16.885J Aircraft Systems Engineering

Dr. Jeffrey A. Hoffman is Professor of the Practice of Aerospace Engineering in the Department of Aeronautics and Astronautics at MIT. Dr. Hoffman received a B.A. (summa cum laude) from Amherst College in 1966 and a Ph.D. in astrophysics from Harvard University in 1971. He subsequently received a M.Sc. in Materials Science from Rice University in 1988. He spent one year as a post-doctoral fellow at the Smithsonian Astrophysical Observatory, after which he worked on the research staff of the Physics Department at Leicester University in the UK (1972-1975) and MIT’s Center for Space Research (1975-1978). He was a NASA astronaut from 1978-1997, having made five space flights and becoming the first astronaut to log 1000 hours of flight time aboard the Space Shuttle. Dr. Hoffman was Payload Commander of STS-46, the first flight of the US-Italian Tethered Satellite System. He played a key role in coordinating the scientific and operational teams working on this project. Dr. Hoffman has performed four spacewalks, including the first unplanned, contingency spacewalk in NASA’s history (STS 51D; April, 1985) and the initial repair/rescue mission for the Hubble Space Telescope (STS 61; December, 1993). He worked for several years as the Astronaut Office representative for EVA and helped develop and carry out tests of advanced high-pressure space suit designs and of new tools and procedures needed for the assembly of the International Space Station. For several years, he was the astronaut office’s representative on the Payload Safety Panel. Following his astronaut career, Dr. Hoffman spent four years as NASA’s European Representative, based at the US Embassy in Paris, where his principal duties were to keep NASA and NASA’s European partners informed about each other’s activities, try to resolve problems in US-European space projects, search for new areas of US-European space cooperation, and represent NASA in European media. In August 2001, Dr. Hoffman joined the MIT faculty, where he teaches courses on space operations and design and space policy. Dr. Hoffman is director of the Massachusetts Space Grant Alliance, responsible for statewide space-related educational activities designed to increase public understanding of space and to attract students into aerospace careers. His principal areas of research are advanced EVA systems, space radiation protection, management of space science projects, and space systems architecture.

Professor Aaron Cohen was born in Corsicana, Texas, on 5 January 1931. He received a B.S. degree in Mechanical Engineering from Texas A&M University in 1952 and an M.S. degree in Applied Mathematics from Stevens Institute of Technology in 1958. He received an Honorary Doctor of Engineering from Stevens Institute of Technology (1982) and an Honorary Doctor of Humane Letters from University of Houston-Clear Lake (UH-CL) (1989). In August 1993, Professor Cohen was appointed H.B. Zachry Professor of Engineering at Texas A&M University, where he taught senior mechanical engineering design. In August 2000 he became a professor emeritus of mechanical engineering. Professor Cohen served as Director of NASA's Lyndon B. Johnson Space Center in Houston, Texas, culminating a career that began there in 1962. He held several positions leading to his appointment as Manager of the Command and Service Module in the Apollo Spacecraft Program Office. In 1972, he was named Space Shuttle Orbiter Project Manager, responsible for design, development, production, and test flights. In 1982, as Director of Research and Engineering, he directed and managed all engineering and life science research and development. In 1986, Professor Cohen was named Center Director, directing approximately 3,600 NASA employees and 14,000 support contractor personnel. In addition, he served for a year as the Acting Deputy Administrator of NASA. Professor Cohen is a Fellow of American Astronautical Society (AAS), an Honorary Member of the American Society of Mechanical Engineers, and an Honorary Fellow in American Institute of Aeronautics and Astronautics. At NASA, he was awarded two Exceptional Service Medals, two Outstanding Leadership Medals, and four Distinguished Service Medals. Other awards include Presidential Rank of Meritorious Executive for Senior Executive Service (SES) (1981); Distinguished Executive for SES (1982, 1988); AAS’ W. Randolph Lovelace II Award, Space Flight Award, and President's Certificate of Recognition; AIAA Von Braun Award for Excellence in Space Program Management; Goddard Astronautics Award (1996); Von Karman Lectureship in Astronautics; 1984 ASME Medal; Texas A&M College of Engineering Alumni Honor Award (1987), Distinguished Alumni Award (1989); and UH-CL Distinguished Leadership Award (1988). He was elected a member of National Academy of Engineering (1988), was a joint recipient of the 1989 Goddard Memorial Trophy, and was awarded the Gold Knight of Manage¬ment Award, NMA Texas Gold Coast Council (1989). He received the Senior Executives Asso¬ciation Professional Development League Executive Excellence Award for Distinguished Executive Service and the National Space Trophy from the Rotary National Award for Space Achievement Foundation, and the 1992 Roger W. Jones Award for Executive Leadership from American University. Professor Cohen has authored many articles for scientific and technical journals and publications and presented the Lawrence Hargrave Lecture at the International Aerospace Congress in 1991.

