Level: L DRA: 24 Science Strategy: Monitor/Clarify Word Count: 294 2.6.28 Build Vocabulary by Ann Takman HOUGHTON MIFFLIN Online Leveled Books 1033122 H O UG H T O N M IF F L IN by Ann Takman PHOTOGRAPHY CREDITS: Cover © Stockbyte/Getty Images. 1 Stocktrek Images/Getty Images. 2 Atlas Photo Bank/ Photo Researchers, Inc. 3 NASA/Photo Researchers, Inc. 4 NASA. 6 NASA. 7 NASA. 8 Stocktrek Images/Getty Images. 9 NASA. 10 Stockbyte/Getty Images. Copyright © by Houghton Mifflin Company. All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying or recording, or by any information storage or retrieval system without the prior written permission of the copyright owner unless such copying is expressly permitted by federal copyright law. With the exception of nonprofit transcription into Braille, Houghton Mifflin is not authorized to grant permission for further uses of this work. Permission must be obtained from the individual copyright owner as identified herein. Address requests for permission to make copies of Houghton Mifflin material to School Permissions, Houghton Mifflin Company, 222 Berkeley Street, Boston, MA 02116. Printed in China ISBN-13: 978-0-547-02988-7 ISBN-10: 0-547-02988-8 1 2 3 4 5 6 7 8 9 SDP 15 14 13 12 11 10 09 08 2_029887_VR6_3BL_Liftoff.indd 1 1/23/08 10:47:51 AM This is a space shuttle. It looks like an airplane, but it travels in space. Astronauts have explored space in space shuttles since 1981. 2 2_029887_VR6_3BL_Liftoff.indd 2 1/23/08 10:47:55 AM Astronauts must learn how to work in space. They study subjects such as astronomy and math. They learn how to move and live in space, too. 3 2_029887_VR6_3BL_Liftoff.indd 3 1/23/08 10:48:08 AM Many people help astronauts get ready to fly. A launch team gets the space shuttle ready to fly. They check the orbiter to be sure its parts work correctly. The orbiter carries astronauts and equipment. The