Liftoff to Learning: Assignment: Spacelab!

Video Title: Assignment: Spacelab! Video Length: 16:05 Videos may be viewed using free RealPlayer Click on the highlighted title to see the video using RealPlayer Description: This program shows how the unique microgravity environment of Earth orbit is used for scientific experiments and how the rules of scientific experimentation and safety that apply to research on Earth also apply to astronauts in space. Science Process Skills: Observing Communicating Measuring Collecting Data Inferring Predicting Making Graphs

Hypothesizing Interpreting Data Controlling Variables Defining Operationally Investigating Subjects: Scientific experimentation in microgravity. Science Standards: Life Science -Organisms and environments -Regulation and behavior -The cell Physical Science - Properties of objects and materials Unifying Concepts and Processes -Change, constancy, and measurement Mathematics Standards: Measurement

Table of Contents

• Glossary of Terms
• Class Activities
• References

Background
In the past three decades, hundreds of astronauts have rocketed into space. Each time, the astronauts' bodies adapted to the unique microgravity environment of space and then re-adapted to Earth's gravity upon return. In spite of this extensive experience, the mechanisms responsible for that adaptation remain a mystery.

The Spacelab Life Sciences (SLS) missions (two flights so far) have sought to collect data that will enable scientists to solve the mystery. During the second SLS mission (SLS-2), a series of comprehensive experiments were conducted that provided researchers from across the nation access to the most unique laboratory available to science--the microgravity environment of space.

In microgravity, virtually every human physiological system undergoes some form of adaptation. The capacity of the cardiovascular system diminishes. Muscle and bone density also begin to decrease. A shifting of the body's fluids affects the renal and endocrine systems, as well as the way the blood system operates. In addition, the balance and position sensing organs of the neurovestibular system must re-adapt to an environment where up and down no longer matter.

SLS-2 consisted of 14 experiments focusing on the cardiovascular, regulatory, neurovestibular, and musculoskeletal systems of the body. Eight of the experiments used the astronaut crew as subjects and six used rats. A broad range of instruments helped gather data on the human subjects including: a Gas Analyzer Mass Spectrometer, a rotating dome, a rotating chair, a Body Mass Measuring Device, an In-flight Blood Collection System, a Urine Monitoring System, strip chart recorders, incubators, refrigerator/freezers, a low-gravity centrifuge, and an echocardiograph.

The primary goal of the SLS-2 mission was to address important biomedical questions about the human body's physiological responses to microgravity and subsequent readaptation to gravity. The science was also constructed to ensure crew health and safety on missions of up to 16 days in duration. A third goal of SLS-2 was to demonstrate the effectiveness of hardware standardization in experiment-to-rack interfaces for future applications on the International Space Station.

Video Background Information
The original idea for this videotape came from a group of LaPorte, Texas teachers who were concerned with getting students to follow laboratory safety procedures. As a result, this videotape emphasizes the importance of safety while conducting basic procedures in space and on Earth. In particular, the importance of eye protection is stressed. Also covered are the reasons for scientific controls and detailed laboratory procedures, such as labeling, to ensure the validity of the experimental data collected

The video features the SLS-2 flight because of the strong science emphasis of its mission. Detailed laboratory procedures, scientific controls, and safety procedures were essential to the success of the mission.

Terms  contents Control - The portion of a scientific experiment used as a reference base to compare the action of variables. Cardiovascular Deconditioning - A weakening of the cardiovascular system caused by the effects of microgravity. Cardiovascular System - A body system consisting of the heart, arteries, and veins. General Purpose Workstation - An enclosed retractable cabinet used to contain materials that might easily get loose in the Spacelab. Hypothesis - An unproven theory that tentatively explains a phenomena. Mass - The amount of matter contained in an object. Mass Measurement Device - A device used to measure mass in microgravity. Microgravity - An environment, produced by freefall, that alters the local effects of gravity and makes objects seem weightless. Repeatability - Conducting the same experiment several times to confirm that the results are consistent. Spacelab - A cylindrical laboratory module containing scientific facilities that is carried in the payload bay of the Space Shuttle. Variable - Materials or conditions that can be changed in a scientific experiment.

Classroom Activities

contents

The following activities can be used to demonstrate some of the concepts presented in this videotape.

