University of Arizona opens major facility for building and launching satellites
ARB’s anechoic chamber
Yesterday I attended the grand opening of the University of Arizona’s (UA) new Applied Research Building (ARB), designed to provide satellite builders as well as its students an almost completely comprehensive facility for the assembly, testing, and launching of satellites. From this event announcement:
To keep the university at the forefront of space science and exploration, ARB will serve as a world-class test and integration center for satellites, probes, and spacecraft, including:
- A 40-foot tall high-bay payload assembly area used for constructing high-altitude stratospheric balloons and nanosatellites also known as “CubeSats.”
- A thermal vacuum chamber that simulates environmental conditions in space to test balloon and satellite performance that is the largest of its kind at any university in the world.
- A non-reflective, echo-free room called an anechoic chamber to test antennae for command, control, and data relay purposes.
- A large lab for testing the performance of a range of objects, from airplane wings to sensors.
The anechoic chamber is pictured above. For scale, if a person was standing in the middle of the chamber their height would reach about six rows up. The carbon-infused styrofoam pyramids are designed to dampen reflections of radio signals in order to simulate the space environment while testing the antennas on a satellite. This is apparently is of the largest such chambers in the United States.
The ARB also includes mission operations room which can be used during launch and space operations, a facility for storing and testing meteorites and samples from other planets or asteroids, a facility for doing 3D printing research, and a laboratory where students and commercial companies can build cubesats.
The UA’s goal with this facility is to not only teach its students the engineering needed to build satellites and planetary probes, but to also attract commercial customers who need such equipment to prepare their satellites for launch. Having a thermal vacuum chamber and an anechoic chamber in the same building will cut costs enormously, especially for those satellite and science probe manufacturers located in Tucson.
In other words, this facility is both an educational building and a commercial operation, with the latter helping to fund the former. It also illustrates the boom-town nature of the global space industry, fueled by the dramatic drop in the cost to get to orbit. UA got the financing and wherewithal to build the ARB because it recognized this growing demand, especially in Arizona’s burgeoning space industry.
For me, however, the most fascinating moment during this grand opening tour of the ARB came when I went up to the cubesat laboratory. There, a student was answering questions, using several mock cubesats for illustration purposes. In the process he described his own cubesat project, aimed at tracking the transits of a known exoplanet in order to demonstrate the capability of cubesats to do such work. He explained that he was going to use the Earth’s magnetic field plus extended arms to control the cubesat’s orientation and attitude in space, since it was too small for thrusters plus fuel. When I told him he was doing the exact same thing that the first satellite engineers did in the early 1960s, he was quite amused, as he had had no idea it had been done before.
This cubesat laboratory will likely benefit UA’s space engineering students the most of all, because it is going to provide them a place to build their own satellites, with the ARB also providing them facilities for testing those cubesats prior to launch.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
ARB’s anechoic chamber
Yesterday I attended the grand opening of the University of Arizona’s (UA) new Applied Research Building (ARB), designed to provide satellite builders as well as its students an almost completely comprehensive facility for the assembly, testing, and launching of satellites. From this event announcement:
To keep the university at the forefront of space science and exploration, ARB will serve as a world-class test and integration center for satellites, probes, and spacecraft, including:
- A 40-foot tall high-bay payload assembly area used for constructing high-altitude stratospheric balloons and nanosatellites also known as “CubeSats.”
- A thermal vacuum chamber that simulates environmental conditions in space to test balloon and satellite performance that is the largest of its kind at any university in the world.
- A non-reflective, echo-free room called an anechoic chamber to test antennae for command, control, and data relay purposes.
- A large lab for testing the performance of a range of objects, from airplane wings to sensors.
The anechoic chamber is pictured above. For scale, if a person was standing in the middle of the chamber their height would reach about six rows up. The carbon-infused styrofoam pyramids are designed to dampen reflections of radio signals in order to simulate the space environment while testing the antennas on a satellite. This is apparently is of the largest such chambers in the United States.
The ARB also includes mission operations room which can be used during launch and space operations, a facility for storing and testing meteorites and samples from other planets or asteroids, a facility for doing 3D printing research, and a laboratory where students and commercial companies can build cubesats.
