Integrated circuit fabrication and applications are continuously being improved and there are breakthroughs happening quite often — on Earth. But what about a way to study ICs in a manner that we cannot do on Earth? In space, in a micro-gravity environment, there have been numerous tests going on over the years as Shuttle experiments. Right now, there are experiments running on the International Space Station (ISS) miles above us.
In 1998, the Orbital Processing of High-Quality Doped and Alloyed CdTe Compound Semiconductors experiment was run on a shuttle mission. It studied the gravitational effect on the crystal growth of bulk compound semiconductors (the doped and alloyed cadmium-telluride in the title). Three accelerometer systems were studied with respect to vibration levels in a quasi-steady acceleration field. This was a very early study and some preliminary results were observed.
Later in 2002, a MEMS (microelectromechanical system)-based, spherical, three-axis accelerometer was developed in space. Ball Semiconductor technology was used. Instead of using flat IC die, a spherical ball fabrication is possible. See Figure 1.
(Source: Stanford University & Ball Semiconductor Inc.)
In another area of interest in space, Jet Propulsion Laboratory (JPL) at California Institute of Technology studied compound semiconductor devices and got an insight into reliability and failure mechanisms and radiation effects Reliability of Compound Semiconductor Devices for Space Applications).
In 2008, the focus was on wafer scale integration for smaller, lighter space craft electronics. The wafer is the substrate in this architecture. This effort has led to the Small Satellite team at NASA Ames. See my EDN article NASA PhoneSat: Crowd-sourced science via ham radio. MEMS and other sensor products are bringing miniaturization and high levels of integration in space systems.
This high integration development in ICs enable launch-on-demand satellites, low cost UAVs and sensor networks. GPS and microthruster systems will lead to space robotics, nano satellites, and small planetary lander spacecraft.
What do you think about lower-cost capabilities that enable space exploration? Is it still worth our efforts?