Google’s Android developer documentation tends to be pretty bare. Third-party documentation and tutorials are usually years out of date and accompanied by code that was obviously hacked together for the tutorial; sometimes, they ask you to clone a GitHub repository to get started.

I learn by example, and all of the above makes it more difficult than it should be. I won’t provide example apps or copy-pasteable classes; instead, I’ll work through a problem, one step at a time.

I hope to make “Getting started with on Android” a regular series; this article covering OpenGL ES 2.0 is the first.

Like all launch vehicles, SpaceX’s Falcon 9 is a marvel of engineering. It starts out at the launchpad, and in less than nine minutes, the second stage (and payload) have reached orbit and are now travelling at over 7500 meters per second (equivalent to a sea-level speed of Mach 22.) That’s really, really fast. And it’s something that every single launch vehicle must do to bring its payload into orbit.

Here’s a very short tl;dr:

• Reaching orbit is not the same as reaching space.
• To accelerate the payload to orbital velocities requires a lot of fuel.
• As the dry mass of the launch vehicle increases, the amount of fuel (and therefore energy) it can store decreases.
• Therefore, you want the vehicle to be as lightweight as possible and hold as much fuel as possible.

Rocket engineers have spent decades trying to make launch vehicles lighter. The original Atlas ICBM used balloon tanks; unlike a stiff internal framework of stringers underneath a metal skin, balloon tanks employ the pressurization of the tanks to maintain their shape. This makes for a very lightweight tank; however, it’s difficult to build and transport (as it must be pressurized at all times.)

The Falcon 9, though, is a bit different.