Time is running out for tiny crowd-funded space mission
BY STEPHEN CLARK
Posted: May 5, 2014
An experimental space mission launched last month has hit trouble, and the project's team is worried the crowd-funded spacecraft will burn up in Earth's atmosphere before releasing a swarm of tiny satellites the size of poker chips.
The KickSat satellite, itself no bigger than a desktop toaster oven, was supposed to spring-eject 104 printed circuit boards May 4 on the command of an automatic timer.
But the daughter satellites, dubbed sprites, never deployed from KickSat. Cornell graduate student Zac Manchester, who leads the project, wrote in a blog posting that KickSat's microcontroller reset April 30, likely due to a high dose of radiation.
The "hard reset" caused KickSat's master clock to restart its 16-day countdown before issuing the order to release the sprites. The timer first initialized when KickSat separated from its Falcon 9 launcher April 18.
Engineers incorporated the 16-day timer to ensure the sprites would not endanger the International Space Station and other satellites.
After the microcontroller reset, deployment of the handmade sprites is now expected May 16, assuming KickSat is still in orbit.
Using data supplied by the U.S. Air Force, which tracks all objects in orbit bigger than a baseball, KickSat volunteers predicted Monday that KickSat would re-enter Earth's atmosphere May 14, with an error of plus-or-minus three days.
KickSat's drag coefficient coupled with its low altitude limits its lifetime in orbit.
KickSat is based on the CubeSat platform, a standardized small satellite form factor used by universities, commercial companies and government agencies to reduce the cost of space missions.
"We've spent the last couple of days here at Cornell trying to think of every possible contingency, but it seems there aren't very many options right now," Manchester wrote May 3 on KickSat's Kickstarter page. "KickSat's uplink radio, which we could use to command the deployment, can't turn on unless the batteries reach 8 volts, and it doesn't look like they'll reach that level in time."
KickSat was designed to keep its main flight computer, based on a smart phone, switched off when power levels in the batteries drain below a certain level.
"While the situation looks a little bleak, there is still some hope that the batteries may recharge sufficiently to command the satellite," Manchester wrote. "There is also a small chance that KickSat could remain in orbit until the 16th, at which point the timer would set off the deployment as originally planned."
"Thank you again for your support," Manchester wrote to KickSat's financial backers. "I promise that this won't be the end of the KickSat project."
KickSat is not the first crowd-funded satellite, but the CubeSat's 104 subsatellites were supposed to set a record in miniaturization, becoming the smallest spacecraft ever put into orbit.
Each sprite is a nearly flat 3.5-centimeter (1.4-inch) square just 3 millimeters thick.
"They weigh about 5 grams, and they have solar cells, a microcontroller, a radio transceiver and a couple of different sensors," Manchester said in an interview before KickSat's launch. "On different ones we have three-axis gyroscopes, three-axis magnetometers, various temperature sensors and stuff like that."
With the help of NASA's Ames Research Center, Manchester and a small cadre of helpers modified off-the-shelf printed circuit boards for the hazards of spaceflight.
Kickstarter contributors who pledged more than $1,000 to the KiskSat project could customize one of the sprites.
KickSat's backers provided more than $74,000 to pay for the construction of KickSat and the sprites.
NASA supplied KickSat's launch at no charge to Cornell or the Kickstarter backers through the space agency's CubeSat launch initiative, which offers flight opportunities to educational institutions.
Follow Stephen Clark on Twitter: @StephenClark1.