Ready to Launch (or 3 - 2 - 1)

In addition to backpacking, I do have a day job. I work in space exploration and have participated in a number of NASA missions in a variety of different roles. For these missions of exploration, there are always particularly critical events (referred to as "Critical Events" oddly enough). They included major deep space maneuvers, landings onto planetary surfaces, orbit insertion burns, and (of course) launch.

In my approach to exploring the wilderness it's quite natural for me to draw analogies and adopt modes of thought similar to those used when exploring the mysteries of our universe. For example, consider the Launch. The concept of "launch" for a deep space mission is about the high-risk endeavor of strapping a (somewhat) controlled explosive device to several-to-many hundred million dollars worth of one-of-a-kind hardware (a robotic explorer, like Voyager, Cassini, Curiosity, and others), and lighting the fuse. The "launch" of a backpacking trip has nothing like that drama, but it is very similar in two important ways.

The first is what happens immediately (for a space mission) or soon (for backpacking) after launch. Once you've "lit the candle" and sent that space probe into orbit, you can't bring it back into the shop and add the gasket, or solder the wire, or plug in the connector, or re-check testbed performance. It's much the same way on the first (or second or...) night when you reach into your gear and realize that you forgot your lighter, or spoon, or warm hat. Interestingly enough, use of a checklist to prevent this kind of "oops" is a pretty standard practice for both applications.

For a NASA mission, the consequences of a mistake in a checklist can be significant or even catastrophic. The checks and balances of NASA's review process are able to guarantee (to a very high degree of certainty) that items aren't forgotten. For the individual backpacker, it's much easier to have something just get left out. Sometimes this is of little consequence, but of course forgetting a tent or a sleeping bag or one's food sack for a multi-day hike can be a deal-breaker.

But it's the second similarity I wanted to focus on in this post. NASA missions all maintain a MEL - a Master Equipment List. A key function of that list is to keep track of every gram of mass in the spacecraft. This list is first put together once there is an initial design for a robotic probe. Of course, as designs mature (or need to be changed), the MEL also changes. Keeping track of the mass of one's spacecraft is no easy task. Every piece needs to be weighed (does this sound familiar) and that weight tracked even if an item is altered or a new item is swapped in for an older or failed component. This is done for two reasons

1. It's incredibly expensive to launch any mass from the Earth's surface. It costs NASA roughly $10,000 per lb to reach geosynchronous orbit (escaping Earth's gravity entirely is a bit more expensive). That's over $20 per gram. (SpaceX is trying to decrease this by about a factor of ten.)
2. When a rocket is launched, it needs to be heading along the proper trajectory. This is not as simple as aiming a gun. If the mass of the rocket plus payload is not accurately known, the probe may either fall back to Earth (and be destroyed in the process) or end up traveling in the depths of space, far from any useful target of exploration.

Although the stakes are lower, and the consequence much less severe, we backpackers also need to be concerned with the mass that we carry (yes, we call it "weight," but indulge the physicist in me for a second).  For backpacking, there are several different kinds of costs that bear on our gear choices and their weight. These include cost of the equipment (dollar cost), the value we apply to having items on the trail other than the most basic ones (convenience cost), and the physical work we do to move through the wilderness from one place to another (hiking cost). Much of our consideration of gear is an attempt to balance those various costs in a way that enables us to get the most out of our experience. It's the fact that different people apply very different weightings to the dollar, convenience, and hiking costs that leads to many of the more infamous debates on various backpacking websites. For example - trail shoes vs boot; tarp vs tent; frameless vs framed pack; quilt vs. sleeping bag; lightweight (or ultra-) vs conventional backpacking.

It's interesting to note that deep space probes commonly diverge wildly in their size, appearance, and scientific instrumentation. That's an expression of the fact that although they share a high-level goal (scientific exploration of the universe), the specific goals they have and the science investigations they need to complete are often very different. In much the same way, hikers who are focused on mileage or on seeing as much as they possibly can will make different choices for their MEL (that's their gear list in this metaphor) than will someone seeking to fish or to spend an entire day or two at each campsite.

So by now, you probably have guessed that the analogy to trajectory for the backpacker is the hiking plan. While one can (and some do) set off with only the roughest idea of where they will go and the time it will take them, most folks have constraints in terms of time and/or money, or simply are too goal oriented for that to work for them. For each of us, the number of miles we can walk in a day or week (along with the vertical elevation gain or loss) is a function of how much mass we carry. The thoughtful backpacker will recognize that this applies to both gear and personal mass, and will distribute efforts accordingly.

Graphic from my gear list on lighterpack.com

As I prepare for my own personal launch (approximately noon Pacific Daylight time, Sept. 4th, from the Mono Meadow trailhead), I've compiled my own personal MEL, which backpackers usually call a gear list, and use it to track their base weight (total of all items carried, minus clothing worn, food, fuel, and other consumables). I've worked hard over the past two years to fall in the ultralight range (<12 lb base weight), but for this trip I've decided that some of the luxury items like an iPhone, a camera, and a notebook are a convenience cost that I'm willing to pay. And while I could reduce my base weight with lighter gear (e.g., cuben tarp or lighter sleeping bag) the dollar cost is too much for my tastes. I'm satisfied that with this base weight, I can meet my planned trajectory of an average of 12 miles per day, while balancing all the other factors that will help me to enjoy this trip.

Maybe that seems a bit over analytical to some of you (and yes, I saw that eyeroll). For me it comes down to two things. First, I actually enjoy the analysis and putting careful thought into my choices. So I enjoy putting these kind of plans in place. More important to me is the payoff: when I've finished my planned hike for the day, and I still feel like walking a mile or more up to the top of a ridge or up along a creek to see the waterfall that someone told me about. That's a direct result of having control over the amount of mass I carry, and the amount of energy I expend on the trail each day.

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