1D_What Challenges Do We Face Going Back to the Moon? An Educator's Guide with Lesson Activities In Science and Mathematics What Challenges Do We ...
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National Aeronautics and Space Administration
1D_What Challenges Do We Face Going Back to the Moon?
An Educator’s Guide with Lesson Activities In Science and
Mathematics
What Challenges Do We Face Going Back to the Moon?
www.nasa.gov Education Product
Educator’s Grades
& Students 5-8
EG-2006-XXXXXXX
Lunar Education Module
Living and Working Safely on the Moon
GR 5-8 Engagement: What Challenges Do We Face Going Back to the Moon?
An Educator Guide with Lesson Activities in Science and Mathematics
I. Investigation Overview
Summary and Objectives ………………………………………………….………………. 2
Student Involvement ………………………………………………………………….. 2
• Inquiry-Based Questions …………………………………………………………. 2
• Hands-On-Activity Description ………………………………… ……………... 2
Grade Level(s) …………………………………………………………………………... 2
Estimated Time Needed ………………………………………………………………….. 2
Pre-Requisites …………………………………………………………………………... 3
Teacher Checklist ………………………………………………………………….. 3
Resources …………………………………………………………………………... 3
II. Hands-On Inquiry- Based Activity Lesson Plan(s)
Background For Teachers and Students ………………………………………………… 3
• Introduction ………………………………………………………………….. 3
• Goals/Objectives ………………………………………………………………….. 3
• Content …………………………………………………………………………... 4
Instructional Objectives ………………………………………………………………….. 4
National Standards/Benchmarks …………………………………………………………. 4
NASA Relevance ………………………………………………………………….. 6
Preparing for the Activity/Introduction ………………………………………………… 6
• Pre-requisites ………………………………………………………………….. 6
• Student Materials ………………………………………………….……................. 6
• Estimated Time Needed …………………………………………………………. 6
• Vocabulary …………………………………………………………..……… 6
The Activity: 5 Es Lesson: Teacher’s Edition ………………………………………... 7
Student Activity Handout …………………………………………………………………. 9
III. Teacher Resources
Teacher checklist, answer keys, any assessment/rubrics,
and any additional activities and resources ………………………………………………. 25
The student activity handout section includes any maps, graphs, articles, charts, journals and data
students need to complete the various lesson(s) in the module.
The Student Observation Network Lunar Module “Living and Working Safely On the Moon’ is a public domain
resource for educators and shall not be used for commercial purposes.
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I. Investigation Overview
Please Note: All of the teacher guides are labeled grades 5-8 or 9-12. The student resources, including selected
science articles and investigations, are separated by appropriate grade level 5-8 and 9-12 for each topic. This
provides more grade appropriate readings, mapping, graphing and processing skill development within the
module. Student resources are included at the end of each teacher guide.
Essential Question: What are the challenges engineers and scientists are working to solve as NASA prepares to
send humans to live and work on the Moon for extended periods of time?
Summary and Objectives
‘What challenges do we face going back to the Moon?’ Good question! When NASA announced the
vision to return to the Moon by 2020, and have humans living and working on the Moon for extended periods of
time, there were many different responses from the science, industry, and academic communities. This
investigation focuses on the challenges of returning to the Moon through a process called the BIDDI
(brainstorm, investigate, discuss, debrief, and identify).
Student groups will brainstorm the challenges of going back to the Moon. They will read what the
experts have to say about these challenges, discuss their value and relevancy, debate the importance of the
challenges, debrief as a class, and identify the most difficult challenges for returning humans to the Moon to live
and work for extended periods of time. They will use skills in reading, interpretation, communication, and
processing to interpret information, make inferences, and draw conclusions.
Student Involvement
• Inquiry-Based Questions
The essential question is a cornerstone for scientific debate about how we can be successful with
humans living and working on the Moon safely. This is the question students will debate and find answers to
during this investigation. Once they have prepared for the debate (brainstorming, readings, and discussion),
conducted the debate, debriefed, and identified the major challenges for sustaining life on the lunar surface, ask
the students this question: ‘If you had to decide whether or not to return humans to the Moon to live and work
for extended periods of time, do you think it could be done successfully with the challenges we face?’ Why do
you or do you not believe this? Explain?
• Hands-On-Activity
This brainstorm-investigate-discuss-debrief-identify (BIDDI) lesson is aligned with the National
Science Education Standards (NSES) and the National Standards for the English Language Arts. Students will
do an inquiry investigation into the challenges we face for returning to the Moon with humans to live and work,
and to maintain a human presence on the lunar surface. They will read relevant science articles addressing these
issues, discuss and debate the importance of these challenges, then debrief and identify, in their conclusions,
which challenges are the most difficult, and why. Ultimately, through the interpretation of information and
knowledge they gain in the readings and discussions, students will be able to draw a scientifically sound
conclusion about the challenges we face for returning to the Moon.
Grade Level(s)
Grades 5-8
Estimated Time Needed
The estimated time for all parts of the BIDDI: 3-4 45-minute class periods as listed below:
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• 1-2 45-minute classes for brainstorming and investigation/article readings
• 1 45-minute class for discussion and preparation for debate
• 1 45-minute class for debate and identification of findings
Pre-Requisites
There are no pre-requisites for this activity.
Teacher Checklist
The teacher checklist is designed to provide the teacher with a method for keeping track of the lesson
activity steps for teachers and students. It is located at the in the ‘Teacher Resource’ section at the end of this
document.
Resources
There is an enormous amount of information about the Moon, both in book form and on the Internet.
