ChipSats—Hoards of Tiny Circuit Boards Sent to Space (or Attached to Cows)
The size of a postage stamp, ChipSats form a sensor network to carry out tasks of larger satellites.
In the summer of 2019, Stanford and NASA announced that they launched a swarm of 105 tiny satellites the size of a computer chip into Earth’s orbit.
Example of the types of ChipSats sent into orbit. Image used courtesy of L.A. Cicero and Stanford News
What's surprising about this chip isn't only its humble beginnings. Since its initial launch into space, developers have used the chip for orbital edge computing and communicating atmospheric conditions to agricultural workers back on Earth.
Where It All Began
Stanford scientist Zac Manchester imagined a world of chip-scale satellites, otherwise known as ChipSats, while still a PhD student at Cornell University.
A ChipSat is a circuit board about the size of a postage stamp. When working in a network, ChipSats can carry out the tasks of larger satellites. One key advantage of ChipSats is that they can be sent out in large numbers and cover large areas around the Earth.
Each ChipSat uses solar cells to power the main systems, which include the radio, microcontroller, and sensors that locate and communicate with one another.
In 2011, Manchester began crowdfunding for ChipSats on Kickstarter (better known as KickSat at the time) and raised about $75,000. His goal was to “make it easy and affordable enough for anyone to explore space.”
Zac Manchester holding a ChipSat, a product of many years of experimentation and development. Image used courtesy of L.A. Cicero and Stanford News
Before the successful launch made headlines, 100 ChipSats were sent into space in 2014. However, a glitched caused them to reenter the atmosphere and combust before they were deployed.
Five years later, however, Manchester’s team deployed ChipSats into low-orbit around the Earth. The ChipSats then detected signals they sent to one another.
A few months later, on June 3rd, the NASA Ames Research Center announced the deployment of the largest swarm of ChipSats in history.
Orbital Edge Computing
The most recent development in Chipsat comes from Brandon Lucia and graduate students at Carnegie Mellon University, who are pushing Manchester's ChipSats even further.
As of December 2019, Lucia’s lab was developing a computer unit on-chip for “orbital edge computing.” We have previously looked at the power of edge computing, and its impact in space is similar.
Because Chipsats are constantly orbiting Earth, they lack a continuous power supply, making them an intermittent computing platform. Orbital edge computing eliminates the delay between when sensor data is collected and when the data is processed because the processing units are co-located with the sensors.
This local processing increases the responsiveness of sensors, which can be a huge asset when these devices are collecting data for disaster relief.
Orbital edge computing on ChipSats eliminates the delay of processing sensor data. Screenshot used courtesy of Carnegie Mellon University
Although the flight dynamics of Chipsats are fundamentally different than CubeSats, which are essentially miniature satellites, both devices include similar hardware that processes the sensor data they collect.
The systems developed at Lucia’s lab apply machine learning inference algorithms to come to useful conclusions based on collected sensor data. Lucia's research identifies sensed signals of interest without using the satellite's radio.
The ChipSats and CubeSats collect energy from their environment and only operate when enough energy is collected, which requires specialized software and hardware.
They can then share the work of collecting and processing sensor signals, creating a network of orbital edge computing devices to support missions that aren’t possible with traditional satellites.
ChipSats (or "Monarchs") Beyond Space
While ChipSats change the way we look at space exploration, they can also have an impact here on Earth. Doctoral student Hunter Adams is using ChipSats to monitor and harvest environmental data and help agriculture workers make informed decisions about growing crops and caring for animals.
Adams states that ChipSats are perfect for “anytime you’re trying to study something that changes significantly over space and over time” because the devices act as a “big distributed sensor when dozens or hundreds of them are deployed simultaneously.”
Adams modified the ChipSats—or as he refers to them, "Monarchs"—and attached them on collars placed on newborn calves.
The Chipsats then survey agricultural conditions like temperature, humidity, and ambient light to gather data about whether these factors affect respiratory conditions in the calves.
Adams also used the Chipsats throughout a grape vineyard to assess how different environmental conditions monitored by the sensors affected growth conditions.
Hunter Adams checks a Monarch for environmental data the device has sensed in a vineyard. Image used courtesy of John Munson, Cornell University
In July 2019, 20 Monarchs were deployed at Anthony Road Vineyard in Penn Yan, New York, followed by another set of 20 at the Cornell Teaching Vineyard in Lansing, New York.
The readings from the Monarchs showed differences of up to 6 degrees Fahrenheit from the readings at the weather station, a factor that Adams said could affect a maintenance decision on a vineyard or at a dairy farm.
A Monarch fastened to a calf at Sunnyside Farm in Scipio Center, New York to monitor conditions that may affect the cow's respiratory health. Screenshot used courtesy of John Munson, Cornell University
The Monarchs include many sensors and position trackers, including a GPS, magnetometer, gyroscope, an antenna, and even electromagnets that allow the devices to change their orientation using Earth’s magnetic field. Similar to ChipSats, Monarchs can be mass-manufactured at an inexpensive rate, roughly $50 apiece.
There are many skeptics of ChipSats/Monarchs, questioning their ability to collect quality data, despite harsh conditions like radiation.
While Adams acknowledges these concerns, he also points out that ChipSats and Monarchs can be sent out in large quantities (because of their affordability), which allows them to gather many data points at once.
He also believes that even if the data rate is low compared to a conventional satellite, the rate is competitive with commercial satellites.
ChipSats bring innovation to several fronts—both on Earth and in space. Yet these devices still face challenges that can be improved through continuous hardware development. Have you worked with chips built for space? Share your experiences in the comments below.