1 / 41

Ballistic Missiles and Getting Into Orbit

Ballistic Missiles and Getting Into Orbit. Ballistic Missiles and Getting Into Orbit. Intercontinental Ballistic Missiles (ICBMs) Understanding Ballistic Missiles and Trajectories Conic Sections ICBM Trajectories ICBM Development The Anti-Ballistic Missile Treaty

clarimonde-jonathan
Download Presentation

Ballistic Missiles and Getting Into Orbit

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ballistic Missiles and Getting Into Orbit

  2. Ballistic Missiles and Getting Into Orbit • Intercontinental Ballistic Missiles (ICBMs) • Understanding Ballistic Missiles and Trajectories • Conic Sections • ICBM Trajectories • ICBM Development • The Anti-Ballistic Missile Treaty • Launch Windows and Times • Getting Into Orbit • Launch Windows • Launch Time Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  3. Understanding Ballistic Missiles and Trajectories • Not all spacecraft launched into space stay there. • Ballistic missiles only travel through space. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit SECTION 7.1

  4. Conic Sections • All objects moving under the influence of gravity must follow paths that form conic sections. • Circles, ellipses, parabolas and hyperbolas are all conic sections because they are all ‘slices’ of a cone. • Parabolas and hyperbolas are useful only for interplanetary motion. • Circular and elliptical paths are for near Earth work. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  5. Conic SectionsBallistic Trajectories The shape of a Ballistic Trajectory is an ellipse that intersects the Earth at two points Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  6. ICBM Trajectories • Ballistics: • Science dealing with motion, behavior, and effects of projectiles—especially bullets, bombs, rockets, and missiles. • Science or art of designing and hurling projectiles to achieve a desired effect. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  7. ICBM Trajectories (cont’d) • Ballistic trajectories • Paths followed by non-thrusting objects • Objects moving under the influence of gravity • Most of the trajectory is outside Earth’s atmosphere (ignore all other forces except for gravity). Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  8. ICBM Trajectories (cont’d)Trajectory Example • As the man in the figure tries to squirt the dog, he has three basic options similar to the options with ballistic trajectories of rockets: • He can squirt the stream of water directly at the dog (low trajectory). • Aim the stream of water at a 45 degree angle (maximum range or accuracy). • Or, squirt the stream high into the air (high trajectory). Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  9. ICBM Trajectories (cont’d)Ballistic Trajectories • Define ballistic trajectories by: • Rocket’s position (radius from the Earth’s center) at burnout • Rocket’s velocity at burnout • Flight-path angle at burnout • Direction of flight at burnout • Latitude at burnout • Longitude at burnout • Shape of ballistic trajectory: ellipse intersecting Earth’s surface at launch and impact Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  10. ICBM Development • ICBMs are long-range missiles using a ballistic trajectory. • ICBMs differ little technically from other ballistic missiles. • Ballistic trajectories have focused on being able to throw things farther and faster. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  11. ICBM Development (cont’d) • V2 was first real intermediate range ballistic missile. • After the war, U.S. and USSR began race to develop ICBMs. • Key players in global space program also took part in developing ICBMs. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  12. ICBM DevelopmentModern ICBMs and MIRVs • Modern ICBMs typically deliver multiple independently targetable re-entry vehicles (MIRVs). • Each Re-entry Vehicle (RV) carries a nuclear-weapon warhead. • Allows a single missile launch to strike a handful of targets. • Proved to be an “easy answer” to deploying anti-ballistic missile (ABM) systems: adding more warheads to a missile costs less than building the missiles to shoot down the additional warheads. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  13. ICBM DevelopmentMinuteman • Minuteman I and II were U.S. ICBMs in service from 1960 to 1997. • Minuteman III entered service in 1978. • Minuteman had two innovations that gave it a long practical service life. • Solid-rocket fuel technology. • Earliest use of integrated circuit for digital flight computer. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  14. ICBM DevelopmentMinuteman (cont’d) Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  15. ICBM DevelopmentMinuteman (cont’d) Early trajectory of a Minuteman Missile shown on it’s way to a test range Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  16. ICBM DevelopmentPeacekeeper • First deployed in 1986. • Canceled, modified, and reinstated over several administrations. • U.S. had to remove it from service to meet SALT II treaty. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  17. ICBM DevelopmentPeacekeeper (cont’d) Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  18. ICBM DevelopmentICBM Missile Silos Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  19. The Anti-Ballistic Missile Treaty • Between U.S. and USSR to limit use of anti-ballistic missile systems in defending against missile attack. • Only two nuclear powers—kept both from believing they could avoid a counter-strike. • In force for 30 years from 1972-2002. • U.S. withdrew from treaty in 2002. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  20. ABM Treaty (cont’d)Arguments for Withdrawal • Allow U.S. to develop a ballistic missile-defense system to protect against rogue nations developing weapons. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  21. ABM Treaty (cont’d)Arguments against Withdrawal • “Fatal blow” to the Nuclear Non-Proliferation Treaty. • Would lead to a world without effective legal limits on nuclear growth. • Reaction from Russia and China would hinder other arms negotiations (but offsetting pluses have made that reaction milder than expected). Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  22. Launch Windows and Times Above: September 1997—The Shuttle Endeavour waits for launch time. Left: April 1998—The Columbia Shuttle propels off the launch pad and accelerates into orbit. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit SECTION 7.2