However, some sources are inaccurate or perpetuate misconceptions. Therefore, a list of website resources is
provided for you in the ‘Teacher Resource’ section at the end of this document. Additionally, a scientifically
reviewed master lunar content document accompanies this module and is located at
http://www.newpaltz.edu/secondaryed/. As new discoveries are made regarding lunar science, the NASA news
and the Science Magazine at NASA will announce the latest updates on lunar science to keep you up-to-date and
current. It is found at http://www.nasa.gov/news/index.html .
II. Hands-On-Activity
Background For Teachers
• Introduction
The ‘What challenges do we face going back to the Moon?’ investigation provides an opportunity to
integrate science with science literature, language skills, processing skills, and communication skills through
group discussion, investigation/readings, interpretation, debates, and decision-making. Using authentic science
articles written in response to the challenge of returning humans to the lunar surface to live and work safely for
extended periods, students will identify the importance of each challenge. Based on the scientific research
documented in the articles, students will decide whether it is possible to meet the challenge of returning to the
Moon for long-duration habitation.
The articles the students will read deal with a variety of issues concerning the planned lunar
colonization. These issues include, but are not limited to, the following:
• Resources: water, oxygen, hydrogen ions, titanium oxides, iron oxides
• Communications systems
• Solar radiation and space weather
• Materials science (fabrics, containment systems, protective gear)
• Technologies
• Moon Dust
• Gravity
• Habitat requirements: power, food, crops, air, temperature control, water, and waste
management
• Meteorite Activity
• Moonquakes
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• Goals/Objectives
The main objective for this activity is to provide an opportunity for students to understand the
challenges NASA faces in returning humans to the Moon, and how these challenges can be overcome.
• Content for Teachers
There is no content needed for this activity. However, please read the articles the students will read to
conduct the activity so that you are aware of the content contained in the readings.
After a teacher-directed brainstorming session to see if students can identify any of the challenges we
face for returning to the Moon with humans, the students will investigate using the readings, and then discuss,
interpret, extrapolate, infer, debrief, and draw conclusions based on the information in the readings. Although
teachers may provide assistance with concepts or vocabulary, allow the groups to figure out what the challenges
are, and identify the ones they believe are most important. To prepare for the debate on important challenges,
students will need to focus on:
:
o Whether or not they believe a challenge is important
o What impact a challenge would have on lunar exploration by humans
o And whether or not a specific challenge to return to the Moon can be accomplished and how.
Please note: we do not have all of the answers to meet the challenges for returning to the Moon. We do
not know the extent of the lunar resources, or all of the resources that may be available on the Moon. We do not
know where all of the best water resources are located, or how to manufacture fabrics that will keep humans safe
from solar radiation on the lunar surface. In fact, the purpose of this activity is to provide an opportunity for
students to think like a scientist or an engineer as they read the articles, and try to figure out which issues are the
most important to the safety and well-being of humans working and living on the Moon, and how difficult it will
be to meet the challenges. NASA will meet these challenges in the next decade working much the same way as
students will be during this activity.
The background information for this activity is included in the articles accessed at the end of this
document. In addition, the lunar content document that accompanies this module can be downloaded at
http://www.newpaltz.edu/secondaryed/.
Instructional Objectives
Students will:
• brainstorm the challenges related to colonizing the Moon
• investigate: read, discuss, and interpret science articles on the return to the Moon
• be able to communicate concepts related to lunar challenges with their group
• be able to identify the major factors and issues related to these challenges
• be able to successfully argue the importance of specific challenges in a class debate
National Standards
Standards for the English Language Arts
• Students read a wide range of print and non-print texts to build an understanding of texts, of
themselves, and of the cultures of the United States and the world; to acquire new information; to
respond to the needs and demands of society and the workplace; and for personal fulfillment.
Among these texts are fiction and nonfiction, classic and contemporary works.
• Students apply a wide range of strategies to comprehend, interpret, evaluate, and appreciate texts.
They draw on their prior experience, their interactions with other readers and writers, their
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knowledge of word meaning and of other texts, their word identification strategies, and their
understanding of textual features (e.g., sound-letter correspondence, sentence structure, context,
graphics).
• Students adjust their use of spoken, written, and visual language (e.g., conventions, style,
vocabulary) to communicate effectively with a variety of audiences and for different purposes.
• Students participate as knowledgeable, reflective, creative, and critical members of a variety of
literacy communities.
• Students use spoken, written, and visual language to accomplish their own purposes (e.g., for
learning, enjoyment, persuasion, and the exchange of information).
National Science Education Standards
CONTENT STANDARD A: As a result of activities in grades 5-8, extended for 9-12, all students should
develop
*Abilities necessary to do scientific inquiry
DEVELOPING STUDENT ABILITIES AND UNDERSTANDING: Students in grades 5-8 can
begin to recognize the relationship between explanation and evidence. They can understand that background
knowledge and theories guide the design of investigations, the types of observations made, and the
interpretations of data. In turn, the experiments and investigations students’ conduct become experiences that
shape and modify their background knowledge.
The language and practices evident in the classroom are an important element of doing inquiries.
Students need opportunities to present their abilities and understanding and to use the knowledge and language
of science to communicate scientific explanations and ideas. Writing, labeling drawings, completing concept
maps, developing spreadsheets, and designing computer graphics should be a part of the science education.
These should be presented in a way that allows students to receive constructive feedback on the quality of
thought and expression and the accuracy of scientific explanations.
*Understandings about scientific inquiry
Different kinds of questions suggest different kinds of scientific investigations. Some investigations
involve observing and describing objects, organisms, or events; some involve collecting specimens; some
involve experiments; some involve seeking more information; some involve discovery of new objects and
phenomena; and some involve making models.
