Sound Space

August 2022 Science Snacks Newsletter

by Marianne Dyson

No one can hear you scream in space. They can’t hear you laugh or cough or clap your hands, either.

Sound is defined as vibrations that travel through a gas, liquid, or solid (e.g. the floor of the apartment upstairs) that is heard when those vibrations “shake” the eardrum of a person or animal.

iphone speakers
Sound is a vibration that travels through a gas, liquid, or solid. Play a song or video on your cell phone and hold your finger near one of the speakers (look for the row of holes at the bottom shown in the photo) to feel the air vibrating. Marianne Dyson photo, 2022.

So despite the loud booms of spacecraft exploding in movies, explosions in space are silent. However, secondary sound effects may be heard. Debris striking a hull or window of a spacecraft might cause a vibration inside that generates sound. Astronauts onboard the space shuttle reported hearing loud bangs as the metal structure of the vehicle shook during jet firings. A spacewalker banging on the hatch could be heard by those inside. Would touching helmets together work? Probably not much, considering the thickness of the glass, but combined with lip reading, it might help!

But wait—people on the ground talk to astronauts in space all the time. How can they do that?

Radio waves are not sound waves. Radio is a band of electromagnetic waves of a frequency between 3 kilohertz to 300 gigahertz [NASA reference]. Radio, just like visible light and x-rays and other frequencies of electromagnetic waves, travels at the speed of light in a vacuum.

Humans cannot hear radio waves directly. (Human eyes “see” electromagnetic waves in the visible light 1015 Hz range.) But clever humans have learned how to convert the energy in a radio wave into vibrations that create sound waves that human and animal ears can sense.

Humans can generally hear sound waves between 12 Hz and 20 KHz. [Reference] Other animals such as dogs, cats, and especially bats can hear higher frequencies, and some, including whales, much lower frequencies than humans. [Reference]

The way an astronaut communicates with Mission Control is to speak into a microphone that converts the vibrations in the air made by her voice into radio waves. Those waves are (after being converted to the proper frequency and chopped into bits for transmission by a computer) sent through the vacuum of space, the atmosphere of Earth, and to a receiver on the ground that distributes the waves to the various devices that convert the radio waves back into sound such as flight controller headsets, someone’s cell phone, or amplified speaker boxes in school auditoriums. A response likewise is converted to radio and back into sounds that the astronaut hears in her headset or through a speaker in a spacecraft or spacesuit.

Author wearing headset
Noise-canceling headsets (shown worn by the author) convert radio to sound while protecting the wearer from hearing loss. Frequent exposure to loud sounds (more than 60 min. above 60% volume/day) or to sounds greater than 165 decibels (a gunshot at close range), can cause permanent damage to the inner ear. [Reference]  Marianne Dyson photo, 2022.

But even at the speed of light, it takes time for the signals to travel back and forth in space—so be prepared for a time lag between questions and answers. As I noted in a previous blog, this time lag almost caused us to hang up on an astronaut who called our house from space!

Because aircraft and spacecraft cockpits are noisy, some sounds, like “d” and “t” are hard to distinguish from each other, especially considering various accents. To avoid confusion, the aviation and space community employ an aviation alphabet to spell out each letter of a word. So instead of spelling out “dot” as “dee oh tee” which might sound like DoD or tot or even pot, in aviation/space speak, it is “Delta Oscar Tango.”

I hope your brain enjoyed this science snack. In case you didn’t hear, that’s Sierra November Alpha Charlie Kilo!

Writing and Speaking About Space

I’m happy to announce I have a short story, “The Power of Apollo (16)” and science article in the September/October 2022 issue of Analog Science Fiction and Fact Magazine (and my name is on the cover!). Single print copies can be found at bookstores and newsstands. Electronic subscriptions are available via Amazon.

Want to live in space? Listen to the Big Picture Science podcast (also broadcast on NPR Science Fridays), “Building a Space Colony.” I’m quoted during the first segment which is followed by a segment with Author Emily St. John Mandel and another with John Adams of Biosphere 2.

Texas friends: I hope to see you at FenCon in Dallas September 16-18, 2022. Stop by my autograph table to get signed copies of Shuttle Mission Control, Fly Me to the Moon, A Passion for Space, and my newest children’s title, Up in Space. Autographed books can also be ordered through Thank you for your support!

Blue Fire in Space

Marianne Dyson, October 2021

As the holiday season approaches, many of us decorate our tables with candles. If we did that in space, they would burn round and blue, not pointy and yellow. Why?

Candle flames heat the air around them. The hot air rises because it is less dense and thus weighs less than cold air. This air movement shapes a candle flame into a cone with a point at the top (see photo). Flames are blue at the base where they are hottest, and yellow above because as the hot air rises it takes some of the unburned wax with it in the form of smoke and soot.

Flames on Earth are cone shaped and blue at the base and yellow at the top because heated air rises. Marianne Dyson photo, 2021.

In space, hot and cold air weigh the same: nothing. Heated air just expands outward in a sphere. Because the air doesn’t rush away in one direction (up) like on Earth, the fire burns hotter and doesn’t produce as much smoke and soot, making the whole flame blue.

space flame
In space, hot air doesn’t rise, so flames are round and blue like this candle lit during a Shuttle flight in 1992. NASA photo STS050-232—011, cropped by author

If there’s a fire on Earth, we quickly head outside into the fresh air. In space, there is no air outside. Fire can quickly fill spacecraft or space station modules with smoke and suffocate the crew. But fresh air is available via oxygen masks and tanks available in all modules. So the first thing astronauts do in case of a fire is to don an oxygen mask.

Luckily both on Earth and in space, flames can be put out by smothering them—depriving them of oxygen.

