The first page includes pictures of the smooth, bald (no felt) and one of the standard tennis balls mounted in the wind tunnel. The second page has pictures of the tunnel set-up. The captions on the pictures may have terminlogy you are unfamilar with - we'll be adding explanations in the web pages.

Best Regards * * * Jani

We've started the warm versus cold tennis ball experiment. The schedule is as follows: The first 4 pages are up and they start at http://wings.avkids.com/Tennis/Project/coldhot.html

• February 5-11th - Define the Problem and Collect Information To Solve The Problem;
• February 12 - 18th - Determine The Materials and Experiment Procedure
• February 19-27th - Conduct The Experiment and Document Your Results;
• February 28-29th - Explain Why The Balls Behave That Way and Share Your Results With Us During the Web Chat.

Our Web Chat on February 29nd will be from 10:30 -11:30 AM PST. NASA staff from the Learning Technology Channel will open the Chat Room at about 10:00 AM so that our experts can get ready. At 10:30 AM NASA will turn the Chat Room over to us and we will start taking our first questions.

Our Principal Investigator, Dr. Jani Macari Pallis and Dr. Rabi Mehta, the team's wind tunnel specialist from NASA Ames, and Dr. Duane Knudson, from the USTA Sport Science Committee will be there to chat with you. We'll also introduce you to Dr. William Aronson, the USTA's new Administrator of Sport Science.

Need any help with your tennis science projects? Tell us how your tennis science experiments are going and "chat" about them with other students. We'll also be talking about our latest wind tunnel test.

Best Regards * * * Jani

You may recall that during our first wind tunnel test we pumped smoke in the tunnel so that you could see the flow around our oversized tennis ball. This time we'll actually calculate the drag forces. This is similar to tests the ITF conducted as they evaluated increasing the Wimbledon ball size .

First, we'll place a smooth sphere in the tunnel and compare our measurements to the known results as a double check. If our results check out then we know that our set-up in the wind tunnel is correct. We have 4 Wilson US Open balls, a ball with no felt on it, a Slazenger Wimbledon (grass court) ball and a Roland Garros French Open (red clay court). Three of the US Open balls are oriented so that the air flow will strike the ball's seams differently. We know that seam orientation affects the flight of a baseball and a cricket ball. Does it affect a tennis ball? The fourth US Open ball is a roughed up, used ball. Do you think the drag on a used ball is different than on a new ball? More or less drag? These pages will be updated during the test - we'll be adding pictures and each day's results.

The team will also conduct a web chat on February 29th from 10:30AM-11:30AM PST. If you can't be there you are welcome to submit your questions ahead of time via email to tennisnet@cislunar.com. You'll be able to enter the chat room through http://quest.arc.nasa.gov/common/events/index.html or http://quest.arc.nasa.gov/ltc/special/special_tips.html.

Regards,

Jani

It's difficult to pick up a tennis magazine without seeing a reference to the International Tennis Federation's (ITF) Technical Commission or a quote from Andrew Coe. As the head of product development and the technical commission for the ITF, Andrew has been involved in tennis' leading edge research projects for the last 4 years. From the studies which led to the proposed ball size increase, to the development of a machine which will reproduce a man's pro serve, Andrew and commission members must balance technological advancement against preserving the basic nature of the game.

We spoke with Andrew about his work from his office at ITF headquarters in Roehampton, London, England.

Best Regards * * * Jani

Funny thing -- the last time you played, the umpire made some bad calls (twice in a row as a matter of fact) and your opponent was really obnoxious. You got ticked off; you were really, really mad! All of a sudden you weren't afraid any more, you had a surge of energy and fought back from 40-0. You not only won the set, you won the match. Looking back, you played better - but you know your angry behavior on the court was wrong. "Do I really have to get angry to get fired up?", you thought. "I don't think I want to (or could) do that every match." We may have a good understanding of how physical fitness and conditioning affect our performance but what about the mental and emotional side of the sport. How do you deal with the pressure?

