The Dayton Engineer

           MAY 2023

Dayton Chapter—Ohio Society of Professional Engineers

PROFESSIONAL BOOK REVIEW: PLANETARY EXPLORATION WITH INGENUITY AND DRAGONFLY: ROTARY_WING FLIGHT ON MARS AND TITAN, by RALPH D. LORENZ

This book outlines the basics of rotary wing flight, these different endeavors, and their intersections, and explains the design goals of Ingenuity and Dragonfly.

Rotary-Wing Flight

Helicopters are controlled by varying the rotary blade pitch as a function of the angle of the blade around the rotary circle.

1. Design of the Mars helicopter Ingenuity

Mars environment: The Martian atmosphere consists mainly of low-density carbon dioxide.

The Ingenuity rotors are made of carbon fiber. Carbon fibers were chosen to limit out-gassing that might contaminate samples that might be collected. The Mach number of the rotor tips determines the rotor span and rotation rate. This design avoids the shock waves that would be produced if the rotor tips should be supersonic.

Power and thermal systems: Electrical power is produced by solar cells. Dust on the solar cells can limit the power output. The flight time of Ingenuity is determined by motor heating—the low atmospheric density limits convective cooling.

The Ingenuity helicopter and the Perseverance rover were delivered by parachute to NASA's 2020 Mars mission in 2021. On April 19 of that year, Ingenuity became the first aircraft to complete a powered, controlled flight on another planet. (Electrical power for the Perseverance rover is produced by a plutonium dioxide-fueled thermoelectric generator.)

1. Dragonfly is a helicopter planned for the operation of Saturn's moon Titan.

Dragonfly is a rotorcraft that is much larger the Ingenuity. It is scheduled to launch in 2027 and arrive on Titan by 2034. Dragonfly is expected to fly many kilometers in each of dozens of flights.

Dragonfly concept:

Dragonfly is planned to be a multi-rotor, relocatable lander roughly the size of Perseverance. Dragonfly is intended to explore dozens of sites across Titan's diverse landscape and access sur- face materials of interest for prebiotic chemistry. Electrical power for Dragonfly is planned to be produced by a plutonium dioxide-fueled thermoelectric generator.

Titan environment

Titan has a thick atmosphere of nitrogen and methane, oceans of methane and ethane, an ice crust, and an internal water ocean.

RALPH D. LORENZ is a Johns Hopkins Applied Physics Lab planetary scientist. His research focuses on understanding how systems and instruments work in planetary environments and exploring surfaces, atmospheres, and their interactions, on Titan, Venus, Earth, and Mars. He is the Mission Architect of Dragonfly, NASA's New Frontiers mission to Titan. He is involved in many NASA and international planetary missions, including Cassini/Huygens, Akatsuki, Insight, Perseverance, and DAVINCI. He received the 2020 International Planetary Probe Workshop (IPPW) Al Seiff memorial award. He is the author or co-author of numerous publications, including Saturn's Moon Titan: Owners' Workshop Manual (2020), Spinning Flight (2006), Space Systems Failures (2005), and Planetary Landers and Entry Probes (2007). He holds a B.Eng. in Aerospace Systems Engineering from Southampton University and a Ph.D. in Space Sciences from the University of Kent.

This book is available at the American Institute of Aeronautics and Astronautics website: AIAA.org.

PROFESSIONAL BOOK REVIEW BY DR. RICHARD HENRY, PE, PH.D., DSPE, PAST PRESIDENT, DSPE

DSPE/OSPE/EFO Calendar

13-16 May   National MATHCOUNTS Competition

       8 Jun            DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club, Ohio Concrete 

       8-9 Jun             All Ohio Engineer Conference, Virtual Presentations

10 Jun            All Ohio Engineer Conference, In-Person annual meetings 

13 Jun               DSPE Board Meeting, 5:15 PM, CHIME Format

       11 Jul           Mark the Date, DSPE Officer/Director Installation, Location TBD

       13 Jul           DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club, Pretek Group, Texas Twin Leaf Precast Concrete Arch Bridge

10 Aug          DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club, Ohio Concrete

       12 Sep         DSPE Board Meeting, 5:15 PM, CHIME Format

       14 Sep         DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club, Annual Legislative Update

The Dayton Engineer

           JANUARY 2023

Dayton Chapter—Ohio Society of Professional Engineers

OSPE is dedicated to advancing professional engineers in Ohio and is the most powerful voice representing all disciplines within the engineering profession. The Dayton Society of Professional Engineers (DSPE) is a chapter of the OSPE serving the local Dayton Region. 

DSPE aspires to conduct a monthly chapter luncheon meeting that will serve our members by providing an opportunity to share professional experiences, network, and gain continuing professional development through exciting presentations on various technical, 

management, and ethics topics in all engineering disciplines. 

Our chapter activities are focused on youth education and college scholarships and include (but are not limited to) the 2nd Grade Coloring Contest via ImagineEngineering, and Middle School MATHCOUNTS.

These are our Society’s flagship events to bring our youth an awareness of the value of science, technology, and especially the engineering profession. It requires hands-on participation and financial contributions from our members, that’s you and me. Your personal and corporate financial contributions are solicited through our Engineers Foundation of Ohio (EFO) to help us host these events locally, state, and nationally (except for the coloring contest). Please consider making a personal contribution and soliciting from your company if they have a community relations department. Contributions through EFO are fully tax-deductible. Please get in touch with us for the tax ID number for your records. 

Even more critical for the success of these events is your hands-on participation. Please get in touch with a board member for opportunities.

Is there anything you would like to see in the Newsletter? Please let me know: — Jon Wheeler, P.E., DSPE Secretary, Newsletter Editor.

DSPE/OSPE/EFO Calendar

9 Feb  DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club

14 Feb DSPE Board Meeting, 5:15 PM CHIME Format

25 Feb MATHCOUNTS Chapter Invitational Wright State University

11 Mar     Ohio MATHCOUNTS Competition, Columbus State Community College 

 9 Mar      DSPE Board meeting, 5:15 PM CHIME Format

14 Mar     DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club 

 8 Apr       State Scholarship Grading

11 Apr      DSPE Board Meeting, 5:15 PM CHIME Format

13 Apr      DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club 

1-13 May DSPE Board of Directors/Officers Elections

9 May DSPE Board Meeting, 5:15 PM CHIME Format

11 May    DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club 

13-16      May National MATHCOUNTS Competition

8 Jun  DSPE Monthly Meeting, 12:00 Noon, Dayton Engineers Club 

13 Jun      DSPE Board Meeting, 5:15 PM, CHIME Format