Farley  Flight Aerospace LLC     FFA logo

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Provides independent consultation for aerospace engineering issues, particularly in the area of high altitude balloon flight, design and flight simulation.

Conditions of Securing Services
All customers will have to sign an indemnification form, in that you the customer are solely responsible for the proper or improper use of any work product that Farley Flight Aerospace LLC produces for you. 
You the customer should in any case verify any work product with a rigorous test program to insure factors of safety and fitness for service.


Zero pressure balloon design (global shape, gore pattern, material selection, load tape configuration, taking material properties into consideration)

Super pressure balloon design (global shape, gore pattern, material selection, tendon configuration, s-cleft and film creep evaluation, taking material properties into consideration)

Altitude control balloon system sizing

Flight performance of high-altitude balloons (zero pressure, super pressure, super pressure blimps, tandem ZP/SP configurations)

Flight dynamics of high-altitude balloons and balloon systems; ascent, float, descent, electric power energy balance

Balloon-launch dynamics and evaluation

Balloon shape analysis at variable conditions

Balloon thermal environments, film and gas temperatures

Gas calculations for balloons (needed for a given amount of freelift, and back-calculating actual gas quantity from before/after readings of supply tanks)

Gas calculations for lift gas supply tanks (from tank pressure and temperature and number of tanks and fill tubes; final cut-off pressure and cooling deduction)

3-DOF modeling and trajectory of parachute descent


Other Services

Sub-sonic aircraft performance, stability and control estimation

Preliminary design for propellers and optimal matching with DC electric motors

Education: instruction for the physics of high-altitude balloon flight and balloon design/anaylsis

Balloon Envelopes Sized/Designed by R. Farley, and Flown

Apex and base fittings are designed by the balloon manufacturer (not me), not so trivial (where the soft goods transition into the hard goods, very delicate engineering and assembly techniques).  Designing the balloons would not have been possible without the incredible efforts that the NASA Balloon Program Office invested in materials research and characterization.  Many people stand behind the designing of a balloon, with years of effort and insights that allowed me to further the methods.  I am humbled by all the history of balloon people and their work that moved the knowledge forward.  The manufacturing of these balloons require the highest skills and is a testament to the dedication of the build crew.  Never underestimate the skill and level of quality control necessary to make these giant structures with reliable performance.

Old balloon design methods use table look-up methods for a generalized characteristic called the Sigma number, which is a non-dimensional parameter relating the balloon film weight forces to the buoyancy forces.  The method I've developed over 20 years culminated in BalloonDesignFFA, which is a comprehensive design program for meridionally-reinforced membrane balloons.  Flexible enough to follow the natural shape (zero hoop stress), or any given amount of hoop stress (zero-pressure to super-pressure shapes).  It takes into consideration orthotropic material properties of elasticity and temperature shrinkage effects.  It includes accessories such as wires, inflation tubes, exhaust ducts, fittings, caps.  It will determine the actual shape by integrating the modified membrane differential equations in the float environment, then “reverse engineer” the gore shape to room temperature and zero stress so as to have the table pattern for manufacturing.  This pattern can be outputted in a dxf drawing and in x-y tables of semi-widths.  There are calculators at the end that propose sizes for escape ducts and load tape sizes that allow for quick iteration to the desired design.  The super pressure balloons can be either load tape tendon type (biaxial film stress), or foreshortened type (no meridional film stress, all hoop stress), along with a tack-point calculator to determine tacking frequency and locations.

Balloon Launch Dynamics

    Launch-3D LDSD-1

    Launch-3D LDSD-2

LDSD launch tower testing.  Tower height and acceptable wind range/direction determined by R. Farley.

Evaluation of best wind speed range and direction for spool release:

    Launch-3D graphic
Short, stiff-high gross inflation balloons are in jeopardy of punching straight up and having a pop-the-top film failure

    Launch-3D CSBF
Large, long-high gross inflation balloons are in jeopardy of sailing-out into a spinnaker shape and having the aerodynamic loads split the film.

    LSI graph
Load stress index split into evaluating the 2 prime failure modes during the launch simulation.

    Launch closeup

    NTC before accident
Nuclear Compton Telescope 2010 in Alice Springs Australia just before the accident where the payload broke loose and dragged on the ground, giving the local populace a scare.
One lesson learned: never call your payload Nuclear anything.  R.Farley was a member of the NASA investigators for this accident.

