Unit 4 Lesson 2 Technology for Space Exploration

Unit 4 Lesson 2 Technology for Space Exploration Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration Beyond the Clouds How do people travel to space? • A rocket is a machine that uses gas, often from burning fuel, to escape Earth’s gravitational pull. Rockets are used to launch vehicles into space. • In early missions, capsules containing the crews detached from the rockets, which burned up. • Upon return, the capsules “splashed down” in the ocean and were recovered but not reused. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How do people travel to space? • A space shuttle is a reusable spacecraft that launches with the aid of rocket boosters and liquid fuel. It lands on Earth like an airplane. • A space shuttle carries astronauts and supplies back and forth into orbit around Earth. • Two white, solid rocket boosters (SRBs) help the shuttle reach orbit. These booster rockets detach and are reused. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How do people live in space? • People live and work in space on space stations. A space station is a long-term crewed spacecraft on which scientific research can be carried out. • Currently, the International Space Station (ISS) is the only space station in Earth orbit. Six-member crews live aboard it for an average of six months. • Many scientific studies are conducted on the ISS, including the effects of weightlessness on the human body and observations of Earth systems. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration What are some challenges people face in space? • For space travel, challenges include having sufficient supplies of air, food, water, and fuel for the long journey. • The spacecraft must be insulated from the intense cold of space and harmful radiation from the sun. • Experiencing weightlessness, astronauts find it difficult to eat, drink, and sleep without floating, and their muscles and bones weaken. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration Looking Up What uncrewed technologies do people use to explore space? • Telescopes have been placed in Earth orbit to circumvent the distortion of light by Earth’s atmosphere. • The Hubble Space Telescope detects light from objects in space and sends images back to Earth. • The Chandra X-Ray Observatory and Compton Gamma-Ray Observatory were placed in space because Earth’s atmosphere blocks most X-rays and gamma rays. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration What uncrewed technologies do people use to explore space? • A space probe is an uncrewed vehicle that carries scientific instruments to distant objects in space. • Probes have been useful for studying the atmospheres of the gas giant planets. • An atmospheric entry probe is dropped from a spacecraft into the planet’s atmosphere. During its descent, it relays data back to the spacecraft. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration What uncrewed technologies do people use to explore space? • An orbiter is an uncrewed spacecraft that is designed to enter into orbit around another object in space. • Controllers on Earth can place a spacecraft into orbit around a distant planet or its moons. • Cameras and other instruments on the orbiter can photograph the planet’s surface and measure temperatures and surface features. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration What uncrewed technologies do people use to explore space? • A lander is a craft designed to land on the surface of a body in space. • Landers have been placed successfully on the moon, Venus, and Mars, and on Saturn’s moon Titan. • The images taken by a lander are more detailed than those taken by an orbiter. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration What uncrewed technologies do people use to explore space? • A rover is a small vehicle that comes out of the lander and explores the surface of a planet or moon beyond the landing site. • Both landers and rovers may have mechanical arms for gathering rock, dust, and soil samples. • In 2004, the twin rovers Spirit and Opportunity landed on Mars. They took images of the surface and found evidence of water below the surface. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration Looking Down How are satellites used to observe Earth? • A satellite is any object in space that orbits another object. • An artificial satellite is any human-made object placed in orbit around a body in space. • Examples of artificial satellites include remotesensing satellites, navigation satellites, weather satellites, and communications satellites. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Remote-sensing satellites are used to map and monitor Earth’s resources. • They can identify sources of pollution and monitor crops, global temperatures, ocean and land heights, and amounts of freshwater ice and sea ice. • Remote-sensing data can also provide information on how Earth systems, such as sea ice or river flows, change over time. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Weather satellites provide a big-picture view of Earth’s atmosphere. • They monitor changes in cloud formation, energy coming from Earth, and events that lead to severe weather conditions. • Weather satellites provide information that allows airplanes to avoid dangerous weather and helps farmers to grow their crops. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Some satellites carry instruments that detect distress signals from emergency beacons. • Many ships, airplanes, and individuals on land have emergency beacons, which can be used anywhere in the world and at any time of day. • When satellites detect distress signals from these beacons, they relay the signals to ground stations, and search-and-rescue operations are begun. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • How can satellites help a lost hiker? Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Data from satellites can be combined into one image, called a composite image. • Composite images can give very detailed information about an area’s surface features and other features. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration Exploring the Ocean • Both deep-sea exploration and space exploration use advanced technologies to observe locations that are difficult or dangerous for humans to explore. • Ocean submersibles can be crewed or uncrewed. • Hydrothermal vents are on the ocean floor where the pressure is too great for humans to withstand. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Communications satellites relay data, including Internet service, some television and radio broadcasts, and long-distance telephone calls. • Although television signals travel in straight lines, they can be transmitted around Earth by a relay system involving communications satellites. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • The Global Positioning System (GPS) is a network of 24 satellites that orbit Earth. These satellites continuously send microwave signals. • A GPS receiver receives signals from at least four satellites at one time. • Once a GPS receiver on Earth picks up the signals, the technology in the receiver can determine the location of the receiver on Earth’s surface. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 4 Lesson 2 Technology for Space Exploration How are satellites used to observe Earth? • Why are at least three GPS satellites needed for sending information to a receiver? Copyright © Houghton Mifflin Harcourt Publishing Company