When we left off, Binar-1 had been in space for weeks, and the team was yet to hear from the satellite. They’d figured out a plan to enable its radio chip remotely, but a new discovery started a race against the clock.
Stuck in a loop
Some experiments with our engineering model – our identical replica of Binar-1 here on the ground – soon turned up a new problem.
“We ran some more numbers on how much power we’d been drawing,” says Dan. “It turns out we were consuming more power than we thought.”
Binar-1 had enough in its batteries to keep it running for the first week or so, but eventually that extra power usage would run the batteries dead.
The solar panels would eventually charge it up again, but each time it ran completely flat, it would ‘forget’ that it had been deployed.
“It will run all of those high power circuits to try to deploy its antennas again and that is a massive power drain.”
“We’re essentially charging from flat, for 24 hours. And then we will try to deploy the antenna, and it’s just draining us back to zero, and it kills the circuit and then we start again,” says Dan.
“There’s a chance that it might not say anything at all… because of one oversight that happened during the rush to get everything shipped out to JAXA.”
“We don’t know if it’s on, or listening. We’re not really sure.”
This meant going back to basics. We had to see if Binar-1 was still powering up at all.
“If the satellite mainboard was working, it would turn on the communications module. Even if it’s in the 24-hour charge loop, the communications module will be on and listening,” says Dan.
“Then, even though it’s not in the mode where you could talk to the satellite itself, you could maybe try and talk to the communications module.”
The communications module had its own built-in beacon, which could send out a signal every few seconds independent of Binar-1’s computer. And, just like the switch to pipe mode, we could enable it from the ground.
It would be a bit like a reflex test. Even though Binar-1 wasn’t talking, we could still check whether it was alive.
Some quick excursions to the roof with our engineering model confirmed that the new ground station code was working, and that if even a single antenna was deployed, it should be possible to get a signal back from Binar-1.
It was time to try talking to space.
Binar-1 had been in space for almost three weeks now, and would be making a good pass over Curtin on Thursday, October 21.
It would pass right overhead, within about 500 kilometers of the ground station – very close in radio terms – so the signal that it would hear would be much stronger. If we were going to hear from Binar-1, and if it was going to hear from us, this was the time to do it.
With the rest of the team busy on the design reviews for Binar-2, the task of enabling Binar-1’s backup beacon fell to Dan.
“It was about 5:30pm, and I was on my way home. I told my partner, ‘can you please drive, I need to be online to tell the satellite to try something new.
“So Louise is driving, and I’m just slowly getting sick because I can’t really look at my laptop while in the car, and I send the signal.”
The first few tries, we saw nothing.
“We were kind of expected to see nothing.”
“This was like two weeks in. We’d almost lost all hope, we didn’t know that this was going to work.”
“And then I sent it again, and I saw something that looked like the tests we did on the roof.”
“So I waited. I didn’t send anything else. I couldn’t get my hopes up. But I saw it again. And it was where we expected our signal to be.
“Sometimes it would be stronger, sometimes it would be weaker, but we could actually see a signal so that was – yes, it’s powered, it’s alive! It’s awesome.”
Even though it wasn’t full contact with the satellite, this was huge. It meant we could meant we could start testing why we’d ended up in safe mode, how often our batteries were running down, and turning those in to improvements for our next launch.
“The comms module wouldn’t be on if the satellite mainboard wasn’t turning it on. We know that the software works. It turns things on, it works. We know the battery works. It cuts things off and on when it needs to.”
The Satellite Village
Getting in touch with Binar-1 wouldn’t have been possible without the help of a whole lot of other satellite operators.
“The satellite operations community is like a small village. If there’s a problem, everyone comes to help,” says Dan. “It’s been awesome to be a part of.”
In particular, we particularly want to thank ESA collaborators running the ESOC SMILE facilities in Darmstadt, UNSW Canberra Space, and UniSA’s ITR, for going out of their way to get data from our first passes to us, and to Space Catapult/Goonhilly along with friends at Fugro and Telstra, who were preparing transmitters to help us wake up Binar-1 from the ground – even if it meant breaking through to undeployed antennas.
And thanks to the WA community, for getting behind us! Everything we’ve learned from Binar-1 will make our next launch even better. We’re in space to stay, and we can’t wait to take you along for the ride.