Alternative Propulsion

Space Settlement relevance

Even though modern chemical rockets have sent us to the moon, to build large space settlements we will need something more. Today, the high cost of launching into space stops people from going there. Alternative propulsion, however, offers a chance to dramatically lower launch costs. Futhermore, many of the ideas being proposed would allow us to move around the solar system much quicker than we do today. Instead of months to Mars it would be weeks. Years to Jupiter and Saturn would be months. And centuries to the stars would become years.

Related links


Group size
Goup activity

Time required
One 45 minute period


Instructional Goal National standards (5-8) addressed

Student Objectives
Student will:

Prerequisite Knowledge
Concept of solar activity, sunspots, solar flares and Coronal Mass Ejections (CME's)

Advance Preparation Time
Get the materials necessary to conduct the activity, this includes graph paper and bookmark appropriate url's.

Lesson Activity:

Step 1
Each student will read the background information brief.

Step 2
Distribute graph paper and explain to the students that astronomers count the number of sunspots they see each day to keep track of solar activity. From the data below have the students plot the number of sunspots on the vertical axis for each year on the horizontal axis. Use the graph to answer the following questions.

  1. How many years are there, on average, between years of minimum activity?
  2. How many years are there, on average, between years of maximum activity?
  3. When did the current cycle (Cycle 23) begin and when will it reach its maximum intensity?
  4. When will the years for Sunspot Minimum occur for the next ten cycles, and how old will you be?
  5. On a trip to Mars, which years would you probably want to avoid for your one year journey?
  6. What precautions would you have to take in space to protect yourself and your crew from solar flares and radiation sickness?

Sunspot numbers for each year from 1950 to 1997:

84, 69, 31, 14, 4, 38, 142, 190, 185, 159, 112, 54, 38, 28, 10, 15, 47, 94, 106, 106, 104, 67, 69, 38, 34, 16, 13, 27, 92, 155, 154, 140, 116, 67, 46, 18, 14, 32, 98, 154, 146, 144, 94, 56, 30, 17, 8

Author: Bryan Yager

[Home] [NASA] Updated: August 3, 1999
WebWork: Al Globus, Tugrul Sezen,
Bryan Yager
NASA Responsible Official: Creon Levit
[Questions] [Help]