184_projects:s20_project_7 [Projects & Practices in Physics]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
===== Project 7 =====
==== Project 7A: Power Is Everything ====

The Artemis 13 was able to turn on its boosters and move the craft towards home. Since power is in short supply, several non-vital systems were shut down. However, to successfully go through the landing sequence they MUST turn on the guidance computer system (GCS), Environmental Control Systems (ECS), Communications Relay (CR), the warm-up control for the primers for the parachutes (PP), and the Command Control Module (CCM), as well as a floodlight (FL) in the cockpit using only the main battery (230 V). 

Your team on the ground has been working in a simulator to figure out how to turn on each of the systems in various orders, but keeps running into problems. If the total current from the main battery on board exceeds 0.35 A, the battery will die and the Artemis will lose power before it can return safely to Earth. Your flight expert has sent over the most recent steps he has tried and the data they collected for each step. 

  - Turn on only the CR, which seems to work properly and only draws 0.242 A from the battery.
  - Then turn on the PP, which decreases the current from the battery. The CR seems to barely be functioning so you conclude that it is running at it's minimum power of 18.35 W.
  - Next they turned everything off, and switched on only the PP and the FL. Immediately the warning light goes off in the simulator because the current from the battery is way too high at 1.48 A and the flood light has burnt out because the power in the bulb was 264.6 W (exceeding their maximum power rating of 120 W).
  - You decide to start over and turn everything off again. You turn on the CS, ECS, and CCM - which seems to be perfectly alright. The current from the battery is maintaining at a nice and safe 0.188 A. Since this combination works well, you grab the hand-dandy multimeter and find that the CS, ECS, and CCM have the same current but that the CS is using the most power (17.7 W) and the ECS is using the least (10.6 W).
  - Just to try one more thing, they turn everything off and then turn on only the PP and the CS. You find that even though they have the same voltage the current going through these elements are different.
 
Mission Control wants to try to turn everything on at once as it is currently configured. They are running out of time and need to get something to the Artemis. Will the current configuration of these elements in a circuit allow the Artemis 13 to get home safely??

<WRAP info>
=== Learning Goals ===
  * Use resistor combination rules, loop rule, and node rule to determine the circuit set up.
  * Calculate the equivalent resistance of a circuit.
</WRAP>


==== Project 7B: Austin, we have a snafu ====
The Artemis 13 is almost home but before they complete their final landing sequence the team needs to launch a top-secret deep space probe that will be piloted by Johnny 5 into the eye of the storm over Lakeview. However, the power supply for the whole ship is running critically low, so you are now only running the ECS to maintain oxygen in the command module. You have to somehow power up the probe to complete your mission. You no longer have communications with Austin. 

You notice as you begin powering up the probe (which operates on its own reserve power system) that although the navigational controls have been primed, there are several components that are not responding to testing. It appears that the circuit switch control board got fried during the test jump, as a result, you now need to create a new circuit that will allow you to provide different amounts of energy to the propulsion system's module on the probe.

That propulsion system consists of the primary burners and the cooling system, which have a total resistance of 65 $\Omega$.
The primary burners require a short burst of 200 J to power-up.
The cooling system requires a short burst 300 J to power-up.

You need to be able to deliver different amounts of power to this module; however, you are growing concerned that the power supply the probe has access to of 100 V may not be sufficient to power these probe systems. You manage to find some additional batteries onboard (three 10 V batteries from the supply room) to use if you need them. 

You also have several  0.125F capacitors and resistors (1 $\Omega$, 5 $\Omega$, 10 $\Omega$, 50 $\Omega$, 100 $\Omega$) on hand. 
You also have access to multiple switches that can be used to open and close parts of the circuit you are designing.  

There is a breaker in the circuit that is a failsafe and will trip if the current reaches 2 A. You also know that there are delicate circuit elements in the primary burners and the cooling system, so the propulsion system should not be connected to any power supplies when charging capacitors.

You should provide a circuit diagram of your design that helps you explain to your crew that the current in the circuit is safe and that you are going to be able to supply the needed power to the systems when the time comes to launch the probe. As a check for yourself, you should make sure that the voltage in the circuit adds up to the correct amount as to not suffer any voltage shortages.

<WRAP info>
=== Learning Goals ===
  * Understand how capacitors charge and discharge
  * Use the relationship between capacitance and energy
  * Understand what happens when capacitors are in parallel or in series
  * Understand how capacitors and resistors combine in a complex circuit
</WRAP>