Current scientific knowledge and understanding guide scientific investigations. Different scientific
domains employ different methods, core theories, and standards to advance scientific knowledge and
understanding.
*Science in Personal and Social Perspectives
As a result of activities in grades 5-8, extended for 9-12, all students should develop understanding of
• Natural hazards
• Risks and benefits
As a result of activities in grades 5-8, extended for 9-12, all students should develop understanding of
• Science as a human endeavor
• Nature of science
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NASA Relevance
NASA’s vision to return humans to the Moon by 2020 has sparked interest around the world. Educators
within NASA are working to incorporate the cutting edge science with the enthusiasm for space travel to
develop educational tools for teachers to use in the classroom that address national standards in the education of
science and mathematics.
Our current knowledge about the Moon is vast, but it is also limited. We have much to learn about the
Moon if we expect to send humans there to live and work for extended periods of time. Scientists are working
diligently to find answers to questions about lunar resources, solar energy relative to the Moon, and
communications issues between the Earth and Moon. The complete Lunar Module addresses each of these
concepts while providing an exciting, innovative way to bring research science to the classroom.
There are missions to the Moon in the planning stages that will help answer many of the questions we
have about the Moon and give us a better understanding of its physical and chemical characteristics. The NASA
Lunar Reconnaissance Orbiter, for one, was launched in 2008. It is designed to map the surface of the Moon and
characterize future landing features.
Preparing for the Activity/Introduction
• Introduction
The investigation begins with a teacher-directed brainstorming session about the challenges we face for
colonizing the Moon. At the end of the brainstorming session, the activity becomes student-directed with groups
of 3-5 students. The classroom setting would be best set up for easy discussion among members of the group.
Teachers are encouraged to allow students to conduct the activities without much direction.
• Pre-Requisites
There are no pre-requisites for this activity.
• Student Materials
• Each group will need a set of articles located at the end of this document. There are 6 sets of articles,
one for each of 6 groups, and each set deals with different issues about the return of humans to live
and work on the Moon for extended periods of time.
• Estimated Time Needed
The estimated time for all parts of the BIDDI: 3-4 45-minute class periods
• 2-45-minute classes for brainstorming and investigate/article readings
• 1 -45-minute class for discussion and preparation for debate
• 1 -45-minute class for debate and identification of findings
• Vocabulary
The articles have been altered to reduce the need for vocabulary development for students. Depending on
the students, teachers may need to read the articles to select some terms for understandings.
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The Activity: 5 E’s Lesson: Teacher’s Edition
Introduction: The ‘What challenges do we face going back to the Moon?’ investigation provides an
opportunity to integrate science with science literature, language skills, processing skills, and communication
skills through group discussion/investigation, readings, interpretation, debates, and decision-making. Using
authentic science articles written in response to the challenges we face for returning humans to the lunar surface
to live and work safely for extended periods of time, students will identify the importance of such challenges,
and, based on the scientific research documented in the articles, decide whether or not it is possible to meet the
challenge of returning to the Moon for long-duration habitation.
• Teachers will direct a brainstorming activity about the challenges we face for colonizing the Moon. These
issues include:
o Resources on the Moon: NASA is looking to find as many useable resources on the Moon as
they can find. The more resources in place on the Moon, the fewer the resources that will have to
be transported to the Moon. Additionally, humans have certain requirements for sustaining life.
Does the Moon have resources to sustain life that they could use? If so, what are they, where are
they located, and how much is there?
o Solar radiation: The Earth has a magnetic field surrounding the entire globe, and an
atmosphere of protective gasses. The atmosphere helps filter out harmful solar radiation and
keeps the temperature from getting too hot or too cold. The magnetic field forms a magnetosphere
that acts like a shield from solar winds, coronal mass ejections and other solar activity that could
be harmful to life on Earth. The Moon has no atmosphere or global magnetic field.
o Technologies: As amazing as it seems, especially after the Apollo program successes, we do
not have the technologies we need to meet challenges of a return to the Moon. New discoveries
about solar activity and the impact of space travel on the human body made over the past 35 years
have changed the way we view space travel and safety. As you will see when you read the
articles, even the spacesuit used by the shuttle program astronauts does not protect our astronauts
from massive energy blasts from the Sun. This is but one of the technological challenges we have
for returning to the Moon by 2020.
Procedure:
Engage: Teacher-directed: Brainstorm with the class about what would be needed in order to colonize
the Moon. Why would we want to go back there? Is there anything there that we want? How does it help us in
our space explorations? What would we need to be able to do to build a colony on the Moon?
• Write the questions (and more if you have any) on the board
• Challenge the students to come up with reasonable ways to answer these questions in a positive way
• Write their answers on the board along with the corresponding questions
• Ask the students which answers they think are better than others, and why
Explore: Student directed; Now, have the students form groups around tables or clustered desks so
they can communicate and investigate easily. The articles are labeled ‘Challenge Articles’ 1 through 9. There
are 3 articles to be given to each group. That will mean that 2 groups will have the same set of articles because
there are a total of 9 articles, with 3 for each group. Later, when the groups are combined to make teams, you
will need to be sure that the teams are evenly matched.
Articles 1, 2, and 3 are given to groups A and B.
Articles 4, 5, and 6 are given to groups C and D
Articles 7, 8, and 9 are given to groups E and F
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When the teams are formed from the groups, one team should be the students in groups A, C, and E, and
the other team will be made up of groups B, D, and F. This will ensure that each team has members who have
background on all of the challenges we face.
As the students read the articles, they need to take notes to keep track of the important facts they find.