Topics Included:
The Shuttle Origin or The Making of a new Program. Dale Myers. Pre Lunar Landing Planning. Jim Webb didn’t want future plans. Tom Paine. NASA increasing budgets, Agnew Study with Bob Seamans, Tom Paine, Lee Dubridge, 12 man Space Station, Lunar orbit, Lunar Base, Two stage fully recoverable Shuttle, SkyLab with 5 visits by Command Modules. Mars program by 1983, Vietnam, Great Society budget, Nixon not a big supporter. Mueller leaves in late 1969, Paine leaves in late 70, Myers (1/70) and Fletcher (4/71). NASA Strategy-1970, Shuttle is first priority, Start 2 stage Shuttle Phase B. Cancel Apollo 18 and 19 and Saturn 1b and V, Cancel 2nd Skylab and CSM’s, Cancel Mars program, Reusability equals low cost. Ballistic systems. The Technology Development 1950-1970, Burnelli lifting body. X-20 Dynasoar delta wing, HL-10 Lifting body, X-24A-Lifting body, X-15-Winged, internal fuel, X-15-Winged, internal and external fuel. Evolution of the Shuttle 1969-1971. Metal shingles (or unobtainium or some ablative), Payload bay 12X40, space servicing (i.e. Hubble). Evolution of Requirements, Non ablative reusable thermal protection, Two fully recoverable piloted stages. Automatic checkout and 30 day turnaround. Phase B showed Development of two stage fully recoverable Shuttle costs $14B for R&D. Nixon says “Build any shuttle you want as long as it doesn’t cost more than $5B”, OMB says “make it cost effective”. NASA looked for alternatives with new Phase A. Single Stage to orbit, Trimese, X24B surrounded with tanks, External Orbiter tanks, Parallel or series booster. The Mathematica Study. To convince OMB, Nixon and Congress we hired Mathematica to do cost effectiveness study, Results showed today’s configuration best, Delta wing for crossrange. Weight increase for military payloads, Parallel External throwaway monocoque tank, 2 Recoverable, abortable solids. Liftoff thrust augmentation with engines in Orbiter Resulting Program, Reusable Orbiter and engines. Reusable solid cases, expendable fuel tank. Design Issues, Straight vs Delta wing, Delta wing required for crossrange. External vs internal tank(s), External much lighter. Fuel transfer difficult. Thermal Insulation. Ceramic tiles, carbon-carbon and blankets. Solids or liquid booster. Solids looked more reliable and cheaper R&D. Engine location and type, Start on ground safer, better performance. Staged combustion better performance. Retractable turbojets. No-Depend on low L/D landings. Series vs parallel boosters. Series heavy, less performance Design. 2 Solids vs. 1 or 2 Liquid strapons. Solids had a better reliability record. Thermal Insulation, Ceramic tiles, carbon-carbon, and external insulation blankets. High pressure staged combustion engine. Crew escape. Operations Costs. Enormous confidence from the Apollo program. Studies by American Airlines, IDA and the Aerospace Corporation confirmed NASA operations costs. Difficult cutting edge technology (Engine and Thermal). FO/FO/FS. Cost tradeoffs between R & D and Operations Operations Cost. In 1970, $10M/flight price was based on same accounting system used for Apollo-hands on only, with a separate account for overhead. With $400M/year overhead, and inflation according to the consumers price index, cost per flight would be:
-1970 1981 2005 40 flts/year, no overhead $10M $23M $50M 40 flts/year, include ovhd. $20M $45M $101M
- 8 flts/yr, include overhead $60M $135M $302M
Shuttle Performance. The Shuttle has done everything it was designed to do. It has delivered Military, commercial, and scientific payloads to LEO and GEO, retrieved and replaced satellites, repaired spacecraft, and launched elements of the Space Station. In the 80’s, shuttle had 4% of launches, 41% of mass launched. Shuttle R&D was within what Nixon and Fletcher agreed. ($5.2B +20% reserve in 1970$). Missed two key design issues (cold O rings and foam shedding). A two stage reusable system would have missed worse. Spacecraft are not “like an airplane”. No reusable space system develops decades of evolutionary model improvement. Every reusable system is exposed to enormous environmental variations. Thermal, vibration, pressure, Mach Number. For the next program, keep it simple. Don’t stretch the technology. Use good margins of safety. Keep it as small as possible. Carry as few passengers as possible. Carry people or cargo, not both. Keep requirements to a minimum. Use as many past components and systems as have been proven reliable. Design for operations. Easy access, one man can replace boxes, etc. Keep a program design reserve to reduce Ops. costs.
 

