At the beginning of this year, NASA scientists had to decide which missions should explore our Solar System. They chose four missions for further study from the 20 intriguing ideas submitted. From these, they will pick two to fund fully.

This is how NASA has done planetary science for decades, and the process has succeeded phenomenally. Yet, there is so much more we can learn about the Solar System.

Two emerging technologies may propel NASA and the rest of the world into an era of faster, low-cost exploration that would lead to more exploration and democratise access to the Solar System.

• A new generation of companies is developing new rockets for small satellites. Rocket Lab has a lunar program for its small Electron rocket, and Virgin Orbit with a group of Polish universities is to launch up to three missions to Mars with its LauncherOne vehicle.
• At the same time, various components of satellites are being miniaturised.
• Tiny satellites are no longer theoretical. Two years ago, a pair of CubeSats, called MarCO-A and MarCO-B, launched with the InSight mission. The briefcase-sized satellites deployed their own solar arrays and journeyed to Mars.