Mission Possible C

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This article is about Mission Possible competition for Division C. For more about the basic competition, see Mission Possible.

Mission Possible is an event in which teams make a Rube Goldberg device which uses certain tasks and runs as close as possible to the ideal time to gain the maximum number of points. The scoring method and start, end, and bonus tasks that the machine must complete differ every year.

Articles in this series

The following is a list of pages pertaining to Mission Possible for Division C. Some of these pages may contain outdated information.

Description and Scoring

For the 2019 season, the rules for Mission Possible specify a list of scorable tasks that score points if implemented into the device. For a full list of tasks, see Mission Possible C/2019 Tasks.

The device must fit within a cube with side lengths of 60 cm. It must begin and end with the Start Task (dropping a ping-pong ball causing a golf ball to move - rule 2.a) and End Task (raising a platform with an unattached 9V battery standing on its end above all parts of the device - rule 2.c). Some or all of the scorable tasks listed under rule 2.b may run in any order in between the Start and End tasks. 50 points are awarded for each successfully-run scorable task.

Each team must submit two Action Sequence Lists (ASL's) at impound, which lists all of the scorable and non-scorable actions taking place in their device. Up to 100 points can be earned for a complete and accurate ASL (see rule 5.b).


A device may have all of the possible transfers, but if they fail to function properly, the participant will end up having to touch the device and will lose 15 point plus any points they would have recieved for the transfer. In other words, more points than the transfers were worth in the first place. This means that every part of your device must be designed to work repeatably and reliably, or it is not worth having it in the machine.

Solid construction is one way to improve reliability. Machines made carelessly of Legos, K-nex, or other toys have a tendency to fall apart during transport to competitions. Hot glue, while very convenient for testing your device, should always be reinforced or replaced with screws where possible.

For more complex machines that attempt to satisfy many of the bonuses, surface area within the device on which to mount transfers is often at a premium. Builders should consider using at least two side walls, which dramatically increases available surfaces without sacrificing accessibility. Three walled devices and multi-decker devices are common at state and national competitions, but make it a lot harder to access your device for setup and troubleshooting.

Possible suppliers for mission possible device parts include:


  • Adafruit
  • Sparkfun
  • Digikey
  • Pololu
  • Amazon
  • Ebay


  • Home Depot
  • Lowes
  • Pololu
  • Amazon
  • Ebay


  • Chemical supply houses

3D printing is also becoming more prevalent in this event.

Image Material Possible Uses, advantages and disadvantages
Wood Wood can be the cheapest and nearly the strongest of all the possible building materials. A box with three or more sides of thick (1/4" - 1/2") plywood, particle board, or solid wood will provide ample support for transfers and should not flex too much while it is being carried. If the machine will be using liquids, avoid particle board as it will deform if gotten wet. Wood is the primary building material of most Missions.
Pegboard Pegboard lies somewhere between cardboard and wood. It provides many convenient attachment points, but it is thin and not very rigid. Pegboard is popular among even the top 10 placing Missions at Nationals, but they always brace it with beams of solid wood. Freestanding pegboard is often too flexible for precisely calibrated transfers.
Extruded aluminium section x3.jpg
80/20® 80/20® is self described as an industrial erector set. It is a set of extruded aluminum beams with slots to attach other beams and components. Extremely rigid frames can be designed and built rapidly, but the frame itself has little surface area to work with. If you want to rapidly build with metal, but lack any tools, it is an option. It is also a professional engineering material, so it is expensive.
The PVC pipe.jpg
PVC PVC can be used to create moderately rigid frames, if it is cemented. A PVC frame with free joints is liable to come loose. Since it lacks flat sides for attaching transfers, PVC is not ideal and may be best for use as tubes or pressure vessels for individual transfers.
Pile of lego blocks.jpg
Toys Legos®, K'nex®, ball-machine parts, erector set, and many other building toys appear in Missions. They are suitable for individual transfers, but not for the superstructure of the machine. Toy building materials are also more likely to vibrate apart during transport than other materials. Secure them firmly to your box with duct tape or superglue. They do slide around, so be careful how much you rely upon these type of items for construction.
Copper Pipe Copper piping, like PVC, can be used to make a fairly rigid frame if the joints are fixed (with solder). Copper pipe is better for transfers like hydraulics or pneumatics than as a main building material.
Led e plexiglass 660, 2011, plexiglass, led e ottiche collimatrici.jpg
Plexiglass Plexiglass always appears as a building material. There are places where it makes sense, but it is not ideal as the main frame of the machine. If there is a transfer that the judge needs to see, but might cause a boundary violation if not contained (like popping a balloon), enclosing it in plexiglass is an excellent idea. Beyond that, plexiglass can be difficult to build with because unless it is very thick, it is not rigid. It may also crack when being drilled or cut. Wood is usually a cheaper, sturdier, and better option unless transparency is truly necessary.
Screen Screen is a cheap alternative to plexiglass for containing possible non-liquid boundary violations.


