1. THE ROCHESTER INSTITUTE OF TECHNOLOGY MICROGRAVITY DROP TOWER P14651 Project Description Background: Microgravity is a condition in which objects experience the effect of ‘floating’ from a relative perspective. Microgravity can be simulated near Earth’s surface for brief periods of time by putting objects in a state of freefall and eliminating all forces, except gravity. One method of achieving this is with the use of a ‘drop tower’. Purpose / Goal: The team was given the task of designing and building a microgravity drop tower to be used for educational and research purposes at RIT. The drop tower design must drop two objects simultaneously within a vacuum environment, while tracking one objects descent to calculate standard gravity. The tower must be fun, educational, easy to operate and aesthetically pleasing. https://edge.rit.edu/edge/P14651/public/Home Project Description Background: Microgravity is a condition in which objects experience the effect of ‘floating’ from a relative perspective. Microgravity can be simulated near Earth’s surface for brief periods of time by putting objects in a state of freefall and eliminating all forces, except gravity. One method of achieving this is with the use of a ‘drop tower’. Purpose / Goal: The team was given the task of designing and building a microgravity drop tower to be used for educational and research purposes at RIT. The drop tower design must drop two objects simultaneously within a vacuum environment, while tracking one objects descent to calculate standard gravity. The tower must be fun, educational, easy to operate and aesthetically pleasing. https://edge.rit.edu/edge/P14651/public/Home Release Mechanism Laser Tracking System Structural Frame Pump Vacuum Chamber & Energy Dissipation Design Achievements  Requirements  Drop two objects simultaneously with zero lateral velocity  Center objects consistently under laser sensor  Support a maximum object weight of 0.23kg (~0.5lb)  Be removable and adaptable  Solution  Used an Arduino Uno microcontroller to actuate servo motors.  Connected the servos to doors via a 3:1 gear ratio. This ensured that the doors were quick enough to allow the objects to fall simultaneously, while strong enough to hold the max object weight.  Used sloped doors with custom geometry to center the object.  Made the mechanism adaptable and removable by using screws to hold all the parts together (no glue).  Results  Objects fell simultaneously with zero horizontal velocity.  The door geometry centered the objects consistently.  The doors were able to hold all tested objects.  The mechanism proved to be quite adaptable and easily removable.  Requirements  Drop two objects simultaneously with zero lateral velocity  Center objects consistently under laser sensor  Support a maximum object weight of 0.23kg (~0.5lb)  Be removable and adaptable  Solution  Used an Arduino Uno microcontroller to actuate servo motors.  Connected the servos to doors via a 3:1 gear ratio. This ensured that the doors were quick enough to allow the objects to fall simultaneously, while strong enough to hold the max object weight.  Used sloped doors with custom geometry to center the object.  Made the mechanism adaptable and removable by using screws to hold all the parts together (no glue).  Results  Objects fell simultaneously with zero horizontal velocity.  The door geometry centered the objects consistently.  The doors were able to hold all tested objects.  The mechanism proved to be quite adaptable and easily removable.  Laser Distance Sensor  MICRO-EPSILON ILR 1030-8, laser class 2  Measuring range of up to 8 meter w/ 10 millisecond response time  Circuit w/ Resistor  Powers laser & converts signal from current to voltage  Data Acquisition Device (DAQ)  Takes laser analog voltage data and sends signal to computer via USB  Labview Program  Allows user to select chamber environment (Atmosphere – Vacuum)  Uses data signal to display graph of object’s position vs time  Allows user to save data for further analysis  Results  Able to capture entire object descent  Measures Standard Gravity (9.81 m/s 2 ) within 1% Error  Laser Distance Sensor  MICRO-EPSILON ILR 1030-8, laser class 2  Measuring range of up to 8 meter w/ 10 millisecond response time  Circuit w/ Resistor  Powers laser & converts signal from current to voltage  Data Acquisition Device (DAQ)  Takes laser analog voltage data and sends signal to computer via USB  Labview Program  Allows user to select chamber environment (Atmosphere – Vacuum)  Uses data signal to display graph of object’s position vs time  Allows user to save data for further analysis  Results  Able to capture entire object descent  Measures Standard Gravity (9.81 m/s 2 ) within 1% Error Customer & Sponsor: Dr. Satish Kandlikar Faculty Guide: Charlie Tabb Team Members: Dustin Bordonaro (ME) Yoem Clara (ME) Jacob Gray (ME) Adam Hertzlin (ME) Santiago Murcia (ME) Customer & Sponsor: Dr. Satish Kandlikar Faculty Guide: Charlie Tabb Team Members: Dustin Bordonaro (ME) Yoem Clara (ME) Jacob Gray (ME) Adam Hertzlin (ME) Santiago Murcia (ME) Dr. Satish KandlikarCharlie TabbSantiago Murcia, Yoem Clara, Dustin Bordonaro, Jacob Gray & Adam Hertzlin  Vacuum Chamber  Schedule 40 clear PVC pipe  0.15m (6in) diameter  2.7m (9ft) tall  Catching Mechanism  Polystyrene bead filled sack  Absorbs energy dissipated by falling objects  Stand  Removable 0.20m (8in) tall stand  Supports any stationary vacuum experiments  Results  Allows full view of drop  Full absorption of energy from falling objects  Adaptable for non-falling experiments  Vacuum Chamber  Schedule 40 clear PVC pipe  0.15m (6in) diameter  2.7m (9ft) tall  Catching Mechanism  Polystyrene bead filled sack  Absorbs energy dissipated by falling objects  Stand  Removable 0.20m (8in) tall stand  Supports any stationary vacuum experiments  Results  Allows full view of drop  Full absorption of energy from falling objects  Adaptable for non-falling experiments  VP6 CPS two stage Vacuum Pump  6.25 CFM at 60 Hz  Ultimate vacuum pressure of 23 microns  Weldless Bulkhead  Connection allows for vacuum hose to be connected though the bottom polycarbonate cap  Seals against each side of plate via gasket  Digital Vacuum Gauge  Measures pressure from atmospheric to vacuum  Piping system  Minimizes pressure leak rate  Results  System reaches ultimate pressure in 10 – 12 minutes  Full integrated system reaches ultimate pressure of 150 microns  Full system leak rate of less than 150 microns per minute  VP6 CPS two stage Vacuum Pump  6.25 CFM at 60 Hz  Ultimate vacuum pressure of 23 microns  Weldless Bulkhead  Connection allows for vacuum hose to be connected though the bottom polycarbonate cap  Seals against each side of plate via gasket  Digital Vacuum Gauge  Measures pressure from atmospheric to vacuum  Piping system  Minimizes pressure leak rate  Results  System reaches ultimate pressure in 10 – 12 minutes  Full integrated system reaches ultimate pressure of 150 microns  Full system leak rate of less than 150 microns per minute  Demonstrates standard local gravity  Drops two objects simultaneously  Allows for full drop visibility  Educational and inspiring  Mobile and stable structure  Aesthetically pleasing  Allows further static experiments  Demonstrates standard local gravity  Drops two objects simultaneously  Allows for full drop visibility  Educational and inspiring  Mobile and stable structure  Aesthetically pleasing  Allows further static experiments  Allows for adjustable pressure  Displays tower pressure  Appropriate tower height  Provides safe and intuitive operation  Drops objects with no horizontal motion  Allows objects to be changed out  Adaptable for a future continuous lift mechanism  Allows for adjustable pressure  Displays tower pressure  Appropriate tower height  Provides safe and intuitive operation  Drops objects with no horizontal motion  Allows objects to be changed out  Adaptable for a future continuous lift mechanism  Drop Tower Frame  Backbone of the microgravity drop tower  Supports vacuum chamber in a stable, upright position  Uses height adjusters at base to level the entire structure  Facilitates easy transportation via wheels, once tipped back  Swing out brackets at base of tower allow for added stability  Frame lays level when placed horizontally during transport and can be pushed flush against a wall during operation  Drop Tower Frame  Backbone of the microgravity drop tower  Supports vacuum chamber in a stable, upright position  Uses height adjusters at base to level the entire structure  Facilitates easy transportation via wheels, once tipped back  Swing out brackets at base of tower allow for added stability  Frame lays level when placed horizontally during transport and can be pushed flush against a wall during operation Pressure Conversions  1 Atmosphere equivalent to: 14.7 psi 101.325 kPa 760 Torr 760,000 microns Pressure Conversions  1 Atmosphere equivalent to: 14.7 psi 101.325 kPa 760 Torr 760,000 microns