CubeSats are flying into space at a fairly regular rate. These are simplistic structures based on a standard “cube” structure measuring 10 centimetres on a side. That’s not a lot of volume, but as anyone who owns a smartphone knows, a lot of gear can be crammed into this space. Join several cubes together, and you can make larger satellites. Or you can go smaller. One recent mission used a CubeSat structure as a dispenser for a huge fleet of tiny satellites, each around 3.5 centimeters square, and less than a centimeter in depth!
More small satellites are planned for the future. More will be launched as constellations. The upcoming QB50 mission plans for 50 cubesats to launch simultaneously.
CubeSats and their cousins are making space more accessible than before. They use a lot of standard components and are cheap to build. They are helping students to gain apprenticeships in building satellites. Some technical projects wouldn’t make it to orbit in any other way. As financial austerity grips space activity around the world, we will probably find that these budget-friendly projects will become even more prominent.
Small satellites seem to have so many advantages, but are there any downsides? Admittedly, there are so many missions and projects that cannot be scaled down to these small proportions. Big birds will always fill our skies. The only potential problem that one could suggest for the small satellite revolution is the potential for more space junk. But will this really be a serious problem?
Let’s consider the orbits. Most CubeSats fly at fairly low altitudes. They will not stay in orbit for decades. Furthermore, their trajectories can be controlled from launch, and they can be tracked fairly easily with radar. We know where they are, and where they are going.
In contrast to some other spacecraft, small satellites are normally deployed with a minimum of jetsam. They are often popped out of launch tubes with no other items released in the process. There will be fewer springs, bolts or rings to clutter nearby space.
When they return to Earth, they will be completely destroyed during reentry. There is no risk to people or property on the ground.
All things considered, the current revolution in small satellites probably poses less of a problem for space junk than many other space projects.