Paul Stenhouse: Amazon reaches 390 satellites, WhatsApp prepares to launch usernames, heatwave forces US data centres to use backup power

Starlink's competitor hits its launch milestone   Amazon's Leo project launched an additional 29 satellites this week, bringing it to 390 satellites in orbit – enough to start its 'preview' service for select customers. SpaceX has been in the game for four years now, and has over 10,000 satellites in orbit, with more than 10 million subscribers. Amazon wants to get to 7,700 satellites, but limited rocket space has slowed its progress.       Get your WhatsApp username while you can   WhatsApp usernames are launching later this year, but right now they're slowly rolling out the ability to reserve your username.   Linking your Instagram and Facebook profiles will unlock those usernames for you, or you can create something new. Some privacy experts say not to use your real name so people can't contact you out of the blue. There is a feature to turn on a PIN so that only those who know your username and that PIN can contact you.   The benefit is not needing to give your phone number to people, but on the flip side is the risk of impersonation. Sceptics think this is a great way for Meta to promote the linking of accounts and identifying users across products.       A heat wave in the Northeast of the USA is forcing data centres to use their backup power   The grid is under strain with the hot temps and increased AC usage. The Energy Secretary has instructed grid operators to get the data centres onto their own generation systems if the power plants can't produce enough. These backup systems sit idle most of the time, which is a good thing according to some environmental consultants who say the diesel burning backups can pollute residential areas.    LISTEN ABOVE See omnystudio.com/listener for privacy information.