AEROSPACE TEAM ONLINE
ATO #115 - August 4,, 2000
Beat the Heat: Thermal Protection Chats!
We will be chatting and with researchers from the Space Technology Division at NASA Ames Research Center. I think you will find this fascinating and a worthwhile topic. This will introduce you to the topic of materials for thermal protection and the use of computer models for predicting the heat generated by vehicles entering different planetary atmospheres. This is a very important topic for those of you who plan to travel in space in the near future. Tuesday, August 8, 2000, 10 - 11 AM Pacific Aerospace Team Online QuestChat with Chuck Cornelison Chuck Cornelison, Ballistics Range Manager The ballistics range is the opposite of a wind tunnel. Instead of blowing air over an object, objects are fired by guns through still air. Learn all about it! Read Chuck's bio at http://quest.nasa.gov/aero/team/cornelison.html Tuesday, August 22, 2000, 10-11 AM Pacific Aerospace Team Online QuestChat with Susan Fehres Susan Fehres works with spacecraft insulation. She develops materials that protect astronauts and equipment from extreme heat and cold experienced by spacecraft during spaceflight and entry into Earth's atmosphere. Read her bio at http://quest.nasa.gov/women/bios/sf.html
Blended Wing Body Airliner Bookmark Check out this new resource on Spacelink! http://spacelink.nasa.gov/Instructional.Materials/NASA.Educational.Products/ Blended.Wing.Body.Bookmark/Blended.Wing.Bookmark.pdf
NEW PROJECTS FOR FALL
Virtual Skies is an air traffic management project for students and teachers in Grades 9-12. It will be a "project based learning activity" with hands on multimedia to enhance student decision making and problem solving skills. Topics to be covered include Aviation Navigation, Aviation Weather, Communication Air Traffic Management, Airport Design, and Air Traffic Research. Materials will be tied to the National Standards in Mathematics, Science, Technology, Geography and Language Arts. Stay tuned for more news as we crank up over the summer! Planetary Flight is an aerospace project for Grades 4-8. We know how to fly on Earth but what will it take to fly on Mars. This will be an inquiry based learning project to design an airplane to fly on Mars. The stuff dreams are made of!! We will also be keeping you posted on this one this summer.
[Editor's Note: Chuck Cornelison, manages two testing facilities: one is used to study how small models traveling at high-speeds behave during flight. The other is used to simulate what happens when a meteor, comet or asteroid impacts a celestial body, such as a planet or moon. Read his bio at http://quest.nasa.gov/aero/team/cornelison.html ]
AN INTRODUCTION TO THE BALLISTIC RANGE COMPLEX
by Chuck Cornelison
June 8, 2000 One of the facilities, the Hypervelocity Free-Flight Aerodynamic Facility, (HFFAF) within the Ballistics Range Complex is an aeroballistic range. Perhaps the easiest way to picture an aeroballistic range is to think of it as being the opposite of a wind tunnel. In a typical wind tunnel you mount a small scale model inside a big tube called a test section, blow air over it and use various devices to measure aerodynamic properties such as lift, drag, and pitching moment. In the aeroballistic range, a large gun is used to launch a small scale model into a test section containing still air. This aeroballistic test section has many windows and reference wires. As the model flies through the test section it is photographed. These photos along with the time history of the model's flight can be used to reconstruct the model's flight path (trajectory). This information is then fed into a sophisticated computer code, which model is held still while air is blown over it. Whereas, in an aeroballistic range the air is still and the model flies through it. Both types of test facilities are used to determine aerodynamic properties. An aeroballistic range is particularly useful for studying very high-speed flight. In fact, practically all of NASA's spacecraft that have entered an atmosphere (such as Mercury, Gemini, Apollo, Shuttle, Viking, and Galileo) have had some testing performed at Ames' Ballistic Range Complex. The information gathered in these tests was crucial to the successful design of these vehicles. The Ames Vertical Gun Range (AVGR) is the name of the other operational facility within the Ballistic Range Complex. This facility also uses a gun to launch particles at high speeds, but for this type of testing we are most interested in what happens when the particle hits a target, and not so much interested in what it does during its flight. The gun is mounted on what is basically a large hinge so that the impact angle can be varied from horizontal to vertical (0 to 9 degrees). The types of particles that can be launched include spheres, cylinders, be metallic (i.e. aluminum, copper, iron), mineral (i.e. quartz, basalt), or glass (i.e. Pyrex). These capabilities are important because crater size, shape and the way material is ejected from the crater during an impact event is closely related to such things as impact angle, particle shape, composition, velocity, etc. Scientists use experimental data they obtain from the AVGR when they to go out to a crater site such as the Chicxylub (pronounced "chicks-ee-lube") crater in the Yucatan peninsula. By comparing the crater characteristics to their laboratory tests, they can develop a good idea as to the size, speed, composition and impact angle of the particle that crashed into the earth at this location some 65 million years ago, and quite possibly triggered the extinction of the dinosaurs. A discussion of the ballistic range wouldn't be complete if I didn't mention a few words about some of the guns we use in these facilities. For very high speed testing we use what are called two-stage light-gas guns. These guns are capable of launching particles at speeds in excess of 26,000 ft/sec (18,000 mph) which in metric terms is equal to 8 km/s. We have several different guns with barrels ranging in size form 0.28 to 1.50 inches in diameter. This allows us to launch models that are only a fraction of an inch to models that are an inch or more in diameter and several inches in length.