They will use the notes to discuss issues with the team members before the class debate. Once the group has
finished reading the articles, (every group member needs to read each article) they will need to discuss the facts,
interpret what they have learned, decide whether the challenges (what makes the most sense) for colonizing the
Moon are important, and whether or not they agree with the findings. They need to keep in mind that they will
debate the important issues later and they need to understand what they are defending or supporting. Example:
A group has an article that discusses the use of mineral resources to mine oxygen for the air humans will need
when living on the Moon. Do they really think that can be done? Is it easy to do or would it make more sense to
bring more plants to the Moon? Would it make more sense to bring all of the oxygen you need to the Moon?
Why? Why not?
This example is simply a learning exercise. Answers to these questions have not been decided yet, and it
may take years before the decisions are made.
Explain: The 6 groups will now merge into 2 teams made up of 3 groups (see the above grouping; ACE
and BDF). One team of students is the ‘agree with the challenge’ team, and the other is the ‘disagree with the
challenge’ team. The teams will have about 15-20 minutes to share the article issues (that’s where the notes
come in handy) and what they mean for colonization. Then, the debate begins!
Teacher-directed, the debate between the teams will be issue-based. For example, if the issue is water
resources, the teacher would make a statement about the water resources like ‘There is plenty of water on the
Moon for human colonization’. Each team would have 1 minute to respond. The students responding to the
questions should be done in some order; otherwise some students may ‘take over’ the responses. The ‘agree’
team would need to state the reasons why the statement is true, and the ‘disagree’ team would need to state why
the reason might be false. Even if a student does not agree with a statement, they need to argue the issue with the
team. This is an exercise in persuasive communications. This debate with the 9-12 students can be conducted
with two teams as well.
Many of the challenges we face are listed in the teacher resource section at the end of this document. As
stated earlier, we do not have answers to all of the issues. If we did, we would not need to conduct the research
and missions designed to answer the questions. Therefore, it is okay for the students to speculate a little, but they
also need to use the facts from the articles to support their debate arguments. If additional time is available, an
Internet search is another good place to find information about the challenges of returning humans to the Moon.
Extend: This is a good time to assign a research paper! Let the students decide what they would like to
research about the characteristics of the Moon, colonization, habitats, or requirements for sustaining life, and
coordinate that with the Lunar Environment section in this Lunar Module.
Evaluate:
-Formative: It is an excellent way to evaluate the working groups and the teams. Walk around the room
checking on discussions, interpretations and findings, as well as the note taking by individuals or groups. Follow
this up in the debate through informal assessment of the quality of the student arguments.
-Summative: The research paper on a lunar topic would fulfill a summative evaluation and extend the
student knowledge base in lunar science.
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Student Activity Handouts
‘What challenges do we face going back to the Moon?’
Student Materials
o Each group or student will need a set of articles from the end of this document, 1, 2, 3 or 4, 5, 6 or 7,
8, 9.
o A copy of the student handout located in the teacher guide
o Notebook
o Pen or pencil
Procedure
1. Form groups with 3-5 students per group
2. Obtain the three lunar articles for your group. They are together in one document. Your group may be
the A, B, C, D, E, or F group. The A and B groups have the same articles, the C and D groups have the
same articles, and the E and F groups have the same articles. Your teacher will have copied these.
3. Read the articles carefully and take notes on the important challenges we face for returning to the
Moon with humans to live and work on the Moon for extended periods of time.
4. After each member of the group has read all three articles and taken notes, discuss the findings, share
interpretations of the results, and identify the results that make the most sense to your group.
5. Decide the importance of each challenge and how we can meet the challenge in order to colonize the
Moon.
6. Your teacher is going to combine three groups into teams. Groups A, C, and E will form a team, and
groups B, D, and F will form a team. The ACE team will be the ‘agree’ challenge team, and the BDF
team will be the ‘disagree’ challenge team. Whether or not you truly do agree or disagree with a
challenge’s importance has nothing to do with why your group is picked for a team.
7. Each team will have 15-20 minutes to share/discus the group findings from the articles with the team
members. Since the A group have different articles than the C or E groups, they would share with the C
and E groups, and so on.
8. The debate will be directed by the teacher and is a series of statements that your team will either
defend (if you are in the ‘agree’ team) or argue against (if you are a ‘disagree’ team member). Only one
person from each team can answer a statement. Each person is allowed only one minute to respond to
the statement. Please take turns responding to the statements to give as many students as possible a
chance to debate.
Example:
Your teacher states that water is not on issue for colonizing on the Moon. The ‘agree’ team would argue
that it is not an issue and why, while the ‘disagree’ team would argue that it is an issue and why. Whatever team
you are on, you must give reasons for the issue based on the team’s stand; whether it agrees or disagrees with a
statement.
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9Article 1
Breathing Moon Rocks
Grades 5-8
05.05.2006 The Moon has plentiful oxygen for future astronauts. It's lying on the ground.
May 5, 2006: An early, problem noted by Apollo astronauts on the Moon was dust. It got everywhere, including
into their lungs. Oddly enough, that may be where future Moon explorers get their next breath of air: The
moon's dusty layer of soil is nearly half oxygen.
The trick is taking it out of the dust! "All you have to do is vaporize the stuff," says Eric Cardiff of NASA's
Goddard Space Flight Center. He leads one of several teams developing a way to provide astronauts with the
oxygen they'll need on the Moon and Mars.
Lunar soil is rich in oxides (minerals that have oxygen in them). The most common is silicon dioxide
(SiO2), "like beach sand," says Cardiff. Also plentiful are oxides of calcium (CaO), iron (FeO) and magnesium
(MgO). Add up all the oxygen atoms: 43% of the mass of lunar soil is oxygen.
