SpaceX just executed its most important and historic launch ever this past weekend, flying NASA astronauts for the first time. On Wednesday, it's set to follow that up with a less significant Falcon 9 rocket launch, but one that's still vital to the company's future. This mission is the latest of SpaceX's Starlink launches, which the company is using to put up a vast network of small satellites to provide low-cost, high-bandwidth internet access to customers globally.
SpaceX's Starlink mission today has a launch window of 9:25 PM EDT (6:25 PM PDT) and includes a payload of 60 more satellites for the constellation, which already has 420 operating in low Earth orbit. The goal is ultimately to launch as many as 40,000 of these small satellites in order to blanket the globe with connectivity that's broadly available, and that provides rock-solid network consistency by handing off connections among the satellites as they make their way around the Earth.
This launch was originally scheduled to fly the week prior to SpaceX's Demo-2 crewed mission, which carried NASA astronauts Bob Behnken and Doug Hurley to the International Space Station on Saturday and Sunday, but was bumped due to a scheduling conflict with a ULA launch, and then further postponed until after the astronaut flight. It's still already the fifth batch of 60 Starlink satellites that SpaceX has flown in 2020. In total, SpaceX is hoping for up to two-dozen Starlink launches in total before year's end, which will help it meet its goal of launching an initial beta service in Canada and the U.S. later this year, with a more global rollout following in 2021 or 2022.
This launch will take off from Cape Canaveral Air Force Station in Florida, and will use a Falcon 9 first stage that flew on four previous missions. SpaceX will attempt to recover the booster again through a controlled landing, and will also try to catch the fairing halves used to protect the satellite cargo using its "Ms. Tree" and "Ms. Chief" ships.
One key novel element for this flight is the test of a new technology SpaceX is hoping will help mitigate the impact of the Starlink constellation on night sky observation from Earth. Scientists have complained that Starlink is bright enough to interfere with sensitive optical instrumentation used to gather data from deep space bodies and phenomena. To address that, SpaceX has designed a deployable "visor" system that extends from Starlink satellites post-launch and attempts to block sunlight reflecting off their communications arrays.
SpaceX has equipped one of the 60 satellites on this launch with that system, as a way of testing its efficacy before making it a standard part of the Starlink satellite build going forward. Depending on results, it could become a permanent fixture on all of SpaceX's Starlink spacecraft for future missions.
Should today's launch be delayed (weather is currently looking around 60% favorable for the mission), there's a backup opportunity tomorrow, June 4 at 9:03 PM EDT (6:03 PM PDT).