As we had mentioned in our previous update, we submitted a joint proposal with a second aerospace partner to a new potential customer for a constellation of Viewpoint satellites. We made it through the first round, and were invited to participate in the second selection round, so we started work on the next phase of meeting the technical and financial detailed requirements. We felt confident about meeting the technical parts, but felt uncomfortable about some of the financial requirements and schedule requirements. After much discussion with our aerospace partner, we both decided there was too much financial risk, and so we withdrew our proposal.
In the meantime, the aerospace partner who we worked with in 2020 has informed us that their customer has re-started their program. That customer had stopped the program because Covid had impacted their country’s economy. Now that Covid is waning, their economy has recovered and the program has picked up where it left off. It’s also possible that the conflict between Russia and Ukraine has shown them the value and importance of timely Earth observation of their territory.
As we also mentioned in our previous update, we have been working on our "omni-material" 3D printer. We are making steady progress. We assembled and tested our first laser control board prototype version, which required some modifications. We have already received, assembled, and started testing the second version laser control board, and it is working well.
The prototype omni-material 3D printer is shown in the picture below. The infrared laser beam is invisible and very powerful, and even reflected laser light is dangerously powerful, so we have built an opaque enclosure around the entire printer. In this prototype, the laser controller, power supply, and the water cooler and radiator are placed for easy access and modification.
We have been heating and melting steel based material, starting with low power and ramping up the power. We did overheat an optical component when running at full power, but changing the optical alignment should fix the problem.
We are continuing testing and characterizing the processing of steel, then we will switch to aluminum. Before we go too much farther, though, we will have to add an inert gas system. We have already started designing that.
The next big milestone will be to print an object that’s made of part steel and part aluminum. After we can demonstrate that, it will be time to start talking to VC’s, hopefully by this summer.
We are going to be using the 3-D printers to print lightweight strong parts for our observation satellites. This allows us not only to reduce weight through exotic materials and hollow prints, but by having fewer parts and fasteners.
We also plan on selling the 3-D multi-material printers as an income stream for SpaceFab.
The last big event we attended was the AAS (American Astronomical Society) meeting January 2020 in Honolulu, where we exhibited our Viewpoint satellite model. Of course, it was a few months later that Covid-19 started to affect the world. We stopped going to conferences, and stopped all in-person meetings. It feels like life now is slowly getting back to normal, at least here in the USA. We have attended two conferences in the last few months, an SPIE conference in San Diego and the Space Tech Expo in Long Beach.
Although the pandemic slowed things down, it hasn't stopped us from continuing work on our Viewpoint satellite. All design work is done on computers these days, and we've adjusted to remote work and remote collaboration. As long as we have fast Internet connections, we can still work with our aerospace partners. We have been working on various project proposals with our aerospace partners for customers interested in our Viewpoint satellite. We did have a change in mindset -- we initially wanted to build our own constellation of imaging satellites, but now we are perfectly willing to sell our satellite to outside customers who want to buy one (or more than one).
One potential customer was interested in a constellation of Viewpoint satellites, and we talked to them during most of 2020. Unfortunately, their country's economy was hit hard by the pandemic, and everything stopped by the end of 2020. Discussions have started with a new potential customer, also for a constellation of Viewpoint satellites. We hope that discussions will continue in a few months.
As a result of our customer discussions, we feel strongly that our Viewpoint satellite has the right features. Because it is easily extendable, we have added two cameras which were not part of our smaller Waypoint imaging satellite. So far, the customers have been looking for Earth observation satellites, so we've made sure that the Viewpoint satellite is an excellent multi-purpose imaging satellite. Our earlier Waypoint satellite had a large 48 megapixel imager, for instance, but in the Viewpoint satellite, we've changed to a 152 megapixel imager. In fact, the design now has two of the 152 megapixel imagers, one of them a monochrome imager and the other one with on-chip RGB color filters. We added a moving mirror to allow long strip mode Earth imaging, allowing the Viewpoint to image about a million square kilometers a day, either in monochrome or in color.
We also upgraded the low noise UV capable imager from 10 megapixels to 37 megapixels. And we added a new 1.3 megapixel short wave IR (SWIR) camera that can sense SWIR out to a wavelength of 1.7 microns.