Apollo 17 geologist Harrison "Jack" Schmitt
scoops up some oxygen-rich moon rocks
and soil. Credit NASA
Cardiff is working on a technique that heats lunar soils until they release oxygen. "It's a simple kind of
chemistry," he explains. "Any material crumbles into atoms if it is made hot enough." The technique is called
vacuum pyrolysis--pyro means, "fire", lysis means, "to separate."
"A number of things make pyrolysis more attractive than other techniques," Cardiff explains. "It requires
no raw materials to be brought from Earth, and you don't have to prospect for a particular mineral." Simply
scoop up what's on the ground and apply the heat.
To prove this idea, Cardiff and his team used a lens to focus sunlight into a tiny vacuum chamber and
heated 10 grams of lunar-like soil to about 2,500 degrees C. Test samples included ilmenite, an iron oxide with
the element titanium. Actual lunar soil is too highly prized for such research now to be used in these
experiments. In their tests, "as much as 20 percent of the lunar-like soil was converted to free oxygen,"
Cardiff estimates. What's leftover is "slag," a low-oxygen, metallic, often-glassy material. Cardiff is working
with colleagues at NASA's Langley Research Center to figure out how to shape slag into useful products like
radiation shielding, bricks, spare parts, or even pavement.
The next step for Cardiff’s team? Increase efficiency. "In May, we're going to run tests at lower
temperatures, with a super thin vacuum pressure. In this way oxygen can be taken out with less power. In other
words, the more you decrease the pressure, the less energy you will need to heat a material to a breaking point.
Article 2
Articles: Gravity Hurts (so Good)
Grades 5-8
Strange things can happen to the human body when people venture into space -- and the familiar pull of
gravity vanishes.
http://science.nasa.gov/headlines/y2001/ast02aug_1.htm?list545931
August 2, 2001: Gravity hurts: you can feel it while carrying a loaded backpack or pushing a bike up a hill. But
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10the lack of gravity hurts, too. When astronauts return from long-term travel into in space, they sometimes need
to be carried away in stretchers.
Gravity is not just a force. It is also a signal that tells the body how to act. For one thing, it tells muscles
and bones how strong they must be. In zero-G (almost no gravity), muscles waste away quickly because they are
not being used so the body thinks it does not need them. The muscles used to fight gravity, like those in the
calves and spine, which maintains posture, can lose around 20 per cent of their mass if you don't use them,
muscles can vanish at a rate as high as 5% of their mass a week.
For bones, the loss can be even higher. Bones in space waste away at a rate of about 1% a month.
Models suggest that the total loss could reach 40 to 60 per cent. Blood feels gravity, too. On Earth, blood pools
in the feet. When people stand, the blood pressure in their feet can be high. In the brain, though, it is much
lower. In space, where the familiar pull of gravity is missing, the head-to-toe difference in blood pressure
disappears. Blood pressure becomes the same (about 100 mmHg) throughout the body. That is why astronauts
can look odd when they are in space. Their faces fill with fluid, and puff up, and their legs, which can each lose
about a liter of fluid, thin out.
But that shift in blood pressure also sends a signal. Our bodies expect a blood pressure gradient. Higher
blood pressure in the head raises an alarm: The body has too much blood! Within two to three days of
weightlessness, astronauts can lose as much as 22 percent of their blood volume as a result of that errant
message. This change affects the heart, too. "If you have less blood," explains Dr. Victor Schneider, research
medical officer for NASA headquarters, "then your heart doesn't need to pump as hard. It's going to waste
away."
The question is, ‘Do such losses matter?’
Perhaps not, if you plan to stay in space forever. But eventually astronauts return to Earth and the
human body has to readjust to the relentless pull of gravity. Most space adaptations appear to be reversible, but
the rebuilding process is not necessarily an easy one.
"Each of the changes has their own normal recovery time," says Schneider. Blood volume, for example, is
typically restored within a few days. "Astronauts get thirsty when they come back," Schneider explains,
"because their body says, you don't have enough blood in your blood vessels, and that causes the messengers to
say, drink more water!
Astronaut Susan Helms on Earth (left)
and on board the International Space
Station (right). Credit NASA JSC.
Muscle, too, can come back to normal. Most muscle comes back "within a month or so, "although it might
take longer to recover completely.”We normally say that it takes a day [of recovery on Earth] for each day that
somebody's in space," says Schneider.
Bone recovery, though, has proven to be a problem. For a three to six month space flight, says
Schneider, it might require two to three years to regain lost bone. However, that is if it comes back. Some
studies have suggested that it doesn't. "You really have to exercise a lot to keep bone mass in space.” says
Schneider. "You really have to work at it."
And Earth isn't the only planet that astronauts might visit. One day soon, humans will journey to Mars.
That is a six-month trip in zero-G before they land on a planet with 38% of Earth's gravity. "[We'll have to
maintain] those astronauts at a fairly high level of fitness," explains Hargens. "When they get to Mars, there
won't be anyone to help them if they get into trouble." They will need to be able to handle everything
themselves.
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11Artist Pat Rawlings created this
beautiful painting (entitled "Inevitable
Descent") of a future astronaut on
Mars. Credit NASA JSC.
Exercise is the key. But exercising in space is different from exercising on Earth. Here, gravity's pull
provides a resistant force that helps us maintain muscles and bones. "[In space] even if you do the same amount
of work that you were doing down here on Earth, you miss the force of gravity," says Schneider.