The UA’s goal with this facility is to not only teach its students the engineering needed to build satellites and planetary probes, but to also attract commercial customers who need such equipment to prepare their satellites for launch. Having a thermal vacuum chamber and an anechoic chamber in the same building will cut costs enormously, especially for those satellite and science probe manufacturers located in Tucson.
In other words, this facility is both an educational building and a commercial operation, with the latter helping to fund the former. It also illustrates the boom-town nature of the global space industry, fueled by the dramatic drop in the cost to get to orbit. UA got the financing and wherewithal to build the ARB because it recognized this growing demand, especially in Arizona’s burgeoning space industry.
For me, however, the most fascinating moment during this grand opening tour of the ARB came when I went up to the cubesat laboratory. There, a student was answering questions, using several mock cubesats for illustration purposes. In the process he described his own cubesat project, aimed at tracking the transits of a known exoplanet in order to demonstrate the capability of cubesats to do such work. He explained that he was going to use the Earth’s magnetic field plus extended arms to control the cubesat’s orientation and attitude in space, since it was too small for thrusters plus fuel. When I told him he was doing the exact same thing that the first satellite engineers did in the early 1960s, he was quite amused, as he had had no idea it had been done before.
This cubesat laboratory will likely benefit UA’s space engineering students the most of all, because it is going to provide them a place to build their own satellites, with the ARB also providing them facilities for testing those cubesats prior to launch.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I know little of satellite design and manufacture.
Can they also simulate the cold swings of temperature? Or would that kind of temperature swing damage the carbon infused pyramids?
sippin_bourbon: In the anechoic chamber, the purpose is only to test the satellite’s antenna and communications systems. For the environmental tests in a vacuum, they use the vacuum chamber, which they said can be run both very cold and very hot (I don’t remember the exact numbers), simulating the wide swings in space.
The amused student probably should have known or been told that this technique has been used before. Torque rods have been around for a few decades.
https://en.wikipedia.org/wiki/Magnetorquer
____________
The anechoic chamber (“an,” as in “not;” “echo,” as in “did you hear that?” and “ic,” as in “doesn’t this make the word look fancy?”), which tests antennas, radio-wave reflections, and other spacecraft-induced interferences, is only one type of environmental test chamber. They sometimes go by the name “range test.” One place I worked had a radio antenna out back, and the anechoic chamber had a window that opened out toward the antenna. Other chambers have had antennas inside the chamber but on moving bridge cranes to test the response to signals coming from various directions. Some chambers have moving test stands that change the direction the satellite faces, toward a fixed antenna inside the chamber, in order to test these responses.
The thermal vacuum chamber (the vacuum chamber that Robert mentioned) is another environmental test chamber that tests the ability of the spacecraft to maintain operating temperatures when in sunlight or in Earth’s shadow (umbra). Cold is generally simulated by having plates cooled with liquid nitrogen or cold gaseous nitrogen (I have used both types of chambers) and hot is often simulated by heating those plates with hot gaseous nitrogen or with heat lamps or heater elements, as in your toaster, but larger (I have used all three of these methods in various chambers). The chambers with liquid nitrogen cooled plates tended to have lamps or heating elements to assure that the test item didn’t get too cold. The hot and cold ranges depend upon the test plan and the type of test. A qualification test may go to colder and warmer extremes, and an acceptance test may be closer to the temperatures expected in space. These temperatures are generally determined by thermal engineers.
Two environmental test chambers that I didn’t notice in the article were the shaker tables, to simulate the vibrations of launch, and the acoustic chamber, which is the opposite of the anechoic chamber. The acoustic chamber has horns that blast loud noises at the test item, and it has concrete walls that makes the sound echo. This simulates the noise that will be generated by the rocket’s fairing. Those fairings vibrate quite a bit and act like gigantic drumheads or speaker diaphragms.
The materials used in the anechoic chamber do well in absorbing radio waves, but they also absorb sound, and these chambers are a bit eerie to work in, as they are extremely quiet, with no echoes of voices when you or your workmate speaks. Ambient sounds just don’t exist in these chambers. You may think that you have been in quiet places before, but these chambers are really quiet. Anechoic chambers can also be used to test airplanes and other hardware.
Qualification testing is used on the first unit of a design, and acceptance testing is used on the rest of the units. The word I heard was that Iridium only did environmental testing for the first five satellites. Any further testing was only to verify workmanship. This was to reduce the cost of each satellite, as environmental testing takes time and a lot of money. I would not be surprised if the Starlink and OneWeb satellites had a similar environmental test plan, testing only the first few of any new design.
