CRICOS No J a university for the world real R ENB443: Launcher Systems Image Credit: ESA Caption: The generic Ariane-5 (Ariane Flight 162) lifting off from the Guiana Space Centre, Europe’s spaceport at Kourou, French Guiana.

CRICOS No J a university for the world real R Today’s Key Learning Objectives Today’s Key Content: Examples of Launcher Systems and Rockets Launch Sites Launch Environment Orbits Issues Learning Objectives: 1.Motivation: Why rockets important.

CRICOS No J a university for the world real R Launcher Systems: Summary Introduction and Overview Examples of Launcher Systems and Rockets Launch Sites Launch Environment Orbits Issues

CRICOS No J a university for the world real R Introduction Roles/attributes of Launch System: –Places S/c in orbit. –Protects S/c during launch. –Create a severe environment. –Delta-Velocity is fundamental measure of performance. A “launcher system” involves: –One of more rocket stages. –Ground station + launch infrastructure.

CRICOS No J a university for the world real R Introduction (cont.) Launcher system typically designed in different organisation than satellite. –Launch payload = whole s/c to be put in orbit. Everything above the “boost adaptor”. Yet, launch process can constrain S/C design: –Lift capacity (mass and dimensions). –Severe environment during launch: Force/shock/vibrations/pressure, etc.

CRICOS No J a university for the world real R Overview: Basic Orbit Injection Three distinct phases: 1.Vertical launch, followed by turn manoeuvre. 2.Elliptical ballistic trajectory 3.Orbit insertion burn at orbit apogee. Apogee burn Image Credit: NASA

CRICOS No J a university for the world real R Overview: Basic Orbit Injection Image Credit: braeunig

CRICOS No J a university for the world real R Overview: Basic Launch Equation Basic performance characterised by velocity. We can estimated the velocity required from the launch vehicle as: where

CRICOS No J a university for the world real R Overview: Launch Losses Image Credit: SMAD, p. 722 The actual losses experienced are system dependent.

CRICOS No J a university for the world real R Overview: Launch Reliability Image Credit: SMAD, p. 727 Has slowly increased from 0.85 to 0.95 in the last 30 years.

CRICOS No J a university for the world real R Overview: Basic S/C Deployment Options 3 main deployment options: 1.Direct injection by launch system. 2.Using various vehicle/stage configurations. 3.Injection using integral propulsion system (kick stage). Small payloads typically use option 1. GEO satellites typically need to augment launch vehicles with upper stage. Third option allows us to both orbit injection and maintain orbit/attitude (if engine restart possible).

CRICOS No J a university for the world real R Overview: Option 2 - Upper Stage An extra stage added to launch system –Not part of satellite. –Different from integral propulsion system (or “Kick” motor). –Discarded during transfer orbit or once final orbit reached. Once discarded, designed to avoid other GEO satellites.

CRICOS No J a university for the world real R Launcher Systems: Overview Image Credit: N. A. Bletsos Orbit insertion Burn: Upper stage? Launcher stage burns

CRICOS No J a university for the world real R Launcher Systems: Summary Introduction and Overview Examples of Launcher Systems and Rockets –Shuttle/ESA –Rocket stages –Upper Stages. Launch Sites Launch Environment Orbits Issues

CRICOS No J a university for the world real R Image Credit: SMAD, p. 728 Notes: - Both mass and dimensional constraints. - Mass constraints depend on desired orbit. Ariane 5 ECA is a higher capacity Ariane 5 Generic launcher. Designed to place up to 9 tonne in GTO (geosynchronous transfer orbit). GTO means mass placed on Holmann Transfer orbit to GEO. Apogee burn required at GEO. A bit dated.. Up to Delta IV and Atlas V.

CRICOS No J a university for the world real R GTO: Transfer orbit? Image Credit: Braeunig Or Holmann transfer orbit Apogee burn required at GEO. Typ. Low earth orbit GEO

CRICOS No J a university for the world real R Space Shuttle: From Nixon (1972) to 2010 An expressive commercial option.. Real cost > 6 times Atlas-Centaur or Ariane cost. By 2010 phase-out 131 successful missions over a 30 year life. In 1973, was “sold” as 580 missions over 12 years.

CRICOS No J a university for the world real R ESA Launcher System: Current An Ariane 5G rocket engine Image Credit: ESA

CRICOS No J a university for the world real R Rocket Engines Stages Some pictures of: Liquid –RL10 –RS-68 Solid –Atlas V solid rocket motor (booster stage) Note: Atlas V has liquid stages, and various configurations.