To help us understand we spoke with world renowned sport psychologist, Dr. James E. Loehr, CEO and President of LGE Sport Science, Inc. We asked Jim to explain to us what mental toughness is and what we can learn from the science of sport psychology.

Best Regards * * * Jani

Several of you have written us questions about court surfaces -- so we asked an expert who works on tennis courts every day. No, he's not a club pro -- he's a tennis court builder. We spoke to John Saviano, president of Saviano Company Inc., one of the largest builder of tennis courts in California. You may be surprised how high tech this field has become. Believe it or not they even use lasers in their work!

You may also want to try some of our Tennis Science Quizzes and check out your knowledge of tennis physics.

Best Regards * * * Jani

Our features this month include an interview with "Howard Brody on Tennis Science" and the results from the ball/court interaction testing.

I had the great pleasure of interviewing Professor Howard Brody, physicist, educator and tennis scientist extraordinary. Among his many accomplishments he has written over 75 technical papers on tennis, appeared on television many times from the children's science show, "Newton's Apple" and Australia's "Beyond 2000" to the physics of football trajectories for the National Football League. He is featured on an instructional video with Vic Braden called "Science and Myths of Tennis" and was even recently interviewed by Time magazine regarding his work in tennis racquet science. A tennis player for almost 60 years, the author of "Tennis Science for Tennis Players" talked with us about tennis physics - what's known today and what he envisions for the future.

I think the most interesting results in our ball/court interaction study dealt with the grass court - ball performance is so different. There are very distinct trends between the courts for parameters like spin rate, post-bounce velocity, ball bounce angle off of the court. What makes a court "fast" versus "slow" may surprise you. Sincere thanks go out to Prof. Howard Brody for the answers to the many questions we asked him.

Best Regards * * * Jani

The coefficients of friction and restitution sections are posted.

There are new additions to our web pages.

Dr. David Noever from the NASA Marshall Space Flight Center told us about his "Rocket Racquet" in our Feature "Anita and Arabella's Legacy to Tennis". No, Anita and Arabella are not the hottest newcomers to the women's tour since the Williams sisters, but they are "out of this world". We want to thank Dr. Noever and will be checking back with him from time to time for an update.

We've added our section on Biomechanics. We want to thank Dr. Tom McLaughlin and Matt Madden, respectively, president and director of R&D of Biomechanics, Inc. for their perspective of the commercial side of biomechanics. Dr. Paul Roetert, Administrator of Sport Science for the USTA and Prof. Duane Knudson, biomechanist and USTA sport science committee member shared their insights into tennis biomechanics. I also want to thank CAI staff members Eric Chattot and Chad Okamoto for their 3D models of a tennis player. These were originally shown during our video conferences and are now up on our site. Eric's model is a male skeleton hitting a forehand while Chad's is a serve from 3 different views.

The textbook materials are up. For the students working on science fair projects on tennis ball trajectories, reviewing the lift and drag sections will be important. Additional sections on the coefficients of friction and restitution will be added with the ball/court interaction section.

Ball/Court Interaction pages are being added to the site now. The videos are up if you'd like to do your own comparisons.There will be another message sent out when all the pages are up.

PC and Unix users will probably have problems with the low resolution wind tunnel videos (high resolution should be fine). We are regenerating the videos and they should be up by close of business on March 5, 1999.

There have been quite a few additions to the web pages. A new section on Motion Capture and Analysis has been added. We want to thank Rick Sutherland of Digital Consortium for talking to us about the past, present and future of this technology.

The Wind Tunnel pages are all up. We have about 50 short video clips of a tennis ball in a wind tunnel. If you've been following the test you know that smoke was blown over the tennis ball. The smoke "colors" the air flow as it passes over the ball. In the videos you can actually see the different patterns topspin creates versus underspin (what we called backspin). Those patterns signify that the topspin ball is dropping faster than the underspin - which you all knew from playing - but you can actually see the air creating the force which pushes the ball down. Our thanks to Dr. Rabi Mehta and Greg Zilliac from NASA Ames Research Center for their support.

