TITLE: Probes, Exploration & Application
AUTHOR: Jan Mader, Great Falls, MT
GRADE LEVEL/SUBJECT: (8-12) It is appropriate for:
Earth science (grade 8 or 9),
Physical Science (grade 8 or 9), and
Physics (grade 11 or 12)
This lesson incorporates the learning cycle format with
space science material. The lesson examines some of the
benefits of the space program to our life on Earth.
This lesson consists of an exploratory lab, concept
development questions and STS application lab to
reinforce the concept of radar mapping and probes.
TITLE: 20,000 LEAGUES UNDER THE SEA
(Exploration)
PURPOSE: How can a surface be described without seeing it?
RESOURCES/MATERIALS
1. Playdough
2. Box template or a video tape box with a cover with 16
holes 1cm apart
3. Straw and millimeter measure
4. Graph paper
5. Tape
ACTIVITIES AND PROCEDURES:
1. Construct your box, measuring straw and planetary
surface as per teacher instructions.
2. When your box is completed, exchange with another
person.
3. Using your millimeter probe, map the unseen surface,
recording position and depth in a data table.
4. Plot your data on the graph paper and then compare the
"map" with the actual surface.
Summary
1. Did your map accurately compare with the actual
surface?
Account for any discrepancies.
2. How could you make the map more accurate?
TYING IT ALL TOGETHER:
1. What is the name given to the process of imaging a
surface without actually touching the surface.
Most students have heard or been exposed to a radar
system. Some may mention sonar.
2. How does a radar or sonar system work?
A radar system sends radio waves at the speed of light
(3 x 108 m/s) toward an object. The waves will bounce
back from the object and distances can be calculated.
Sonar uses sound waves that travel slower, but does
essentially the same thing.
3. Show a relief map of Earth.
What do the colors show - various elevations,
vegetation, weather etc.
How are maps like this created?
Through actual surveying or through the use of
satellite imaging.
How can we create this type of map for a planet on
which we have never landed?
It is enough just to take "pictures" of the surface.
What if the surface is obscured, as Venus is by thick
clouds?
See NASA Magellan material.
TITLE: IS THERE ANYONE OUT THERE ?
(Application)
OBJECTIVES: How are probes designed to map planets?
What precautions do developers take?
RESOURCES/MATERIALS: You will need to order the Magellan
Fact sheets from a NASA resource center, and borrow the NASA
video series on MARS or Voyager.he manned space missions may have received more
public attention over the years, NASA has also managed many
exciting and successful unmanned exploratory flights: the
Ranger and Surveyor missions to the Moon; the Mariner
missions that explored Mars, Venus, and Mercury; the Viking
Mars Orbiters; the Pioneer voyages to Venus, Jupiter,
Saturn, and Neptune; and the Voyager missions to Jupiter,
Saturn, Uranus, and Neptune.
Beginning in 1989, NASA embarked on a new round of planetary
missions, including Magellan, a Venus orbiter, and Galileo,
a Jupiter orbiter and probe. NASA is also a major
participant in an international mission to observe the poles
of the Sun (Ulysses).
Once the Magellan spacecraft arrives at Venus, in early
August 1990, it will be placed in an elliptical orbit whose
distance from the planet ranges between 250 kilometers (155
miles) and 8,029 kilometers (4,889 miles). When it is close
to Venus, the spacecraft will point its imaging radar at the
planet's surface to collect data. When farther away, the
spacecraft will transmit its data to Earth. From 70 to 90
percent of the surface of Venus is expected to be mapped.
The Magellan imaging radar will send out several thousand
pulses of radio energy each second at the speed of light
300,000,000 meters a second, (186,000 miles a second) across
a target swath. Magellan's swath will range between 17 and
28 kilometers (10 and 17 miles) wide. The signals will
bounce off the target and be detected by the spacecraft's
radar antenna.
A two-dimensional radar image is constructed from three
characteristics of each radar pulse:
1) The time the signal takes to make the round trip
between instrument and target;
2) The Doppler shift, a measurement of relative motion
that is akin to a change in pitch; and
3) Finally, the brightness, or reflectivity, of each
component
Your group has just been selected to design a new planetary
probe to fly on the next generation of exploratory missions.
The following procedure describes your task.
ACTIVITIES AND PROCEDURES:
1. Decide the three scientific objectives your probe will
try to fulfill. Be specific about the target planet(s)
and the methods for meeting your objectives. (If it is
going to study something, will it have to land or can
it remain in orbit? Will it be taking pictures or
collecting samples? Will it continue on to other
planets?)
Purpose #1:
Purpose #2:
Purpose #3:
2. Given the three objectives selected, decide how your
probe will address them and what type of equipment is
needed. Remember that all components must operate in
the environment of space, and may need to provide
protection from space hazards, such as meteorite
collisions.
Design and draw your group's complete probe, labeling
individual pieces. If you wish, you may show several
angles, cross-sections, or magnifications of the
complete probe.
3. Groups present and discuss results.
Have the groups identified similar objectives? If so,
are their designs similar? Do you think NASA develops
just one design for each of its probes?
How do the groups' probes compare to those actually
launched? Which features are similar? Which are not?
4. View the Mars video.
TYING IT ALL TOGETHER:
1. How have the probes differed?
2. What are the pros and cons of landing on a planet vs.
orbiting it? How will design differ based on whether
the probe lands or not?
3. What type of hazards might a probe encounter? What are
some way s you can try to prevent damage?
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John Kurilecjmk@ofcn.org