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Ham Satellite news

GOLF Program Updates

This is a re-post from ANS-161:

For those who missed the AMSAT Forum at the 2024 Hamvention, here is an excerpt from the engineering update presented by Jerry Buxton, N0JY, AMSAT VP-Engineering about the exciting GOLF program.

Some main events happening with the GOLF program. Golf is the acronym for Greater Orbit Larger Footprint. The program is a series of satellites for flight testing and qualifications. We will be looking at testing various devices and systems that we will need as we move to HEO. Each one carries an amateur radio payload that will continue once the main testing mission is complete.

We are looking to increase orbital heights but that is getting more difficult due to the orbital debris rules. Something that we have to harness before we get out of LEO is the ability to make accurate maneuvers and collision avoidance because there is a lot of traffic up there now and hopefully, we will be able to get beyond that and ultimately our perigee is still about 2,000 kilometers that exempt us from the orbital debris rules. But the fact that we can maneuver give us the opportunity not only for deorbiting when we need to but to raise or lower our orbit to a degree so we can have a longer mission.

Speaking of longer missions, survivability is a big thing especially as we get into the Van Allen radiation belt and such. As you get further away from LEO, there is a lot more radiation bombarding you so the idea of radiation tolerance for commercial off-the-shelf (COTS) parts or in some cases when we do a HEO or a GTO we may want to use some radiation hardened parts so we get the best life out of it. So, what we’re looking at is the lowest cost versus performance. It’s a trade balance so we can keep as many satellites in space as we can successfully and return to HEO.

In order to do this, we’re going to master some satellite operations necessary for higher orbit. This doesn’t include engineering. It includes operations who will be controlling the satellites. They will need a good understanding of what the satellites will do and have good instructions to know how to control them.

Some of the main things we need for going higher are:

Power generation. We’re going to need more gain on your power amplifiers, for example to help overcome the link budget. SDR’s can get busy and require a bit of power. There are other systems that we will want to keep running as well as experiments. Power is a premium thing that we need, that is getting power generated by the sun.

Attitude detection and control systems. ADCS something that is vital to control the satellite to point for the best sun or to maneuver. We have to be pointed very precisely if we are going to fire any thrusters. And, we need to point our microwave antennas back toward earth.

Radiation tolerance is essential to survival. In the older satellites there weren’t so many chips, the IC’s if you will, so the analog parts, the carbon resistors and such were much hardier in the radiation belt.

Microwaves – We’re going to be moving into the microwaves. 10 GHz is the ultimate downlink band. There’s a lot of bandwidth up there with 10 GHz, X-Band for downlink and 5 GHz, the C-Band for uplink.

We are also adding 2.4 GHz, S-Band uplink because that is shared with Europe and QO-100.

Thrust and propulsion will be the icing on the cake.

We have to master all of this to be responsible spacefarers.

GOLF-TEE Mission
We have Golf-Tee which stands for Technology Exploration Environment. Key features of it are:

It has deployable solar panels that we are developing inhouse. These address the need for more power.

We have secured CubeSpace ADCS, that we will use for the Attitude Detection and Control System. We were working earlier with a startup that would have given us the opportunity to fly cheaper and be part of the development but that did not come to fruition. We looked at a long list of possible ADCS systems and decided that CubeSpace would be suitable for our GOLF-TEE, GOLF-ONE and possible beyond.

We have the RT-IHU, Radiation Tolerant Internal Housekeeping Unit, which was developed as an ASCENT project using COTS, commercial-off-the-shelf, parts intended to reduce the number of upsets that cause the IHU to “latch-up” and have to re-boot. We’re going to compare that to the IHU we had on the legacy LTM, linear transponder module, used in the FOX satellites to see if, with the South Atlantic anomaly problem, if we are doing any better with resets on each of those IHU systems.

For the 10 GHz X-Band we’re going to have an experimental microwave high speed data downlink which is tricky at LEO, but as we get higher at HEO there is a lot of data we will want to download, not to mention that from experiments. It also gives us an opportunity to possibly use it as a transponder where we would pick off the downlink from the V/U transponder and send it down on 10 GHz as an entryway for people to try working with the microwave bands.

