This fall, we’ve had the unreal pleasure of listening to the satellite we built transmit from space. But we aren’t resting on EQUiSat’s success – it’s propelling us into a new chapter of the club’s history. We’ve increased our number of active members since last year and launched our third high altitude balloon. We have also decided on the core mission for our new satellite which we’re excited to announce later in this post!
EQUiSat Status and Research
We are elated to share that we have been hearing from EQUiSat almost continuously since it launched on July 13th. We’ve gotten megabytes of data from it that we’ve had lots of fun analyzing. The satellite passed through several critical phases of its mission with no major setbacks, from a successful antenna deployment to a successful charging and recharging of all its battery banks, to its first successful flash and transmission of crucial flash data! These observations and data will be essential for our research on EQUiSat’s batteries and general mission performance.
Due to a software bug EQUiSat only flashed for a few hours every couple of weeks during the most active portion of its mission, so we haven’t gotten reports that anyone has seen it yet. However, the data we’ve received confirms that it did flash periodically and that the experimental LiFePO4 batteries perform well in space!
Unfortunately, this period of intermittent flashing ended around the beginning of September with a large drop in the percentage of time EQUiSat spends in the sun, resulting in decreased temperature and battery performance (in addition to normal degradation in battery efficiency). EQUiSat has remained in its low power mode almost exclusively since then.
The Future of the Mission and Seeing EQUiSat
Our understanding of the satellite’s past performance came from a recent analysis of EQUiSat’s daily hours spent in the sun (related to a satellite’s “Beta Angle”) by Ladd Observatory curator Michael Umbricht and members of the club, and helps us predict the future performance of EQUiSat.
The graph below shows EQUiSat’s daily sun exposure over time. The large peak in exposure in July and August correlates strongly with EQUiSat high temperature and performance during the initial phase of the mission, while the low exposure during the past few months explains the satellite’s reduced performance. Luckily for us, there is a global maximum of sun exposure coming in December followed by another large peak in February, so there is a chance EQUiSat will heat up, charge its batteries, and resume flashing!
If this peak in sun exposure in December results in EQUiSat flashing again, we will call on you and everyone around the world to try and see EQUiSat! We learned from the initial phase of the mission that a concerted effort by people around the world will be needed to see it, and we’ll be doing everything we can to achieve this!
Be sure to read up on how to see EQUiSat at http://brownspace.org/viewing-equisat. You can also keep up with EQUiSat with our tracking app, available on the iOS App Store, Google Play, and at http://equisat.brownspace.org. If you want to learn more about EQUiSat’s mission analysis, Michael Umbricht has been producing amazing blog posts on the subject (for which we are very grateful!).
We’ve been hearing from EQUiSat via our small ground station network. About 75% of the data has come from a motorized (satellite-tracking) station at La Sapienza University in Rome, which we were able to use thanks to the generous help and support of the university and its staff. We’d like to thank in particular Gianluca Palermo who handled much of the station’s configuration, Paolo Gaudenzi who was instrumental in obtaining the money and support for the station, and our own faculty advisor Rick Fleeter who made these connections and supported us in Rome. We’re extremely grateful for their assistance and were quite saddened to hear that their station was partially destroyed in a recent storm – the roof of the building housing its electronics blew off!
As such, we’ve been hard at work on our station at Brown. We currently have a small omnidirectional antenna that’s providing us with small but consistent amounts of data, but we’re working on a motorized station to hear from EQUiSat even when it’s just barely above the horizon and several thousand miles away.
We’ve also been extremely fortunate to be supported by the Amateur Radio community around the world. HAMs (as they are called) have sent us transmissions from around the world and were instrumental in the early stages of the mission. If you’re interesting in hearing EQUiSat yourself over the radio (even if you know nothing about radio), check out our page at https://brownspace.org/receiving-equisat/ for info on getting started!
We have also been using the fantastic SatNOGS network project, consisting of a large network of internet-connected ground stations, to check up on EQUiSat around the world (though it cannot decode EQUiSat’s data yet – we’re working on that too). We also recently connected our own software-defined radio to the SatNOGS network to play our part in receiving other satellites for the SatNOGS community!
We are excited to announce the concept of our next satellite – a deployable robotic arm! No robotic arms have flown on CubeSats and none of the current proposed designs are open source. CubeSats could benefit from robotic arms for a variety of reasons from self-inspection to attitude control and we can’t wait to explore the ramifications. Just like EQUiSat, all of our designs will be open source and as cheap as can be – we hope to keep costs for this satellite under $5,000 again.
In early October, we launched our third high-altitude balloon. It was testing deployable solar panel technology for the first time. Unfortunately, the solar panels did not deploy and our livestream was cut short due to thermal failures. We learned a valuable lesson – everything needs to be tested in low temperature, no matter how small! The balloon team is hard at work prototyping their next project – they’re currently deciding between payloads that would test a robotic arm prototype or listen to EQUiSat from the air.
Fulfilling EQUiSat’s primary mission, we’ve also kept up on outreach. We have tabled at Ladd Observatory’s Open Tuesdays and sent members to present to a couple of schools in the Providence area. We also had an EQUiSat listening party at Waterfire’s Big Bang Science Night, and hope to hold more listening sessions on Brown’s campus in the coming months. One night we hope to see it flash!