Planning is key! Before building, one should first make sure that in theory, the build will at least work. Less time will be wasted building something that won't work properly. Likewise, prepare extra ideas - they may be needed later since after a few trials it may become apparent that not all steps will work as expected (but don't let this prevent you from trying!)

  • Brainstorm possible solutions to the tasks and bonuses. Before building it is best to determine what arrangement of tasks will work best. A good planning tip is to write out the tasks on flashcards, then arrange them and see in what order the tasks should be accomplished. This is a very good visual for planning.
  • Try to have transfers begin and end with a common, useful interface. If every transfer starts and ends with an electrical circuit, it is easier to put everything together.
  • All transfers must follow a linear, sequential path. Parallel paths of tasks or transfers will result in penalties or violations, though for the 2014 rules, parallel paths/transfers may be used for the Bonus Task.
  • Order transfers in the machine physically, so that one triggers the one next to it. This makes the machine easier to troubleshoot and judge.
  • Timing is important. Not only are points rewarded for having an accurate time, but the judge must be able to follow the action of the machine. Time the runs of the machine before competition day. If it's too slow or fast adjustments need to be made. Know that points will not only be lost if the device runs over the ideal time, but also for 2014 rules, no points will be earned from transfers that occur after 3 minutes!

Definitions and Terminology

The 2018 rules no longer classify transfers/tasks/bonuses into these categories, but they are still useful ways to think about the different ways of accomplishing a task.

Mechanical Devices

Mechanical energy is by far the easiest to use. Anything that moves, or has the potential to move, can be considered mechanical energy: from rolling balls, to fans blowing air, to releasing a spring.

Here are some tips to help you use mechanical energy successfully:

  • Use as little mechanical as you possibly can.

It is highly advised to avoid gross mechanical. Mechanical transfers are the most likely to fail. Every mechanical device has the potential to jam, break, vibrate loose during transportation. Use the smallest, simplest mechanical actions possible. A ball rolling down 6 ramps is no better than a ball rolling down 1 ramp.

  • Don't fight thermodynamics, or, let the machine do the work.

If you have the option of having your device raise a weight or drop a weight, opt for dropping. Gravity always works.

  • Switches are your friend.

Hitting a switch is the easiest way to get back to electricity.

Electrical Devices

Electrical transfers are incredibly easy to incorporate into a device, as well as the very versatile and reliable. There are a wide variety of products on the market that can convert electrical energy into just about anything. Electrical energy is also the safest of all forms of energy allowed in the Mission Possible. When properly done, electrical transfers never fail. Here are some tips to ensure success with electrical transfers.

  • Learn to solder. Even though using wire nuts or terminal strips is a lot easier and less permanent than soldering, the quality of the connection is inferior and can lead to increased failure.
  • Get a good book website and read it. To succeed in electronics, teams need some knowledge about electronics. Radio shack is basically gone, so unless you happen to have some of those books, check out sparkfun and adafruit for tutorials.
  • Design before hand. Design how every circuit will work on paper first and use ideas from the web or books.
  • Cannibalize stuff. Go to yard sales and thrift shops and pick up various electrical gizmos to take apart.
  • Think carefully about batteries. Consider the type of battery needed and whether it is best to use separate batteries for every transfer or a single large centralized set.
  • Replace/recharge the batteries before an official run. This is just a good idea and will save a great deal of potential heartbreak.

Chemical Devices

Chemical transfers may look hard to the casual observer, but in all actuality, they are not. Burning anything is a chemical transfer, so is the timeless baking soda and vinegar trick. For the best chemical transfers, as well as most of the chemical bonuses, teams have to think creatively. A local chemistry teacher is an invaluable resource in the quest for the chemical transfer.

