Space Invaders

by Nate Ball

  I could get used to this hero thing.

  A cheerful, festive celebration was underway on the beach. The sun was lifting above the trees, and the air had warmed nicely.

  One of the soldiers had produced a small speaker, and he had plugged it into his cell phone. Dance music with a fast-thumping beat swept over the sand.

  I was perched up high up on my dad’s shoulders as he spun and danced around. Olivia was on her grandfather’s shoulders. We were receiving high fives from the soldiers, who happily snacked on whatever Ritz Crackers and SweeTarts the Erdians had been unable to fit into their ships.

  Even the general had pulled off his shoes and now danced barefoot in the sand with a laughing female soldier. He kept looking my way and giving me thumbs-ups.

  Mom was weeping happy tears as she used her phone to snap photos and video of the jubilation. I couldn’t wait to show them to my little brother later so he could see what he’d missed. Even my aunt Joni might finally be impressed with what her flakey nephew had done.

  Mr. Prentiss was waving his credit card around, entertaining two soldiers with stories of shocked grocery store clerks who had never sold so much to a single customer.

  It was quite the scene.

  I was only in the fourth grade, but it occurred to me that this morning might just be the best moment of my life. Certainly top five, even if I lived to be one hundred.

  How can you beat saving the world?

  That was when, from the corner of my eye, I noticed one last spaceship hovering alongside the dock. One remaining Erdian was standing there, watching us. It was Amp.

  I knew what was happening by the way he stood; his shoulders were slumped, his chin had dropped to his chest, and his six blue fingers clutched nervously at his belly.

  Amp was leaving.

  Leaving me.

  Leaving Olivia.

  Leaving us.

  Leaving Earth.

  “AMP!” I shouted. I scrambled down from my dad’s shoulders.

  Olivia looked back over her shoulder at the sound of alarm in my voice.

  “OLIVIA, LOOK!” I shouted.

  Her face fell.

  Soon we were racing over the sand as fast as we could. We pounded down the boards of the dock. My breath seemed to get stuck in my clenched throat.

  I could feel the crowd stopping to watch us from the beach, somehow understanding that they should keep their distance.

  Nobody liked to share in good-byes.

  “You don’t have to—” I began.

  He held up both hands, cutting me off. “The time has come, my friend.” He pointed to the sky, where the entire fleet of Erdian spaceships hovered silently high up. “They’re all waiting for me.”

  Olivia fell to her knees. “Now? How about staying a few more weeks? In the summer we’ll have a lot more time to—”

  His shaking head stopped her. “Sorry. It sounds great. But it has come time for me to go back. I’ve learned so much from you both. I’ve grown so fond of you two odd creatures. But on this planet I am a stranger in a strange land.”

  I knelt down and put my face in front of him. I sniffed. My eyes were filling with hot tears, despite my best effort to keep that from happening. “Stay for the party, at least. Say good-bye to everyone,” I said in a strained, croaky voice.

  He let out a deep sigh. “I don’t know them,” he said with a crooked smile. “I really know only you two. You are the ones I will take with me in my three hearts.”

  “You have three hearts?” Olivia whispered, tears starting to roll down her face. “See, we didn’t even know that.”

  “It just never came up,” Amp said with a shrug. “Now, look, I’ve made your eyes start to sweat.”

  Olivia laughed through her tears. “This isn’t sweat, Amp.”

  I wiped my face with the back of my hand. “Hey, you can stay in touch, right? Come back and visit? Write letters? Send us messages?”

  He smiled and shook his head. “You know that’s impossible, Zack. It’s too far, too risky. You both know this is my best opportunity to get back to where I belong.”

  “But your ship is broken,” Olivia said. “You can’t fly.”

  “Oh, it’s been repaired,” he said, glancing back at the Dingle. “Erdians always bring plenty of spare parts when so many travel through space and time.”

  “Oh, shoot,” Olivia said, pushing her face up next to mine. “What are we going to do with ourselves without you to babysit?”

  “You’re going to have happy, normal lives. I am so proud to know both of you. You have extended so much kindness to me. I will never forget you.”

  “Well, I guess this is really is good-bye then,” I said, smiling through my tears.

  “I wish I could cry like you two,” Amp said. “It must feel so interesting. He lifted his wrist to his mouth and announced:

  “Note to Erdian Council . . .”

  “No!” I said.

  “Just joking,” he said, dropping his arm. “Got you.” He sighed. “Now let me hug your faces.”

  He reached up on his tippy toes and hugged my face, then Olivia’s.

  “Gross, you both got me all wet!” he said, pretending to be annoyed.

  We were both too broken up to even smile at his attempt at humor.

  “You two will do great things,” he said in a clipped voice. With that, he spun around and, with two quick hops, disappeared into his ship, the tiny hatch closing behind him.

  After a few seconds the Dingle shot off like a silent rocket.

  It was so odd to see his spaceship work the way it was supposed to. We watched it rise, like when you let go of a helium balloon and follow its flight path for as long as you can. Soon we lost track of it as it joined the thousands of other ships high up in the sky.