On Earth, firefighters remove brush that fuels fire and smother and cool the fire with water or chemicals. In space, when the space station’s smoke detector sounds the alarm, the station’s main computer automatically shuts off the fans and the flow of oxygen. This helps keep the fire from spreading and makes it easier for the crew to fight the fire.

Spraying water does not work well in space because water forms balls which wobble away in weightlessness. Using chemicals in a closed environment could be as harmful to the crew as breathing smoke and clog up the air filters. Both water and chemicals could also ruin expensive experiments and computers that are cooled by blowing air.

Instead of water or foam, crew members use fire extinguishers that spray carbon dioxide. The crew have to anchor themselves while spraying in free fall. Otherwise, the force of the spray will send them flying backward. After the fire is out, the crew continue to wear oxygen masks until the air system filters out the smoke particles and removes the extra carbon dioxide.

Whether on Earth or in space, fires goes out when deprived of fuel and oxygen. But the best way to put out a fire is to not let it start in the first place. This holiday season, please don’t leave a burning candle unattended!

Fire needs oxygen to burn. A birthday candle goes out in a few seconds when deprived of oxygen (via placing a glass jar upside down over it).  Marianne Dyson photo, 2021.


Preorder my memoir, short story collection, or children’s nonfiction space books through

Cover of Up in Space: we build a station by Marianne J. Dyson "Space Nanna"
NEW FOR KIDS: Up in Space: we built a station, a 32-page hardcover, introduces the International Space Station to children through a rhyming story illustrated with full-color photographs. Three hands-on activities plus glossary and index included.
NEW FOR ADULTS: Shuttle Mission Control: Flight Controller Photos and Stories, 1981-1992 showcases twenty first-person accounts, illustrated with 150 images.

To guarantee a copy before Christmas, please order by November 10. If you want to buy multiple books, please contact me by email for a reduced postage rate. Thank you for sharing the excitement of space with your friends and family!

Space Tourism Takes Off

Marianne Dyson, June 2021

Space tourism is finally getting off the ground. For young people interested in STEM careers, the future is full of stars. And space tourism might lead to some cool jobs on the ground as well.

It has now been 20 years since Dennis Tito paid $20 million to the Russians to spend a week on the ISS. Six more wealthy fliers, including the first woman (Anousheh Ansari) bought flights through 2009. No “spaceflight participants” (the fancy name for tourists) have flown since because, with the Space Shuttle retirement, NASA bought all the available seats—at a cost of $90 million each last year.

But now that SpaceX is flying crew for NASA, Russia is set to fly two more tourists (for $50 million each) to the ISS later this year. [Ref:]

And SpaceX is also entering the space tourism business. Their first all-civilian three-day flight to orbit is scheduled to launch from Florida with a crew of four, including the youngest woman to ever fly (Hayley Arseneau is 29) in September. [Ref:] Four SpaceX flights to the ISS in conjunction with Axiom Space (that plans to build a private space station) begin next January, with seats costing about $55 million each. [Ref: CNBC]

Boeing’s Starliner is slated to start flying crews of four to the ISS in 2022 for a cost of about $90 million each. [Ref: cnbc] However, once Starliner flights are offered to the public (via Space Adventures), the price is expected to drop to $50 million or less. [Ref: Spaceflightnow]

No word yet on whether the Chinese will sell rides on a Shenzhou to their new Tiangong (heavenly palace) space station.

All this activity means more jobs for engineers, scientists, and pilots—some of whom will get to accompany the rich tourists into space. But if you aren’t longing to be an astronaut, and you’re not a billionaire (yet), you may still have a chance to fly to space.

Suborbital Options

Suborbital flights don’t go into orbit, but arc to the boundary of space (62 miles altitude) and then freefall for 3 to 8 minutes.

Virgin Galactic completed a successful manned test flight of their winged ship in May. Rather than riding atop a rocket, it is carried to a high altitude and released to rocket up the rest of the way and glide back to Earth. Their next test flight is the first week of July. They expect to fly paying customers (four per flight with two pilots onboard) out of Spaceport America in New Mexico next year. [Ref: arsTechnica] They presold more than 600 tickets for $250,000 each, enough to fill their first 150 flights. That price is no longer available and going up. So if you’re not a millionaire, you might need to sell your house or win the lottery to buy a ticket.

Virgin Galactic’s SpaceShipTwo was carried aloft by White KnightTwo, released, and flown (by a crew of two) to 51.4 miles altitude in December 2018. The total flight time was about 2.5 hours. Photo credit Virgin Galactic.

Blue Origin’s first manned suborbital flight (with billionaire Jeff Bezos aboard) is scheduled for July 20. [Ref: BBC] They plan to offer flights to the public eventually, including orbital flights, but no tickets or prices are yet available. They auctioned off a seat for $28 million, though.

Blue Origin’s reusable New Shepard rocket, shown on its 12th flight in December 2019, launches from west Texas. Photo credit: Blue Origin.

Suborbital flight companies need not depend on rich tourists to be successful. Many business travelers, as well as emergency response teams and the military, are willing to pay a premium to fly to the other side of the planet in an hour. We can all hope that eventually prices for a one-hour nonstop from Houston to Tokyo will drop to less than the price of a mansion.

Parabolic Flights

I got to try out being weightless without having to be an astronaut or sell my house to buy a ticket. That’s because weightlessness is a result of falling, not being in space. [See my blog: Say No to Zero G] The key is to fall without hitting the ground!