  • Safety first!

Chemical reactions can be dangerous. If it risks the safety of others, don't use it because the event supervisor might not allow it.

  • Where should I start?

Here are some questions to ponder when brainstorming chemical reactions.

  1. What reacts to make gas, and what can be done with that gas?
  2. What reacts to make heat, and can that heat be detected or used to do something?
  3. What reactions produce a precipitate? What does that precipitate do to the opacity of the reagents?
  4. What does it take to make light, and how can it be detected?
  • The next step: Implementation

Once teams have decided on what chemical reactions they are going to use, they have to figure out how to implement them in a safe and rule abiding manor. If the reaction foams or bubbles, make sure it can't spill. If solid and a liquid are being mixed, consider powdering the solid to speed up the reaction.

  • Your chemistry teacher is your best friend.

A chemistry teacher makes a great consultant during the design phase, as well as providing access to the chemical storage room.

  • Ambient conditions matter

A reaction will occur slower or faster depending on the ambient temperature, so calibrate on-site.

  • Room temperature matters

Most reactions are not affected by slight changes in temperature, but be prepared to test the device in a room with or without heating.

Thermal Devices

Thermal reactions are right in the middle as far as difficulty and complexity, but with a little creative thought they aren't that hard. Thermal energy transfers incorporate changes in - you guessed it - temperature. The change can be either an increase or a decrease.

  • Combustion is heat. If you get it hot enough, it will burn.
  • The Peltier Effect can provide hot and cold. The Peltier Effect Thermoelectric Cooling Module is really cool and can be purchased from almost any surplus catalog. When power is applied, these junctions get hot on one side and cold on the other.
  • Use radiant heat. Radiant heat is also a possibility when looking for a thermal transfer. If you can melt something with radiant heat, you could trip off a mechanical transfer.
  • Consider exothermic and endothermic chemical reactions: Some chemical reactions produce or consume large quantities of heat. Use them to melt something or trigger a sensor.
  • Nichrome wire! When nichrome wire is used to conduct electricity, it gets really hot - hot enough to ignite a match or cut a string.

Optical Devices

Optical transfers can be very useful to detect motion without touching anything, chemiluminescent reactions, light bulbs, and other devices. Please note that for the 2018 season, sensors cannot terminate the clock reaction, so this is not an appropriate way of timing that part of the machine.

  • Use references for circuits. Make sure to look at things like Sparkfun's and Adafruit's guides.
  • Ambient lighting matters. If the lighting conditions on-site are different from where the transfer was calibrated, it may fail. Shield optical transfers from ambient lighting as much as possible.

The Action Sequence List

Action sequence lists are team's interface to the judges, and thus, very important. Any energy transfers on the list will be counted towards the team's overall score. However, the list must be accurate because any deviation in the list from the actual machine will result in point deductions. It is best to hold off on making the list until right before the deadline so that any additions to the device can be easily incorporated into the list. What follows are some pointers on how to be successful when writing an action transfer list.

  • Don't be late! The judges will not accept a late list, which means teams will either lose points or be disqualified altogether. No matter how convincing an argument, there will be no exceptions from judges. Additionally, some judges may ask teams to send in the list days before the competition - check with your tournament director to be sure.
  • Be neat. It's just good practice to make a clean and organized list.
  • Be accurate. An incorrect ASL will cost points.
  • Follow the format mandated in the rules. A sample format that will be acceptable for all competitions can be found on the official Science Olympiad website.
  • Only include relevant information.
  • Document tasks and bonuses by number. For 2018 rules, only number tasks that earn you points, and make sure they match the numbers labeled on the device.

Transportation and Final Shakedown

Without an effective method of transportation, all hard work could end up being for nothing. Even then, once teams reach their destination, it is very advisable to run a test run or two, just to make sure everything works as it should.

