Aerospace engineering on the back of an envelope /
Alber, Irwin E.,
Aerospace engineering on the back of an envelope / Irwin E. Alber. - xix, 326 pages : illustrations ; 25 cm. - Springer-Praxis books in astronautical engineering . - Springer-Praxis books in astronautical engineering. .
Includes bibliographical references and index.
1. Introduction -- 2. Design of a high school science-fair electro-mechanical robot -- 3. Estimating Shuttle launch, orbit, and payload magnitudes -- 4. Columbia Shuttle accident analysis with Back-of-the-Envelope methods -- 5. Estimating the Orbiter reentry trajectory and the associated peak heating rates -- 6. Estimating the dimensions and performance of the Hubble Space Telescope -- -- Introduction -- Why Back-of-the-Envelope engineering? -- Back-of-the-Envelope engineering; an important adaptation and survival skill for students and practicing engineers -- Design of a high school science fair electro-mechanical robot -- Design of a new commercial rocket launch vehicle for a senior engineering student's design project -- Preliminary design of a new telescope system by an engineer transferred to a new optical project -- Examining the principles and ideas behind Back-of-the- Envelope estimation -- What is a Back-of-the-Envelope engineering estimate? -- Tradeoffbetween complexity and accuracy -- Back-of-the-Envelope reasoning -- Fermi problems -- An engineering Fermi problem -- General guidelines for building a good engineering model -- Step by step towards estimation -- Quick-Fire estimates -- Quick-Fire estimate of cargo mass delivered to orbit by the Space Shuttle -- Cargo mass problem definition -- Level-0 estimate: the empirical ''rule of thumb'' model -- Level-1 estimate: cargo mass using a single stage mathematical model based on the ideal rocket velocity equation -- Level-2 estimate: cargo mass using a two stage vehicle model based on the ideal rocket velocity equation -- Level-3 estimate: cargo mass delivered by a two stage vehicle; based on a revised estimate for second stage structural mass fraction -- Impact of added knowledge and degree of model complexity -- Moving from the Shuttle to the Hubble Space Telescope -- Estimating the size of the optical system for the Hubble Space Telescope -- System requirements for the HST -- Shuttle constraint on HST size -- Estimating the length of the HST optical package -- Concluding remarks -- Outline of this book -- References -- Design of a high school science-fair electro-mechanical robot -- The Robot-Kicker Science Fair Project -- Back-of-the-Envelope model and analysis for a solenoid kicking device -- Defining basic dimensions and required soccer ball velocity -- Setting up a Bot Emodel for the solenoid kicking soccer ball problem -- Model for solenoid kicker work and force -- Final design requirements for linear-actuator solenoid and supporting electrical system -- Appendix: Modeling of the temperature rise produced by ohmic heating from single or multiple solenoid-actuator kicks -- Quick-Fire problem approach -- Problem definition and sketch -- The baseline mathematical model -- Physical parameters and data -- Numerical results -- Interpretation of results -- References -- Estimating Shuttle launch, orbit, and payload magnitudes -- Introduction -- Early Space Shuttle goals and the design phase -- The Shuttle testing philosophy and the need for modeling -- Back-of-the-Envelope analysis of Shuttle launch, orbit, and payload magnitudes -- Shuttle launch, orbit, and reentry basics -- The liftoffto orbit sequence -- Reentry -- Inventory of the Shuttle's mass and thrust as input to the calculation of burnout velocity -- Burnout velocity -- The velocity budget -- Mass inventory -- Thrust and specific impulse