Many devices have been developed to mimic the help that gravity provides. One Russian experiment
provides resistance by strapping jogging cosmonauts to a treadmill with bungee cords. But that particular
combination has not yet proven effective in preventing bone loss. "
There's also IRED, a NASA-developed Interim Resistive Exercise Device. The IRED is made up of
canisters that can provide more than 300 pounds of resistance for a variety of exercises. IRED's effectiveness is
still being monitored, says Schneider.
Another promising device attempts to mimic gravity even more closely. Hargens and his team are
developing a Lower Body Negative Pressure (LBNP) device, a chamber that contains a treadmill, and that relies,
says Hargens, on the suction of an ordinary vacuum cleaner. "We've found," he says "that we can provide body
weight by applying negative pressure over the lower body."
S73-20713 (03/01/73) - Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, wipes
perspiration from his face following an exercise session on the bicycle ergometer during Skylab training at JSC.
Credit NASA.
The device prevents much of the loss of cardiovascular function and of muscle. It also seems to be
effective in reducing some bone loss. One reason is that the LBNP allows astronauts to exercise with an
effective body weight between 100% and 120% of what they would feel on Earth. Another is that it restores the
blood pressure gradient, by increasing blood pressure to the legs.
Article 3
Moonquakes
Grades 5-8
March 15, 2006: NASA astronauts are going back to the moon and when they get there they may need
quakeproof housing.
That's the surprising conclusion of Clive R. Neal, associate professor at the University of Notre Dame
after he and a team of 15 other scientists examined Apollo data from the 1970s. "The moon is seismically
active," he told scientists at NASA's Lunar Exploration Analysis Group (LEAG) meeting in League City, Texas,
last October. Between 1969 and 1972, Apollo astronauts placed seismometers at their landing sites around the
moon. The Apollo 12, 14, 15, and 16 instruments radioed data back to Earth until they were switched off in
1977.
12
12Buzz Aldrin deploys a seismometer
in the Sea of Tranquility
And what did they reveal?
There are at least four different kinds of moonquakes: (1) deep moonquakes about 700 km below the
surface, probably caused by tides; (2) vibrations from the impact of meteorites; (3) thermal quakes caused by the
expansion of the cold crust when first illuminated by the morning sun after two weeks of deep-freeze lunar
night; and (4) shallow moonquakes only 20 or 30 kilometers below the surface. The first three were generally
mild and harmless. Shallow moonquakes on the other hand were very big. Between 1972 and 1977, the Apollo
seismic instruments saw twenty-eight of them; a few were up to 5.5 on the Richter scale," says Neal. A
magnitude 5 quake on Earth is energetic enough to move heavy furniture and crack plaster.
In addition, shallow moonquakes lasted a long time. Once they got going, they continued for more than 10
minutes. "The moon was ringing like a bell," Neal says. On Earth, vibrations from quakes usually die away in
only half a minute. The reason has to do with chemical weathering, Neal explains: "Water weakens stone,
expanding the structure of different minerals. When energy moves outward across such a tightly formed
structure, it acts like a foam sponge and deadens the vibrations." Even the biggest earthquakes stop shaking in
less than 2 minutes.
The moon, however, is dry, cool and mostly rigid, like a chunk of stone or iron. So moonquakes make it
vibrate like a tuning fork. Even if a moonquake isn't strong, "it just keeps going and going," Neal says. And for a
lunar habitat, that long time quaking could be more important than a moonquake's strength. "Any habitat would
have to be built of materials that are somewhat flexible," so no air-leaking cracks could develop. "We'd also
need to know how much repeated bending and shaking the materials could stand.
What causes the shallow moonquakes? And where do they occur? "We're not sure," he says. "The Apollo
seismometers were in one small region on the near side of the moon, so we can't pinpoint [the exact locations of
these quakes]." He does have some good ideas. One idea for the cause of the moonquakes is that the rims of
large, young craters may fall away to the crater floor.
“We do not know much about the lunar poles," Neal continues. That's important, because one possible
location for a lunar base is on a sunlit region on the rim of Shackleton Crater at the Moon's South Pole.
Neal and his colleagues are writing a proposal to send a network of 10 to 12 seismometers around the
entire moon to gather data for at least five years. This kind of work is necessary, Neal believes, to find the safest
spots for permanent lunar bases.
And that's just the beginning, he says. Other planets may be shaking, too: "The moon is a technology test
bed for establishing such networks on Mars and beyond."
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13Article 4
Sickening Solar Flares
Grades 5-8
The biggest solar proton storm in 15 years erupted last week. NASA researchers discuss what it might
have done to someone on the Moon.
January 27, 2005:
NASA is returning to the Moon and not with just robots, but with people as well. In the decades ahead we can
expect to see habitats, greenhouses and power stations up there. Astronauts will be out among the moondust and
craters, exploring, prospecting, and building.
Last week, though, there were no humans walking around on the Moon. Good thing.
On January 20th, 2005, a giant sunspot named "NOAA 720" exploded. The blast sparked an X-class solar
flare, the most powerful kind, and hurled a billion-ton cloud of electrified gas (a "coronal mass ejection") into
space. Solar protons accelerated to nearly light speed by time the explosion reached the Earth-Moon system
minutes after the flare."
Here on Earth, no one suffered. Our planet's thick atmosphere and magnetic field protects us from
protons and other forms of solar radiation. In fact, the storm was good. When the plodding coronal mass ejection
arrived 36 hours later and hit Earth's magnetic field, sky watchers in Europe saw the brightest and prettiest
auroras in years.
The Moon is a different story.
"The Moon is totally exposed to solar flares," explains solar physicist David Hathaway of the Marshall
Space Flight Center. "It has no atmosphere or magnetic field to deflect radiation." Charged particles (protons in
this case) rushing at the Moon simply hit the ground or whoever might be walking around outside.