Topics Included:
1952 fully reusable launch vehicle concept discussed
1962 fully reusable vehicle seriously considered.
Air Force studied project dynasoar, cancelled in
1969 NASA adopted the idea of a fully reusable space ship

Top Level Requirements: fully reusable, 14 day turn around to next flight, deploy and retrieve payloads, design, development & test phase estimated to be 5.1b in 1971 dollars. Original cost per flight for 65,000 pounds was 10.5m per flight in 1971 $ for a flight rate of 60 per year

Shuttle studies: Phase “A” studies conducted to determine basic requirements and their effect on design in 1969
Principal Issues: size and weight of payload, cross range of the orbiter, heat-resistant structure or reusable insulating material, hypergolic reaction control system or liquid oxygen/hydrogen, fly- by-wire flight control system, wind tunnel tests to determine wing size and configuration, air breathing engines were considered for fly back; later were determined to be too heavy, entry techniques, landing speed, approach patter.

Shuttle Studies: Phase “B” studies were performed in mid 1970’s to determine a preliminary design.
Results: fully recoverable orbiter, disposable fuel tank, parachute-recoverable solid rocket boosters, high performance hydrogen-oxygen engines placed in the orbiter to be recovered, fully reusable with fly-back booster was greater than 5.1b. Many configurations were studied. Turn around time required landing a winged vehicle on a runway. Payload deployment and retrieval requirement determined location of orbiter on launch configuration.

Major shuttle configuration decisions: hydrogen/oxygen main engines. Sized the liquid oxygen/hydrogen tank, which is not reusable. Solid rocket boosters provided the additional propulsion required to get the orbiter into earth orbit. Solid rocket boosters designed to be recovered and re-used. Orbiter entry cross range required delta wings. Deletion of air breathing engines for moving orbiter required the Boeing 747 to carry the orbiter. FO/FS guidance, navigation, and control system. Fly- by- wire with a digital auto pilot. Size of payload bay 60 feet long by 15 feet diameter. Size of crew cabin defined to be over 2600 cubic feet. Payload 65,000 pounds at lift off and 35,ooo pounds at landing. The orbiter is a launch vehicle, a space craft, and an aircraft.

Hardware Sub-Systems: thermal protection system, structures, space shuttle main engines, hydraulic, aux power, fuel cells. OMS, & RCS systems. Guidance, navigation, and control. Environmental control & life support in crew cabin. Landing & mechanical systems, communications, electrical power.