For the GOLF-Tee mission, we are looking at a 500-550 km LEO orbit, accessible through a CSLI/ELaNa launch. Its purpose is to test and qualify new technologies. It will carry the Vanderbilt/ISDE Low Energy Proton Experiment that we have flown before. This will help provide a comparison of what the environment is like with the IHU, RT-IHU and L-IHU units.

We should have a good radio footprint at 550 km. It’s orbital debris regulation “friendly” because it will decay rather rapidly with the current sunspot cycle. We’ll see how that goes because when we go will make a difference.

GOLF-1 Mission
The goals for GOLF-1 are the same as GOLF-TEE that are, hopefully, developed quite well. In the meantime, though, if there are things with the construction or during the on-orbit phases, then hopefully we will have time to make adjustments to improve on things. That’s always the way you want to go with a series of similar satellites.

This will be a typical mission versus the technology mission that GOLF-TEE is. We will carry STEM, educational based experiments. We have a high school in the San Diego area that wants to fly a camera for earth weather views. We’ll fly the Vanderbilt/ISDE Student Radiation Experiment again because there are a lot of students who like to put those together and write papers.

We’ll expand the microwave/SDR experimentation. We’ll open up the Five and Dime – that’s the 5 GHz uplink to 10 GHz downlink. Of course, at LEO it is tricky at best. Nonetheless, it will be there for experimentation with GOLF-1.

The S-Band/X-Band transponder – 2.4 GHz uplink and 10 GHz downlink (a la QO-100) – will be available.

And, we have a L-Band 1.2 GHz uplink possibility. We aren’t certain what that will be used for, perhaps commands. It’s not a worldwide band so depending on resources, we’ll probably concentrate primarily on the other bands.

Again, we’ll have a standard V/U transponder operation. However, it will be the SDR, not the LTM so it gives us the opportunity to make the transponder a variety of things such as an FM repeater or a linear transponder.

Readiness Dates
The target Readiness Date for GOLF-TEE is December 1, 2025. The Readiness Date indicates to NASA that we are ready to hand it over for integration. Integration is the activity when the satellite is put into the dispenser that then goes to the rocket. NASA holds off basically until our CDR, or Comprehensive Design Review, which will be March 2025 and looking at that readiness date in order to judge when to find a good launch for us.

The integration is typically 45 days prior to launch therefore we would not see a launch until early 2026. But it could happen that fast as they have been pretty good at lining up some launches.

For GOLF-1 the Readiness Date would be a year later, December 27, 2026. Again, we want to look at everything we can learn from GOLF-Tee and put it into GOLF-1 and make it better.

GOLF-2 and Beyond
From GOLF-2 and beyond the push for opportunities, and I say it is a good push, opportunities for higher than LEO are going to require specialized systems. We know that and is why GOLF-2 will be testing more of these systems.

The deorbit devices are just coming to commercial availability in CubeSats which is very good. They were not available until just recently. We saw at the CDW, CubeSat Developers Workshop quite a few companies with some items coming out that are helpful to us. We have a team looking at thrusters and propulsion in the ASCENT group, ASCENT meaning Advanced Satellite Communications and Exploration of New Technology.

These things can be mastered, I like to use that word, developed and mastered in LEO. We’ll be careful about what we fly so it will be a successful mission as we go for those higher and more expensive orbits.

[ANS thanks Jerry Buxton, N0JY, AMSAT VP-Engineering for the above information.]

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Ham Satellite news

Setting Up Your Own Satellite Ground Station with SatNOGS

This is a repost from ANS-154:

Robert Theiss, W5ITR, had the pleasure of interviewing Dan White, ADØCQ, from the Libre Space Foundation at the 2024 Dayton Hamvention about their innovative SatNOGS project. This initiative enables anyone to set up a satellite ground station, collect valuable data, and contribute to global satellite operations. You can watch the interview here on the Digital Rancher YouTube channel: https://www.youtube.com/watch?v=edNfD_YXZps

Dan explained that SatNOGS provides detailed blueprints and documentation for building a satellite ground station from scratch. The foundation offers the necessary software, identifies accessible hardware, and maintains the infrastructure that allows citizen scientists to engage in satellite-related sciences. Their vision of making outer space open and accessible through open-source technology is truly inspiring.