inventory -- Mass fraction rules of thumb -- Quick-Fire modeling of the takeoffmass components and takeoffthrust using SMAD rules of thumb -- Quick-Fire problem approach -- Problem definition and sketch -- Mathematical/''Rule of Thumb'' empirical models -- Physical parameters and data -- Numerical calculation of total takeoffmass, cargo bay mass, and total takeoffthrust -- Interpretation of the Quick-Fire results -- From Quick-Fire estimates to Shuttle solutions using more accurate inputs -- Ideal velocity change Dv for each stage of an ideal rocket system -- Propellant mass versus time -- Time varying velocity change -- Effective burnout time and average flow rate -- Ideal altitude or height for each rocket stage -- Dvideal estimate for Shuttle first stage, without gravity loss -- Estimate of SSME propellant mass burned during first stage -- First stage mass ratio and average effective exhaust velocity -- Average specific impulse for the ''parallel'' (solidþliquid) first stage burn -- Dvideal estimate for Shuttle first stage -- Dvideal and altitude as functions of time, for the Shuttle first stage -- The effect of gravity on velocity during first stage flight -- Modeling the effects of gravity for a curved flight trajectory -- Time-varying pitch angle model -- Effect of gravity on rocket velocity during first stage flight -- Effect of gravity on rocket height during first stage flight -- Comparing model velocity and altitude with Shuttle data -- Gravity loss magnitudes for previously flown launch systems -- Model velocity, with gravity loss, compared with flight data -- Calculation of gravity-loss corrected velocity at first stage burnout -- The effect of drag on Shuttle velocity at end of first stage flight -- Modeling the effects of drag in the equation of motion -- Estimating first stage drag loss -- Final drag and gravity-corrected velocity at first stage burnout; key elements of the overall ''velocity budget'' for the first stage -- Calculation of second stage velocities and gravity losses -- Pitch and gravity loss modeling for the second stage flight period -- Time-varying gravity loss solution, region 2a -- Time-varying velocity solution, region 2b -- Combined velocity solution for regions1, 2a, and 2b and v(MECO) -- Summary of predicted Dv budget for the Shuttle -- Comparison of Back-of-the-Envelope modeled Shuttle velocity and altitude as a function of time to NASA's numerical prediction for all stages -- Comparison of model velocity with NASA's numerical prediction -- Comparison of model altitude with NASA's numerical prediction -- Modeled altitude sensitivity to pitch time scale -- Estimating mission orbital velocity requirements for the Shuttle -- Part1: circular orbital velocity -- Part2: elliptical orbits and the Hohmann transfer Dv's -- Numerical values for transfer orbit Dv's -- Time of flight for a Hohmann transfer -- Direct insertion to a final orbital altitude (without using a parking orbit) -- A Back-of-the-Envelope model to determine Shuttle payload as a function of orbit altitude -- Analytic model for payload as a function of orbital altitude -- Approximate linearized solution for payload -- Reduction in useful cargo mass due to increases in OMS propellant mass -- OMS models for correcting cargo or payload mass -- Model for rate of change of ''useful cargo'' with altitude -- Approximate analytic model for useful cargo -- Modeling missions to the International Space Station -- Tabulated summary of Back-of-the-Envelope equations and numerical results -- References -- 1. 1.1. 1.1.1. 1.1.2. 1.1.3. 1.1.4. 1.1.5. 1.2. 1.2.1. 1.2.2. 1.2.3. 1.2.4. 1.3. 1.3.1. 1.3.2. 1.4. 1.4.1. 1.4.2. 1.4.3. 1.4.4. 1.4.5. 1.4.6. 1.4.7. 1.5. 1.5.1. 1.5.2. 1.5.3. 1.6. 1.7. 1.8. 2. 2.1. 