show, an academic conference, or a month long retreat for internet bloggers? It’s the packaging, and the packaging is a lot of work. There is real work to be done in getting from LEO to Mars; you have to move sausage around more to fry it up than you do an egg, you have to pack a piano more carefully than you do a couch, and a retreat might benefit from the extra step of matching coaches to residents. But surprisingly often it turns out the most of the effort spent on a goal seems like setup, a prelude to the real effort.
Getting to orbit is halfway to anywhere.
There are some implications of this I don’t think are properly appreciated. In no particular order:
Expertise in one field generalizes. Or rather, it’s more accurate to say that some kinds of expertise slice across fields; a skilled boat captain can be useful to many organizations, as long as they want to move things by boat. Blur your eyes a bit, step back, and check sometimes what skills you actually need and whether seemingly different organizations must be doing the same thing as you for some part of their supply chain.
Motivation can be hit hard by everyone in the setup. Neil Armstrong is famous, Buzz Aldrin is famous. Evan Michael Collins, the pilot, gets mentioned in the first paragraph of the Apollo 11 Wikipedia page. You have to scroll down a ways to get to the guy in charge of the launch pad construction. (Kurt Debus.) Good thing they didn’t do it for fame, but at least the launch pad is still pretty clearly about rockets. Be wary of burnout if you have too much of the team working on a conference who never get to attend.
Common links in the chain are good places to be in some ways. There’s an aphorism I heard growing up, “selling shovels in a gold rush,” that touches on this. They're also good places to optimize. The software industry rightly puts incredible attention on frequently used function calls, and if you're looking at part of your regular work that gets used for every project, I suggest trying to make that part sing.
Pace yourself based on the actual work needed, not the most iconic moments. If you got worried two thirds of the way through the Ascent stage of a Mars launch because you’re halfway out of fuel, you’d never get anywhere. You’re 130 km done out of a 200 million km trip, you’re not even done with the preparation of getting to LEO, and that’s fine.
(Don’t run yourself out of fuel before you leave Earth orbit, and don’t burn yourself out before the conference starts. And leave some energy for getting home again and for wrapping up with the venue or feedback forms. But don’t get too worried if you’ve done a lot of work wrapping boxes and yet no pianos are in Boston yet.)
Small changes late in the process can be expensive to fix. Imagine getting to LEO and realizing you forgot the Mars Rover back on the loading bay floor, or even that someone didn’t add the right kind of chemical analyzer. You can’t exactly turn around and swing by NASA real quick to pick it up. Likewise, many parents confirm that getting the kids into the car and getting out the driveway is a big part of the hurdle to going places; the twenty feet to the end of the driveway takes more effort than the twenty miles to the grocery store. They too don’t want to turn around and hope nobody gets antsy and unbuckles for a bathroom trip just to grab the nice grocery bags.
It’s one of the most frustrating things for me as I’ve worked on larger and larger projects, how much effort and energy I burn on activities that are like icebergs under the surface.
When I feel that way, I try to remember that getting to orbit takes the most fuel. Once I’m there, I’m halfway done.