  • Do not use a courier to ship a mission possible! - Even if teams pay for a great deal for insurance and the best shipping plan, the middle-men within the company are not paid anything extra. Thus, they may not exclusively tend to a box labeled "extremely fragile". Instead, use a straight line shipping service. One recommendation is to ship via Greyhound Bus - the package never leaves the vehicle the entire way there. Or, if you are charting a bus, bring the Mission with you.
  • Build a sturdy crate. - A wooden box to encase a mission is just a good idea. Half inch plywood works great.
  • Secure the device to its crate. - That way it won't get crushed if it is turned upside-down. Wood screws work best to mount a mission into a box.
  • Do not bring chemicals on an airplane carry on! - Airport security does not like chemicals, especially oxidizers. If teams need to bring chemicals, ship them out or arrange to buy them at the other end. It is also not a good idea to bring any fragile parts that even resemble anything potentially hazardous. Batteries are another thing that cannot be brought on carry on. While it is up to the teams to decide whether or not to take the risk, it is not advised to bring them along for if they are found, they will almost certainly be confiscated.
  • Run a pre-competition run. - This is a crucial step before competition. Geographic changes, such as elevation, temperature, and humidity can affect the performance of a mission possible, especially chemical transfers. Run a pre-competition run to make necessary adjustments.

Battery Choices

During the 2018 season there is a bonus for using only one battery to power the entire device. Depending on how much power your different transfers need, you'll need to select an appropriate type of battery.

There is also a restriction on all Lithium-containing batteries. That means no LiPos, etc. There was a clarification released that trace amounts of lithium in NiMH batteries is allowable, the main idea with the new rule was to restrict more hazardous batteries from the competition.

Batteries are typically rated using:

  • Voltage (V): a measure of the electric potential. You simply have to choose the right voltage for your motor or it won't run or will overheat. Typically when a battery is charged, the voltage of the battery will be 1-2 volts above the labeled voltage. This isn't generally a problem with most systems but it is something to be aware of. A voltage regulator can and in many cases should be used to ensure consistent performance.
  • Amp-hours (Ah or mAh/1000): this can be used to compare how long two batteries will last when doing the same thing or how much larger of a load one battery can support than the other. A larger Ah rating means a battery that will last longer under the same load or can power a more demanding device. Ah rating always appears on rechargeable batteries, but you will have to check manufacturer websites or just the table below as a general guide for Alkaline and Zinc Carbon batteries. You may also see mAh, which is simply milliamp hours. There are 1000 milliamp hours to an amp hour. To calculate how many amp hours you need, estimate your average load on the battery and how long you will need to run your device between charges, in hours.
  • Max Discharge Rate (C) - This is important for most rechargeable battery packs. If you multiply the max discharge rate by the capacity in amp-hours, you'll know how many amps your battery can produce all at once. You'll need to look at the highest current draw possible from your device, including any possible spikes from high-inductance loads such as motors, solenoids and electromagnets. Then make sure you pick a battery that can discharge at a higher rate than that.

See this article for information on different battery chemistries: Comparison of commercial battery types (Wikipedia)

  • Rechargeable batteries
    • Upfront cost is high, but they pay themselves off. If your school could use the batteries and charger again in another event even if Mission Possible is not back the next year, investing in Rechargeable batteries is worth it.
    • Use only the right kind of charger for your batteries. If you don't, you will ruin the batteries and possibly the charger.
    • Battery packs can be convenient and powerful. All rechargeable battery technologies are sold in packs of already connected batteries. This simplifies charging, though demands a compatible charger.
    • Don't use lithium-based batteries. They're against the new SO battery policy.
  • Non-rechargeable batteries
    • Choose Alkaline over Zinc Carbon (Heavy Duty) batteries. Alkaline batteries have more than twice the Amp Hours of Zinc Carbon batteries. A typical D-size Alkaline battery will have about 20 Ah to a Zinc Carbon's 6 Ah. The cost difference is justified by a longer useful life.
    • Larger batteries last longer. A D-cell battery should last between 5 and 7 times longer than a AA-cell. If the price makes sense, you are better off with a bigger battery.
    • For electrically intensive machines, consider a centralized large battery. A large 6V Alkaline lantern battery is equivalent to about 8 D-cells. A small lantern battery is equal to about 4 D-cells. A centralized battery means only one thing to check, one thing to hook up.

Microcontrollers for Mission Possible

  • Please note: Microcontrollers and any other programmable devices are not competition legal for the 2018-19 season*

Microcontrollers are becoming more prevalent in this event. You can use something ready-to-go like an Arduino, or you can make your own system using something cheap like an Attiny25 microcontroller. Microcontrollers can make devices more complex and expensive, but they can also make them more reliable and flexible.

Make sure that no microcontroller-controlled action lasts for more than ten seconds.