2.2. 2.2.1. 2.2.2. 2.2.3. 2.2.4. 2.3. 2.3.1. 2.3.2. 2.3.3. 2.3.4. 2.3.5. 2.3.6. 2.4. 3. 3.1. 3.1.1. 3.1.2. 3.1.3. 3.2. 3.2.1. 3.2.2. 3.3. 3.3.1. 3.3.2. 3.3.3. 3.3.4. 3.4. 3.5. 3.5.1. 3.5.2. 3.5.3. 3.5.4. 3.5.5. 3.5.6. 3.5.7. 3.6. 3.6.1. 3.6.2. 3.6.3. 3.6.4. 3.7. 3.7.1. 3.7.2. 3.7.3. 3.7.4. 3.7.5. 3.8. 3.8.1. 3.8.2. 3.8.3. 3.8.4. 3.8.5. 3.8.6. 3.8.7. 3.8.8. 3.9. 3.9.1. 3.9.2. 3.9.3. 3.10. 3.10.1. 3.10.2. 3.10.3. 3.10.4. 3.11. 3.12. 3.12.1. 3.12.2. 3.12.3. 3.13. 3.13.1. 3.13.2. 3.13.3. 3.13.4. 3.13.5. 3.14. 3.14.1. 3.14.2. 3.14.3. 3.14.4. 3.14.5. 3.14.6. 3.14.7. 3.15. 3.16. Columbia Shuttle accident analysis with Back-of-the-Envelope methods -- The Columbia accident and Back-of-the-Envelope analysis -- Bot Emodeling goals for the Columbia accident -- Quick estimation vs accurate estimation -- Quick-Fire modeling of the impact velocity of a piece of foam striking the Orbiter wing -- Interpretation of Quick-Fire results -- The bridge to more accurate Bot Eresults -- Modeling the impact velocity of a piece of foam debris relative to the Orbiter wing; estimations beyond the Quick-Fire time results -- Looking at the collision from an earth-fixed or moving Shuttle coordinate system -- The constant drag approximation -- Analytically solving for the impact velocity and mass, given the time to impact -- Summary of results for constant acceleration model compared to data -- The non-constant acceleration solution -- An estimate of impact velocity and particle mass, taking the time to impact as given (the ''inverse'' problem) -- Comparing Osheroff 's ''inverse'' calculations to our ''direct'' estimate results -- Concluding thoughts on the impact velocity estimate -- Modeling the impact pressure and load caused by impact of foam debris with an RCC wing panel -- The impact load -- Impact overview -- Impact load mathematical modeling -- Elastic model for the impact stress -- Elastic-plastic impact of a one-dimensional rod against a rigid-wall -- The elastic-plastic model -- Numerical results and plotted trends -- Impact area estimate -- Load estimate -- Impact loading time scale (Bot E) -- Loading time histories, numerical simulations -- Develop a Back-of-the-Envelope engineering stress equation for the maximum stress in the RCC panel face for a given panel load -- Bot Epanel stress model -- Estimates for the allowable maximum stress or critical load parameters for failure -- Final comments on the prediction of possible wing damage or failure -- Summary of results for Sections 4.2, 4.3, and 4.4 -- References -- Estimating the Orbiter reentry trajectory and the associated peak heating rates -- Introduction -- The deorbit and reentry sequence -- Using Quick-Fire methods to crudely estimate peak heating rate and total heat loads from the initial Orbiter kinetic energy -- Quick-Fire problem definition and sketch -- The Quick-Fire baseline mathematical model, initial results, and interpretation -- Alook at heat flux prediction levels based on an analytical model for blunt-body heating -- Numerical estimates of Stanton number using the Sutton- Graves constant -- Simple flight trajectory model -- Asimple Bot Emodel for the initial entry period; the entry solution -- The equilibrium glide model -- Calculating heat transfer rates in the peak heating region -- Selecting the nose radius -- Comparing the model maximum rate of heat transfer, q_wmax , with data -- Model estimate for nose radiation equilibrium temperature, Tmax -- Model calculations of q_w as a function of time -- Model calculations for total heat load at the stagnation point -- Appendix: Bot Emodeling of non-Orbiter entry problems -- References -- Estimating the dimensions and performance of the Hubble Space Telescope -- The Hubble Space Telescope -- HST system requirements -- HST engineering systems -- Requirements for fitting the HST into the Orbiter -- The HST Optical Telescope design -- The equivalent system focal length -- How do designers determine the required system focal ratio, Feq? -- Telescope plate scale -- Selection of HST's primary mirror focal ratio, F 1 1/4 jf1j=D -- Calculating the magnification m and exact constructional length L -- Estimating the secondary mirror diameter -- Estimating the radius of curvature of the HST secondary mirror -- Modeling the HST length -- The light-shield baffle extension -- Modeling the length of the light shield -- The length of the instrument section -- Calculating the total HST telescope length -- Summary of calculated HST dimensions -- Estimating HST mass -- Primary mirror design -- Estimating primary mirror mass -- The estimated total HST system mass and areal density -- Some final words on the HST mass estimation exercise -- Onward to an estimate of HST's sensitivity -- Back-of-the-Envelope modeling of the HST's sensitivity or signal to noise ratio -- Defining signal to noise ratio -- Modeling the mean signal, S -- Modeling the noise -- Final equation for signal to noise ratio -- Final thoughts on Bot Eestimates for HST sensitivity -- References. 4. 4.1. 4.1.1. 4.1.2. 4.2. 4.2.1. 4.2.2. 4.3. 4.3.1. 4.3.2. 4.3.3. 4.3.4. 4.3.5. 4.3.6. 4.3.7. 4.3.8. 4.4. 4.4.1. 4.4.2. 4.4.3. 4.4.4. 4.4.5. 4.4.6. 4.4.7. 4.4.8. 4.4.9. 4.4.10. 4.4.11. 4.5. 4.5.1. 4.5.2. 4.5.3. 4.6. 4.7. 5. 5.1. 5.2. 5.3. 5.3.1. 5.3.2. 5.4. 5.4.1. 5.5. 5.5.1. 5.5.2. 5.6. 5.6.1. 5.6.2. 5.6.3. 5.6.4. 5.6.5. 5.7. 5.8. 6. 6.1. 6.1.1. 6.1.2. 6.1.3. 6.2. 6.2.1. 6.2.2. 6.2.3. 6.2.4. 6.2.5. 6.2.6. 6.2.7. 6.3. 6.3.1. 6.3.2. 6.3.3. 6.3.4. 6.4. 6.5. 6.5.1. 6.5.2. 6.5.3. 6.5.4. 6.5.5. 6.6. 6.6.1. 6.6.2. 6.6.3. 6.6.4. 6.6.5. 6.7.
3642225365 9783642225369
Aerospace engineering
Engineering design.
TL545 / .A43 2012
629.1
Aerospace engineering on the back of an envelope / Irwin E. Alber. - xix, 326 pages : illustrations ; 25 cm. - Springer-Praxis books in astronautical engineering . - Springer-Praxis books in astronautical engineering. .
Includes bibliographical references and index.
1. Introduction -- 2. Design of a high school science-fair electro-mechanical robot -- 3. Estimating Shuttle launch, orbit, and payload magnitudes -- 4. Columbia Shuttle accident analysis with Back-of-the-Envelope methods -- 5. Estimating the Orbiter reentry trajectory and the associated peak heating rates -- 6. Estimating the dimensions and performance of the Hubble Space Telescope -- -- Introduction -- Why Back-of-the-Envelope engineering? -- Back-of-the-Envelope engineering; an important adaptation and survival skill for students and practicing engineers -- Design of a high school science fair electro-mechanical robot -- Design of a new commercial rocket launch vehicle for a senior engineering student's design project -- Preliminary design of a new telescope system by an engineer transferred to a new optical project -- Examining the principles and ideas behind Back-of-the- Envelope estimation -- What is a Back-of-the-Envelope engineering estimate? -- Tradeoffbetween complexity and accuracy -- Back-of-the-Envelope reasoning -- Fermi problems -- An engineering Fermi problem -- General guidelines for building a good engineering model -- Step by step towards estimation -- Quick-Fire estimates -- Quick-Fire estimate of cargo mass delivered to orbit by the Space Shuttle -- Cargo mass problem definition -- Level-0 estimate: the empirical ''rule of thumb'' model -- Level-1 estimate: cargo mass using a single stage mathematical model based on the ideal rocket velocity equation -- Level-2 estimate: cargo mass using a two stage vehicle model based on the