NASA managed this feat using a modified KC-135 (later a C-9, both dubbed the “Vomit Comet”). It flew up to 25,000 feet and then fell through 10,000 feet to provide 30 seconds of weightlessness. I flew 40 parabolas and then one each of lunar and Martian gravity in 1999. The “uphill” portions subjected me to 2 g’s, what astronauts feel on the way to and from space.

Space Adventures and ZERO G offer parabolic flights for $6700 each. Catch a flight from airports on either coast or from Las Vegas. [Ref: Space Adventures and ZERO G]  

The cover of my eBook describing my experiences preparing for and flying on NASA’s “Vomit Comet” in 1999.

I wrote about my experience with loss of cabin pressure (via training in a hyperbaric chamber) and freefall for Ad Astra and Analog magazines. For those who want to know what it is REALLY like, check out my 99-cent eBook on Amazon called “Science Fiction Versus the Real Thing: What I Learned on NASA’s Vomit Comet.”

If none of these options work for you, you can always let your imagination take you to space for the price of a good book. (Check out Fly Me to the Moon and other stories.) However you go to space, as a tourist, through your job, as a passenger, or through your imagination, I hope you enjoy your flight!

Writing about Space

My new book, Shuttle Mission Control: Flight Controller Stories and Photos, 1981-1992, is now available in print and eBook forms via Amazon. Order autographed copies through my website,

Speaking about Space

I am now fully vaccinated and willing to do in-person author visits. I also offer virtual author visits. See details on the Author Visits tab of my website. I look forward to sharing space stories with you!

Shuttle Mission Control

Marianne Dyson, April 2021

After a year-long hiatus during the COVID crisis, Science Snacks is back! Hopefully, you are ready for some geeky stories because I used my “shut-in” time to finish a new book, Shuttle Mission Control: Flight Controller Stories and Photos, 1981-1992.

Cover Design by Lindsey Cousins. Black and white photo is of the author, FAO Marianne J. Dyson, and her husband Guidance Officer Thornton E (Thor/Ted) Dyson who were the first married couple in the “front room” of Mission Control during the fourth Space Shuttle flight which landed on July 4, 1982. NASA photo S82-36159 by Pat Patnesky. The Dysons were both at consoles in Mission Control when Space Shuttle Columbia launched on April 12, 1981. The external tank was painted white only for the first and second launches. NASA/KSC photo.

The book showcases twenty first-person accounts, illustrated with 150 images, of Space Shuttle controllers solving problems from dangerous pressure readings to the capture of slippery satellites. Why did I self-publish this book instead of going with a traditional trade house? Why did it take me 30 years to get it done?! I explain in my Author’s Note, excerpted from the book:

Begin Excerpt

While sorting materials for donation to the Johnson Space Center Archive at UHCL, I came across a manuscript I wrote nearly thirty years ago, titled Shuttle Mission Control.

I was in a unique position to write that story. I had the privilege of serving as a flight controller for the first five Space Transportation System (STS) flights. I had joined NASA in 1979, coming in on the “ground floor” of the Shuttle Program. Six years and five flights later, I still loved my job, but with a husband who was also a flight controller, and no affordable childcare for unpredictable all-night shifts, I decided to find a more “normal” job until our children were older. Hernandez Engineering offered a perfect parttime position helping “customers” fly their experiments on the Shuttle and prepare for Space Station Freedom.

I was excited to be part of the commercial space era!

But the Challenger accident in 1986 changed everything. Commercial and military use of the Shuttle stopped. Freedom was subsumed into the Shuttle/Mir Program (announced in 1992) and morphed into the International Space Station. I pivoted from working in the space program to writing about it. In the decades since, I’ve won top awards for my children’s books, coauthored books with Buzz Aldrin, and educated hundreds of thousands of people about space via writing and speaking. I documented my person story in my memoir, A Passion for Space: Adventures of a Pioneering Female NASA Flight Controller (Springer, 2015). But the stories I collected from other controllers in 1992 remain mostly untold.

I drafted Shuttle Mission Control in 1990-92 when books were printed on paper and sold in bookstores. My agent and I collected a stack of rejection letters calling it too “narrowly focused” to sell enough copies to make publishers a profit. So the book languished in my closet all this time. Now, armed with decades of experience in publishing, no longer required to satisfy some gatekeeper’s profit margin, and with the help of my writing community (special thanks to Tom and Lindsey!), I am publishing it myself.

Scanning, color-correcting, and cropping faded photos and slides proved difficult, as was reformatting/merging old text files (from 5.25” floppy disks!) and typing hand-written lists (sorry if some names are misspelled!) into a modern document. Tracking down interview subjects (sadly, at least one has died) allowed me to add (thanks, Paul!) some “where they are now” information. I also added updated the Flight Control Room data and positions, replaced/supplemented drawings with photos, and enhanced the NASA-provided generic captions with names of flight controllers pictured (thanks, Space Hipsters!).

One of the old (rare) slides that I scanned for the book. Shown here are employees of Bingswanger Glass, the company who made the original 10-by-20-foot screens, replacing the old with the new in 1990. The new screens were 800 pounds heavier but had better optical properties and could be easily washed. NASA Photo S9026138.

To the lists of the first flight controllers to work each Shuttle “front room” position from STS-1 in April 1981 through STS-39 (the 40th flight, in April 1991), I added what data I could uncover about the first women/minorities using photos, contacts, and the Manned Spaceflight Operations Association ( manning lists (thanks, Bill!). Flight Director Bob Castle supplied the list of flight controllers honored to hang the mission plaque after each Shuttle flight (thanks, Bob!).

The original photos/slides, references, and manuscript of Shuttle Mission Control will be donated to the NASA JSC Archive at UHCL in Houston. Proceeds from sales of this book will be donated organizations and museums to help preserve more of the history of Mission Control.