  • Always include a copy of your code at device impound. If the judge doesn't want it, that's fine, but he might.
  • At least one person present for the running of the device should be able to fully explain the code.
  • Comment your code enough that a reader will at least get the general idea of what is going on.
  • Be especially clear in your comments whenever you use a timer or wait(variable) command if the event prohibits certain time manipulations or parallel events.
  • When you can, code the actions so that they trigger at variables that are dependent on the current environment, rather than a static number. What I mean by this is that you should try to include sections of code that let your machine adapt to the current light/sound/temperature conditions. Take a sample of the conditions and then have the transfer trigger whenever the sensor reaches "conditions + 5" or whatever is appropriate.

Past Years

Description and Scoring for 2014 and 2015 seasons

Teams must design, test, build, and document a Rube Goldberg® - like device that completes a required Final Task using a sequence of consecutive Energy Transfers. Specific rules have varied widely over the years, so this wiki attempts to address the more recent iterations.

The rules for 2014 require that the builders document their device as a sequence of "energy transfers" , in which the form of energy (mechanical/electrical/chemical/thermal/electromagnetic) changes as the sequence of events progresses. In contrast, the most recent previous B and C division Mission Possible events allowed students to choose from a list of specified transfers, such as "Release the energy stored in a spring, such that it causes the next action." Some general rules that are usually part of every Mission Possible event are:

  • The machine must start and end with specific tasks, which are heavily weighted for scoring purposes. It is recommended for teams to use very reliable steps for such tasks because of the significant amount of points awarded.
  • Bonus Tasks can be attempted to earn more points.
  • A Target Time is specified with maximum points being awarded when the device achieves the Target time exactly. They are usually penalties for going over time.
  • Limits are placed on maximum device dimensions, battery voltage, run time, and danger level of components.
  • Penalties are assessed for violating construction rules and for touching the device during operation.
  • Additional requirements or opportunities for points are specified for the different levels of competition or the rules for each year.
  • An Energy Transfer List (ETL) is required to list the steps that the device performs.

Wow! If you are new to Mission Possible, you may be thinking, "This is too much! There is no way I will ever be able to do all of that!" The result of this reaction is that many competitions have only about half as many Missions as there are teams. Many students are intimidated to the point of not even trying. But here is something to think about - you don't need a Mission that has the maximum steps possible in order to compete or win. If the only thing you did was to build the Starting and Ending tasks - for 2014 that would mean to dump the items into the device and figure out a way to light the bulb, you would score 350 points - far more than all of the teams that didn't even try. And you could probably make this pretty much smaller than 60X60 x 60 cm, so you would score points according to rule 5c as well. A modest number of steps that work well is better than a large number that are unreliable!

Sample ETL (2005 and before)
  • Here is a sample list: Check your event rules for exact formating specifications.
     START ------------------------ quarter is dropped ------------------------------- M
     M ------------------------- quarter connect switch ------------------------------ E
     E ------------------------- power ignites magnesium ----------------------------- T
     T ------------------ heated magnesium sets off thermite ------------------------- C
     C --------------------------- Thermite creates light --------------------------- EM
     EM --------------------- intense light powers photo cell ------------------------ E
     E -- Power activates Jacob's ladder, making heat and launching ping pong ball --- T
     T ---------------------------- heat ignites rodent ------------------------------ C
     C ---------------------- Burning rodent runs in tread mill ---------------------- M
     M --------- rotating tread mill tips vial, spilling ammonia into clorox --------- C
     C ---------------- Pressurized chlorine gas shatters glass container ------------ M
     M --- flying shards impact lever, launching ping pong ball and closing switch --- E
     E -------------- power activates 1000w spark gap transmitter ------------------- EM
     EM ------------------ interference interrupts TV reception ---------------------- E
     E ---------------- screwed up TV makes toddler have tantrum --------------------- M
     M ---------------------- sound from toddler trips circuit ----------------------- E
     E ----------------------------- circuit rings bell ------------------------------ M
     M ---------------- sound from bell activates Pavlov Dog, causing drool ---------- M
     M ------------------- drool fills cup, tripping liquid sensor ------------------- E
     E ----------------------- motor turns launching ping pong ball ---------------- END


Training info for Mission Possible from 2002 - originally presented at a workshop in Ohio