Our feature story is called: "Adding It All Up in Tennis" We want to thank Mr. Philippe Dore, the Ranking and Statistics Coordinator for the ATP Tour for taking the time to discuss his duties and the mathematics that he uses every day on the job. Philippe shared some interesting statistical trends and the fantastic new technology that the ATP Tour is using for men's pro tennis tour players. This has become a very high tech endeavor and we wanted to share the story and of course "THE MATH" that goes into "adding it all up in tennis".

We're still revising wind tunnel pages, but everyone is welcome to take a peak. A portion of the video clips of the test are up - the rest should be up this weekend.

We've posted the Motion Capture and Analysis section.

We'd like to thank Rick Sutherland of Digital Consortium for sharing the history and future of this technology with us.

As well we've posted a little tennis sign language. Some of the students that have followed the project use sign language and we developed a few animations in our other educational project with NASA that we thought you might find interesting.

We're posted our first "Feature Presentation". The story of how tennis helped Dr. Sally Ride become the first American woman in space. A fun story I think, with a couple of twists I wasn't aware of. She was coached by a 4 time national champion and US Open winner. A famous tennis legend (who still works with the USTA) encouraged her to turn pro. Yes, you'll have to hit the Web Page to see who these people were.

I also want to share with you that the students are doing very well on their projects. There are some creative young tennis scientists out there and its been a lot of fun working with them. The kids are doing everything from biomechanics to ball physics and racket studies. There's even a group in Loretto, Tenn. that is modeling part of their research after our project to study baseball pitches. They even have a professional pitcher, David Weathers from the Milwaukee Brewers helping them.

There are some people I'd like to thank:
Dr. Paul Roetert from the USTA for his ever-constant support;

Prof. Howard Brody from the USTA's sport science committee for letting me bounce questions off of him;

Dr. Andrew Lutz, fellow CFDer and tennis coach, for providing his knowledge of the game to the team;

Dr. Cliff Kurtzman from Tennis Server - Cliff, a fellow aero/astro engineer has been posting notes in his monthly newsletter encouraging students to participate in our project;

Dr. Rabi Mehta from NASA Ames for continuing support on this project.

Last - a congratulations - Shishir Pandya is now "Dr." Pandya. Well Done! (And having been there - what a relief!)

We've posted results for the Ball Speed in Pro Tennis .

We hope to add a bit more information explaining the results. Several of you had commented to us that the numbers are nice but that you would like to understand the science a bit more.

We've completed the Conducting Your Research Project section.

We also want to thank those of you who have been writing us as you have been conducting your own projects. Some very interesting and clever projects that we hope to share with everyone else following the our web pages.

We've added some new results dealing with the amount of ball spin observed before and after the bounce during the 1997 U.S. Open.

We would also like to thank and continue to encourage those of you starting tennis science projects!

Hope everyone had a wonderful Thanksgiving holiday! We added a link and a few more pages on the results from the U.S. Open Player Ball Spin section. You can also reach that section from the "Our Research Project"page. We've also digitized and posted a few QuickTime movies of a flat (no spin) ball bouncing on different court surfaces: hard court, green clay, red clay, and grass court. You can really see the difference after the bounce in the "rebound height" of the ball.

Over the last few days we have been posting new pages. We hope to continue adding a few new pages every day. The new sections that we have added are: Computational Fluid Dynamics and Conducting Your Own Research Project. This later section is still under construction, but the first 10 pages have been posted. If you are just getting started with your research this might help you pull your research together.

With the school year now in full swing, students are pondering over what to do for science fair or school projects. One answer: combine their enthusiasm for tennis with science. The team from NASA's "Aerodynamics in Sports" project (http://wings.avkids.com/Tennis) is there to help any student learn about tennis science.