Orbiter Sub-Systems: functions that are required to be performed (functional requirements), performance that is required (performance requirements), weight, interfaces, available technology, schedule, cost
Analytical Studies: aerodynamics, aerothermodynamics

Professor Aaron Cohen was born in Corsicana, Texas, on 5 January 1931. He received a B.S. degree in Mechanical Engineering from Texas A&M University in 1952 and an M.S. degree in Applied Mathematics from Stevens Institute of Technology in 1958. He received an Honorary Doctor of Engineering from Stevens Institute of Technology (1982) and an Honorary Doctor of Humane Letters from University of Houston-Clear Lake (UH-CL) (1989). In August 1993, Professor Cohen was appointed H.B. Zachry Professor of Engineering at Texas A&M University, where he taught senior mechanical engineering design. In August 2000 he became a professor emeritus of mechanical engineering. Professor Cohen served as Director of NASA's Lyndon B. Johnson Space Center in Houston, Texas, culminating a career that began there in 1962. He held several positions leading to his appointment as Manager of the Command and Service Module in the Apollo Spacecraft Program Office. In 1972, he was named Space Shuttle Orbiter Project Manager, responsible for design, development, production, and test flights. In 1982, as Director of Research and Engineering, he directed and managed all engineering and life science research and development. In 1986, Professor Cohen was named Center Director, directing approximately 3,600 NASA employees and 14,000 support contractor personnel. In addition, he served for a year as the Acting Deputy Administrator of NASA. Professor Cohen is a Fellow of American Astronautical Society (AAS), an Honorary Member of the American Society of Mechanical Engineers, and an Honorary Fellow in American Institute of Aeronautics and Astronautics. At NASA, he was awarded two Exceptional Service Medals, two Outstanding Leadership Medals, and four Distinguished Service Medals. Other awards include Presidential Rank of Meritorious Executive for Senior Executive Service (SES) (1981); Distinguished Executive for SES (1982, 1988); AAS’ W. Randolph Lovelace II Award, Space Flight Award, and President's Certificate of Recognition; AIAA Von Braun Award for Excellence in Space Program Management; Goddard Astronautics Award (1996); Von Karman Lectureship in Astronautics; 1984 ASME Medal; Texas A&M College of Engineering Alumni Honor Award (1987), Distinguished Alumni Award (1989); and UH-CL Distinguished Leadership Award (1988). He was elected a member of National Academy of Engineering (1988), was a joint recipient of the 1989 Goddard Memorial Trophy, and was awarded the Gold Knight of Manage¬ment Award, NMA Texas Gold Coast Council (1989). He received the Senior Executives Asso¬ciation Professional Development League Executive Excellence Award for Distinguished Executive Service and the National Space Trophy from the Rotary National Award for Space Achievement Foundation, and the 1992 Roger W. Jones Award for Executive Leadership from American University. Professor Cohen has authored many articles for scientific and technical journals and publications and presented the Lawrence Hargrave Lecture at the International Aerospace Congress in 1991.

Topics Included:
Auxiliary Power Unit subsystem, coupling, shut-off valve, flexible nose, dynatube fitting, pressure relief, APU, Rockwell, Hydraulic Actuator System, aerosurfaces, umbilical retraction, main engine, thrust vector control actuator, FCS - Flight Control System, IMU - Inertial Measurement Unit, MDM - Multiplexer, Demultiplexer, MPS - Main Propulsion System, RCS - Reaction Control System, SRB - Solid-Rock Booster, TACAN - Tactical Air Control and Navigation, TVC - Thrust Vector Control, Apollo Lunar Return, Apollo Orbital Return, Shuttle Orbiter, Integrated Heat Load, Maximum Heating Rate, Main Engine, Servoactuators, Body Flap Power, Elevon Four-Channel Servoactuators, Main Landing Gear, Main Power Pumps, Nose Landing Gear Valves, Nose Landing Gear Strut Actuator, Nose Landing Gear Uplock Actuator, Fuselage, Tail, Aluminium Honeycomb Covers, Conventional Aluminium Structure, Maximum Temperature, Final Design Refinement, Comparative Launch costs, Saturn, Atlas, Titan, Thor Delta, Orbiter, Thermal protection System, Emittance Coating, Tile Body, RTV, SIP
 

Topics included:
Cryogenic fuel tanks, comparative space programs, costs, Nixon Space Doctrine. NASA budget. Exploration if the Moon. Phase B. Shuttle Family Tree. Factor for a decision on a New Reusable Space Transportation System. Economical Feasibility. Thrust Assisted Orbiter Shuttle (TAOS). External Oxygen/Hydrogen tanks the economically preferred choice. Demand for space transportation. Costs summary. Payload costs (satellites). Recurring costs. Non-recurring costs.