The balloon launch dynamics prediction tool is captured in BalloonLaunch-3D which is a 12 degree of freedom dynamic simulation of a balloon launch with the ability to define various winds at different altitudes.  There is perspective-view visual output as well as graphed results.  This informs one as to how viable a launch will be according to the wind response and to the load stress indices.

Ascent, Float, and Descent Balloon Flight Dynamics

BalloonAscent is a flexible balloon flight dynamics simulation prediction tool.  This software is a physics-based 3-D simulation of launch and float behavior for small or large high-altitude polyethylene balloons using atmosphere and winds data.   It calculates the buoyant and drag forces, the radiant and convective heat loads.   It determines flow through horse-tail ducts, and flow through the opening of apex valves.   Simulations are carried out from any longitude and latitude, and at any time of the year.  The earth IR environment is calculated by using an attenuation function reducing the ground source IR value based on the ground temperature and the given emissivity.  The attenuation is calculated from the air mass separating the balloon and source. Ground temperatures are varied sinusoidally between a max day and min night value which combined with the given ground emissivity and the attenuation produces an instantaneous IR flux at the balloon altitude. Combined with this is the atmosphere's IR contribution.

The BalloonAscentFFA software was based on R. Farley’s paper given at the AIAA 2005 Balloon and Aerodynamic Decelerator Conference (Ref AIAA 2005-7412, BalloonAscent: 3-D Simulation Tool for the Ascent and Float of High-Altitude Balloons).

 Ascent profile for 34mcf ZP
34 mcf ZP in Fort Sumner NM allowed to float down during the night until some ballast was dropped.  Simulation nearly perfectly matches flight!
Ascent, float, solar noon, slow afternoon roll-off, sunset, sinking, ballast drops in the night, dawn, ballast drop to kick up back to float altitude.

BalloonAscent-ZP version:
BalloonAscent-ZP GUI

BalloonAscent-SP version:
BalloonAscent-SP GUI

BalloonAscent-VAABBS version (Sky anchor or altitude control configuration):
BalloonAscent-VAABBS GUI

BalloonAscent-Airship version:
BalloonAscent-Airship GUI

image of main form for BalloonAscent-PB

Trajectory Analysis

Of balloon:

    Balloon trajectory grid  

    Balloon trajectory world

For an altitude control balloon station-keeping in June:
station keeping trajectory

Of parachute:

    Parachute trajectory

FFA Parachute Systems Simulator:
     Parachute Traj GUI

And with a general Balloon Calculator package called the Stratospheric Balloon Toolkit:

Stratospheric Balloon Toolkit GUI


Balloon environments 

    Balloon Environment

Detailed physics modeling

Balloon shape generation and stresses
    Line loads

    Day in the life of a balloon

    complex environment

    Natural shape spectrum

    SP vs ZP

    SP 27m group photo
27m 200 gore model super pressure pumpkin designed to defeat the "s-cleft", a global shape instability.  R. Farley is in red shirt on left. 2007 Elizabeth City NC.
Not all the names, but David Pierce, Debbie Fairbrother, Dr. Sergio Pelligrino, Dr. David Wakefield, Dr. Jim Rand, Dr. Frank Baginski, Henry Cathey, Gabe Garde, Dwyane Orr, Mike Smith.

    Size comparisons
Size comparisons to show how enormous these Lighter Than Air (LTA) vehicles can get.

    WV launch
World View launches stratollite (VAABBS vehicle), from Tucson newspaper photo. Link to article

    VAABBS flys over Mt Lemmon
World View VAABBS as captured by University of Arizona Astronomy Department Observatory over Tucson AZ. Link to photo

Altitude control balloon like the Loon explained:
Altitude control explained

SPY Balloon?
Of late in the news has been the odyssey of the Chinese spy balloon as it flew into US air space.  Stratocat and Wikipedia have excellent summeries, but I took the extra step of making a technical analysis from afar for this amazing vehicle.  The balloon designers are to be congratulated.  You can download a pdf version of my report here --> Technical Evaluation of Chinese Spy Balloon