We have ensured that the Viewpoint satellite uses export approved components and has export approved capabilities. The 50 cm diameter mirror is the largest telescope mirror that can be export approved for Earth observation. We have also restricted the hyperspectral camera to 39 spectral bands, while providing very high resolution (1.5 meter) to conform with export regulations. (For more than 39 bands, the resolution would have to be degraded 30 meters.) Finally, we have removed the control moment gyros and will be using standard momentum wheels.
The title of this posting is "3D Printed Satellites". In addition to all the improvements we've made to the Viewpoint satellite, we've also decided to 3D print large amounts of the satellite. We'll be doing this for cost reasons and for improved performance. We couldn't find the perfect 3D printer, so we invented our own.
There aren't many choices for types of 3D printers that can print out parts for a satellite. Resin type 3D printers can't print strong engineering grade plastics. Metal 3D printers are very expensive and can't print very large parts. Filament based 3D printers can print large parts, can print with engineering grade plastics that won't outgas, but we want to print large parts with a mix of metals and plastics all in the same part. Such a 3D printer doesn't exist.
We've been working on just such a 3D printer. It will be able to print a mix of metals, not just one metal. It will also be able to print a mix of plastics. And it will also be able to print ceramics. It will be able to print all these types of materials all in the same part. We see that such a 3D printer can be used to print strong structural components, light and strong light baffles and other large optical support components, and many others.
One key to building this "omni-material" 3D printer is to have a laser controller that modulates the laser power very precisely, able to adjust the power as the laser beam moves over the 3D printed material so that a consistent amount of power is delivered even as the laser beam is accelerating, decelerating, or changing directions.
In the picture above, we have a fiber coupled 30 watt laser diode module. The laser is about 40% efficient at best, so circuitry must deliver up to 75 watts of electrical power. The laser driver circuitry is similar to the laser driver we have developed for our optical communications. Since we don't have to worry about operating in space (at least not this version!), we can use water cooling to keep the laser diode cool. We've finished assembling our first laser control board prototype, and will be testing soon, right after we finish programming the FPGA and writing some software.
By ADAM ENGELSTAD for OUTERSPACELAND
November 27, 2020It's one of the biggest and most valuable rocks tumbling around the asteroid belt. Some people say the amount of metal in the exposed core of 16 Psyche is worth more than the entire economy of Planet Earth. There may even be gold there.
But Psyche is worth much more than its weight in gold to SpaceFab, a small satellite startup with the ultimate goal to build big things in outer space. To SpaceFab, resource rich M-type asteroids like Psyche are absolutely essential to sustaining a space-faring civilization. And if everything falls into place for this scrappy business, SpaceFab will be running space station shipyards on Psyche in the second half of the 21st century and building enormous planet-to-planet luxury liners Buzz Aldrin himself would be proud to pilot. . . .outerspaceland.com/003-SpaceFab-Dreams-Shipyards-Psyche.html
We had been working toward our first generation Waypoint satellite, which was a 12U cubesat weighing 18 kg. It had a 21 cm primary mirror and could provide 1 meter ground resolution. To keep the satellite small enough to fit the 12U cubesat form factor, the secondary mirror was kept inside before launch, then it would be extended to full length when in orbit.
In early 2019, we updated our business plan to include our second generation Viewpoint satellite, which would be a 150 kg smallsat. It has a 50 cm primary mirror and will be able to provide 30 cm ground resolution. When we did a financial analysis, we saw that the Viewpoint satellite had a better business case than the smaller Waypoint satellite. When we talked to potential customers and investors, there was more interest in the Viewpoint satellite because of its higher resolution.
It really didn’t make sense to do both at the same time, so we put the Waypoint satellite on hold, and switched our priority to the Viewpoint. Although building and launching the Viewpoint was more expensive than the Waypoint, it had much more capability per dollar. The Viewpoint satellite is much larger than the Waypoint, so it’s much easier to make everything fit. It took extra work and time to fit all the components like batteries and momentum wheels into the Waypoint, which had a volume of about 12 liters ( one cubesat “U” is one liter). Now it is much easier fitting even more components into the Viewpoint, which has a volume of about 450 liters.