Setting up a basic SatNOGS station is surprisingly straightforward. All you need is a Raspberry Pi and an RTL-SDR dongle. Dan explained the process: the Libre Space Foundation provides a ready-to-use image for the Raspberry Pi, which includes the operating system and necessary configurations. You just create an account, register your station, and schedule a test observation.

Robert Theiss, W5ITR, interviews Dan White, ADØCQ, with Libre Space at the 2024 Dayton Hamvention. [Credit: Robert Theiss, W5ITR]

For those looking to enhance their setup, SatNOGS offers extensive documentation on building antennas and integrating additional components like low noise amplifiers and band pass filters. Although they plan to offer kits in the future, you can currently follow the detailed instructions and suggested links available on the SatNOGS Wiki: https://wiki.satnogs.org.

One of the most fascinating aspects of SatNOGS is its network of interconnected ground stations. Once your station is set up, it can schedule satellite passes and collect data, even while you’re asleep. This data is shared across the network, allowing other users to access it, and vice versa. This system ensures continuous monitoring and data collection, maximizing the utility of each station.

The SatNOGS community is highly active and supportive. The forums on the Libre Space Foundation’s website are a great resource for troubleshooting, sharing experiences, and staying updated on new satellite launches and developments.

Dan White, ADØCQ explains the makeup of their SatNOGS Demonstration Ground Station. [Credit: Robert Theiss, W5ITR]

For those interested in taking their ground station to the next level, SatNOGS supports more advanced setups with full azimuth and elevation rotators and larger antennas. These setups, while more costly, significantly increase data collection capabilities and overall performance. The Raspberry Pi used in the basic setup can interface with these advanced systems, allowing for automated tracking and data collection.

Dan shared insights into practical aspects such as bandwidth requirements and equipment wear and tear. While the data collected by a SatNOGS station can be bandwidth-intensive, there are settings to optimize for lower bandwidth situations by disabling audio uploads. Additionally, proper setup and maintenance of antennas and rotators can ensure long-term operation without significant issues.

The Libre Space Foundation and its SatNOGS project provide a unique opportunity for anyone interested in satellite and space communications to get involved. Their open-source approach and comprehensive support make it accessible even for beginners. Setting up your own satellite ground station is a rewarding experience, contributing to global space exploration and satellite communication. Check out the resources at https://satnogs.org and get involved!

[ANS thanks Robert Theiss, W5ITR, for the above information]

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Ham Satellite news

AMSAT Italia Enters Into the Ownership of IO-117 “GreenCube” Satellite

Re-posted from ANS-123:

Rome, April 30, 2024 – AMSAT Italia is proud to announce the acquisition of the quote of property of the IO-117 “GreenCube” satellite. The other part of the property remains on behalf of “Sapienza University”, Rome, Italy.

A collaborative work of the parts will let the satellite continue the amateur radio operations after the completion of the primary scientific mission. This will definitively avert the satellite decommissioning process by transferring the legal responsibility of the satellite from the Italian Space Agency to AMSAT Italia. Even formally and legally, the satellite, already known with its original name of GreenCube, becomes for the exclusive use of amateur radio. The scientific community continue the study of the behavior of this type of satellite placed in MEO orbit.

GreenCube was designed and developed by Sapienza University, ENEA and University of Naples Federico II for the Italian Space Agency. AMSAT Italia contributed to design the digipeater and supported amateur radio operations. IARU coordinated the use of the operations in the amateur radio frequency bands.

The satellite was carried on the qualification flight of Vega-C launcher on July 13, 2022 from the French Guiana Space Center in Kourou. On October 29, 2022, the on-board digipeater was activated, allowing GreenCube to become the first ham radio satellite to operate in a MEO orbit. Being a radio amateur worldwide success, AMSAT officially designated the satellite as Italy-OSCAR 117 (IO-117).

AMSAT Italia and Sapienza Space Systems and Space Surveillance Laboratory – S5LAB- are now committed to operate the satellite and to continue to offer the service to the amateur radio community.