End Excerpt

So I hope you will get a copy of this book (autographed via my Book Orders page, or print/eBook via Amazon) for your geek-reading pleasure, or perhaps for a young person who could use some inspiration for choosing a STEM career. And if you enjoy the book and want to support capturing and preserving more NASA history, I’d sure appreciate some reviews on Amazon and sharing of links via social media. With no publisher backing me, the encouragement and support of friends means the world to me!

Writing about Space

Hey teachers and space enthusiasts: a welcome distraction and hours of fun for all ages: Dyson’s Space Puzzles. Ten original space-themed puzzles and their solutions to download and print out for only $1.00.

My short story and poetry eBook collection are full of stories with thoughtful/hopeful endings and are appropriate for younger readers (rated “PG”). I hope Fly Me to the Moon and Space Poems provide some pleasant reading for you!

Speaking about Space

I am now fully vaccinated and willing to do in-person author visits with appropriate distancing guidelines. I also offer virtual author visits. See details on the Author Visits tab of my website.

Fever Temperature

Marianne Dyson, April 2020

One of the major symptoms of COVID-19 is fever. A fever is defined as a temperature about 2˚F above normal. Next question is, of course, what is normal? It depends…

Though doctors and scientists have known for decades that body temperatures vary from person to person, 98.6˚F (37˚C) has been considered the average since the 1800s. But new data has reset the average to 97.9˚F. The lower average is attributed to less inflammation today than in the 1800s when many people suffered with infections and chronic illnesses such as TB. [Ref. “Forget 98.6” by Kristin Fischer.]

Thus, today, if someone’s temperature is 100˚F (37.8˚C) or higher, they may have a fever. The 100˚F value is what airport screeners use as a threshold to decide to detain someone in quarantine or keep someone from boarding a plane.

There are multiple reasons why a simple screening will yield false positives and miss many people who are sick. Even when the thermometer “guns” are held at the proper distance from the subject, the reading might be incorrect because of dust, heat sources (car or outside temperature), or because the person was exercising, drank strong coffee, or took medication. [Ref. “Thermometer guns…” by Morgan McFall-Johnson.]

Two other important factors affecting body temperature are age and gender. People over 65 are warmer (98.6˚F) on average than younger adults (97 to 99˚F) or babies (97.9 to 99˚F).   [Ref. “What is the Normal Body Temperature Range?” by Carissa Stephens.]

Mostly because women have a larger body surface to mass ratio and have more subcutaneous fat than men, women are generally hotter (96.3˚F to 99.5˚F) than men (95.9˚F to 99.5˚F). This explains why women are more likely to need extra blankets than men! [Ref. “Gender differences in thermoregulation” by Kaciuba-Uscilko, and Grucza.]

Also, the temperature of women of child-bearing age changes by about half a degree during the menstrual cycle. At the time of ovulation at mid cycle, temperature drops to its lowest for about three days. Women are most fertile during this time, leading to the “rhythm method” of planning or avoiding pregnancy. [Ref. “Basal body temperature for natural family planning.” Mayo Clinic Staff.]

Time of day and activity level also impact temperature. Temperatures are the lowest in the morning after at least three hours of sleep. Temperatures rise throughout the day and may be several degrees higher during periods of physical activity—especially if you’re an astronaut! (You knew I’d find a way to include space in this topic, right?!)

A study onboard the International Space Station showed that after two and a half months in space, astronauts’ core body temperature was 100.4˚F on average. This “space fever” is attributed to the difficulty of cooling off in the space environment. Sweat doesn’t evaporate as well in freefall, resulting in some astronauts’ temps spiking to 104˚F during exercise. [Ref. “Space Fever” by Charite-Universitatsmedizin.]

So temperature alone does not indicate fever. The only way to know for sure if YOU have a fever is to know your baseline temperature.  

To find my baseline, I gathered five different thermometers from around my house. My average turned out to be 97.8˚F, just a tad under average. [Ref.  “7 Types of Thermometers…” by Jeff Calaway.]

Five thermometers
Five thermometers found around my house provided temperature readings from 97.4˚F to 98.4˚F, with an average of 97.8 ˚F during the same 15-minute period. Digital thermometers were faster, but not more accurate than old-fashioned mercury ones. Photo by Marianne Dyson, 2020.

If I suspect a fever, the first thing I will do is to repeat the measurement in case I didn’t shake my (mercury) or reset my (digital) thermometer correctly, or I didn’t place it properly in my mouth or on my temple.

If I confirm a fever, I will then visit the CDC Self Checker to see if I should call my doctor and/or get tested for COVID-19.

Knowing my normal temperature range and recording it every day at the same time provides me a measure of comfort. I hope you give this a try and that this knowledge helps ease your mind a bit, too!

Writing about Space

  • A welcome distraction and hours of fun for space enthusiasts of all ages: Dyson’s Space Puzzles.
  • Ten original space-themed puzzles and their solutions to download and print out for only $1.00.

I have dropped the price of my short story and poetry eBook collections to 99 cents for the duration of the pandemic. Both are full of stories with thoughtful/hopeful endings and are appropriate for younger readers (rated “PG”). I hope Fly Me to the Moon and Space Poems provide some pleasant reading for you!

Speaking about Space

With conferences cancelled and schools closed, all my speaking engagements through the end of June have been suspended. I am offering virtual author visits at a discount for the 2020-21 school year. See details on the Author Visits tab of my website.

Goodnight Crescent Moon

Marianne Dyson, November 2019

Despite the art you may find in some popular children’s books, the crescent Moon seen out the window when tucking a child into bed will never be shaped like a letter C (unless you live in the southern hemisphere). The waxing crescent, first quarter, and a full Moon are the only phases visible between sunset and 9 pm (standard time).

