EARLY APOLLO PILOTED FLIGHT CONTROL SIMULATION -

R&D Defining Pilot Role

in Lunar Mission AIAA ASAT Conference

May 3, 2014

Ron Oglevie Erv Ulbrich

Contents – “How the Moon Was Won”

• PREFACE/INTRODUCTION – HISTORICAL PERSPECTIVE – APOLLO TECHNOLOGY SHORTFALLS

• “MAN-IN-LOOP” SIMULATOR APPROACH – NATIONAL FACILITY SEARCH NAA Columbus Div.

• RENDEZVOUS & DOCKING – SIMULATION SETUP – PILOTING TECHNIQUES – RESULTS

• LUNAR LANDING – SIMULATION SETUP – PILOTING TECHNIQUES – RESULTS

• CONCLUSIONS/OBSERVATIONS – * The contributions of Mr. Erv Ulbrich & the NAA Columbus Division

staff are gratefully acknowledged

PREFACE & MOTIVATION • THE CHRONOLOGY -

– Sputnick had flown,

– Mercury flights planned

– NASA announces Apollo objectives – July, 1960

– Kennedy mandate to send men to the moon* – May 25. 1961

– Apollo contract award (CM & SM) to NAA Downey – November, 1961

• TECHNOLOGY OF THE ERA –

– Analog /discrete circuitry, very slow computers & no PCs

– Piloted control of rocket powered space vehicles not yet demonstrated

• APOLLO TECHNOLOGY SHORTFALL - How can crew best contribute to flight control?

– Rendezvous & Docking -

– Lunar Landing – Terminal maneuvering phase

• Landscape survey, site selection & landing within hover propellant budget

• APPROACH –

– Needed crew validation, & man-in-loop simulation

– National search for simulation facility/talent –

• Yielded North American Aviation, Columbus Div.

• Beautiful M.I.L. simulation studio, originally designed for aircraft, was ideally suited

N.A.A. COLUMBUS M.I.L. SIMULATION STUDIO – Camera Transport Rig

NAA COLUMBUS M.I.L. SIMULATION STUDIO- CREW CAPSULE & PROJECTION EQUIPMENT

EARLY L.E.M. CONCEPT

APOLLO CM & SM DOCKING MODEL

RENDEZVOUS AND DOCKING Visual Piloting Techniques

• Rendezvous Visual Guidance

– Classical proportional navigation at large ranges

– Stabilize target against star-field background

• Docking – primary study emphasis

– Align attitude in 3 axes, translation in 3 D.

– Variety of alignment aids tested – not needed

– Simple probe and drogue system (for visual cues)

• Results – Minimal mechanical capture & attenuation system reqs.

• Results/Conclusions –

– Simple attitude rate command controller adequate

– Modest docking mechanism requirements

– R&D requirements met with simple piloted control systems

LUNAR TERRAIN MODEL AND CAMERA TRANSPORT RIG

LUNAR LANDING –

• PILOTED ROCKET CONTROL – No existing experience

• EMPHASIS – How to fly the Apollo stack (or LEM) to successful landing:

– Touchdown vertical & translational velocity consistent with reasonable leg structure

– Reasonable propellant requirements

– Simple pilot controls and sensors

• CONTROL ALTERNATIVES – Gimbaled TVC

– Attitude – rate, attitude, position command systems

– Throttle – direct or radar altimeter augmented

• PILOT TECHNIQUE -

– Survey terrain during powered descent (facedown) & select preferred area

– Begin control at hover point & maneuvers to selected area

• PERFORMANCE ACHIEVED – Well within reasonable design limits

Piloted Landing Phase

TOUCHDOWN PERFORMANCE

EXAMPLE PILOT PERFORMANCE

CONCLUSIONS/OBSERVATIONS • NAA Columbus OH based simulations validated

feasibility of critical new Apollo lunar mission requirements, rapidly and economically

• Very simple pilot controls found to be adequate for space rendezvous/docking and lunar landing.

• Apollo program success was tremendous achievement in light of Avionics technology of the era

• Helped sell the LEM program – (better visibility) • NAA Columbus simulation studio continued to be used

in refining the Apollo piloted flight control systems, astronaut training, other space systems (including Gemini), & was later moved to Downey CA

• Disclaimer – inaccuracies