For further information please contact AMSAT Italia at segreteria at amsat.it

The original press release can be found at https://www.amsat.org/wordpress/wp-content/uploads/2024/05/AMSAT_Italia_acquires_the_IO-117_Greencube_satellite.pdf

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Ham Satellite news

AO-109 Re-enters

Re-posted from ANS-119:

AO-109’s orbit decayed on or about April 21, 2024 after just over three years in space.

Launched on January 17, 2021, as part of the ELaNa 20 mission using a LauncherOne rocket operated by Virgin Orbit, AO-109, known prior to launch as RadFxSat-2 / Fox-1E, was carried aloft by a modified Boeing 747 named “Cosmic Girl” from the Mojave Air and Space Port in California, United States. After reaching an altitude of approximately 35,000 feet (11,000 meters), the rocket was released into space. This launch, conducted under NASA’s CubeSat Launch Initiative program, marked the beginning of the satellite’s mission to facilitate amateur radio communications and technology research. A video of the launch can be seen on YouTube.

AO-109 represented the fifth iteration of the “Fox” 1U amateur radio satellites series developed by AMSAT, featuring a 30KHz linear transponder radio.

After launch, AMSAT’s Engineering and Operations teams listened for the expected beacon signal, but nothing was initially heard. On January 27, 2021, Brad Schumacher, W5SAT, was able to hear his weak CW signals relayed through the satellite’s transponder. This was confirmed by AMSAT Engineering and Operations the next day and the satellite was designated AMSAT-OSCAR 109. Continued monitoring confirmed that the satellite was operating properly, but with an extremely low signal output. It is likely that the satellite’s final power amplifier transistor failed, limiting power output to just 8 mW.

Although the signal was extremely weak, the satellite was able to support QSOs by CW, FT4/8, and even SSB. Five amateur stations successfully copied the weak telemetry signal from the satellite and provided valuable data about the health of the satellite: the PI9CAM radio telescope in Dwingeloo, Netherlands, provided the bulk of the data from the satellite. WA7FWF, W7KKE, K8DP, and the AMSAT Operations team also copied telemetry.

Upon being declared operational and open for amateur use, despite the limitation of its low power output, on July 20, 2021, AO-109 embarked on a mission to serve both amateur radio and technology research objectives.

The final telemetry data was received on April 5, 2024 from PI9CAM and revealed that the satellite had achieved a remarkable milestone: AO-109 had set a new Fox-1 program record for processor uptime. This information was gathered by Alan Biddle, WA4SCA, who has meticulously monitored telemetry reports on a daily basis and calculated the duration of each reset, allowing for precise correlation of telemetry frames with UTC time.

The Fox satellites are designed to undergo onboard computer resets triggered by factors like radiation exposure and low battery voltage. Time on these satellites is measured by counting resets plus the duration since the last reset. It is common for the Fox satellites to reset every few days or weeks, especially when passing over the South Atlantic Anomaly. However, the processor on AO-109 ran continuously from September 2023 until at least April 5, 2024, accumulating over 18 million seconds of uptime—far surpassing any other Fox satellite.

Among its key payloads was the RadFx-2 experiment, a collaboration with Vanderbilt University, aimed at studying the effects of space radiation on specific SRAM types. Consistent with the Fox-1A design blueprint, AO-109 was equipped with a 2-meter whip antenna and a 70 cm whip antenna.

The linear transponder module developed for AO-109 also evolved into a program to equip other CubeSats with linear transponders. Evolutions of this transponder previously flew aboard HO-107 (HuskySat-1) and the next one is scheduled to fly aboard MESAT-1 later this year. AMSAT’s GOLF program will also carry this linear transponder module for VHF/UHF communications.

[ANS thanks AMSAT Operations and Engineering for the above information]

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Ham Satellite news

AMSAT-DL next generation of a GEO/MEO amateur radio payload

AMSAT-DL has released their proposal about next generation GEO/MEO payload. AMSAT-DL’s proposal is written by the authors Kai Siebels, DH0SK and Matthias Bopp, DD1US. The proposal takes into account the technical requirements and needs of radio amateurs. Various aspects such as orbit, satellite and platform as well as payload are taken into account.

Please see: https://amsat-dl.org/en/the-next-generation-of-a-geo-meo-amateur-radio-payload/

Categories
Ham Satellite news

AO-73 transponder active

Strong but fading signal. See video clip for example.