The waxing crescent Moon rises about 9 am (in the east), is highest around 3 pm (due south), and sets about 9 pm (in the west). This is the only crescent Moon that may appear outside the window in the early evening hours. Note the large round Sea of Crises near the equator. Observers in the southern hemisphere see this image “upside down,” in a C shape. [NASA 2015 Photo]

The Earth and Moon are spherical, so one side is always sunlit and the other side is in shadow. The side facing the Sun changes as each world rotates. The Moon rotates once for each orbit around Earth, making dayspan and nightspan for any location (except the poles) each about two weeks long.

The length of Earth’s day and night at any location depends on the season and latitude. But at the equator (and elsewhere at the equinoxes), day and night are 12 hours long. The Earth’s rotation carries observers counterclockwise (as seen from above the north pole) which is west to east. Observers at the location crossing the terminator from night to day experience sunrise at around 6 am. They continue rotating east so that the Sun seems to rise up from the east and reach its highest point (south) at noon. As the rotation continues, the Sun slides down to set in the west around 6 pm.

When the Moon is new, it is between the Earth and Sun. As the observers rotate through the day, the Moon moves with the Sun: it rises in the east with the Sun, is high at noon, and sets with the Sun in the west at 6 pm.

Each day the Moon moves east in its orbit. The day after the new Moon, the Sun rises again at 6 am as the terminator is crossed. But the Moon is “ahead” of the Sun, so the observer must rotate farther around to the day side before it appears to rise in the east. The waxing crescent (a backwards C) rises about 50 minutes after sunrise. The Sun again sets at 6 pm, and the Moon sets at about 6:50 pm.

The next day, the Moon has moved east some more and rises another 50 minutes later: at about 7:40 am. It sets at about 7:40 pm.

About a week after new Moon, the crescent has grown to the first quarter, showing the eastern half of the near side. The first quarter Moon rises around 9 am, is overhead at 6 pm, and sets about 9 pm.

The Moon continues moving in its orbit, rising 50 minutes later each day, and shifting the times it rises, is overhead, and sets by 50 minutes. After two weeks, the Moon is full and halfway through its orbit. So instead of rising at sunrise with the Sun, the full Moon rises at sunset, is overhead at midnight, and sets at 6 am.

Three weeks after new Moon, the Moon is in last quarter phase, with only the western side of the near side showing. It rises at midnight, is overhead at 6 am, and sets at noon. As it moves ever eastward, it turns into the waning crescent “C-shaped” Moon that rises around 3 am, is overhead at 9 am, and sets around 3 pm. This is not the Moon seen out the window when putting a child to bed!

The waning crescent Moon is a C shape (viewed from the northern hemisphere of Earth). It rises about 3 am (in the east), is highest around 9 am (due south), and sets about 3 pm (in the west). This is the only crescent Moon that may appear outside the window in the early morning hours. Note the small dark Crater Grimaldi near the equator. Observers in the southern hemisphere see this image “upside down,” in a backwards C shape. [NASA 2015 Photo]

Next time you read a children’s book with a Moon in the sky, check that the phase and direction of the Moon are correct for the time of day (or night) in the story. If not, let the child know, and then take them outside to see the real Moon for themselves!

Share Space for the Holidays

Give a gift that encourages a child to read and possibly sparks a life-long interest! Many studies show that children’s success in school correlates highly with the number of books in the home. For the younger children (kindergarten to grade 4) on your list, I recommend the pop-up book, To the Moon and Back: my Apollo 11 Adventure that I coauthored with Buzz Aldrin to celebrate the 50th anniversary of the first Moon landing this year. For middle school (and gifted upper elementary) students, I recommend Welcome to Mars which won the Best STEM book award and its new companion, Welcome to the Moon which is available in print or eBook formats.

For high school and college students considering a space career and adults interested in biographies of women and insiders’ stories of the space program, I suggest my memoir, A Passion for Space: the Adventures of a Pioneering Female NASA Flight Controller. To order copies of my books, visit my website Book Orders page which has PayPal/credit card info for autographed books and links to Amazon for discounted copies and eBooks. And Thank You!

Teachers, librarians, and event organizers, please consider me for Author Visits in 2020!

Lumpy Lunar Gravity

Marianne Dyson, September 2019

The Moon’s gravity is lumpy. Areas where mass is concentrated have stronger gravity such as where impacts have compressed the ground. These mass concentrations, called mascons, pull spacecraft forward, back, left, right, and down—making most low lunar orbits unstable.

NASA launched the Gravity Recovery and Interior Laboratory (GRAIL) mission in 2011 to map the location and strength of mascons. GRAIL consisted of twin satellites named Ebb and Flow that were placed in a low lunar orbit of only 34 miles. The distance between the two satellites varied slightly as they flew over areas of greater or lesser gravity caused by masses hidden under mountains and craters.

Large mascons were found underneath all the biggest impact craters on both the near and far sides. (Unlike the Sea of Rains and Serenity (the “eyes” of the Moon), the Sea of Tranquility where Apollo 11 landed didn’t form by impact, has no ring around it, and GRAIL showed no mascon under it. )

This map based on GRAIL data shows that the Moon’s crust is up to 37 miles (60 km) thick (white) on the far side. Impacts compressed and thinned the crust under large impact craters (blue and purple). The Sea of Rains, Serenity, and Crises form a row of low spots across the northern near side (left image). The crust is so thin at the Sea of Crises and the Moscow Sea (upper far side-right image) that olivine (purple stars), a mineral from the Moon’s mantle mapped by Kaguya is exposed on the surface. Credit: NASA/JPL-Caltech/IPGP

Because of mascons, the Lunar Prospector spacecraft (1998-99) had to do a maneuver every two months to stay in a 60-mile (100 km) polar orbit, and once a month to stay at 20 miles (30 km) above the surface. Luckily future missions have some better long-term “parking” options.