Then in August, SpaceX announced their smallsat rideshare program. They would launch smallsats up to 200 kg for $1M. The cost to launch the Viewpoint and the much smaller Waypoint was suddenly about the same! This situation improved the business case for the Viewpoint satellite even more. We haven’t made a decision on which launcher will be used, but it’s nice to have another provider.
The Viewpoint will use the same optical architecture as the Waypoint, except the mirrors will be larger, and the secondary mirror and main light baffle will be fixed rather than extending. The cameras, electronics, and software architecture will be the same, except a low noise ultraviolet CMOS camera will be substituted for the EMCCD camera. The manufacturer of the EMCCD we were going to use is stopping production of all their CCD’s and will be only making CMOS imagers. Because we are able to re-use so much of the Waypoint design for the Viewpoint satellite, we should be able to launch the first Viewpoint in early 2022.
With all the extra room in the Viewpoint, we will add an ion engine for propulsion to maintain a low orbital height of 330 km, where it will allow better ground resolution. This orbital height is below the ISS (International Space Station) and will be below all of the communication satellites from SpaceX and Amazon. The lower orbital height shouldn’t make a difference for astronomy and Space Domain Awareness (which used to be called Space Situational Awareness). We’ll also use the propulsion capability to avoid space debris, although there will be a lot less debris at 330 km than at higher orbits. Overall, propulsion will provide a lot more Earth observation performance with only a small increase in cost.
In September, we attended AMOS, the Advanced Maui Optical and Space Surveillance Technologies Conference. We learned a lot about satellite collision avoidance, and now we see how the Viewpoint constellation can help in collision avoidance. When two space objects look like they might collide, the US Air Force (and soon, private industry) will issue a “conjunction alert” about a week before the possible collision. The conjunction alert isn’t precise enough to determine if an actual collision may occur, so ground radar and ground telescopes are used to take additional measurements to refine the orbital information of the two objects. If the objects still look like they will get too close, and if one or both objects can maneuver, the refined orbital information can help decide the maneuver direction. We had the opportunity to talk to companies about the Viewpoint capabilities for orbit determination, and there is definite interest there, especially when we have multiple Viewpoint satellites available. This capability will become more and more important as thousands and tens of thousands of satellites are put into space.
Also in September, we filed a patent application for our ion engine accelerator. This accelerator can be used for high power ion engines, and we plan to use it for asteroid mining. It probably won’t make sense to use it on our Viewpoint satellites, since it is better suited for very large space vehicles, but small prototype versions can be tested on future Viewpoint satellites. We’ll talk more about this accelerator when the patent application is published by the US patent office in two years.
In the meantime, we have been hard at work at building a full scale model of the Viewpoint satellite. We will be showing the Viewpoint model at our exhibit booth at the AAS (American Astronomical Society) conference in early January. The model uses 6061 aluminum with laser drilled holes and includes 3D printed plastic sub-panels. Here’s a photo of the model and the exhibit gear on a pallet, ready to be shipped to Hawaii.
We wish you the best of the holidays!
SpaceFab has selected the Supernova Cosmology research program proposed by David Rubin for the grant of observation time on its Waypoint 1 space telescope.
The Waypoint satellite is a multipurpose cubesat space telescope, used for Earth observation and astronomy. The Waypoint 1 will be the first satellite of a constellation of sixteen, and will be launched in late 2020.
Dr. Rubin’s program will use the Waypoint satellite’s EMCCD (Electron Multiplying Charge Coupled Device) camera to make rapid UV (ultraviolet) observations of newly discovered type Ia supernovae. Almost all UV light is absorbed by the Earth’s atmosphere, so only a telescope in the vacuum of space can make these types of measurements. The Waypoint satellite can be rapidly tasked to take priority observations within 90 minutes.
Dr. Rubin is currently a postdoctoral researcher at the Space Telescope Science Institute, but has accepted a faculty position at the University of Hawaii starting in August 2019. His primary focus is on supernova cosmology, and is currently co-running a program to dramatically increase the number of distant SNe Ia to get substantially improved cosmological constraints.