Because the Arizona students are likely to make new designs each year or semester, I am not surprised that they have their own environmental chambers.
Back in the 1970’s they sent up their E,R,T,S Earth Resources Technology Sattlite it seems it didn,t last long but Vanguard is still up there
” . . . he had had no idea it had been done before.”
One of the first things I do with a problem is find out how it’s been handled previously, because it almost certainly has. No point in re-inventing the wheel. Satellite design is in it’s eighth decade. Read some history, kid!
Blair Ivey: I would blame his teacher, who should be teaching exactly what you say.
But then, no one reads books anymore, or anything older than five years ago. The world is now in an unending amnesia loop, where only the most recent events matter.
Edward, thanks, that was very informative.
I don’t see the point of it (the anechoic chamber), though. I understand that in space there are no reflected radio waves (or very few) given the lack of things to reflect from, but isn’t “outside” the same thing? Why does it need a special chamber?
markedup2 asked: “I don’t see the point of it (the anechoic chamber), though. I understand that in space there are no reflected radio waves (or very few) given the lack of things to reflect from, but isn’t “outside” the same thing? Why does it need a special chamber?”
This chamber tests how well signals are received by the spacecraft and how well they are sent. Various antennas can be tested to make sure that their signals do not interfere with any other antennas on the spacecraft, as there are multiple antennas on each, especially for the case that one fails, contact can still be made with the spacecraft. The range test also discovers whether there are reflections off parts of the spacecraft, such as solar arrays, struts, other antennas, other instruments, etc. Speaking of which, other instruments could be noisy, as in broadcasting electromagnetic radiation that interferes with antennas or other instruments. I once worked on a spacecraft instrument that had a noisy neighboring power supply, and we had to build a faraday cup around ours (we had a field of view that had to have a cup-like opening), as we were the only one affected, and we had fewer wires and harnesses to go through the shielding than the power supply had.
Communication satellites have dishes that reflect and shape the broadcast from the satellite. For instance, if a satellite-TV company broadcasts to the U.S., then its signal must drop off between the tip of Florida and Cuba. If they don’t have permission to broadcast in Canada, then the signal must drop off at the 49th parallel and at the Great Lakes. The anechoic chamber can test this response.
“Outside” is not the same thing, because if any interference or defect is detected, it is hard to prove that it came from the satellite, not some other source, such as another satellite being built and tested in the same cleanroom. Inside the anechoic chamber, the only sources are the test unit and the ground support antenna that sends and receives the test signals. Inside the chamber, any stray signals are absorbed by the cones — or rather pyramids. By the way, before a test would begin, more of those absorption pyramids would be placed on the floor that is shown in the picture. They don’t want reflections off the floor, either.
The series of environmental tests are performed to ensure that the satellites worked as they are intended to work, that they were built properly, and that they would survive launch. On rare occasion, the shake test would show that screws were not torqued properly and had backed out or that a wall had not been strengthened enough and had cracked.* We actually had one structural wall on a satellite crack because an engineering order had not been incorporated during the wall’s initial construction; the normal design was for one thickness, but that particular satellite had a heavier payload (yes, even the rocket’s payload can have its own payload), and the wall was supposed to be built thicker to accommodate the added weight and vibration forces. The darnedest things happen during these environmental tests, so it is a good thing that we perform them.
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* The shake test is rather interesting. It may start with a sine sweep, where the satellite is shaken from 5 or 20 Hz up to around 2,000 Hz at a very low level. This gives a response for each of the many accelerometers on the spacecraft. There are peaks in the responses at the natural frequencies of the various parts of the satellite.
As the random vibration test is performed, the response from each accelerometer is put through a Fourier transform to show the response at each frequency, and it should look similar to the sine sweep. If the peaks move, split into two peaks, or are not as sharp (rounded rather than pointy), these are indications of broken parts or loosened screws. The engineers review these Fourier transform plots before performing a higher level shake test, and they typically perform another sine sweep at the end, before moving on to the next axis. Often they will start with low shake levels and work their way up to the level expected to be experienced during launch. If something is going to break, it is better that it isn’t at such a high shake level that the rest of the satellite breaks, too.