**E178: Assignment 2** |[home](../index.md.html)|[syllabus](../syllabus.md.html)|[assignments](../assignments.md.html)|[labs](../labs.md.html)|[final project](../finalproject.md.html)|[flight data](../FlightData.md.html)|[getting certified](../RocketryCertification.md.html)| # Open Rocket Open Rocket is a Java app, but a group of dedicated volunteers have created installers for it. Go to [Open Rocket](https://openrocket.info/) to get a version that is appropriate for your computer and OS. There are some outdated hints for usage at [Some Hints for Open Rocket](../PDF/OpenRocketHints.pdf). Create an Open Rocket model of your LOC Weasel from the data you measured for [Lab 1](../labs/lab1.md.html). Weigh your avionics assembly or the example model avionics assembly (use 84 g if you don't have access to the avionics, or you don't have access to a scale), and include it as a mass in your model. Record and report the model mass and center of mass as calculated by Open Rocket. Record and report the actual model mass and center of mass for the example rocket. Comment on the differences from the modeled mass and CM. # F67-9W Flight Simulate a flight of your LOC Weasel with an Aerotech F67-9W two different ways: 1. Use Open Rocket and your measured mass and CM. 2. Use the model from Assignment 1 and approximate the F67-9W thrust curve as you think appropriate. # H128W-14A Flight Simulate a flight of your LOC Weasel with an Aerotech H128-14A two different ways: 1. Use Open Rocket and your measured mass and CM. 2. Use your 1D model from Assignment 1 and approximate the H128-14A thrust curve as you think appropriate. For ground conditions, use the likely or reported weather conditions at 9 am in [Lucerne Valley](https://www.wunderground.com/forecast/us/ca/lucerne-valley) on Saturday, 10 February 2024 Compare your results from the two models. Determine if the ejection happens before or after apogee. If it's after apogee, determine the optimal delay adjustment so that the parachute ejects right at apogee. It is _not_ cheating to use the column labeled "Optimum delay" in the Open Rocket results. Rerun your Open Rocket model with the optimal delay. Compare these results with the GPS altitude data from the Weasel H128W-14A flight on 07/08/2023 in [2023-07-08-LogExcel.xlsx](../FlightData/Weasel/2023-07-08-LogExcel.xlsx). # Deliverables Your deliverables are: 1. A written report describing your process and results that must include: 1. A comparison of the rocket mass and center of mass as determined by the Open Rocket model constructed from your parts measurements from Lab 1, with the measured values from the example rocket. 2. A graph plotting the results of your two models for _acceleration_ for the F67-9W motor from liftoff past ejection. 3. A graph plotting the results of your two models for _velocity_ for the F67-9W motor from liftoff past ejection. 4. A graph plotting the results of your two models for _altitude_ for the F67-9W motor from liftoff past ejection. 5. A graph plotting the results of your two models for _altitude_ for the H128W motor from liftoff past ejection for the optimal delay time with the GPS Altitude data from the 07/08/2023 flight 6. An explanation, possibly including a marked graph, explaining how you calculated the optimal delay adjustment. 2. The model file from Open Rocket that includes your runs. Standard report components, such as introduction, conclusions, and recommendations would be nice, but aren't required.