The Jan. 20th proton storm was one of the biggest since 1989. It was very rich in high-speed protons with
more than 100 million electron volts. Such protons can burrow through 11 centimeters of water. A thin-skinned
spacesuit would have offered little resistance.
"An astronaut caught outside when the storm hit would've gotten sick," says Francis Cucinotta, NASA's
radiation health officer at the Johnson Space Center. At first, he'd feel fine, but a few days later symptoms of
radiation sickness would appear: vomiting, fatigue, low blood counts. These symptoms might persist for days.
Astronauts on the International Space Station (ISS), by the way, were safe. The ISS is heavily shielded,
plus the station orbits Earth inside of our planet's protective magnetic field. "The crew probably absorbed no
more than 1 rem," says Cucinotta.
One rem, short for Roentgen Equivalent Man, is the radiation dose that causes the same injury to human
tissue as 1 roentgen of x-rays. A typical diagnostic CAT scan, the kind you might get to check for tumors,
delivers about 1 rem. So, for the crew of the ISS, the Jan. 20th proton storm was no worse than a trip to the
doctor on Earth.
On the Moon, an astronaut protected by no more than a space suit would have absorbed about 50 rem of
radiation. That's enough to cause radiation sickness. "But it would not have been fatal," he adds. To die, you'd
need to absorb, suddenly, 300 rem or more.
The key word is suddenly. You can get 300 rem spread out over a number of days or weeks with little
effect. Spreading the dose gives the body time to repair and replace its own damaged cells. But if the 300 rem
14
14comes all at once ... "we estimate that 50% of people exposed would die within 60 days without medical care,"
says Cucinotta. Such doses from a solar flare are possible.
It's legendary (at NASA) because it happened during the Apollo program when astronauts were going
back and forth to the Moon regularly. At the time, the crew of Apollo 16 had just returned to Earth in April
while the crew of Apollo 17 was preparing for a moon landing in December. Luckily, everyone was safely on
Earth when the flares occurred.
"A large sunspot appeared on August 2, 1972, and for the next 10 days it erupted again and again," recalls
Hathaway. The explosions caused, "a proton storm much worse than the one we just experienced," adds
Cucinotta.
Cucinotta estimates that a moonwalker caught in the August 1972 storm might have absorbed 400 rem.
Deadly? "Not necessarily," he says. A quick trip back to Earth for medical care could have saved the average
astronaut's life.
Surely, though, no astronaut is going to walk around on the Moon when there's a giant sunspot threatening
to explode. "They're going to stay inside their spaceship (or habitat)," says Cucinotta. An Apollo command
module with its aluminum hull would have absorbed a lot of the energy from the 1972 storm. It would have
brought it from 400 rem to less than 35 rem at the astronaut's blood-forming organs. That's the difference
between needing a bone marrow transplant or just a headache pill.
Modern spaceships are even safer. "We measure the shielding of our ships in units of grams per
centimeter-squared," says Cucinotta. Big numbers that represent thick hulls are better:
• The hull of an Apollo command module rated 7 to 8 g/cm2.
• A modern space shuttle has 10 to 11 g/cm2.
• The hull of the ISS, in its most heavily shielded areas, has 15 g/cm2.
• Future moon bases will have storm shelters made of polyethylene and aluminum possibly exceeding
20 g/cm2.
• A typical space suit, meanwhile, has only 0.25 g/cm2, offering little protection. "That's why you want
to be indoors when the proton storm hits," says Cucinotta.
•
However, when explorers get to the Moon they're not going to want to stay indoors. A simple precaution:
Like explorers on Earth, they can check the weather forecast (the space weather forecast). Are there any big
'spots on the sun? What's the chance of a proton storm? Is a coronal mass ejection coming?
All clear? It's time to step out.
Article 5
NASA Science News
Grades 5-8
Hard-nosed Advice to Lunar Prospectors May 22, 2006:
Long before David Beaty became associate Chief Scientist for NASA's Mars Program, he was a
prospector. Beaty spent 10 years surveying remote parts of Earth for precious metals and another 12 years
hunting for oil.
And this qualifies him to work for NASA? Precisely.
Beaty has the kind of experience NASA needs as the agency prepares to implement the Vision for Space
Exploration. "Mining and prospecting are going to be key skills for settlers on the Moon and Mars," he explains.
15
15"We can send them air and water and fuel from Earth, but eventually, they'll have to learn to live off the land,
using local resources to meet their needs.”
S99-04195 (1995) (Artist's concept of possible exploration
programs.) Just a few kilometers from the Apollo 17 Taurus Littrow
landing site, a lunar mining facility harvests oxygen from the
resource-rich volcanic soil of the eastern Mare Serenitatis and which
could be used as raw material for a lunar metals production plant.
This image produced for NASA by Pat Rawlings, (SAIC), Johnson
Space Center.
On the Moon, for instance, mission planners hope to find water frozen in the dark recesses of polar
craters. Water can be split into hydrogen for rocket fuel and oxygen for breathing. Water is also good for
drinking and as a bonus it is one of the best-known radiation shields. "In many ways," notes Beaty, "water is key
to a sustained human presence." Ice mining on the Moon could become a big industry.
Beaty has learned a lot from his long career prospecting, exploring and mining on Earth. Now, with an
eye on other worlds, he has distilled four pieces of wisdom he calls "Dave's Postulates" for prospectors working
anywhere in the solar system:
Postulate #1: "Wishful thinking is no substitute for scientific evidence."
"On Earth, banks won't lend money for less than proven reserves. From a bank's viewpoint, anything less
than proven is not really there. This lesson has been learned the hard way by many a prospector," he laughs.