Short History of Stratospheric Balloons

1933 Jean Piccard 1933 flew to 61k ft

1935 Capt. Anderson flew to 72.4k ft

1944 Japanese discover the jet streams and launch “fire” balloons at U.S. west coast

1947 Otto Winzen makes polyethylene balloon with heat seals and load tapes

1947  Holloman AFB home of the military’s use of stratospheric balloons

1950’s Plastic stratospheric balloons used for spying over Soviet Union

1957-1960 MANHIGH/EXCELSIOR III mission, Joe Kittenger jumps from 102.8k ft

1960 National Center for Atmospheric Research (NCAR) became operational

1963 Permanent NCAR balloon base in Palestine Texas NSBF (National Scientific Balloon Facility)

1960’s small, light, Mylar super pressure spheres (GHOST) fly around the world

1970’s NASA started using the facility for heavy lift operations

1987 NASA managed the NSBF (later changed to CSBF)

1990 NASA heavy lift long duration circle Antarctica in polar vortex

2008 NASA 7mcf super pressure pumpkin had 54 day Antarctic flight

2012 Red Bull’s Stratos manned jump from 128.1k ft

2013 Google’s Loon Balloon (super pressure blimp), carries 10kg payload

2015 Paragon’s StratEx manned jump from 135.9k ft

2016 NASA 18.8 mcf super pressure pumpkin circumnavigates the southern hemisphere

2016 World View Gryphon-01 demonstrates altitude control VAABBS (Variable Altitude Air Ballast Balloon System)

 Please excuse if I have missed important dates and projects. I know there are many other history-making balloon projects, but I've focused on the really high-altitude ones.

Rodger E Farley, single member, founder, CTO for Farley Flight Aerospace LLC

B.S. Aerospace Engineering, University of Maryland
M.S. Aerospace Engineering University of Maryland  (flight dynamics, structural dynamics, helicopter design)

1 year at Sikorsky Helicopters as a Rotor Systems Engineer, 35 years as NASA Aerospace Engineer working on such projects as COBE, XTE, TRMM, Lena, TopHat, NightGlow, Sample Analysis on Mars/MSL, MOMA, JWST, sounding rockets, etc.  Then working with the NASA Balloon Program Office as Systems Engineer and envelope designer for the Super Pressure Balloon Program.  He designed the balloon envelopes for a 27m diameter model SP pumpkin, 2 mcf, 7mcf, 14.9 mcf, and 18.8 mcf SP pumpkins, along with a future 26 mcf pumpkin.  Also serverd on investigation teams for balloon incidents such as the NCT in Australia 2010.  After retiring in 2016 he started working as Chief Systems Engineer for Balloon Design, Performance, and Flight Dynamics at World View Enterprises, Tucson AZ, almost 4 years.

 Mr. Farley has produced numerous trade studies and preliminary design studies for projects like JWST, ISIS, CON-X, DUET, FKSI, SPECS, Tirana, LISA, SPIRIT, Decadal Planning, VALOR (Venus balloon), TOAMS (Titan balloon).  He has trouble-shot and reviewed for projects like UARS, MAP, IMAGE, ICESAT, INFOCUS, GOES, SWIFT, STEREO, TWINS, GALEX, QUICKTOMS, SDO, and GPM for problems ranging from light-pressure pin-wheeling, poorly functioning non-explosive actuators, to wire-boom deployment dynamics for spacecraft and sounding rockets.  He has worked on technology development with studies and hardware demos on large precision deployable structures and booms, and x-ray grazing-incidence foil mirrors.  Mr. Farley served as a branch consultant on spacecraft rotary actuator mechanisms, DC and stepper motor sizing for mechanisms, mechanical deployment and pyro actuated devices, and dynamics analyses for non-linear, difficult to model problems.

For out-reach programs, Mr. Farley taught the 2003 and 2005 mechanical design portion of a spacecraft systems design class in the graduate department of aerospace engineering, University of Maryland.  He also taught a virtual seminar for spacecraft deployable structures to NASA engineers from numerous NASA centers.  In 2016 he produced a 15 chapter balloon design class he presented to NASA Wallops Engineers.  He has given his time for several High School presentations on Aerospace Engineering and Celestial Navigation.  Also he has led winning teams for the High School Engineering Challenges for both the cargo ship and cargo airplane contests.  Back in the 1990’s he also evaluated the performance and structural modifications of a home-built aircraft (Quail) that a High School shop teacher was using as a class project.

On loan to the NTSB in 2008 and 2012, he helped in the determination of accident causation for the Zodiac home built aircraft which had wing-aileron flutter issues (2008), and the modified P-51 Mustang Reno racer “Galloping Ghost” which crashed into the stands in 2012 when the elevator trim tab fluttered and broke off.  Mr. Farley’s analyses of stick force and aerodynamic flutter, as well as observations of the wreckage helped to pin point the causes and cures for the problems. 