ideal rocket velocity equation -- Level-3 estimate: cargo mass delivered by a two stage vehicle; based on a revised estimate for second stage structural mass fraction -- Impact of added knowledge and degree of model complexity -- Moving from the Shuttle to the Hubble Space Telescope -- Estimating the size of the optical system for the Hubble Space Telescope -- System requirements for the HST -- Shuttle constraint on HST size -- Estimating the length of the HST optical package -- Concluding remarks -- Outline of this book -- References -- Design of a high school science-fair electro-mechanical robot -- The Robot-Kicker Science Fair Project -- Back-of-the-Envelope model and analysis for a solenoid kicking device -- Defining basic dimensions and required soccer ball velocity -- Setting up a Bot Emodel for the solenoid kicking soccer ball problem -- Model for solenoid kicker work and force -- Final design requirements for linear-actuator solenoid and supporting electrical system -- Appendix: Modeling of the temperature rise produced by ohmic heating from single or multiple solenoid-actuator kicks -- Quick-Fire problem approach -- Problem definition and sketch -- The baseline mathematical model -- Physical parameters and data -- Numerical results -- Interpretation of results -- References -- Estimating Shuttle launch, orbit, and payload magnitudes -- Introduction -- Early Space Shuttle goals and the design phase -- The Shuttle testing philosophy and the need for modeling -- Back-of-the-Envelope analysis of Shuttle launch, orbit, and payload magnitudes -- Shuttle launch, orbit, and reentry basics -- The liftoffto orbit sequence -- Reentry -- Inventory of the Shuttle's mass and thrust as input to the calculation of burnout velocity -- Burnout velocity -- The velocity budget -- Mass inventory -- Thrust and specific impulse inventory -- Mass fraction rules of thumb -- Quick-Fire modeling of the takeoffmass components and takeoffthrust using SMAD rules of thumb -- Quick-Fire problem approach -- Problem definition and sketch -- Mathematical/''Rule of Thumb'' empirical models -- Physical parameters and data -- Numerical calculation of total takeoffmass, cargo bay mass, and total takeoffthrust -- Interpretation of the Quick-Fire results -- From Quick-Fire estimates to Shuttle solutions using more accurate inputs -- Ideal velocity change Dv for each stage of an ideal rocket system -- Propellant mass versus time -- Time varying velocity change -- Effective burnout time and average flow rate -- Ideal altitude or height for each rocket stage -- Dvideal estimate for Shuttle first stage, without gravity loss -- Estimate of SSME propellant mass burned during first stage -- First stage mass ratio and average effective exhaust velocity -- Average specific impulse for the ''parallel'' (solidþliquid) first stage burn -- Dvideal estimate for Shuttle first stage -- Dvideal and altitude as functions of time, for the Shuttle first stage -- The effect of gravity on velocity during first stage flight -- Modeling the effects of gravity for a curved flight trajectory -- Time-varying pitch angle model -- Effect of gravity on rocket velocity during first stage flight -- Effect of gravity on rocket height during first stage flight -- Comparing model velocity and altitude with Shuttle data -- Gravity loss magnitudes for previously flown launch systems -- Model velocity, with gravity loss, compared with flight data -- Calculation of gravity-loss corrected velocity at first stage burnout -- The effect of drag on Shuttle velocity at end of first stage flight -- Modeling the effects of drag in the equation of motion -- Estimating first stage drag loss -- Final drag and gravity-corrected velocity at first stage burnout; key