CRICOS No J a university for the world real R RS-68 The Delta IV RS-68 main engine is the world's most powerful hydrogen/oxygen engine. Bi-propellant Image Credit: NASA

CRICOS No J a university for the world real R Atlas V solid rocket motor Image Credit: International Launch Services

CRICOS No J a university for the world real R RL10 The RL10 engine propels the Delta IV and Atlas V upper stages to their final orbit for payload delivery. Initial version used in the Surveyor program (Late 1960s). Upgrade version, still used today… 45 years.. Image Credit: US Air Force

CRICOS No J a university for the world real R Upper stages Image Credit: SMAD, p. 730

CRICOS No J a university for the world real R Launcher Systems: Summary Introduction and Overview Examples of Launcher Systems and Rockets Launch Sites –Sites –Direction –Launch Related Orbit Issues Launch Environment Orbits Issues

CRICOS No J a university for the world real R Launch Sites Launch from near the equator is preferred: –To take maximum advantage of easterly rotation of the Earth. Launch from higher latitudes cannot easily access orbit inclination below their latitude. –1 degree of inclination change ~ 210m/s delta-v in LEO. –The Delta-V cost of inclination changes decreases with altitude. Hence ??? are typically done towards the end of the transfer orbit.

CRICOS No J a university for the world real R Launch Sites Image Credit: SMAD, p. 733

CRICOS No J a university for the world real R Launch Directions Image Credit: SMAD, p. 734 Western Range Eastern Range Why not out here? Retrograde launch

CRICOS No J a university for the world real R Launch Performance Image Credit: SMAD, p. 729 Mini-Quiz: Which system to put 10,000kg in LEO? Answer: Assume LEO is 300km, then red box suggests: Proton, Titan IV or Zenit.

CRICOS No J a university for the world real R Polar Launch performance Image Credit: SMAD, p. 729

CRICOS No J a university for the world real R Launcher Systems: Summary Introduction and Overview Examples of Launcher systems and Rockets Launch Sites Launch Environment –Accelerations and Shocks –Vibration and Fundamental Frequencies –Pressure Orbits Issues Sort of numbers might be required in structure sub-system design

CRICOS No J a university for the world real R Launch Acceleration loads. Image Credit: SMAD, p. 740 During several important events.

CRICOS No J a university for the world real R Fundamental Frequencies. Image Credit: SMAD, p. 741 Payload/boost-adaptor stiffness should be above these.

CRICOS No J a university for the world real R Vibration loads Image Credit: SMAD, p. 740 But payload/adaptor stiffness should avoid these. That is, dampen vibration energy at these frequencies.

CRICOS No J a university for the world real R Shock Environment. Image Credit: SMAD, p. 741 Often payload separation by pyrotechnic device. Causes a shock load. For example:

CRICOS No J a university for the world real R Image Credit: SMAD, p. 737 Must withstand and vent pressure differentials Fairing and Pressure Low pressure High pressure

CRICOS No J a university for the world real R Launch Differential Pressures Image Credit: SMAD, p. 739

CRICOS No J a university for the world real R Launcher Systems: Summary Introduction and Overview Examples of Launcher Systems and Rockets Launch Sites Launch Environment Orbits Issues –Accuracy –Ground tracks –Orbital Transfers

CRICOS No J a university for the world real R Injection Accuracy Important because injection errors typically need to be corrected: –Often the job of the last stage of launcher. –Might require some of the mission delta-v budget.

CRICOS No J a university for the world real R Ground Tracks Image Credit: SMAD, p. 138  L =change in longitude

CRICOS No J a university for the world real R Points from Figure E is geosynchronous. –Question: Period of E is ? –Answer: 1436 mins (matching Earth rotation). An orbit’s inclination can be determined by the ground tracks maximum latitude. (SMAD p. 138). –Question: Geostationary has a maximum latitude of? –Answer=0 degrees (ie. at/above the equator). Retrograde orbit track ground tracking in an westerly direction. (Direct orbits shown in the figure).

CRICOS No J a university for the world real R Least Energy Transfer Image Credit: Braeunig

CRICOS No J a university for the world real R Fastest Transfer Image Credit: Braeunig These are larger

CRICOS No J a university for the world real R Transfer Orbits Often, satellite is initially placed in low- earth orbit. Must transition to operational orbit. Image Credit: SMAD, p. 185 Remember their low thrust profile

CRICOS No J a university for the world real R Today’s Key Learning Objectives Today’s Key Content: Examples of Launcher Systems and Rockets Launch Sites Launch Environment Orbits Issues Learning Objectives: 1.Motivation: Why rockets important.