PLAN: NASA'S RETURN TO FLIGHT: TESTING INSULATING MATERIALS
Background, Activities and Critical Analysis
Rene Flores, Educational Specialist at the National Aeronautics and Space Administration
Johnson Space Center in Houston, Texas.
Physical Science, Physics, Technology
Time: 10-30 min Prep Time, 3 classes of 45-minutes
Lesson Objectives: Students
the basic components of the space shuttle stack.
the chemical fuel makeup and storage used on the external tank of the space shuttle.
able to list pros and cons associated with using liquid fuel propulsion.
able to discuss the findings of Columbia mission accident.
able to discuss the safety improvements that have been made to NASA's "Return
to Flight" Discovery mission.
the insulating qualities that must be considered in choosing the right insulation
for space travel.
On Feb. 1, 2003, the space shuttle Columbia broke up during re-entry over
Texas, en route to landing at Kennedy Space Center. All seven crew members aboard
perished. The Columbia accident revealed a major problem with the insulating foam
used to connect the shuttle's external tank to the orbiter. Investigators found
that foam falling off the tank had damaged Columbia's left wing, letting superheated
gases into the orbiter upon reentry Redesigning the external tank became priority
No. 1 as the agency prepared for the shuttle's return to flight.
NASA's Return to Flight mission STS 114 approaches, the main change exists on
the "bipod fitting" that connects the external tank to the orbiter.
This mechanism is susceptible to icing due to the cold temperatures in which the
liquid hydrogen and oxygen fuel must be stored. Engineers needed to find a way
to prevent this icing from occurring; up until the Columbia accident, the critical
connection points were protected with thick sheets of foam.
experiment in this lesson allows you to step into the role of a NASA engineer
to determine the best material for insulation. Since weight is always a concern
for NASA, your insulation should be low-cost and as light as possible.
2 or 3 pound coffee cans with plastic lids
smaller cans to fit inside coffee cans
for background reading
Handouts: Image of the Space Shuttle Stack, Vocabulary
list, Data Table
make these lesson plans better
to National Standards
Online Articles for Lesson Objective Reading
components of the space shuttle stack
The space shuttle stack consists
of three main parts: the orbiter which houses the crew; a large external fuel
tank which feeds into the main engines; and two solid rocket boosters which, during
the first two minutes of launch, provide most of the shuttle's lift. All of the
components are reused with the exception of the external fuel tank which burns
up in the atmosphere after each launch. For further information on basic shuttle
components, visit http://spaceflight1.nasa.gov/shuttle/reference/basics/index.html.
fuel makeup used on the external tank of the space shuttle
The fuel used
for the space shuttle consists of liquid hydrogen and liquid oxygen as the oxidizer,
which provides the propulsion for the shuttle. This combination provides the most
efficient propellant for liquid rockets but falls into the cryogenic (super cold)
category, which means both liquids must be stored at temperatures about 200 degrees
below zero and both require delicate handling, special chilled storage tanks and
strict temperature requirements to maintain their liquid form. More information
on the external tank can be researched at the following Web site: http://spaceflight1.nasa.gov/shuttle/reference/basics/ssme/index.html.
and cons of using liquid fuel propulsion
There are some distinct advantages
and disadvantages to using liquid propellants over their solid counterparts.
The main advantages
of using liquid propellant are they:
typically have higher impulse ratings than solid rockets, which makes them essentially
more efficient, and
2) in cases of emergencies all liquid engines can be shut
off before the fuel is all used up. This is very different from a solid rocket
which, once ignited, cannot be shut off until all of its propellant has been consumed.
1) the strict temperature requirements,
that are fueled by liquid tend to require many intricate pumps, and
fuel usually requires a spark of some sort to start the combustion process.
information can be found at: http://www.space.edu/projects/book/chapter6.html.
STS 107 results and safety improvements made to NASA's Return to Flight Mission
The Columbia accident revealed a major problem with the insulating foam used to
connect the external tank to the orbiter. Investigators found that foam falling
off the tank had damaged Columbia's left wing, letting superheated atmospheric
gasses into the orbiter upon reentry After many safety improvements, NASA is aiming
to launch the next shuttle within a launch window of May 22 to June 3, 2005. The
enhancements designed to ensure the safety of the crew and the shuttle can be
found at NASA's Web site: http://www1.nasa.gov/returntoflight/system/rtfupgrades_partI.html.
Testing Insulating Materials Experiment
experiment allows students to take on the role of shuttle engineers to protect
the orbiter from icing during launch. NASA now knows that the liquid fuels used
must be contained in very cold temperatures. Therefore, in order to protect the
shuttle, NASA engineers need a good insulating material. This experiment allows
students to find the material that works best.
experiment is a modified version from the NASA Explores Web site at http://nasaexplores.com.
Break students into four groups.
Assemble three insulation testers (coffee cans with lids) using a different type
of insulation in each container. One should be used as your control and should
not contain any insulation. For assembly: Place the smaller can into the coffee
can. Put the insulation chosen around the smaller can. Cut a small hole in the
coffee can plastic lid. Insert a thermometer through the hole, and put the lid
on the coffee can. The thermometer should be inserted into the middle of the smaller
3. Use a hot plate to heat enough water in a beaker to fill all four
small cans. Heat the water to 90-100º C.
When the water is hot, remove the plastic lid from the coffee can and use tongs
or a hot pad to pour the hot water through a funnel and into the small can. Do
not get the insulation wet. As soon as the hot water is poured into the small
can, insert the thermometer and put the plastic lid back on the coffee can.
Record the initial temperature of the hot water on the data
Continue recording the water temperature every 5 minutes for 30 minutes.
Repeat with the other three insulator testers.
Discussion and Conclusion
conducting their experiment, students will share their results and compare them
to the results of other groups.
Students should discuss:
went well and what problems did they confront?
2) What changes would they
make to the experiment if they had to do it again?
3) What new insulating
materials would they like to try?
4) Is the insulation that achieved the best
results low in cost and as light as possible?
For further information on the shuttle's return to flight or
many other space-related topics, NASA provides live videoconferencing programs
through its Digital Learning Network at http://nasadln.nmsu.edu/dln/.
Correlation to National Education Standards:
Math: 5a, 6b, 6c, 12a, 22b
Technology (ITEA): 20c, 20d, 20e
the Author: Rene Flores serves as an educational specialist and on-camera
host for NASA's Digital Learning Network. Through NASA he has been able to connect
and provide lessons for students across the nation. He comes from San Antonio,
Texas, where he taught earth science at Christa McAuliffe Junior High School in
the Southwest Independent School District. There, he served as Science Department
chairman and established a partnership with NASA through the Middle-School Aerospace
Scholars Program. He also has been invited to serve as a speaker on the education
panel for the national conference of the American Astronautical Society.
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