elements of the overall ''velocity budget'' for the first stage -- Calculation of second stage velocities and gravity losses -- Pitch and gravity loss modeling for the second stage flight period -- Time-varying gravity loss solution, region 2a -- Time-varying velocity solution, region 2b -- Combined velocity solution for regions1, 2a, and 2b and v(MECO) -- Summary of predicted Dv budget for the Shuttle -- Comparison of Back-of-the-Envelope modeled Shuttle velocity and altitude as a function of time to NASA's numerical prediction for all stages -- Comparison of model velocity with NASA's numerical prediction -- Comparison of model altitude with NASA's numerical prediction -- Modeled altitude sensitivity to pitch time scale -- Estimating mission orbital velocity requirements for the Shuttle -- Part1: circular orbital velocity -- Part2: elliptical orbits and the Hohmann transfer Dv's -- Numerical values for transfer orbit Dv's -- Time of flight for a Hohmann transfer -- Direct insertion to a final orbital altitude (without using a parking orbit) -- A Back-of-the-Envelope model to determine Shuttle payload as a function of orbit altitude -- Analytic model for payload as a function of orbital altitude -- Approximate linearized solution for payload -- Reduction in useful cargo mass due to increases in OMS propellant mass -- OMS models for correcting cargo or payload mass -- Model for rate of change of ''useful cargo'' with altitude -- Approximate analytic model for useful cargo -- Modeling missions to the International Space Station -- Tabulated summary of Back-of-the-Envelope equations and numerical results -- References -- 1. 1.1. 1.1.1. 1.1.2. 1.1.3. 1.1.4. 1.1.5. 1.2. 1.2.1. 1.2.2. 1.2.3. 1.2.4. 1.3. 1.3.1. 1.3.2. 1.4. 1.4.1. 1.4.2. 1.4.3. 1.4.4. 1.4.5. 1.4.6. 1.4.7. 1.5. 1.5.1. 1.5.2. 1.5.3. 1.6. 1.7. 1.8. 2. 2.1. 2.2. 2.2.1. 2.2.2. 2.2.3. 2.2.4. 2.3. 2.3.1. 2.3.2. 2.3.3. 2.3.4. 2.3.5. 2.3.6. 2.4. 3. 3.1. 3.1.1. 3.1.2. 3.1.3. 3.2. 3.2.1. 3.2.2. 3.3. 3.3.1. 3.3.2. 3.3.3. 3.3.4. 3.4. 3.5. 3.5.1. 3.5.2. 3.5.3. 3.5.4. 3.5.5. 3.5.6. 3.5.7. 3.6. 3.6.1. 3.6.2. 3.6.3. 3.6.4. 3.7. 3.7.1. 3.7.2. 3.7.3. 3.7.4. 3.7.5. 3.8. 3.8.1. 3.8.2. 3.8.3. 3.8.4. 3.8.5. 3.8.6. 3.8.7. 3.8.8. 3.9. 3.9.1. 3.9.2. 3.9.3. 3.10. 3.10.1. 3.10.2. 3.10.3. 3.10.4. 3.11. 3.12. 3.12.1. 3.12.2. 3.12.3. 3.13. 3.13.1. 3.13.2. 3.13.3. 3.13.4. 3.13.5. 3.14. 3.14.1. 3.14.2. 3.14.3. 3.14.4. 3.14.5. 3.14.6. 3.14.7. 3.15. 3.16. Columbia Shuttle accident analysis with Back-of-the-Envelope methods -- The Columbia accident and Back-of-the-Envelope analysis -- Bot Emodeling goals for the Columbia accident -- Quick estimation vs accurate estimation -- Quick-Fire modeling of the impact velocity of a piece of foam striking the Orbiter wing -- Interpretation of Quick-Fire results -- The bridge to more accurate Bot Eresults -- Modeling the impact velocity of a piece of foam debris relative to the Orbiter wing; estimations beyond the Quick-Fire time results -- Looking at the collision from an earth-fixed or moving Shuttle coordinate system -- The constant drag approximation -- Analytically solving for the impact velocity and mass, given the time to impact -- Summary of results for constant acceleration model compared to data -- The non-constant acceleration solution -- An estimate of impact velocity and particle mass, taking the time to impact as given (the ''inverse'' problem) -- Comparing Osheroff 's ''inverse'' calculations to our ''direct'' estimate results -- Concluding thoughts on the impact velocity estimate -- Modeling the impact pressure and load caused by impact of foam debris with an RCC wing panel -- The impact load -- Impact overview -- Impact load mathematical modeling -- Elastic model for the impact stress -- Elastic-plastic