Frozen Orbits

Apollo 16 released two subsatellites into lunar orbits. PFS-1 stayed in orbit for one and a half years. PFS-2 crashed after 35 days. Scientists soon discovered that mascons lured PFS-2 to its early demise. PFS-1 avoided the same fate because its orbit was inclined (at 28 versus PFS-1 at 11 degrees) so that it spent less time passing over mascons. (Inclination is the angle that the orbit plane makes with the equator.) Their different fates led to the identification of four stable or “frozen” orbits with inclinations of 27, 50, 76, and 86 degrees. These orbits require less fuel to maintain.

A first base on the Moon will likely be placed near the south lunar pole because of deep ice deposits (for fuel and life support) as well as tall mountains that offer almost continuous sunlight (for power). Therefore, the 86-degree frozen orbit offers a reasonable parking spot for return vehicles. The disadvantage of parking there is that launch windows from those orbits to Earth occur only about every two weeks.

Moon Direct

Instead of parking near the Moon, Earth return vehicles can remain in Earth orbits. This Moon Direct  plan is explained by Robert Zubrin in his book, The Case for Space. Astronauts would ride commercial rockets to Earth orbit and catch their shuttle (called a Lunar Excursion Vehicle, LEV) from there to the Moon. LEV then fly directly to the surface of the Moon with no rendezvous in lunar orbit on the way out or back. The LEV can be resupplied with fuel in Earth orbit (using lunar water) and support multiple roundtrips.

NASA’s Lunar Gateway space station is not planned to be in lunar orbit at all. Instead, it is slated for an ellipse around a place in space called Lagrange Point 2 (L2, above the far side) and never come any closer to the surface than about a lunar diameter. Zubrin and NASA’s former Administrator and others consider this an unfortunate choice.  From the surface of the Moon, it actually takes more fuel to reach L2 than it does to reach Earth orbit. It also requires fuel to “park” anything there and can only be accessed once a week. Some have suggested that the Gateway move instead to an Earth-Moon cycling obit (to the Moon and back on a regular schedule) and serve as a fuel depot.

Lumpy lunar gravity requires some creative solutions for parking Earth return vehicles while working on the surface. The main purpose for a first lunar base, in my opinion, is to process lunar water into fuel. This lunar “gas station” will enable easier access to all other destinations in space, including Earth, any Gateway stations, and missions to Mars. A lunar gas station will also hopefully lead to affordable flights for those of us who want to experience lumpy gravity for ourselves!

Writing & Speaking about Space

There’s an article about me in my hometown newspaper, The Canton Repository:

To order copies of my books, visit my website Book Orders page. And Thank You!

Teachers, librarians, and event organizers, please consider me for Author Visits.

Apollo 11, a view from Summer Camp

Marianne Dyson, July 2019

I was a teenager at summer camp when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin landed on the Moon 50 years ago this month. Below is the story of that day as recorded in my memoir.

Marianne and "Red" in 1969 at Rambling Acres. Photo courtesy Marianne Dyson

Marianne and “Red” in 1969 at Rambling Acres. Photo courtesy Marianne Dyson

Begin excerpt from A Passion for Space copyright Marianne Dyson–

July 20, 1969, Ohio

“Girls! Girls!” someone hollered from outside the big red barn. I was at Rambling Acres Horseback-Riding Camp, near Canton, Ohio. “Put your brooms away and come up to the house! They’ve landed on the Moon!”

I didn’t need a second invitation. I’d enthusiastically followed the space program since first grade when John Glenn had orbited the Earth. I was 14 now, and I loved space even more than horses. The previous spring, I’d even written and hand printed a 60-page book, “The Apollo Program” for my eighth-grade English class.

I dashed from the stall, latching the gate behind me, and ran up the dusty road to the camp owner’s house. “Wait up!” my best friend Chrisse hollered as she scampered up the road behind me, followed by the other girls.

The owner, Mrs. Noll, insisted we brush dust and straw off each other’s clothes and remove our dirty shoes before entering her house. Then we filed into her living room and settled down cross-legged on the carpet, facing the television set. The TV was a stand-alone piece of furniture, a box on legs about three feet tall with “rabbit ears” antenna. The picture was in black and white.

The familiar face of CBS News anchor Walter Cronkite appeared on the screen. In his deep voice, he explained that Mission Control in Houston had given Apollo 11 astronauts Neil Armstrong and Buzz Aldrin the “go” to exit their spacecraft. The men had been scheduled to sleep but were too keyed up after the exciting first landing on the Moon.

I was keyed up, too. It was the first day of camp, and I’d just met five new girls. We had plenty to talk about while we waited for the astronauts to leave the lunar lander. “Which one do you think is the cutest?” Sue asked me as we loaded our plates for dinner.

“It doesn’t matter,” I said, snatching a roll. “They’re married!”

Sue frowned and then sighed as she scooped beans onto her plate. “Wouldn’t it be dreamy to marry an astronaut?”

“Yeah,” I agreed. Then I added silently, “But even better if you could be one!”

We finished dinner, and the astronauts still hadn’t emerged from their ship. We wondered what they were having for dinner. (I found out later, bacon cubes. Yuk!) We trotted back to the barn for evening chores. I brushed the horse who shared my nickname, Red. Then we got our showers and returned to Mrs. Noll’s house.

