{"id":17690,"date":"2020-06-08T21:22:41","date_gmt":"2020-06-08T13:22:41","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/5-trillion-bytes-a-day-spacex-engineers-flash-some-facts-about-starlink-satellites\/"},"modified":"2020-06-08T21:22:41","modified_gmt":"2020-06-08T13:22:41","slug":"5-trillion-bytes-a-day-spacex-engineers-flash-some-facts-about-starlink-satellites","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/5-trillion-bytes-a-day-spacex-engineers-flash-some-facts-about-starlink-satellites\/","title":{"rendered":"5 trillion bytes a day: SpaceX engineers flash some facts about Starlink satellites"},"content":{"rendered":"
\"Starlink
An artist\u2019s conception shows the deployment of SpaceX\u2019s Starlink satellites. (SpaceX Illustration)<\/figcaption><\/figure>\n

SpaceX\u2019s Starlink satellite constellation is still deep into testing mode, but it\u2019s already generating 5 trillion bytes of data on a daily basis and getting software updates on a weekly basis.<\/p>\n

Those are a couple of the nuggets coming from a weekend Reddit \u201cAsk Me Anything\u201d session featuring SpaceX\u2019s software team.<\/p>\n

The main focus of the online chat was SpaceX\u2019s successful mission sending NASA astronauts Bob Behnken and Doug Hurley to the International Space Station in a Crew Dragon capsule \u2014 but one of the team members, Matt Monson, has moved on from Dragon to take charge of Starlink software development.<\/p>\n

Although SpaceX\u2019s HQ is in Hawthorne, Calif., most of the work relating to the Starlink satellites is being done at the company\u2019s facilities in Redmond, Wash.<\/p>\n

SpaceX tends to play its satellite cards close to the vest, in part because the process of building a satellite system is \u201chighly proprietary\u201d \u2014 as one of the company\u2019s vice presidents, Patricia Cooper, said in a 2016 filing with the Federal Communications Commission. For that reason, any nuggets about Starlink\u2019s workings are avidly sought by SpaceX\u2019s fans as well as the occasional inquiring journalist.<\/p>\n

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SpaceX employees in Redmond, Wash., give a cheer during the countdown to a Falcon 9 launch that put the company\u2019s second batch of 60 Starlink satellites into orbit last November. (SpaceX via YouTube)<\/figcaption><\/figure>\n

This weekend\u2019s Reddit AMA attracted more than 7,000 questions and comments, and the engineers could reply to only a few of them. That made it easy to avoid sensitive subjects \u2014 for example, the timetable for adding satellite-to-satellite laser communication links to the constellation. Despite the limitations, Monson and the other developers shed light on Starlink\u2019s inner workings, including these highlights:<\/p>\n

    \n
  • The technology used for the display screens on the Crew Dragon also provided the basis for the user interface on the first two prototype Starlink satellites, launched in 2018. \u201cIt\u2019s grown a ton since then, but it was awesome to see Bob and Doug using something that somehow felt familiar to us too,\u201d Monson wrote.<\/li>\n
  • SpaceX relies on the Linux operating system in its satellites as well as its rockets. \u201cEach launch of 60 satellites contains more than 4,000 Linux computers,\u201d Monson said. \u201cThe constellation has more than 30,000 Linux nodes (and more than 6,000 microcontrollers) in space right now. And because we share a lot of our Linux platform infrastructure with Falcon and Dragon, they get the benefit of our more than 180 vehicle-years of on-orbit test time.\u201d<\/li>\n
  • Not everything has gone right with Starlink\u2019s software. \u201cWe\u2019ve had many instances where a satellite on orbit had a failure we\u2019d never even conceived of before, but was able to keep itself safe long enough for us to debug it, figure out a fix or a workaround, and push up a software update,\u201d Monson wrote. He said SpaceX usually updates the software on all the satellites about once a week, \u201cwith a bunch of smaller test deployments happening as well.\u201d<\/li>\n
  • Monson said \u201cwe\u2019re currently generating more than 5TB [5 trillion bytes] a day of data\u201d for Starlink. \u201cDoing the detection of problems onboard is one of the best ways to reduce how much telemetry we need to send and store (only send it when it\u2019s interesting). The alerting system we use for this is shared between Starlink and Dragon.\u201d<\/li>\n<\/ul>\n

    As of last week, SpaceX has launched eight batches of 60 Starlink satellites, forming a constellation of roughly 480 spacecraft (with a few that have gone out of service). There\u2019s a continuing controversy over the satellites\u2019 visibility and potential interference with astronomical observations. If the skies are clear, you can use Heavens-Above.com as your guide to spot the satellite train passing across the sky.<\/p>\n

    The broadband data network is already being tested for military applications. Just last month, SpaceX and the U.S. Army struck a deal for three more years of experimentation and evaluation. Limited commercial service could begin later this year, though it\u2019s not yet clear exactly how the service will be marketed.<\/p>\n