Mission
- To apply measurement and computation to gain insight into the large numbers associated with distances in space
- To plan a trip to a planet in the solar system
This lesson focuses on human travel in space. One problem associated with traveling in the solar system is the distance from on planet to another. But other problems arise. A spacecraft needs fuel to make the long journeys in space, and humans need food and water throughout the long journeys. The effects of microgravity, that is, near zero gravity, on humans over time are unknown. The probability of collisions with asteroids is uncertain, and many other aspects of long manned flights make the task of space travel very complex.
Image courtesy of the NASA
Human Space Flight Gallery.
However, publicity about unmanned flights to the planets continues to raise the question of humans' traveling in space. Research is required to increase the probability that prolonged space travel for humans can be accomplished safely. One of the NASA projects that will move us closer to space travel is the International Space Station, which will serve as a platform for many research agendas associated with living and working in space for long periods of time.
Getting Started
Begin the class by engaging students in a discussion about humans traveling through the universe. In the movies and on television, students encounter science-fiction stories about traveling at the speed of light and beyond to
cross entire galaxies in a matter of seconds. Point out that most of our travel speeds are quite slow. We have not come close to traveling at the speed of light. Although radio signals can return from Mars in a short time, it takes much longer for a spacecraft from Earth to reach Mars.
Developing the Activity
Use the data about the Space Shuttle below to determine its speed in miles per hour. Remind students that the Shuttle is not designed for travel among the planets. It is designed for Earth-orbit tasks. However, its speed is helpful in judging the speeds for twentieth century spacecraft. After students have done the calculations, come to some agreement on an approximate speed for interplanetary travel. Assume that the agreement is about 50,000 miles per hour. This figure gives us a reasonable speed to use in thinking about space travel today. In the future, speeds will undoubtedly increase.
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Space Shuttle Data:
Distance traveled by Shuttle: 4,164,183 miles
Time to travel given distance: 9d 23h 30m
Speed Computation:
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Using the data sheet, The Planets at a Glance,
students can determine the distance from Earth to each of the other planets. This task is not trivial. The distances in the chart are given in millions of miles. To facilitate computation and estimation, students need to translate 67.2
million miles, the distance from the Sun to Venus, into its full numeric form, 67,200,000. Before thinking about traveling to Venus, students must remember that Earth is about 93,000,000 miles from the Sun. Use the mean distance from the Sun to specified planets to calculate each distance from Earth to the targeted planet.
Alternatively, you may require your students to search for the information themselves and complete a blank The Planets at a Glance activity sheet. Students may obtain data from the NASA website.
To make this exploration manageable for middle school students, we are assuming that the planets are aligned at their mean distances. Teachers should explain to students that in actuality, this greatly simplified situation is
unlikely to occur.
The students' next task is to calculate the time required to travel to each planet on spacecraft that travel from 20,000 to 100,000 miles per hour.
Group the students into their mission teams of four students. Ask them to complete a chart for travel to all the planets (and Pluto) of the solar system at the speeds shown below. They should use the mean distance of each planet from Earth.
Distribute the Speeding Through the Universe activity sheet, so students may complete the chart.
| MPH |
Mercury |
Venus |
Mars |
Jupiter |
Saturn |
Uranus |
Neptune |
Pluto |
| 20,000 | | | | | | | | |
| 30,000 | | | | | | | | |
| 40,000 | | | | | | | | |
| 50,000 | | | | | | | | |
| 60,000 | | | | | | | | |
| 70,000 | | | | | | | | |
| 80,000 | | | | | | | | |
| 90,000 | | | | | | | | |
| 100,000 | | | | | | | | |
In a typical class, students groan at the prospect of completing a chart with eighty entries. The groans provide the opportunity to challenge the teams to think of strategies for reducing the amount of calculations required to complete the chart. When patterns are used to complete entries, the teams should record them. All students in the teams should make the chart.
Discuss the patterns that teams used to complete the chart. List the patterns on the chalkboard. After all team members have shared how their patterns helped reduce their workload, ask each team how many different patterns they
used.
The class now has a complete chart for travel to the solar system's planets computed in hours of travel. It is time to develop some better notions of what these times mean. Pose the Questions for Students, which require students to think about the practicality of space travel.
These questions should be posed to the mission teams. The teams should discuss the questions and agree on a team response. After students begin thinking about time questions, have each mission team make up questions for the class to solve.