The television spurted static-filled voices of the crew talking with Mission Control. What was taking so long? Why didn’t they just open the door and hop out? Bedtime came and went. Luckily, Mrs. Noll let us stay up for this historic occasion.

Finally, six hours after Apollo 11 landed, the ghostly black and white “live from the Moon” image flickered on the screen. At 10:39 p.m. Eastern time, Armstrong spoke the now-famous words, “That’s one small step for man, one giant leap for mankind,” as he stepped backwards off the ladder onto the lunar surface. I remember thinking how I’d like to follow in his footsteps.

But in 1969, there was no such thing as a female astronaut. No woman in my family had even gone to college. Yet, the previous winter, I’d written in my diary, “I wish very much to be able to be an astronaut. I’m sorry I’m a girl, but I’ll have to try harder then.”

As I gazed up at the half-full Moon that July night, I marveled that there were men up there looking back at me. If those men could walk on the Moon, then maybe a skinny red-headed girl from a small town in Ohio could find a way to go to college and one day work for NASA.

–End excerpt from A Passion for Space, copyright Marianne Dyson—

Just ten years after the Moon landing, I was hired by NASA to become one of the first female flight controllers. In 1982, I had the privilege of working at a console in the historic Mission Control room (during the fifth Space Shuttle flight) that has now been restored to the way it looked in 1969.

While at summer camp, I could never have imagined that 50 years later, I’d not only have worked in Mission Control alongside some of the “unsung heroes” of Apollo and the first female astronauts, but I’d also coauthored two children’s books with Buzz Aldrin and be releasing a new book, Welcome to the Moon, commissioned by Buzz’s son, Andrew, to help inspire a new generation of lunar explorers. (See below.)

One thing I also could not have imagined back then is that 50 years would pass without a woman setting foot on the Moon. So as I gaze up at the Moon this July and celebrate the historic achievement, I’ll be thinking about what more I can do to help young people acquire that “can-do” Apollo spirit that will motivate them to harvest the unlimited resources and exciting opportunities space still has to offer.

Writing about Space

Apollo 11 lifted off at 9:32 EDT on July 16, 1969. The Eagle landed on July 20 and lifted off the Moon on July 21.

So, in honor of the 50th anniversary of the first trip to the Moon, at 9 am on July 16, the Amazon eBook of Welcome to the Moon (by Marianne Dyson and Lindsey Cousins with a foreword by Buzz Aldrin’s son Andrew), drops from $9.98 to 99 cents and stays that price until 5 PM on July 21 when they lifted off of the Moon. Autographed print copies can be ordered through Marianne’s website. All proceeds benefit STEM education via the Aldrin Family Foundation and ShareSpace Education.

To the Moon and Back: my Apollo 11 Adventure by Buzz Aldrin with Marianne Dyson.

Share the story of Apollo with the children in your life! Order To the Moon and Back: my Apollo 11 Adventure, by Buzz Aldrin and Marianne Dyson with pop-ups by Bruce Foster.

Not sure Apollo or other space programs are worth it? Read my oped, 10 Ways the Space Program has Benefited America, in the June 2019 copy of The Ripon Forum magazine.

Speaking about Space

July 25, 1:30-4 PM, event: Two Space Authors & an Astronaut. Join Marianne Dyson, Melanie Chrismer, and a surprise astronaut (sorry, not Buzz!) at Evelyn Meador Library, 2400 North Meyer Ave, Seabrook, TX 77596, 281-474-9142. I’ll use models and share excerpts from my books to show how Apollo went to the Moon and Back. Books may be offered for sale by the Friends of the Library. Free and open to the public. Sponsored by the Rotary Club of Seabrook.

Luna 13 a Solid Success

Author Marianne Dyson’s
May 2019 Science Snacks Newsletter

Hello, and a special welcome to new subscribers.

As we celebrate the 50th anniversary of Apollo, I thought I’d devote this Science Snack to some little-known lunar science performed by Soviet scientists in preparation for their own planned human landings on the Moon. The following is mostly an excerpt from my new book, Welcome to the Moon, which will be released June 17 from the Aldrin Family Foundation. (See book ordering information below.)

Buzz Aldrin tested soil hardness with this boot print. The length of the shadows reveal this print is less than an inch deep. (NASA/B. Aldrin)

One of the first questions that scientists had to answer is How Hard is it? “It” being the lunar surface! How strong do the legs of a lunar lander need to be? Will the foot pads sink deep into fluffy powder, break rocks into glasslike shards, or smack into solid stone? To find out, Russian engineers devised an experiment for Luna 13 to test the hardness of the lunar surface.

Like its predecessors, at an altitude of 46 miles, Luna 13 inflated airbags and fired its landing rockets. When it was 16 feet above the surface, the engines shut down as a sensor contacted the ground (a method still employed by Soyuz capsules). The landing capsule, in its airbag cocoon, was ejected and bounced several times before coming to rest in the Ocean of Storms.

After bouncing to a stop, Luna 13’s airbag deflated, and two booms sprang out from the body of the spacecraft. One boom contained a small solid rocket, pointed down. The rocket shot a titanium cone penetrator (with a diameter of 1.4”) into the ground. A pin slid along a groove in the side of the casing to measure how deep it went. The engineers had tested this penetrator on 14 different surfaces on Earth, including dust and concrete, and in a vacuum chamber ahead of time. Depending on the surface material, the penetrator could drill down two inches.

On Christmas Eve of 1966, the engineers got the gift of data from the Moon. The penetrator dove in 1.7 inches. The team concluded that the surface was volcanic rock (basalt) covered by a layer of powder.