Whether its helping them scope out a sport science project, answer specific tennis science questions, help figure out how to conduct sport science experiments, or mentoring their project, the team welcomes these opportunities to encourage and support young tennis scientists.

Sponsored by NASA's Learning Technology Project, "Aerodynamics in Sports" is part of the agency's K-12 educational outreach program helping meet NASA's mission to communicate science.

Whether its your own family members or kids that you teach or coach think about encouraging them to consider a "tennis science" project for school. The kids not only learn about science but more about the sport. For more information or to get started write the team at tennisnet@cislunar.com.

The September 30th Web chat has been postponed. A new schedule for the school year will be available on October 1st. We apologize for any inconvenience.

Our Project Manager, John Yandell, Dr. Paul Roetert, Director of Player Development from the US Tennis Association, Lew Brewer from the US Tennis Association and principal investigator Dr. Jani Macari Pallis will all be there to discuss the research conducted at this years US Open, what the team has discovered so far and answer your questions on tennis science.

We have some great video footage to show you on ball/court interaction and player biomechanics. And John can explain what the team has discovered on the spin of the ball in pro tennis.

We've already received some great questions on eye tracking of the ball. You are welcome to e-mail me questions or submit them through the chat line tomorrow.

For more information on these subjects and the teams biographies follow the links above.

Join us for the next "live" Aerodynamics in Sports Internet video conference hosted by NASA's Learning Technology Channel. The live video conference and chat will be Wed., September 9, 1998 between 9-10AM Pacific Time (12-1PM Eastern Time).

Join us for the next "live" Aerodynamics in Sports Internet video conference hosted by NASA's Learning Technology Channel. The live video conference and chat will be Wed., September 9, 1998 between 9-10AM Pacific Time (12-1PM Eastern Time).

Join us for the next "live" Aerodynamics in Sports Internet video conference hosted by NASA's Learning Technology Channel. The live video conference and chat will be Wed., June 10, 1998 between 10-11AM Pacific Time (1-2PM Eastern Time).

Our wind tunnel test was finished this past Monday and we are going to play the actual wind tunnel test via the Internet! We placed a foot long Wilson tennis ball and two other smooth balls in the tunnel. We wanted to show you the difference in aerodynamics between a rough ball - like a tennis ball with its fuzzed surface - and a smooth ball. You can see the difference in "lift" on the balls based on whether the ball has topspin or underspin.

If you haven't tried a video conference with NASA before - there is some free software that you need to download and NASA provides a way for you to "check it out" (its at the bottom of the page "Download the Real Player") to make sure you are ready for our event.

The team has just completed the wind tunnel test at NASA Ames and the first pictures are available on the Web page. The results look great! An 11 inch (diameter) Wilson tennis ball was placed in the 3' X 4' indraft wind tunnel (a regular tennis ball is about 2 1/2 inches in diameter). Smoke was blown over the model.

All this week we will be posting information about the test. There will be a video conference over the internet next week where the team will show you the wind tunnel running! Here are a sample of the results. Click on the pictures to enlarge them.

Many thanks go to Dr. Rabi Mehta, Greg Zilliac and Dr. Sanford Davis of NASA Ames' Fluid Mechanics Laboratory for their support and help!

Our Web Chat on May 8th will be from 10-11:30 AM PDT. NASA staff from the Learning Technology Channel will open the Chat Room at about 9:30 AM so that our experts can get ready. At 10 AM NASA will turn the Chat Room over to us and we will start taking our first questions.

Our Project Manager, John Yandell, Dr. Rabi Mehta, the team's wind tunnel specialist from NASA Ames, Shishir Pandya, the team's computer simulation specialist also from NASA Ames, Nasif Iskander, our teacher/physicist and project Principal Investigator, Dr. Jani Macari Pallis will all be there to chat with you.

