NASA's Dellingr spacecraft paves way for more reliable CubeSats
NASA is carrying out pre-commissioning tests on a small satellite that could have a big impact on future missions. Launched into low-Earth orbit with little fanfare on November 20 from the International Space Station (ISS) using the NanoRacks CubeSat Deployer, the shoebox-sized Dellingr spacecraft is designed to not only carry out science operations, but to demonstrate that it is possible to produce robust, reliable CubeSats with a low failure rate.
Originally created in 1999 by the California Polytechnic State University, the CubeSat concept has captured the imagination of engineers, scientists, students, and private companies. The small satellites are made of cubical units 10 cm (4 in) on a side that are cheap to build and launch as piggyback payloads alongside larger spacecraft or deployed from the ISS. In addition to economy, CubeSats hold the promise of using smaller, more expendable spacecraft that can work alone or in swarms to perform tasks that today can only be done by satellites the size of a bus.
The problem is that CubeSats have a reputation for poor reliability. This isn't surprising because most small satellites are experimental jobs that are often designed and built on an ad hoc basis with little or no quality control. According to NASA, CubeSats have a failure rate of 50 percent.
To overcome this reliability problem, in 2014 Michael Johnson, chief technologist of the Applied Engineering and Technology Directorate at NASA's Goddard Space Flight Center in Greenbelt, Maryland, came up with the idea of Dellingr. It's named after the Norse god of the dawn and is the focus of a small team of scientists and engineers who were given the task of producing the CubeSat for not much money in not much time.
They were also told to make it robust, yet capable of sending back high-quality data on the effects of the Sun on the Earth's upper atmosphere.
What sets Dellingr apart is that the team used systems-development techniques for its design and construction. This approach involves planning, creating, testing, and deploying new technologies like an assembly line, with a number of clearly defined and distinct work phases, including planning, analysis, design, and implementation, that operate in a repeating cycle until the CubeSat reaches the desired requirements and level of quality.
When Dellingr is declared operational, it will begin its science mission using an Ion-Neutral Mass Spectrometer to sample the densities of neutral and ionized atom species in the atmosphere, two miniaturized magnetometer systems to measure Earth's magnetic fields, and a fine sun sensor to orient itself to the Sun. Meanwhile, a new thermal-control technology will regulate spacecraft temperatures.
Johnson claims that although Dellingr has only been in orbit for eight days, it has been a success so far and that the lessons learned from its development will help in building CubeSats for future missions.
"We believe Dellingr will inaugurate a new era for scientists wanting to use small, highly reliable satellites to carry out important, and in some cases, never-before-tried science," Johnson says.