Spacecraft cameras revealed rocks scattered on the surface. Of 181 counted, most were pebbles. Only three were larger than four inches and all less than eight inches in diameter. The experiment gave the engineers confidence they could safely land a cosmonaut on this surface.

To learn more about the historical and current science of the Moon in “layman’s” terms (written for gifted middle-school students), order your copy of Welcome to the Moon
via my Book Orders page. (And Thank You!)

Writing about Space

To share what the first journey to the Moon was like, Buzz and I teamed up with pop-up artist Bruce Foster to create To the Moon and Back: my Apollo 11 Adventure. We hope you’ll share this historical American story with the whole family.

I’m pleased to announce that my fact article, In Defense of the Planet, won the AnLab Readers’ poll! It is available FREE on the Analog website.

Speaking about Space

I offer programs appropriate for school-aged children up through senior citizens, as well as science workshops for students and teachers. See my list of programs on the Author Visits tab of my website.

Friday May 31, WriteFest Weekend Festival, Anderson-Clarke Center (6100 S. Main St. Houston, 77005), Rice University. The weekend festival includes panels, presentations, agent pitch sessions, and a book fair. Look for me on panels at 2:45 and 4 pm.

See my website’s contact page for a complete appearance schedule.

Miles and Miles? Judging Distance in Space

Marianne Dyson, April 2019

On Apollo 14, Alan Shepard famously hit the first golf ball on the Moon. Because of the stiff space suit, he had to hit one-handed. After several tries, he sent it off camera and claimed it went “Miles and miles and miles.” But did it really go that far?

Judging distance in space is tricky. Studies have shown that even on Earth, people routinely underestimate horizontal distances by ten percent. On the other hand, heights are usually overestimated by as much as 30 percent, especially when looking down or from a distance. (A pyramid appears steeper from a distance than it does up close.)

NASA AS14-67-9367.
Credit: NASA AS14-67-9367.

Does the Apollo 14 lander seem closer than 650 feet (two football fields) or taller than 10’7”? The near horizon, sharp shadows, and a tendency to underestimate distance and overestimate height of objects makes judging distances  difficult on the Moon. 

A study conducted on space station astronauts shows these effects are exaggerated in space. Astronauts underestimated distances by as much as 35 percent, even for objects at close range. Astronauts with long arms perceived targets within reach that were out of range. They also perceived objects to be taller than on Earth. This effect may be in part because people use the height of their eyes above the ground to provide scale—and there is no floor when floating in space. [Reference: Distance and Size Perception in Astronauts during Long-Duration Spaceflight]

On the surface of the Moon, many of the cues used to judge distance, such as trees and trucks, are missing. The lack of air also makes objects appear sharper and thus closer—adding to the tendency to underestimate distance and size of objects. Finally, the Moon is a smaller world than Earth, so the horizon is much closer. From a height of about six feet, the horizon is about 1.5 miles away (compared to about 2.8 miles on Earth). Combining all these effects means that what first appears to be a small nearby rock is actually a distant boulder.

Astronauts also have difficulty predicting the motions of objects in space. During a space shuttle mission, catching balls moving at constant speeds was difficult. People are used to balls accelerating as they fall on Earth. So astronauts think they are moving faster than actual and reach for the balls too soon (and miss the catch!). [Reference: Does the brain model Newton’s laws?]

So did Shepard’s ball go miles and miles and miles? [Watch video.] The record for a golf drive (Mike Austin, 1974) on Earth is 515 yards/0.3 miles. Some people have speculated that because of the Moon’s low gravity and lack of air, a golf ball hit that hard might sail more than two miles. Considering Shepard was likely underestimating the distance by up to a third, I wouldn’t be surprised if the ball went a mile—but not more than 1.5 miles since it didn’t disappear over the horizon.

On a more serious note, distortions in perceived distance, height, and motions could have grave consequences during space missions. A poor sense of closing speed has been cited as a contributing factor in a collision with a docking port on the Mir space station in 1997. [Reference: Shuttle-Mir’s lessons for the ISS]

More studies on how people judge distances and react in space will help us better understand our ingrained biases when it comes to judging distances in space.  Laser range finders and future AI lunar golf advisers may even help us figure out how much of a handicap to give an astronaut in a stiff space suit!

Writing about Space

I’m thrilled to announce my newest space book! Watch my website Book Orders page for Welcome to the Moon ordering information.

A Summer 2019 Release!

My fact article about a practice drill for what to do if an asteroid threatens Earth, In Defense of the Planet, is a finalist in the AnLab Readers’ poll. It is available FREE on the Analog website until the winners are announced at the Nebula Awards in May.

Speaking about Space

I offer programs appropriate for school-aged children up through senior citizens, as well as science workshops for students and teachers. See my list of programs on the Author Visits tab of my website.

Saturday, May 11, Comicpalooza, GRB convention center, Houston. I’m on two panels in the Literary Track (upstairs rooms).  From 3-4 PM, Worldbuilding Tips and Tricks: How to Create Believable Worlds, and from 6-7 PM, Writing Historical Fantasy—Getting the Details Right!

Thursday, May 23, Bay Area Writers League, Clear Lake Park, Houston, 7 pm. “Beyond Self-Publishing: Becoming a Publisher. What are the financial, legal, personnel, quality, quantity, and time considerations of creating books for companies or individuals?

Friday May 31, WriteFest Weekend Festival, Anderson-Clarke Center (6100 S. Main St. Houston, 77005), Rice University. The weekend festival includes panels, presentations, agent pitch sessions, and a book fair. Look for me on panels and at the book fair. Register early for the best price ($95 to $185 one day only & $180-$375 F-Sun).

See my website’s contact page for a complete appearance schedule.