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

Beyond the Clouds How do people travel to space? 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 2

How do people travel to space? 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 3

How do people live in space? 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 4

What are some challenges people face in space? 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 5

Looking Up What uncrewed technologies do people use to explore space? 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 6

What uncrewed technologies do people use to explore space? 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 7

What uncrewed technologies do people use to explore space? 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 8

What uncrewed technologies do people use to explore space? 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 9

What uncrewed technologies do people use to explore space? 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 10

Looking Down How are satellites used to observe Earth? 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 remote-sensing satellites, navigation satellites, weather satellites, and communications satellites. Copyright © Houghton Mifflin Harcourt Publishing Company 11

How are satellites used to observe Earth? 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 12

How are satellites used to observe Earth? 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 13

How are satellites used to observe Earth? 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 14

How are satellites used to observe Earth? 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 15

How are satellites used to observe Earth? 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 16

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 17

How are satellites used to observe Earth? 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 18

How are satellites used to observe Earth? 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 19

How are satellites used to observe Earth? 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 20