  A moment later the entire swarm of Erdian ships, stuffed with Ritz Crackers, SweeTarts, and sunflower seeds, shot off in neat rows. The sky flashed when the ships exited our atmosphere.

  In just seconds they were all gone.

  And so was Amp.

  Olivia and I hugged for a full minute.

  “We’ll never forget him,” Olivia said. “At least we’ll always have that.”

  As we headed back down the dock to the crowd of onlookers, I knew she was right. We would be in Amp’s three hearts, and I would have my memory of him in mine—no matter how much space and time separated us.

  He hadn’t even been here that long, but I was a different kind of a kid for knowing him.

  I was such a mess when he arrived.

  Now anything seemed possible. I believed I could do whatever I set my mind to. I might just do great things after all, like Amp had said.

  Like two balls that collide on a pool table, I’d been knocked in a different direction when Amp had come crashing into my life.

  And for that I would always be grateful.

  Try It Yourself: Stomp Rocket

  When Olivia, Zack, Amp, and Mr. Larry are stuck in the middle of the lake with a dead battery and an emergency on their hands, they hatch a plan to use pieces of trash from the bottom of the boat to launch a message to the shore, using a rocket.

  In this experiment, you’ll use recycled materials to build a “stomp rocket” that can reach heights up to a hundred feet in the air!

  For this project, you’ll need:

  • A two-liter bottle or milk jug

  • A piece of flexible hose that can fit or stretch over the jug’s mouth. An old bicycle inner tube works well.

  • A sheet of paper

  • Cardboard for fins

  • Scissors

  • Duct tape

  • A Ping-Pong ball

  • 14–20 inches of any rigid, smooth pipe or tube—like a ¾ inch PVC pipe

  • Something you can tape the launcher tube to, like a folding chair or bookend

  • An adult to help with safety—but not to do the project for you!

  Stage 1: Build the Launcher

  1. Cut the bicycle inner tube or
flexible hose to about 18 inches long. A bit shorter or longer is fine.

  2. Insert one end of the rigid pipe about one inch into the inner tube.

  3. Fold the slack of the inner tube tight around the pipe, and duct tape it in place with a few wraps.

  4. Insert the mouth of the two-liter bottle into the other end of the inner tube and tape the tube securely onto the bottle.

  5. Tape the rigid tube to the stand you found (like a folding chair or bookend) so it aims nearly straight up. Make sure at least 12 inches of the tube is sticking freely above the stand. You’ll need this to make and launch the rocket.

  Stage 2: Make the Rocket

  1. Wrap the paper around the launch tube and tape it so it’s almost a tight fit but can still smoothly slide up and down. You may need to cinch the paper tighter by grabbing the inside corner and coiling the paper inward.

  2. Stack the protruding wraps flat and tape the tube near the top and bottom. This is the rocket’s fuselage.

  3. Keeping the fuselage on the launch tube to support the paper from the inside, place the Ping-Pong ball on top of the tube and use several shorter pieces of tape to attach it to the top of the rocket. Add enough tape that no air can sneak between the fuselage and the Ping-Pong ball.

  4. Use the scissors to cut your favorite shape of rocket fins and tape them on the bottom of the fuselage.

  5. Decorate the rocket if you wish!

  Stage 3: Launch Test

  1. Clear the area! Make sure the people around you know you’re going to launch a rocket. Remember what rockets do after they go up: They come back down. Everybody nearby should be thinking about this.

  2. Make sure the launch tube is secure and that it’s pointing almost straight up.

  3. Ensure the rocket slides smoothly up and down on the launch tube, and then leave it on the tube, ready for launch.

  4. Safety Tip 1: Make sure the rocket will go up in the air only—never toward anybody!

  5. Safety Tip 2: With every experiment, it’s safest to “start small” so you can learn how a new system works before you increase the energy level.

  6. Yell out a countdown, and step (don’t stomp) onto the bottle. How did it work?

  Stage 4: Big Launch!

  1. To reset, blow high-pressure air from your lungs back into the bottle through the launch tube. The pressure should reinflate it. You can also squeeze the bottle back open with your hands to help.

  2. Slide the rocket back onto the launch tube.

  3. Now it’s time to go big! Yell out a loud countdown and give the bottle a great big stomp!

  Experiments

  Now that you’ve got a reliable launch system, you can start doing some experiments to discover how to make your rocket go higher! Here are a few things you may want to learn more about:

  Discover:

  Which parts of the system are the most important in making the rocket go high? Try changing something about the setup:

  • Make a shorter or longer rocket

  • Try taping a smaller or bigger bottle to the end of the hose

  • Change the length of the hose

  Which changes make the biggest difference in launch height? Remember to only change one thing at a time! Otherwise you won’t know which change made the difference.

  Test:

  What launch angle makes a rocket go the farthest? Make sure nobody is downrange during this test!

  • Start with a high angle, launch the rocket, and mark where it landed.

  • Progressively lower the launch angle, marking where each launch hits the ground. Try taking a photograph of each launch angle, and hold up fingers in the photo for which launch it is so you can figure out which angle went the farthest.

