What if the Voyager Space Probe Could Send Data Back For Another Few Billion Miles?

The biggest challenge of sending anything into space is that once it’s gone, it’s gone. You can’t send a guy with a screwdriver up, fly past Jupiter, and fix or change something. It costs a lot of money to build and launch a spacecraft. Yet, they aren’t accessible for any amount of money once they clear the launch pad.

Let’s return to the question: Why did the Voyager stop sending photos and is only sending a trickle of data? Wouldn’t it be great to keep the science data flowing, and even see some images as it ventures farther into space?

The reason is simple: it can’t. 

As the spacecraft started to run out of power, ground control had to turn off equipment on board one by one. If a once-in-a-lifetime astronomical selfie-worthy event happens, we’re out of luck.

But we aren’t just talking about Instagram-worthy moments for us earthlings. Unplugging the scientific instruments could mean we’re missing out on a stream of data that may eventually lead to a better understanding of the universe.

So, we need to solve the power problem. 

But spacecraft, like satellites and deep-space probes, don’t have many options for where their power comes from and gets stored. Practical options are limited to radioisotope thermoelectric generators (RTGs) for deep space applications, and solar cells (photovoltaics, or PV) for things that stay close to the sun (astronomically speaking.) Both can only count on batteries for energy storage. Unfortunately, all three deteriorate and eventually fail. 

While we can’t defy the law of physics (i.e., the power sources will deteriorate), we can radically increase the system's reliability, fault tolerance, and longevity. 

Let’s say a spacecraft has a 28-volt, 100-amp power bus. As a traditional power system ages, the 100 amp limit must be progressively de-rated to avoid brownouts — impacting the system’s performance and preventing some instruments from functioning. 

But it doesn’t have to be that way. Imagine a battery pack that can fulfill all the original specs even decades after launch (except for one, more on that later). Such an unthinkable objective is now perfectly achievable with software-defined batteries (SDBs).

SDBs built on the Tanktwo Battery Operating System (TBOS) can support most devices to work as intended. The software consolidates the available capacity into slow bursts so the system can retain close to 100% of the original functionality. If a once-in-a-lifetime event occurs, we'll have the power to capture the details with the desired fidelity.

Let’s start from the beginning to understand how that works.

Challenges of current spacecraft power systems

Most of today’s spacecraft energy systems involve batteries. They gradually deteriorate, reducing power over time. If one battery cell fails, systems often follow a step decay curve — removing a chunk of cells from the circuit and hastening the deterioration of the entire system. 

This is the most common way an earth-orbiting satellite fails. In a best-case scenario, ground control must switch off instruments in phases to avoid overloading the system, but more commonly, satellite functionality is completely lost. 

But that isn’t the only problem. 

You can’t change anything once a spacecraft is launched. Therefore, aerospace engineers must spend an enormous amount of time planning and testing every component on the ground, including the battery and power system. These cycles take years, even decades, to complete. By the time a spacecraft is ready, the technologies often become obsolete.

Also, the inability to adapt the system in-flight (e.g., directing more power to a specific instrument for higher performance functions) hampers the flexibility to pivot and respond to new research insights or scientifically significant events. 

Here’s an example of how such adaptability works: A Doppler radar-equipped satellite can be given a power reserve in its radar transmitter, so when an unusually dense hurricane system develops, the radar can temporarily be "turned up to 11.” The battery will be able to support the exceptional power demand and revert to optimal efficiency configuration afterward.

Maximize lifecycle value with granular control over spacecraft power systems

Software-defined batteries are the small hinge that moves a big door in aerospace technologies. TBOS offers unprecedented reliability, configurability, and data-driven insights to maximize the value each spacecraft delivers over its lifespan.

Maximum performance, reliability, and longevity

A TBOS-driven battery solution treats each cell as an individual unit. Our proprietary Dycromax™️ architecture bypasses failed ones so the system can keep operating until the last cell reaches its failure point. The technology also prevents fluctuations in output as power sources deteriorate — inevitable in traditional battery technology — to deliver reliable performance. 

