We landed in a long hallway at the United States Geological Survey EROS Data Center in Sioux Falls, South Dakota.
When we told Sacagawea where we were, her eyes darkened. “I am afraid,” she admitted.
“Is it the time travel?” Jacob asked. “Are you scared about the future?”
“Native Americans believe in all the mysteries of the world. If you say we passed through time, I believe you.” Sacagawea wrapped her arms around her waist and shivered. “It is the Sioux Indians I fear. I have never met the Sioux, but I hear they are a mighty tribe.”
I would have laughed had she not looked so serious. “Sacagawea,” I explained, “yes, the Sioux are a tribe, but we aren’t visiting them. We are at a special place in a city called Sioux Falls.”
She nodded, still cautious, but her face appeared calmer. “We cannot keep my brother waiting,” she said at last. “Show me this special place in Sioux Falls.”
I turned to Bo and asked, “Where exactly we are going?”
“I’ve never been to the USGS before,” Bo said as we headed down the hall. “I was hoping for a big door marked ‘Shuttle Radar Topography Mission’ or ‘SRTM’ or something like that.”
We all glanced around. There were a few doors. But no signs.
“For a place that houses mapping data,” Zack said with wonder, “they sure could use a map.”
I laughed.
Jacob looked at his watch. “We’re down to seventeen minutes before this cartridge runs out of time. We’d better hurry.”
Just then, a door opened to our right and a woman wearing a white lab coat over a long, flowered skirt entered the hallway. A group of kids about our own age were following her.
“The tour continues this way,” she announced to the kids. “Next we will walk past a computer room where our scientists review satellite and Space Shuttle data.”
“Space Shuttle data!” I cheered. “Let’s follow.”
We snuck in behind the group. We tried hard not to be noticed, but we were wearing old-fashioned U.S. Army uniforms that were too big and we were walking with a young Native-American woman with a baby strapped to her back. Kids in the class kept turning their heads to stare at us, and the woman leading the group began giving us suspicious looks.
We pretended not to notice their stares and walked along, heads held high, as if we belonged.
“So far, so good,” Jacob leaned over and whispered in my ear. “But it won’t be long before someone calls security.”
“Hopefully before they do that, we’ll find something that will convince Sacagawea,” I whispered back, noticing that Sacagawea was playing with the beads on her dress again. Not interested at all in our surroundings.
The guide was wearing a name badge that said DR. LIZ BAKER. We followed Dr. Baker and the tour farther down the hall.
To our left, through a glass window, I saw rows and rows of computers on matching desks. Dr. Baker pointed at the computers and said, “This is a computer lab. Today, our data-gathering equipment is much more advanced than the tools Lewis and Clark had on their expedition.” Suddenly interested, Sacagawea tilted her head to listen.
“In fact,” Dr. Baker said, and looked directly at Sacagawea, “the United States Geological Survey was established in 1879 to continue the fine mapping and surveying work of Lewis and Clark.”
Dr. Baker and Sacagawea locked eyes and held each other’s gaze. They might have stayed there, staring into each other’s eyes forever. But Pomp let out a mighty wail.
As hard as Sacagawea tried to quiet the baby, Pomp just kept crying. We couldn’t keep pretending we were part of the tour. We had to get out of there as quickly as possible.
I grabbed Sacagawea’s hand and we all dashed into the computer lab. It wasn’t private, but at least the baby wasn’t shrieking in the hallway anymore. The door closed solidly behind us.
While Sacagawea bounced on her toes and sang a soothing chant, lulling Pomp to sleep, we watched as Dr. Baker led the tour farther down the hall, away from us.
“We totally lucked out,” Bo said, looking around the empty room. “I don’t know where the scientists are. But I’m sure that someone will be back soon. Let’s show Sacagawea the SRTM data.” He turned to Jacob and said, “If you can get a computer to work, I think I can explain to Sacagawea what the numbers mean.”
Jacob sat at the closest desk and pressed a few buttons on a computer keyboard. “Uh-oh. I need a password to get into the system,” he said, scratching his head. He pressed a few numbers. “Nothing.” He tried a few more.
“We’re running out of time.” I begged Jacob to work faster.
“I’ll help,” Bo said. He went to stand next to Jacob, the two of them working together to crack the computer password code. While they were banging away at the computer keyboard, I explained to Sacagawea how, in our time, people rocket into space.