Bass Redd was employed for twenty-six years by the National Aeronautics And Space Administration as Chief of the Flight Technology Branch on the Apollo Program, Head of Conceptual Design and Chief of Flight Performance on the Space Shuttle Program, and Chief of Conceptual Design on the Space Station Program. He also served on the Academic Advisory Board of The Texas A&M Aerospace Department. After leaving NASA he became President of Eagle Aerospace while also serving on the board of directors of the Southern Baptist North American Mission Board for eight years. As Chief of Flight Performance he was responsible for ascent flight performance, ascent aerodynamics, ascent heating, SRB separation, ET separation, and Orbiter separation from the 747. For the Space Shuttle Orbiter, his responsibility included entry flight dynamics, entry aerodynamics, and entry heating.

Topics Included:
Aerodynamic design history of the Space Shuttle Orbiter and Integrated Vehicle, Phase A, small personnel vehicle, program requirements, aerodynamics, payload and cruise sizes, body shape, Phase B, Phase C, Phase D, Delta wing, Lockheed and the single stage blended body, two stages fully reused, stage and a half, changing the Newtonian flow, body flaps, boundary layer, CFB program, CG, CP, uncertainties in pressure distributions, new engineers and lack of cooperation, observation, accountability and quality, comeback of engineers after shuttle accident, ethic school recommended to engineers, aerodynamics, Apollo 8, nose engines, entry interface, dynamic pressure, blended control system, angle of attack constant and the velocity vector, aerodynamic heating, dynamic pressure, energy control, touchdown speed, rolling around the velocity vector to control the energy and cross range, vertical stabilizers, reversing engines

BS Mechanical Engineer, Texas A & M. 38 years with the federal government. Worked at the Army Ballistic Missile Agency, under direction of Werner Von Braun, Marshall Space Flight Center and Manned Spacecraft Center (now Johnson Space Center). Test Engineer on Redstone, Subsystem Manager on Apollo, Section Head, Branch Chief, Division Chief, and Director of Engineering at Johnson Space Center. Worked on Redstone, Jupiter, Saturn 1, Saturn 5, Mercury, Gemini, Apollo and the Space Shuttle. Member AIAA since 1957 (American Rocket Society then)
Fellow: AIAA
Fellow: American Astronautical Society
Numerous Awards, Including ASME Westinghouse Gold Medal, Presidential Medal of Freedom, Presidential Meritorious Executive Service, NASA’s Outstanding Leadership, Dwight Look College Of Engineering Outstanding Alumni Honor Award and Several Patents.

Topics Included:

Waste Management and the US$ 20 million toilet, OMS/RCS, OMS RCS, APU Hydraulics, Space Shuttle Program, Jim Chamberlain, Fail OP, 2 engine aircraft, Oxygen/Hydrogen, Oxygen/ Methane, Oxygen/Alcohol, Low development costs, OMS, Bipropellant, MMH-N204, experience-Apollo Agena, Long steady state burns, RCS Monopropellant hydrazine, Too Heavy-Weight, Bi Propellant MMH-N2O4, no gravity, no pressure, Helium bottle, Vibration test, VS fail safe, APU Auxiliary Power unit, PPU-Primary power unit, Dual Tandem actuators, 4 VS 3 Systems, Hydraulics VS Electromechanical, Low Operational costs VS low development costs, Electric VS Turbine, Pressure modulated VS Pulse Modulated, Absent of air and gravity on gas Generator development, Heat soaked to valve in vacuum, Importance of good test program and to think in terms of no gravity and no pressure