For NASA the stakes are higher than profit. The lives of astronauts could hang in the balance. "Proven
reserves on the Moon can perhaps be thought of as having enough confidence to risk the lives of astronauts to go
after it."
What does it take to "prove" a reserve—that is, to know with confidence that a resource exists in high
enough concentration to be produced?
"That depends on the nature of the deposit," explains Beaty. "Searching for oil on Earth, you can drill one
hole, measure the pressure, and calculate how much oil is there. You know that oil probably exists 100 feet
away because liquids flow. However, for gold you must drill holes 100 feet apart, and assay the concentration of
gold every five feet down each hole. That's because the solid earth is heterogeneous. One-hundred feet away the
rocks may be completely different."
Deposits on the Moon aren't so well understood. Is lunar ice widespread or patchy, deep or shallow? Does
it even exist? "We don't know," says Beaty. "We still have a lot to learn."
Postulate #2: "You cannot define a reserve without specifying how it can be extracted. If it can't be mined, it's
of no use." Enough said.
Postulate #3: "Perfect knowledge is not possible. Exploration costs money, and we can't afford to buy all the
information we want. We have to make choices, deciding what information is critical and what's not."
16
16A robotic ice miner; an
artist's concept. Credit:
NASA/John Frassanito
& Associates
He offers the following hypothetical example:
"Suppose we decide to send a robot with a little drill and an onboard laboratory into the Shackleton
Crater, a place on the Moon with suspected ice deposits. We're going to have to think pretty carefully about that
lab. Maybe it can contain only two instruments. What are the two things we most need to know?"
"Suppose further that someone on Earth has invented a machine that can extract water from lunar soil. But
it only works if the ice is close to the surface and if the ice is not too salty." The choice is made. "We'd better
equip the robot with instruments to measure the saltiness of the ice and its depth in the drill hole."
Postulate #4: "Don't underestimate the potential effects of heterogeneity. All parts of the Moon are not alike,
just as all parts of Earth are not alike. So where you land matters."
Ultimately, says Beaty, if geologists and engineers work together applying these rules as they go, living
off the land on alien worlds might not be so hard after all.
Article 6
Magnetic Moon Dust
5-8
April 4, 2006: Thirty-plus years ago on the moon, Apollo astronauts made an important discovery: Moon dust
can be a annoying. The fine powdery grit was everywhere and had a curious way of getting into things. Moon
dust plugged bolt holes, clogged tools, coated astronauts' visors and wore down their gloves. Very often while
working on the surface, they had to stop what they were doing to clean their cameras and equipment using large
brushes.
Dealing with "the dust problem" is going to be important for the next generation of NASA explorers.
But how?
Professor Larry Taylor of the University of Tennessee, believes he has an answer to the problem;
"Magnets." The idea came to him in the year 2000. Taylor was in his lab studying a moon dust sample from the
Apollo 17 mission and, curious to see what would happen, he ran a magnet through the dust. To his surprise, "all
of the little grains jumped up and stuck to the magnet."
"I didn't appreciate what I had discovered," recalls Taylor, "until I was explaining it to Apollo 17
astronaut Jack Schmitt one day in my office, and he said, 'Gads, just think what we could have done with a
brush with a magnet attached!'"
17
17At the end of a long day on the moon, Apollo 17 astronaut
Gene Cernan rests inside the lunar module Challenger.
Note the smudges of dust on his long johns and forehead.
Photo credit: Jack Schmitt.
"Only the finest grains respond completely to the magnet," notes Taylor, but that's okay because the finest
dust was often the most troublesome. Fine grains were more likely to get through seals at the joints of spacesuits
and around the lids of sealed sample containers. And when astronauts returned to the Lunar Module wearing
their dusty boots, the fine grains billowed into the air where they could be inhaled. This gave at least one
astronaut (Schmitt) a case of "moon dust hay fever."
Taylor has since designed a prototype air filter with permanent magnets inside. "When the filter gets dirty,
you pull the magnets out, and the dust falls into a box." A later design with electromagnets works more
efficiently: "You pull the plug on the electromagnet, tap it, and the dust rains down into a container." He's now
working on a prototype design for a "dust brush" using permanent magnets.
Earth dust is not magnetic, so why should moon dust be?
"Moon dust is strange stuff," explains Taylor. "Each little grain of moon dust is coated with a very thin
layer of glass. Taylor and colleagues have examined the coating through a microscope and found "millions of
tiny specks of iron suspended in the glass like stars in the sky." Those iron specks are the source of the
magnetism.
Researchers believe the glass is a result of bombardment by meteorites. Tiny micrometeorites hit the
surface of the moon, creating temperatures hotter than 2,000°C. This is the surface temperature of red stars.
Such extreme heat vaporizes molecules in the melted soil.
"The vapors consist of compounds such as iron oxide and silica," says Taylor. If the temperature is high
enough, the molecules split into their elements: Si, Fe, O and so on. Later, when the vapors cool, the atoms
recombine and condense on grains of moondust, depositing a layer of silicon dioxide (SiO2), a glass peppered
with tiny nuggets of pure iron (Fe).
A thin coating of iron isn't enough to make sand or gravel-sized particles magnetic, any more than
spraying a thin coating of iron on a heavy basketball would make it stick to a magnet, says Taylor. But a thin
coating is plenty for very tiny particles. They have so little mass compared to their surface area they are easily
lifted by Taylor's magnets.
Magnets aren't the only way to deal with moondust. NASA is considering lot of options, from airlocks
to vacuum cleaners. But, if Taylor is right, magnets will prove important, and astronauts won't find moondust so
troublesome the next time around.
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