TBOS ensures a system can operate at its maximum power point to run the required applications at all times, regardless of the status of the RTG, solar panels, or battery cells. Each component can work at the highest efficiency — from cradle to grave.

By tracking the state of health (SoH) of each battery cell, TBOS can yellow-flag those at risk of failure or thermal runaway events. It will disable these cells to maximize the system’s safety without compromising the overall power output and performance. 

Moreover, system designers can mix and match cells to meet specific requirements. For instance, they can combine cells with endurance benefits with those best for delivering bursts of power to improve longevity while increasing the maximum power output of a battery pack to get the best of both worlds.

Ongoing system reconfigurability

Let’s go back to Voyager’s challenges. Only a few instruments are still functional due to a decaying RTG a decade after launch. The situation would be completely different with an SDB system, which enables ground control to reconfigure the system via software upgrades (like updating a smartphone) as long as there’s communication. 

So the “2024 edition” of the power system may see the RTG decay to 25% and some deteriorated or failed cells in the battery pack. But it can still deliver power at an elevated level to achieve specific scientific objectives when needed.

This capability allows operators to increase endurance and extract maximum value from aging power sources. They can program batteries to reconfigure themselves automatically and provide controlled bursts of power to meet the original specs, despite the deteriorating physical assets.

For example, the system can accumulate enough power to support a camera for 3 hours a day instead of switching it off altogether — trading instantaneous performance for overall energy density. Instruments can take turns to become active at the right moment. As a result, the spacecraft can preserve all capabilities for much longer until hard failure.

TBOS reconfigurability can also support the communication system: Talking to a deep-space probe like the Voyager requires massive dishes and the most sensitive receivers. An SDB-powered spacecraft can temporarily reconfigure its architecture to provide higher voltages during telemetry downlink for increased transmitter power. The extra few dB of margin will enable us to communicate with the spacecraft for several billion extra miles.  

Additionally, TBOS collects the lifecycle index of each power source, including individual battery cells, and communicates the data to ground control. It can decide when to activate which instrument and for how long by balancing factors such as importance to the mission, power consumption, stability requirements, etc., to optimize resource allocation and achieve the mission’s goals.

Mission-planning flexibility

TBOS makes it possible to respond to shifting circumstances from afar and maintain complete control of the power system. Since ground control can change the system’s configuration on the fly, the mission isn’t locked into decisions made pre-launch.

In fact, most decisions regarding the power system can be reversible or adjusted to respond to new scientific insights, shifts in priority, or external events. 

The software-defined nature allows mission control to fine-tune operational parameters and push new technologies or upgrades post-launch. The ability to respond on a dime means you don’t need to test a system for 10, 20, or 30 years to understand its behaviors before sending it to space.

As such, operators can adopt new technologies with minimum risks to achieve better performance at a lower overall cost. (This case study discusses how we helped a primary defense contractor use commercial off-the-shelf components in its vehicles and equipment.)

Additionally, TBOS’s power source agnostic approach means you can respond to changes (e.g., new battery chemistry) without reconfiguring everything else — making it possible to adopt new technology without extensive lead times. 

Reimagine what’s possible

It’s, of course, not possible to distill humanity’s combined efforts in interstellar science into a few paragraphs. Plus, aerospace technologies come in many flavors, and we appreciate the differences between a deep space probe and a low-earth orbiting satellite.

Many instruments in deep space probes are thermally limited. No software can fix the power required for heating — it’s just physics. But a better power system can open up more deep space exploration opportunities by increasing the longevity and flexibility of the system.

Meanwhile, there’s a growing number of satellites with dead batteries orbiting Earth — they would be functional for much longer if we could just bypass a few bad cells to keep the power system humming along.

Most instruments on a spacecraft require electricity to operate, whether they’re just 300 miles overhead and barely outside of the atmosphere or a couple of billion miles outside of the heliosphere.

By overcoming the constraints of conventional power solutions, software-defined batteries can help accelerate the development of aerospace technologies while making existing systems work harder, longer, and more reliably to achieve mission goals more effectively.