  23. Getting into Orbit • To meet the conditions of a space mission, launch-team members need to: • Launch the spacecraft from a specific place. • Launch the spacecraft at a specific time. • Launch the spacecraft in a specific direction. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  24. Launch WindowsDefinition • An opportunity to launch a satellite from Earth directly into the desired orbit from a given launch site. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  25. Launch WindowsConcept • A launch window is an opportunity to launch a satellite from Earth directly into the desired orbit from a given launch site. • We can always launch into parking orbit and then perform a Hohmann Transfer to put a spacecraft in the desired orbit, but this is complicated and requires more fuel. • A launch window means getting directly into the desired orbit without having to maneuver. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  26. Launch WindowsConcept (cont’d) • Launch windows are like bus schedules. • Launch windows normally cover a period of time. • Launch vehicles must follow trajectory rules by Newton’s Laws of Motion. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  27. Launch Windows and Launch Time Columbia accelerates into orbit on STS-87 Endeavour clears the tower on STS-47 Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  28. Launch Time • To determine what time a launch site passes into a launch window, we need a new definition of how to tell time. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  29. Orbital Racetrack • If the car is one mile past the starting line, and the pit is one-half mile past the starting line, then the car must be one-half mile from the pit. • Given the car’s speed, we can figure out how long before the car reaches the pit. • Knowing this rate allows us to determine the best time to launch a spacecraft directly into orbit, or the launch window. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  30. Launch TimeSolar Time • The spacecraft must launch in a specific direction: • The vernal equinox direction is the main direction we use to describe the motion of spacecraft that orbit the Earth. • Because the Earth and the launch site rotate, it’s an easy reference from which to measure the angular distance between the orbital plane and our launch site. • Knowing this angular distance and Earth’s rotation rate, we can figure out the best times to launch. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  31. Launch TimeSolar Time (cont’d) • Greenwich Mean Time (GMT)— is the basis for the time kept on watches to handle daily business. • GMT is the mean solar time for the Prime Meridian (Greenwich, UK). • All other time zones are GMT plus or minus a certain number of hours. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  32. Launch TimeSolar Time (cont’d) The Royal Observatory in Greenwich, England Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  33. Launch TimeSolar Time • Apparent Solar Day • An Apparent Solar Day is the time between successive passages of the Sun overhead, which is from noon one day to noon the next day. • Apparent solar day’s length varies throughout the year (Earth’s orbit around the Sun is elliptical). • Average of the lengths for one year gives us a mean solar day. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  34. Launch TimeSidereal Time • Because there is a problem using solar time, the reference point for GMT rotates with the Earth, we seek an inertial (fixed) reference point: • We use the same reference point as the geocentric-equatorial coordinate frame—vernal equinox direction. • A sidereal day is the time between the subsequent passings of the vernal equinox direction overhead a particular longitude line. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  35. Launch TimeSidereal Time (cont’d) • Because the inertial reference vernal equinox is so far away, the length of a sidereal day corresponds to exactly 360° of Earth rotation. • A sidereal day is slightly shorter than an apparent solar day: 23 hours, 56 minutes, 4 seconds in solar time. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  36. Launch TimeSidereal Time (cont’d) • We can tell sidereal time in degrees. • Earth rotates 360° in 24 hours. • So, 3 a.m. (0300) is 45° of Earth’s full rotation. • Similarly, noon (1200) is 180° and 6 p.m. (1800) is 270°. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  37. Launch TimeLocal Sidereal Time (LST) • Time since the first point of constellation Aries was last overhead. • Can be expressed in time or angle • If Earth has rotated 90° since the local longitude line was aligned with the vernal equinox direction, LST is: • 90° • 0600 hrs • Mission planners mathematically convert LST back to GMT for launch timing. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  38. Launch TimeLocal Sidereal Time (LST) Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  39. Launch TimeSolar Time versus Sidereal Time Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  40. Summary • Intercontinental Ballistic Missiles (ICBMs) • Understanding Ballistic Missiles and Trajectories • Conic Sections • ICBM Trajectories • ICBM Development • The Anti-Ballistic Missile Treaty • Launch Windows and Times • Getting into Orbit • Launch Windows • Launch Time Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

  41. Next • For some payloads, the mission requires us to get a payload into orbit and get it back to Earth from space. • On the next lesson we’ll tackle the last part of a space journey: atmospheric re-entry. Unit 2, Chapter 7, Lesson 7: Ballistic Missiles and Getting into Orbit

More Related