His research program will use about 25 hours of high priority observation time and 10 hours of lower priority time over three years. Here is an abstract of his research program:
Rapid Progress with Rapid Observations: Supernova Cosmology and Astrophysics with the Waypoint 1 Satellite
Distances from type Ia supernovae (SNe Ia) measure distances across billions of years. Together with the redshift of the SN, they trace the expansion history of the universe, constraining the properties of dark energy. However, the progenitors of Type Ia SNe are still not well understood, and could be causing systematic uncertainties in the measurements. Rapid UV observations are key for shedding light on this issue. This program will observe 30 SNe Ia, each discovered early, rapidly targeting them with Waypoint 1 observations. In combination with ground-based data, these observations will enable strong constraints on the astrophysical scenario that yielded the SN. In addition to learning more about these astrophysically important objects, these data will help us to improve the standardization of SNe Ia, enabling us to learn more about the history and fate of the universe.
Our last update was October 1, and a lot has been happening since then.
We’ve been very busy preparing for exhibiting at the American Astronomical Society (AAS) conference, which was held in early January 2019 in Seattle.
We planned on showing two spacecraft models, one that was entirely made of 3D printed plastic, and one very similar to the flight model with a CNC (Computer Numerically Controlled) milled metal structure. Unfortunately due to the holidays, the metal version took much longer than expected to machine and to have a protective anodized coating applied. We do expect the metal parts to arrive by the end of January.
We did exhibit the 3D printed plastic version, and a picture of our booth is shown below.
The model was painted with aluminum paint, so it resembles metal. In the picture above, the front side shows two square antennas, one for GPS (on the green printed circuit board) and the gold colored one for a Globalstar radio. There is also a white rectangular plastic panel which insulates the internal optical bench from external temperature variations. The side of the spacecraft is open, to show the primary mirror in the top half of the spacecraft and the filter wheel in the bottom half. The Android tablet computer screen on the table behind the business cards was used to demonstrate the remote control of the filter wheel. Attendees could use it to move the filter wheel and select the twelve different filter positions. In the flight model, the spacecraft will control the filter wheel directly, but for this demo, the tablet is controlling the wheel via an app and Bluetooth wireless interface.
The model also shows the final configuration for the solar panels. The panel with the exposed solar cells is initially folded down to cover the aperture for the telescope. When in orbit, the panel flips up to allow the telescope to extend. The two sets of main solar panel wings are initially folded up into the bottom of the spacecraft, then unfold when in orbit.
We also presented attendees with our research grant program, where we will award free space telescope time in four different categories:
- Best professional researcher proposal
- Best amateur astronomer proposal
- Best proposal from a university student in a physics/astronomy program
- Best general public submission proposal, open to anyone with an interest in astronomy
More details on our research grant program are here: http://www.spacefab.us/request-for-proposals.html
We will be accepting research proposals up to February 28, 2019, and we will announce our space telescope grant winners by March 31, 2019.
Now that we are done with the AAS conference, we are preparing our business plan and presentations for discussions with venture capital companies. To assist us with writing and analyzing our business plan, we have added a business advisor, Christof Kern, who is currently CEO of Fibersat, a satellite communications company. While at Fibersat, he secured pre-launch orders of $495 million and government business orders of over $50 million for his company. We appreciate his deep background and experience in business development, strategy, and financial analysis for satellite companies.
We are very happy with our latest business plan, and we are now finalizing it and starting work on our Powerpoint presentations. We plan to raise enough funds to finish our first generation space telescope, the Waypoint, and launch it at the end of 2020, then build and launch additional Waypoint satellites for our space telescope constellation every twelve to eighteen months thereafter. And we are very excited about our second generation space telescope, the Viewpoint satellite. It will have comparable resolution to the best commercial Earth observation satellite in existence today, while being more than an order of magnitude less expensive.
We will be busy preparing for our next stage of fund raising for the next few months, so we may not be able to update you until April or May.
SpaceFab is a company that is currently building a 8 inch space telescope built around a 12U Cubesat. Scheduled for launch in 2020, this space telescope will be made available to everyone. There are plans to launch a network of these space telescopes to be used for everything from taking selfies and taking your own pics of the early universe to looking at your property from space. Join us as Tony Darnell and Dustin Gibson discuss this amazing opportunity with Sean League, the Director of Spacecraft Development at SpaceFab.