impact of a one-dimensional rod against a rigid-wall -- The elastic-plastic model -- Numerical results and plotted trends -- Impact area estimate -- Load estimate -- Impact loading time scale (Bot E) -- Loading time histories, numerical simulations -- Develop a Back-of-the-Envelope engineering stress equation for the maximum stress in the RCC panel face for a given panel load -- Bot Epanel stress model -- Estimates for the allowable maximum stress or critical load parameters for failure -- Final comments on the prediction of possible wing damage or failure -- Summary of results for Sections 4.2, 4.3, and 4.4 -- References -- Estimating the Orbiter reentry trajectory and the associated peak heating rates -- Introduction -- The deorbit and reentry sequence -- Using Quick-Fire methods to crudely estimate peak heating rate and total heat loads from the initial Orbiter kinetic energy -- Quick-Fire problem definition and sketch -- The Quick-Fire baseline mathematical model, initial results, and interpretation -- Alook at heat flux prediction levels based on an analytical model for blunt-body heating -- Numerical estimates of Stanton number using the Sutton- Graves constant -- Simple flight trajectory model -- Asimple Bot Emodel for the initial entry period; the entry solution -- The equilibrium glide model -- Calculating heat transfer rates in the peak heating region -- Selecting the nose radius -- Comparing the model maximum rate of heat transfer, q_wmax , with data -- Model estimate for nose radiation equilibrium temperature, Tmax -- Model calculations of q_w as a function of time -- Model calculations for total heat load at the stagnation point -- Appendix: Bot Emodeling of non-Orbiter entry problems -- References -- Estimating the dimensions and performance of the Hubble Space Telescope -- The Hubble Space Telescope -- HST system requirements -- HST engineering systems -- Requirements for fitting the HST into the Orbiter -- The HST Optical Telescope design -- The equivalent system focal length -- How do designers determine the required system focal ratio, Feq? -- Telescope plate scale -- Selection of HST's primary mirror focal ratio, F 1 1/4 jf1j=D -- Calculating the magnification m and exact constructional length L -- Estimating the secondary mirror diameter -- Estimating the radius of curvature of the HST secondary mirror -- Modeling the HST length -- The light-shield baffle extension -- Modeling the length of the light shield -- The length of the instrument section -- Calculating the total HST telescope length -- Summary of calculated HST dimensions -- Estimating HST mass -- Primary mirror design -- Estimating primary mirror mass -- The estimated total HST system mass and areal density -- Some final words on the HST mass estimation exercise -- Onward to an estimate of HST's sensitivity -- Back-of-the-Envelope modeling of the HST's sensitivity or signal to noise ratio -- Defining signal to noise ratio -- Modeling the mean signal, S -- Modeling the noise -- Final equation for signal to noise ratio -- Final thoughts on Bot Eestimates for HST sensitivity -- References. 4. 4.1. 4.1.1. 4.1.2. 4.2. 4.2.1. 4.2.2. 4.3. 4.3.1. 4.3.2. 4.3.3. 4.3.4. 4.3.5. 4.3.6. 4.3.7. 4.3.8. 4.4. 4.4.1. 4.4.2. 4.4.3. 4.4.4. 4.4.5. 4.4.6. 4.4.7. 4.4.8. 4.4.9. 4.4.10. 4.4.11. 4.5. 4.5.1. 4.5.2. 4.5.3. 4.6. 4.7. 5. 5.1. 5.2. 5.3. 5.3.1. 5.3.2. 5.4. 5.4.1. 5.5. 5.5.1. 5.5.2. 5.6. 5.6.1. 5.6.2. 5.6.3. 5.6.4. 5.6.5. 5.7. 5.8. 6. 6.1. 6.1.1. 6.1.2. 6.1.3. 6.2. 6.2.1. 6.2.2. 6.2.3. 6.2.4. 6.2.5. 6.2.6. 6.2.7. 6.3. 6.3.1. 6.3.2. 6.3.3. 6.3.4. 6.4. 6.5. 6.5.1. 6.5.2. 6.5.3. 6.5.4. 6.5.5. 6.6. 6.6.1. 6.6.2. 6.6.3. 6.6.4. 6.6.5. 6.7.
3642225365 9783642225369
Aerospace engineering
Engineering design.
TL545 / .A43 2012
629.1