Designing For Space Science Experiments

Materials

Paper and pencils

Procedure
Challenge students to design a science experiment that could be conducted in microgravity on the Space Shuttle. The students should state a hypothesis to be tested and design the research procedures to be followed. The design should include a sketch of the apparatus used. If time is available, students can construct working models of their apparatus and actually conduct the ground-based control portion of the experiment. Students can gather information for their experiments by connecting to Spacelink via computers and modems. See the reference section of this guide for details.

Antacid Tablet Experiment Materials (per experiment setup) Antacid tablet Beakers or jars Cold and hot water Stopwatch Thermometer Eye protection

Procedure

Partially fill two beakers with water. The water in one beaker should be hot and the other cold. Measure and chart the temperature of the two beakers. Formulate a hypothesis that relates the amount of time required to consume an antacid tablet with the temperature of the water into which it is placed. Using a stopwatch to time the reaction, drop an antacid tablet in each beaker. How long did it take for each tablet to be consumed?

If small groups of students are each conducting the experiment, the temperatures of each beaker can be varied so that groups can share a broad range of data with each other. Have students plot a graph for the time it takes for each tablet to be consumed against the temperature of the water. Analyze the results to confirm or reject the experiment hypothesis.


Inertial Balance

(This activity was adapted from the NASA curriculum resource Microgravity - Teacher's Guide With Activities for Physical Science, EG-103. Refer to the reference section for more information about this guide.)

Materials

Metal yardstick* 2 C-clamps* Plastic 35mm film canister Pillow foam (cut in plug shape to fit canister) Masking tape Wood blocks 2 bolts and nuts Drill and bit Coins or other objects to be measured Graph paper, ruler, and pencil Pennies and nickels Stopwatch *Available from hardware store

Background

On Earth, mass measurement is simple. The samples and subjects are measured on a scale or beam balance. Calibrated springs in scales are compressed to derive the needed measurement. Beam balances measure an unknown mass by comparison to a known mass (kilogram weights). In both of these methods, the measurement is dependent upon the force produced by Earth's gravitational pull.

In space, neither method works because of the freefall condition of orbit. However, a third method for mass measurement is possible using the principle of inertia. Inertia is the property of matter that causes it to resist acceleration. The amount of resistance to acceleration is directly proportional to the object's mass.

To measure mass in space, scientists use an inertial balance. An inertial balance is a spring device that vibrates the subject or sample being measured. The frequency of the vibration will vary with the mass of the object and the stiffness of the spring (in this diagram, the yard stick). For a given spring, an object with greater mass will vibrate more slowly than an object with less mass. The object to be measured is placed in the inertial balance, and a spring mechanism starts the vibration. The time needed to complete a given number of cycles is measured, and the mass of the object is calculated.

Procedure

Using the drill and bit to make the necessary holes, bolt two blocks of wood to the opposite sides of one end of the steel yardstick. Tape an empty plastic film canister to the opposite end of the yardstick. Insert the foam plug. Anchor the wood block end of the inertial balance to a table top with C-clamps. The other end of the yardstick should be free to swing from side to side.

Calibrate the inertial balance by placing objects of known mass (pennies) in the sample bucket (canister with foam plug). Begin with just the bucket. Push the end of the yardstick to one side and release it. Using a stopwatch or clock with a second hand, time how long it takes for the stick to complete 25 cycles. Plot the time on a graph above the value of 0. (See sample graph) Place a single penny in the bucket. Use the foam to anchor the penny so that it does not move inside the bucket. Any movement of the sample mass will result in an error (oscillations of the mass can cause a dampening effect). Measure the time needed to complete 25 cycles. Plot the number over the value of 1 on the graph. Repeat the procedure for different numbers of pennies up to 10. Draw a line on the graph through the plotted points.

Use your inertial balance to measure the mass of unknown objects by placing them in the film canister. Find the horizontal line that represents the number of vibrations for the unknown object. Follow the line until it intersects the graph plot. Follow a vertical line from that point on the plot to the penny scale at the bottom of the graph. This will give the mass of the object in "penny" units.

Note: This activity makes use of pennies as a standard of measurement. If you have access to a metric beam balance, you can calibrate the inertial balance into metric mass measurements using the weights as the standards. Questions 1. Does the length of the ruler make a difference in the results? 2. What are some of the possible sources of error in measuring the cycles? 3. Why is it important to use foam to anchor the pennies in the bucket?

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