Smallest fully functional space probes now in orbit are precursors to interstellar chipsats

Breakthrough Starshot plans to launch a fleet of tiny interstellar chipsize probes to Proxima Centauri in 30 or 40 years. Small chip probes have been launched into low Earth orbit on June 23. Sprites are ‘satellites on a chip,’. Research performed by Mason Peck and his team at Cornell University included Breakthrough Starshot’s Zac Manchester Zac used a Kickstarter campaign to develop the concept in 2011.

These are the smallest fully functional space probes ever put into space. Each 3.5-by-3.5 centimeter probe built upon a single circuit board and weighing in at just four grams. A Sprite can contain solar panels, computers, communications capability and an array of sensors. The tiny spacecraft’s electronics all function off the 100 milliwatts of electricity each generates.

Russian entrepreneur Yuri Milner has put $100 million into funding the first five years of the Breakthrough Starshot project. Th goal is to develop chips with a weight of roughly one gram and fit them to a lightweight sail before propelling them through space with a 100-billion watt laser.

“The reason one needs to push the weight down is because in order to reach the nearest stars within our lifetime, the spacecraft needs to move at a fraction of the speed of light – a fifth of the speed of light or so,” said Loeb.

If a Sprite could be made thin enough, then its entire body could act as a solar sail. We calculate that at a thickness of about 20 micrometers—which is feasible with existing fabrication techniques—a 7.5-mg Sprite would have the right ratio of surface area to volume to accelerate at about 0.06 mm/s2, maybe 10 times as fast as IKAROS [the Japanese solar sail]. That should be enough for some interplanetary missions. If Sprites could be printed on even thinner material, they could accelerate to speeds that might even take them out of the solar system and on toward distant stars.

Breakthrough Starshot executive director Pete Worden refers to Sprites as ‘a very early version of what we would send to interstellar distances,’ a notion that highlights the enormity of the challenge while pointing to the revolutionary changes that may make such payloads possible. The issues multiply the more you think about them — chip-like satellites in space have no radiation shielding and are susceptible to damage along the route of flight. But missions like these will help us analyze these problems and refine the technology.

Two Sprites are currently glued to the outside of the Latvian Venta satellite and the Italian Max Valier satellite, small systems built by the Germany-based company OHB System AG and launched together in June.

Four Sprites are also travelling inside the Max Valier satellite and are designed to be released into space – although that plan is up in the air given a technical hitch in communication with the Italian satellite.

Mason Peck has proposed letting Sprites become charged through plasma interactions and then using a huge magnetic field like Jupiter’s as a particle accelerator to push the chips to thousands of kilometers per second.

Consider communications. In an email yesterday, Mason Peck told me that the Cornell team has juiced up the networking capabilities of the tiny spacecraft. “Now we have them talking to each other in a peer-to-peer network, and this demonstration shows how they synchronize like fireflies,”