Located in the city of Santa Clara at the southern end of San Francisco Bay, California, there is a private Catholic university-Santa Clara University. Santa Clara University, established in 1851, is the oldest institution of higher learning in California, with a history of 170 years. Santa Clara University is located in the heart of the world-famous Silicon Valley, adjacent to Stanford University, known as the “cradle of scientists”. Santa Clara University is a research university whose goal is to help shape the next generation of leaders and global thinkers.
In 1997, six girls from the School of Engineering of Santa Clara University formed the “Moon Goddess” team, determined to develop the world’s smallest satellite and the world’s first university student satellite. For this reason, they proposed the “Moon Goddess” satellite program, or “Luna” satellite program for short. They raised about $5,000 for each satellite.
”The sparrow is small, but it has all five internal organs.” Although the satellite is small, its functions and components cannot be missing. Girls can only make satellites using parts available on the market. After hard work, the girls finally assembled the satellite. One day, Teresa said in a low voice: “Now, we need a communication antenna that can be automatically turned on in space to send and receive signals.” In this regard, Amanda and Blanche said with confidence: “This does not seem to be difficult. I will find it.”
But the result is very regrettable! In the market, such antennas are difficult to find. For this reason, Blanche suggested: “Let’s consult NASA experts, they will definitely help us solve the problem.”
After that, the girls got a reply from NASA scientists: “Common antennas on satellites There are three types, namely C-band antennas, Ku-band antennas and Ka-band antennas. Your low-orbit satellites are suitable for S-band antennas. The receiving frequency range of this very low frequency band is 3 to 30 kHz, and rod antennas or rods are required. Antenna.”
Hearing the expert’s answer, Annie looked sad: “What to do? The large satellite antenna has a sophisticated and flexible mechanism and system, which is very complicated and expensive. Our small satellite cannot be loaded at all.” Dorothy also She frowned and said, “Yes! It is impossible for the small satellite to carry this huge and valuable mechanism.” Blanche even shed tears: “The weight of the small satellite is only equivalent to a small part of the big satellite. do?”
How to do it? If you design and develop an antenna that can be folded and opened automatically, you need to apply mechanical, electronic, communication and remote control and other complicated structures and procedures. Then the weight and volume of the satellite will greatly exceed the satellite itself, and the antenna cannot be guaranteed. It must be opened in space. It’s hard to break the girls of the “Moon Goddess” team.
Science, don’t get into the horns! A major function of science is to simplify complex issues. Amanda, a philosophical girl, summarized the antenna into several characteristics: conductivity, folding, bending, winding, toughness, flexibility, elasticity and opening. They must find parts with this characteristic, but where are the parts with this characteristic?
One day, Amanda murmured about the characteristics of the antenna while sorting out the satellite’s components. When she threw a small hammer into the toolbox, suddenly a steel tape was ejected. She suddenly felt her eyes bright, and said excitedly: “Steel tape! Doesn’t it have these characteristics? Oh my God, it’s far in the
sky , right in front of you!” The sky is endless! Steel tape measure is the best antenna. The steel tape has been verified by conductivity, frequency, impedance, gain, radiation pattern, polarization, efficiency and bandwidth, which proves that the communication effect of steel tape is very good. From electrical conduction to winding, it is a small step in the way of thinking, but a big step in making satellites. Imagination is more important than knowledge!
The girls plan to use a steel tape from a small hardware store as antennas for the three satellites. The girls bend, wrap and wrap the steel skin of the tape measure around the satellite. When entering space, the satellite ejects from the separation mechanism and automatically pops off the steel tape measure, and the antenna can be opened without any suspense. This design is simple and safe, and it will never go wrong.
The “Luna” satellites were named “Selma”, “Louis” and “Jacco” respectively. They all carry solar cells and deployable antennas. The “Selma” satellite weighs 0.5 kilograms, is 0.2 meters wide and 0.3 meters long; the “Louis” satellite weighs 0.5 kilograms, is 0.2 meters wide, and is 0.3 meters long; the “Giaco” satellite weighs 0.2 kilograms and is wide. 0.1 meters, 0.2 meters long. The total weight of these three satellites is 1.2 kilograms, occupying only about 0.4 liters of space, and the design life is 15 days.
The scientific missions of the “Selma” and “Louis” satellites are to test the satellite’s survival in extremely harsh environments, the impact of lightning on the ionosphere outside the satellite, and to measure very low frequency radio signals. The scientific mission of the “Jacques” satellite is to test beacon transmitters, satellite broadcasting and ground receiving capabilities.
On January 27, 2000, the U.S. Air Force launched a “Minotaur-1” rocket from Vandenberg Air Force Base, sending 11 satellites, including 3 small satellites designed by the girls, into space. After the rocket was launched into space, the three small satellites entered the orbit with a perigee of 750 kilometers, an apogee of 805 kilometers, an orbital inclination of 100.22°, and an orbital period of 99.6 minutes. So far, the world’s first university student satellite and the world’s first female university student satellite have been successfully launched! The girls cheered.
However, unfortunately, after half a month, the three small satellites disappeared after completing their mission, and could no longer receive any information. But in any case, the “Lunar” satellite opened the prelude to the launch of student satellites, and it inspired students to develop satellites. On December 6, 2015, the world’s first elementary school satellite, the “St. Thomas More”, was successfully launched at the Kennedy Space Center in the United States. By the end of 2020, students from various countries have launched more than 1,000 satellites of various types.
In addition, the “Luna” satellite has expanded the students’ vision of imagination and innovation! Since then, hundreds of small satellites have been launched in the world, including the US Department of Defense, the US Central Intelligence Agency and the small satellites of various countries, all using steel tape measures or materials similar to steel tape measures as antennas.
Satellites are not big or small, as long as you have a heart of science, wisdom and dreams, you will eventually succeed!