We'll be talking about the wind tunnel test that we'll be conducting at the end of May at NASA, and also chatting about the teams work at the 1997 US Open, the 1997-1998 Sybase Open and our work at the US Tennis Association Training Center in Key Biscayne, Florida.

For more information on these subjects and the teams biographies follow the links above.

On Friday May 8, 1998 between 9:30A - 11:30 AM you will be able to click right here and enter the chat room. The chat will start at 10 AM.

Our team would like to give special thanks to Karen Traicoff and Bill Strathearn of NASA's Quest Project for hosting our Web chat.

A reminder that our next Web Chat is Friday, May 8th at 10:00 AM Pacific Time. We'll keep the chat room open until about 11:30 AM since some of the schools have mentioned that they would like to bring different classes into their computer labs at different times to chat with us.

You are welcome to submit questions ahead of time by writing us at tennisnet@cislunar.com. A transcript of the chat will be available on-line.

Hope to "chat" with you soon!

A reminder that our first Web Chat is this Wednesday, January 14th at 10:00 AM Pacific Time. We'll keep the chat room open until about 11:30 AM since some of the schools have mentioned that they would like to bring different classes into their computer labs at different times to chat with us.

Some of you have asked about software. As long as you have a functioning Web browser no additional software or passwords are needed to participate in the chat. Just go to NASA's Web page on the project and follow the links to the chat room.

You are welcome to submit questions ahead of time by writing us at tennisnet@cislunar.com. A transcript of the chat will be available on-line.

And hope to "chat" with you soon!

Information on how to use the chat room, how to participate in the upcoming video conferences, some software you may need to download, and some instructions on "practicing" to make sure that everything is working before you participate is now available.

Please note that the date for the first Web Chat has changed and is now scheduled for Wednesday, January 14, 1998 at 10 -11 AM Pacific Time. Principal Investigator, Dr. Jani Macari Pallis, John Yandell, our project manager, as well as our NASA Ames Research Center team members Dr. Rabi Mehta, our wind tunnel specialist and Shishir Pandya, our computational fluid dynamicist will be on hand to answer any of your questions regarding the project, our progress, and tennis sports science.

Next week team biographies, background research information and progress reports from several team members will be posted on our Web site.

The entire "Aerodynamics in Sports" project team wants to wish everyone a "Happy New Year."

Our new web pages are now available. The URL for our site is: "http://wings.avkids.com/Tennis".

The project team was in New York for the U.S. Open in September with a state of the art digital camera that films at 250 and 500 frames per second. The camera performed beautifully and its light sensitivity was so good we were even able to use it during night matches. We were able to record video of over 20 of the top players in the world on the new Arthur Ashe Stadium court.

We have been cataloging and viewing over 120 hours of footage! The project team feels the data will allow us to quantify the spin in pro tennis for the first time, in terms of RPM on the various strokes.

We are also investigating state of the art software packages that allow us to reconstruct 3D views of the players and may allow us to make a wide variety of quantitative biomechanical measurements. We'll keep you posted!

Next up, the team goes to the USTA training facility in Key Biscayne in late January. Using the same camera, we plan to film ball/court interaction and attempt to quantify the differences in the speed and the bounce on the four major surfaces: grass, red and green clay, and hard courts. The cooperation we have received from Dr. Paul Roetert, director of research at USTA Sports Science, has been fantastic!

We will also be hosting our first video conference at that time which is tentatively scheduled for January 29, 1998 at 1PM Eastern time. Information on the event can be found at on our Web site in the How To Participate section. More specific details on downloading the software to participate will be available a month before the event.

Thanks again for your interest and we'll keep you posted as we begin to develop results! New materials and updates will be available on our Web site every two weeks. For those of you who expressed interest in our project and are on this mail list, we'll be sure to e-mail you monthly and give you a "heads up" on what's coming up.

If you have questions, feel free to email us at tennisnet@cislunar.com.

Best Regards,

Jani Macari Pallis, Ph.D., Principal Investigator
John Yandell, Project Manager