This is a picture of the smallest satellite yet to be launched into orbit around Earth. If all goes well, it and 103 identical siblings, known as sprites, will be scattered into space on May 4th from a mother ship (itself a mere 10cm by 10cm by 30cm) that rode shotgun on a rocket put up last month by SpaceX, a private rocketry firm, to resupply the International Space Station. These sprites, which weigh 5 grams and cost $25 a pop, are the creation of Zac Manchester of Cornell University. Each has a microprocessor, a radio powerful enough to transmit a message to Earth, two aerials, a solar cell, a magnetometer and a gyroscope to tell the satellite in which direction it is pointing. Though this is just a test, paid for by a campaign on Kickstarter, a crowdfunding website, and launched gratis by NASA, SpaceX’s customer for the resupply mission, Mr Manchester thinks clouds of sprites could have real applications. Swarms of magnetometer-armed sprites might, for example, be a cheaper and more comprehensive way than existing satellites of monitoring the ebb and flow of charged particles that constitute space “weather”, which sometimes interferes with telecommunications back on Earth.