1. Critical Design Review Team Floating Point MIT 16.00 April 25, 2003

2. Team Members Caroline Reilly David Lafferty Elsa Castillo Synthia Tonn Tudor Masek

3. Objectives To demonstrate the final design for the Lighter Than Air vehicle. And to demonstrate the expected performance of the final design in order to ensure that it is optimal and ready to be built.

4. Previously Approved Design

5. Final Design

6. Final Design Concept Beam as main body 2 balloons 1motor 1rudder 2 servos (1 for the rudder and 1 for the motor) Horizontal Stabilizer

7. Control Systems The rudder is the main control surface for our design. It gives us the ability to turn, and it also acts as a stabilizer. Use of the motor for vector thrust (acts as an elevator). Use of a horizontal stabilizer in order to maintain steady flight.

8. Vehicle Mass Estimates ComponentMass (in grams) Battery160 Speed controller8 Receiver27 Servo (Elevator) 43 Motor230 Propeller10 Servo (Rudder) 43 Rudder48 Body87 Subtotal656 Payload 500 Total1056

9. Aerodynamic Analysis Assuming mass is 1.056 kilograms (full payload) Thrust needs to equal 1.4 N for steady level flight Drag is equal to.43 N with 10% increase for body drag =.473 N Estimated cruising speed = 1.9 m/s

10. Final Design Evolution The changes made to the design were to make the structure lighter and faster: The second motor was removed from the design because the advantage it would provide in speed is not worth the additional weight. We decided that for our purpose a beam of balsa wood was just as effective and more convenient than a truss structure. We also concluded that 2 balloons would provide sufficient lift for our vehicle.

11. Gnatt Chart

12. Picture of our LTA (so far)

13. Questions???