Zack told her all he knew about the Space Shuttle Endeavor and the SRTM mission to map the earth. Which wasn’t much.
I always have a ton of questions, so when Sacagawea had a question about radar, my chest swelled with pride. The thing was, though, I didn’t know how to answer.
“Do you know how radar works?” I asked Zack.
“Not even the smallest bit of an idea,” Zack replied. “I try not to think about anything that has to do with cartography.”
I nearly jumped out of my skin when a voice behind us said, “Radar is a signal that bounces off objects. It is then measured for strength and how much time the signal takes to return.” I turned around to discover that it was Dr. Baker who’d spoken.
“Please don’t kick us out,” I begged. “We’re only going to be here a few more minutes.” I was panicked.
Before Dr. Baker could reply, Jacob shouted out, “I did it! I broke into the computer! You aren’t going to believe it, but the password is the same as the one in that Internet computer game I was telling you about, LC Advent—”
“LC Adventures?” Dr. Baker interrupted. “I invented that game. Do you like LC Adventures?” she asked Jacob.
“I love it,” Jacob replied, noticing Dr. Baker for the first time since she’d entered the computer lab. He was looking at her all moony-eyed, like she was a huge celebrity because she had invented a computer game he likes. “Are you going to call security?”
“And have us hauled off? Thrown out? Tossed in the street like garbage?” Zack added.
“No. I’m not going to throw you out,” Dr. Baker said. Then she looked over at Sacagawea and asked, “Is that who I think it is?”
Since Sacagawea was still holding the translation stone, she understood Dr. Baker, pointed to herself, and said her own name. It was in Shoshone, but sounded close enough that Dr. Baker was convinced.
“Wow!” she exclaimed. Then she asked, “Where are you kids from, and how did you get Sacagawea here?”
“Well, we have this teacher . . . ,” I started, then stopped. I had to make a split-second decision about how much to tell her. She was already a scientist, so I figured it wouldn’t hurt. I quickly explained about Mr. C and the time-travel machine.
“Hmm.” Dr. Baker pressed her lips together. “I’ve read articles about time travel, but had no idea that someone got a machine to work. Mr. Caruthers must be a really great inventor.”
“But Mr. C has a problem.” Jacob told her about Babs Magee and how we had to convince Sacagawea not to quit. “We think that if we can show her how the Lewis and Clark map will be important to the future, she’ll want to help them.” He also pointed out that we only had eleven minutes left to get the job done.
“Well then,” Dr. Baker exclaimed, “let’s get to work!”
She told us how scientists can make a topographical map by using the data collected by radar measurements. “Topography means the map shows the bumps on the earth, like mountains and valleys. It shows lakes and forests and cities. Plus, it pays attention to stuff that constantly changes, like volcanoes, earthquakes, and floods.”
Sacagawea was really interested. Especially when Dr. Baker took over for Jacob on the computer and brought up some pictures. Even Zack leaned in to take a better look.
I paid attention too. And didn’t even yawn one time. Dr. Baker was showing us some really cool stuff.
“These pictures aren’t actually from the Space Shuttle data,” she told us. “These pictures are from satellite images.” Dr. Baker explained to Sacagawea about satellites in outer space, and what a photograph is.
“I want you to see the pictures from the Landsat 7 satellite,” Dr. Baker said, pointing at the computer screen. “These are actual pictures of the Lewis and Clark Trail as seen from space.”
She told us that by combining the Landsat 7 satellite pictures and the Space Shuttle data, the best maps of the earth’s surface are being created.
Gathered around the computer screen, Dr. Baker showed us the Lewis and Clark Trail, focusing on the Camp Fortunate area. “On our maps, plants show up in shades of green. Rivers, lakes, and streams appear blue—”
“What about the ocean?” Sacagawea asked. I translated for Dr. Baker.
“Blue too,” Dr. Baker went on, but I swear I saw that glint in Sacagawea’s eye again. “Soil and rock formations are brown. Cities are purple.” Dr. Baker was excited to show us all the parts of the map. She clearly loved her job.
Zack was studying Dr. Baker’s map so carefully, I gave him a curious look. “Lewis and Clark never would have thought the Rocky Mountains were just a big hill if they’d had satellite and Space Shuttle maps!” Zack exclaimed at last.