How cleaning up space debris could grow to become a big business

This depicts the satellite-filled sky that is now a reality and getting more crowded every week. (Photo by: Alan Dyer/VWPics/Universal Images Group via Getty Images)Vw Pics | Universal Images Group | Getty ImagesThousands of satellites are circling the Earth, and when they die, they don't just disappear. Neither do the rockets that put them there. This week, a spent SpaceX Falcon 9 upper stage crashed into the moon, more than a year after it was left on an uncontrolled trajectory following a lunar mission.Closer to Earth, defunct satellites, spent rocket parts and other debris can remain in orbit for years, adding to an increasingly congested environment and an elevated risk of collisions.Now, a growing group of companies is betting that cleaning up this orbital junk, and servicing satellites before they become it, could become a business in its own right.Space infrastructure has become foundational for the global economy, crucial in everything from financial transactions and GPS navigation to weather forecasting and missile tracking. "Space is a global commons, and we're mucking it up," Andrew Faiola, commercial vice president at Tokyo-listed orbital services firm Astroscale, told...