Games have long been used as teaching tools, and there's now a bunch of mobile apps designed to make physics-based problems fun to solve for budding and experienced engineers alike.
The acme of virtual-rocketry software is probably Kerbal Space Program, but that needs a PC or Mac, and while it runs on Linux as well as Windows, there isn't (yet) a mobile version. So if you want to play Wernher von Braun or Elon Musk on your iPhone or Android, you are probably going to want SimpleRockets instead.
As with most of these games it sticks to two-dimensional space, but so in large part does our solar system. Within that 2D plane it models orbital physics very well, and as a spaceship builder and pilot you will need to learn about escape velocities, periapsis and apoapsis, closest approach orbits, and other astrodynamics concepts. Fortunately there is a trajectory prediction tool to help with your calculations.
After a brief tutorial, you begin with some basic exercises, which include learning how to assemble the available parts into complete rockets. You can build some pretty weird contraptions, strapping fuel tanks and rocket engines on here and there, but at this stage you just need the basics. Your ship shows on-screen with a ring around it: this highlights both its real heading and the direction it's pointing, and can be used to turn it. This ring also shows the horizon, which helps in gaining orbit.
After the basic exercises come challenges such as flying the furthest, getting to orbit using the least possible fuel etc. Once you've completed all these and got a feel for how the controls and instrumentation work, you can move into the sandbox. Here you can explore the game's Solar system – or Smolar system, as everything gets prefixed with S or Sm – which is a version of ours that has been scaled down to speed things up.
Now you can build space stations and moon (sorry, Smoon) bases, dock ships in orbit, try taking off from other planets to see how the orbital mechanics change, and launch missions to distant planets or moons, where you can land a rover on the surface and drive it around. The game is also hackable, or extensible, with players for example adding asteroids and extra planets, although this is not a trivial process.
Bridge Constructor Playground
£1.59 or free with ads
If you prefer your engineering more land-based, a popular genre is bridge-building games. These typically teach a variety of skills around stress and strain, inviting you to construct suitably strong bridges from an available pool of materials. Some, such as Bridge Architect, bring the engineering to the front, with blueprints and a physics engine that highlights where the stresses and strains are as the bridge is tested.
Others, such as the Bridge Constructor series, are more game-like and youth-friendly in their approach, with cartoon characters and background landscapes, and a more sophisticated system for scoring points. Bridge Constructor Playground also has a fairly intuitive approach of selecting your material and simply drawing it between two points on the screen; it then adds a pseudo third dimension of depth by filling in the middle of the bridge, where other apps of this kind simply leave it as a 2D drawing.
A nice touch is that as well as building a bridge strong enough to carry cars and lorries, you are also challenged to do it for the lowest cost and with a decent safety margin. Along the way pieces of advice may pop up and new materials become available to you, such as cables for suspension bridges, and concrete, which saves you from spending all your time building triangles of girders or wooden beams. Once completed, you can test your bridge, just with cars if you are aiming for a lower price and material content, or with lorries too for a higher bonus.
Cut the Rope 2
Free with ads
The original Cut the Rope was a big hit, with hundreds of millions of copies downloaded, and is still a neat and subversive way to get kids engaged with the basics of Newtonian mechanics. Subsequent versions such as Cut the Rope 2 have added all sorts of extras, from new characters to decorative locations, but the essence remains the same: you must feed a hungry monster called Om Nom.
Around the screen will be doughnuts, sweeties, lollies and the like, typically hanging from strings or balanced on ledges. Om Nom just sits there (in the original game, at least – the later versions add mobility in some of the game levels) so you must turn wheels, burst balloons, knock out bricks and set pendulums swinging, before cutting the strings at just the right moment and in the right order so the sugary treat at last flies or rolls free, right into his mouth.
Although supposedly it's aimed at older children (and adults, of course!), our four-year-old tester loved the original game on a seven-inch Android tablet, quickly figuring out how to fling candy around with very little help from mum and dad.
A few caveats: it will run on Android and Apple phones, but younger kids will find it easier on a tablet; the free versions have some pretty intrusive adverts; and you can buy extra powers and the like. Cut the Rope 2 does warn you to disable in-app purchases if you don't want your kids using them to buy extra goodies.
Free with in-app purchases
As the blurb says, cranes are cool and rockets are cool. So how about a rocket-powered crane? For those too young to remember classics such as Lunar Lander, the premise is simple: you have a flying platform which must pick up payloads and then land them in the right places, and your only controls are its retro-rockets, which of course have a finite amount of fuel. Fire the rockets too hard and you fly too high, too little and you crash, hover too long and you run out of juice.
Meanwhile, your rocket crane must lift parts and place them where they are needed as quickly as possible, either to beat the specific challenge for that game level or to build the tallest structure possible with the parts on offer. In addition, there's a sandbox where you can simply build for fun.
Rocket Crane makes things a little easier by only working in two dimensions rather than three (or in three rather than four, if you count time), but that is probably just as well given the 2D screens it must work on. So you get throttle controls to control both the lift and the lateral thrust for left/right movement, and buttons to release the grab and pause the game. You can also tap the screen to zoom the view in and out. On the more complex levels you can land your crane to refuel it, but of course you are being timed so don't do this too often.
The game runs on Android and Apple. As it goes on, you can collect or purchase game currency and use this to buy more powerful cranes, with more lift, higher speed or higher fuel capacity. You can also upgrade to the full version, which brings 90 ever-tougher game levels on top of the 10 that are free, plus unlimited building parts.