It’s the end of a very productive summer with our interns, Jack and Phil. They have now returned to school, Jack to UC San Diego, and Phil to Cal Poly San Luis Obispo, to start their senior year toward their bachelor’s degree in engineering.
As a company, we made a tremendous amount of progress in a short amount of time. On the mechanical engineering side, Phil helped us determine that the spacecraft structure would hold up to the stress of launch. The largest rocket launchers typically have the lowest g-forces, around 5 G’s (five times the force of Earth gravity), while the smaller launchers have g-forces of up to 9 G’s. Our satellite structure is designed to handle 9 G’s plus some additional margin, so we can use any of the launch vendors, large or small.
We also decided that certain parts of the structure could be made of a high strength engineering plastic. These plastic pieces are strong enough to hold our telescope optics, while keeping the optics thermally isolated from the aluminum walls of the spacecraft. It’s important to keep the optics at the same overall temperature, even if one side of the spacecraft is hot from sunlight while another side is cold by radiating heat out into space.
The picture above is a computer generated rendering of the entire spacecraft with the solar panels, secondary mirror, and large light baffle deployed. The light gray or white colored panels are made of aluminum, and the darker gray panels are the high strength plastic panels. The design has five solar panels, four of them folded into the bottom of the cubesat, and the fifth one acting as the aperture cover for the telescope.
All of the major mechanical pieces have been designed, and we have been printing the pieces on our big 3D printer for an initial prototype. We have already found a few minor issues and corrected them, and we will be sending the updated designs out to our manufacturing partner to have metal parts machined out of aluminum. This will let us have two spacecraft models, one of plastic so we can make quick checks and modifications, and one of metal that we can use for strength and thermal testing.
We have also been working with a number of different vendors for the most complex pieces of our space telescope. We now have a full design of the optics, which includes the sizes, positions, and prescriptions for the three mirrors and four lenses in the main optical path. And we have been working with other vendors on the secondary mirror booms, the fine optics adjusters, and the folding solar panels. These are all things that must move, unfold, or extend at the right time and with the right amount of movement and clearance. We’ve had to make a few adjustments to our CAD drawings to make sure everything fits, but there have been no major issues.
On the electronics side, intern Jack made a great deal of progress on the laser communication circuits. The transmitter test board is working extremely well. It can switch several amps of laser current in a nanosecond, so we can transmit data down to the ground at 200 MHz or even a little faster. This corresponds to a data rate of 100 megabits per second.
Jack built two versions of the laser receiver test board. The first version had quite a bit of noise, so we tried several different receiver circuits. The second version of the board can actually receive the light pulses at 200 MHz and translate them into electrical signals. However, although the noise level was reduced, the laser receiver board still isn’t sensitive enough. We do have some ideas on how to reduce the noise and boost the sensitivity to the right level, and we’ll build and test a third version.
The picture above shows the laser transmitter board on the left, and the laser receiver board on the right, behind a light diffuser screen. The receiver board is mounted to an X-Y stage, so it can be aligned with the laser beam by turning the metal knobs.
The oscilloscope picture below shows the laser drive signal on the transmitter board in black (oscilloscope channel 1). The signal is inverted, so laser light is generated when the voltage is low -- the signal shows two pulses 5 nanoseconds wide and 10 nanoseconds apart. The laser light is beamed to the receiver board, where it is detected (converted from photons to electrons), amplified several times, then converted from an analog voltage to a digital signal. The non-inverted digital received signal is shown in green (oscilloscope channel 4), with the proper pulse timings.
As far as the laser transmitter is concerned, it is working so well that we are thinking of turning it into a product and selling it. It would be the best overall laser communication module available for cubesats - fast, low power, compact, and low priced. It could be a quick way to get some sales revenue -- but it would be a distraction from our main goal of getting our satellite into space.
Our plan is to talk to venture capital companies at the beginning of 2019. If we don’t get interest in our space telescope business plan, we’ll do a slight pivot and turn the laser communicator into a product, while still working on our space telescope. So we will be busy until the end of the year working on our satellite design, refining our business plan, and talking to prospective customers.
Good-bye to our 2018 summer interns Jack and Phil - you guys are the best!!