  Improvise:

  What ideas does this project give you? What would it take to test them out? Run your ideas by an adult, and then get out there and try them yourself! It’s a big and wonderful world out there, and the more you try, the more you’ll learn. And the more you learn, the more you can do!

  Bonus Experiment from Alien in My Pocket #1: Blast Off!

  Turn the page for the experiment from the first Alien in My Pocket book.

  Try it again now and see if the outcome is any different.

  Try It Yourself: Bottle Rocket Blastoff

  Rockets work by pushing exhaust downward (really fast), which pushes the rocket upward (really fast). You can build your own bottle rocket that uses air pressure to push water downward out of the rocket, which will propel the rocket upward for a big launch.

  YOU WILL NEED: 2-liter soda bottle, cardboard, duct tape, a bicycle pump with a pressure gauge, an inflation needle, a rubber stopper, and some stakes.

  Building Your Rocket

  1. Make sure the rubber stopper can be inserted into the end of the soda bottle so it holds air inside. You can check for a seal by squeezing the bottle when the stopper is pushed in.

  2. With the help of an adult, drill a small hole through the stopper so that when you push the inflation needle in, it fits tightly. Try starting with a smaller drill bit than you think you’ll need, and redrill the hole bigger later if you really need to. The goal is to have the rubber tight around the needle, making a good seal.

  3. Push the inflation needle through the rubber stopper till the end pokes out a little bit. The end with the small hole should be poking out of the smaller tapered end of the stopper.

  4. Add fins and a nose cone to your bottle to turn it into a rocket! You can design them however you want. Putting the fins near the rocket’s nozzle will help it go straight.

  5. Build a launchpad by driving some stakes or sticks into the ground so that your rocket can sit upright while you’re pumping the air in.

  6. Attach the bike pump’s nozzle to the inflation needle that’s now going through the stopper. Now we’re ready to fly!

  Launch Sequence

  1. When you don’t know how something works yet, it’s always safer to start small. Do an air test by gently pushing the stopper into the nozzle. Put the rocket on the launchpad and pump air into the bottle till the stopper pops out. Try to watch the pressure gauge on the bike pump and see what pressure made the stopper pop out.

  2. Do a second air test by pushing the stopper into the rocket nozzle with a little bit more force than last time. Put the rocket back on the pad and pump again till the stopper pops out. You may see a little launch this time, and it should have taken more pressure than last time to force the stopper out. Cool! All systems are “go” for launch.

  3. Put some water in the bottle, push the stopper back in, stand back, and start pumping! This time, the rocket should get at least a little launch if the pressure was around 10 PSI or higher before the stopper popped out. Now your rocket works; it’s time to do some experiments!

  Experiment Time

  1. Try varying the amount of force you use to insert the stopper each time. What happens when you push it in very lightly versus with more force? How does it change the pressure required for a launch?

  2. Change the amount of water you put in the rocket for each launch. What other important property of the rocket changes when you add lots of water versus a little bit?

  3. Test out some different nose cones. Does the rocket fly better with a big, long nose cone that’s heavy? How about a short one that uses less material?

  4. Vary the size and placement of the fins. What would you need to do to make the rocket spin on its way up?

  Tips

  • When you’re trying to learn about something by changing things, it’s important to only change one thing at a time so you can see what a difference it made. That means if you’re trying out different nose cones, try to use the same amount of water and air pressure for each launch. That way, if the rocket’s flight changes from trial to trial, you know it’s because of the different nose cone and not something else.

  • If you think you have an idea that explains how something works, think of ways to test out if that idea is true! Do you think t
hat the air pressure is related to how high the rocket flies? How would you test that out?

  • Be patient with yourself! When you’re trying something new, it might not work right the first or second or third time you try it. Maybe even more times than that. Learn by making observations about the rocket’s performance so you can make the right adjustments as you proceed.

  Safety Notes

  • Rockets store and release a lot of energy! Always make sure that if the rocket were to launch when you don’t expect it to, it won’t hit anything or anybody that’s nearby.

  • Make sure everybody around knows that you’re going to launch when you’re pumping air into the rocket. Doing a countdown helps, especially if you know how many pumps it takes to launch your rocket.

  • If you’ve pumped a lot of air into the rocket and the pressure is high but the rocket’s not launching, don’t go up to the rocket and try to pull the stopper out. It might launch before you’re ready and hit you! Instead, wait till the pressure dies down and reinsert the stopper with less force than you used last time.

  Dedication and Thanks

  This series is dedicated to my parents, John and Sarah, whose bold support of my childhood interests catalyzed a lifetime of joyful experimentation and learning.

  Bringing big new ideas from imagination to reality is rarely the work of a single person, and Alien in My Pocket is no exception. Sincere appreciation and thanks are due to many people—especially my creative and collaborative editor, Dave Linker; my fabulous agent, Linda Loewenthal; the amazing Macky Pamintuan, whose art exceeds my own imagination; and the incredibly talented Dave Keane for breathing life and laughter into these characters and their adventures.