With an educational background of aerodynamics, aircraft design, flight dynamics and structural dynamics, he has produced computer modeling codes for simulating the dynamic behavior of deployable appendages, stepper motor rotary actuators, rotating beam vibrations, motored-powered flexible mechanisms with PID controllers, 6 DOF rigid body flight simulators, orbit simulations using multi-body special perturbation methods, re-entry vehicle dynamic simulation, propeller design, helicopter blade dynamics and loads, aircraft design, helicopter performance, balloon envelope design and balloon flight dynamics simulation.

When working at World View he invented the Variable Altitude Air Ballast Balloon System (VAABBS) configuration and flight simulated the expected performance to prove efficacy, in tanden with Iain Beveridge who was finding the perfect compressor. He sized and designed all of the super pressure pumpkin balloons and zero pressure lift balloons, including the largest lifting zero pressure balloon ever to fly to 50,000 ft (27,590 lbs gross lift).  Of course none of it would have been possible without the help of a dedicated team who would push for the crazy ideas and start the company (thanks to Taber and Jane), and all of the talented engineers and manufacturing people at World View turning the dream into reality with all of the required detail engineering and manufacturing processes necessary (Iain Beveridge, Ryan Lee, Zane Maccagnano, John Strauss, Esteban Garcia, Sebastian Padilla, and many more).  The devil is in the details, and if it were not for the people commiting to a startup company, and all those involved in ironing out a new design, the dream would just stay as a cartoon and a calculation and never see the light of day.  It does indeed take a village. And vision. And money...

First there was Bill Gibson who had invited me on the super pressure balloon incident investigation in 2003.  That got me tied into the balloon folks at NASA Wallops flight facility (David Pierce, Debbie Fairbrother, Henry Cathey, Gabe Garde, Dr. Jim Rand of Winzen, Julian Nott, etc.) which lead to CSBF folks in Palestine TX (Danny Ball, Dwayne Orr, Robert Mullinax, Erich Kline, etc.), and many more.  But I have to say that again, my (deceased) friend Bill Gibson took me farther down the rabbit hole when one day out of the blue he called me in 2014 and said, "Rodger, I want you to start thinking about altitude control!"  And I did.



“Celestial Navigation in a Teacup”, 2010, LuLu publishing, ISBN-978-1-105-36437-2

“Balloon Design”, 2013, author of chapter 13 in AIAA education series book “Fundamentals of Aircraft and Airship Design Vol 2” ISBN 978-1-60086-898-6



 “Ribbon Cable Strap Free of Backlash, limited rotation joint at cryogenic temperatures” 1990, Published in NASA Tech Briefs GSC-13371

 "Spacecraft Deployable Appendages", 1992, contributing author, GSFC/NASA published internal report

 "Development of the Solar Array Deployment and Drive System for the XTE Spacecraft", 29th Aerospace Mechanism Symposium 1995, conference publication 3293

 “Tethered Formation Configurations:  Meeting The Scientific Objectives of Large Aperture and Interferometric Science”, 2001, AIAA published paper 2001-4770, Space 2001 Symposium

 "BalloonAscent: 3-D Simulation Tool for the Ascent and Float of High-Altitude Balloons", AIAA conference paper 2005-7412

 “Predicting the Deployment Pressure in an Ascending Pumpkin Balloon”, AIAA 2011-6831 contributing author

 “The Sample Analysis at Mars Investigation and Instrument Suite”, 2012, contributing author, Space Science Review

 “Wide Range Vacuum Pumps for the SAM Instrument on the MSL Curiosity Rover”, 2014, contributing author, presented at the 2014 Aerospace Mechanism Symposium

 “Qualification of the NASA Super Pressure Balloon”, 2015, AIAA 2015-2909 contributing author

 “Designing Super Pressure Pumpkin Balloons”, 2016, NASA/TM-2016-217549 Jan 2016 (never released due to formatting non-conformities, and then I retired and it has stayed in limbo)

AWARDS/HONORS since 2000

2001 Exceptional Service Medal,   2001 Group Achievement LENA Imager development team

2002 Group Achievement Award to the Top-Hat project team

2003 Excellence in Outreach Group Award for University of Maryland Aero 691 class instructor

2008 Moe Schneebaum Award for Engineering Excellence at NASA/GSFC

2013 Goddard Exceptional Engineering Award for Sample Analysis on Mars design and integration team

2016 Goddard Honor Award Engineering Team Award for the Super Pressure Balloon Development

2018 AIAA Regional and National Engineer of the Year Awards “For the system design of a controlled lighter than air vehicle which is capable of station keeping in the stratosphere.”

2021 AIAA Otto Winzen Lifetime Achievement Award

    DH84 and me

    me BW



     Teacup Navigation