The first mission of the year was Starlink-2, where a SpaceX Falcon 9 rocket launched 60 additional satellites into orbit on January 7, 2020 at 2:19 AM (UTC).  

Before we go on, we need to chat about the mission name.  Yes, it was the third launch of Starlink satellites. And yes, the mission is really named Starlink-2.  Why? There’s two ways to count: starting with one (what most people do), and starting with zero (what computers and therefore tech people do).  SpaceX apparently decided to use the tech-centric naming convention for these launches, which leaves us with “Starlink” for the first launch, “Starlink-1” for the second launch, and “Starlink-2” for the third launch.  Yeah, I know, it’s a little confusing. But it is what it is.

With this deployment SpaceX becomes the operator of the world’s largest satellite fleet, with 180 satellites in orbit. Planet Labs, an Earth-imaging and test bed small-sat operator has launched more than 350 satellites into orbit to this point, but only 140 of those are still currently in orbit. Most of Planet Labs’ satellites have deorbited because they’re really small and just don’t have the room for additional tech to counteract drag from the atmosphere.

Additionally, this batch of satellites includes a single Starlink satellite that isn’t quite like the others.  That one lone satellite has what SpaceX calls “an experimental darkening treatment” that’s designed to reduce its visible reflection to make it appear darker in the nighttime sky.  The goal is to compare the visibility and performance of that satellite to the others in the constellation to assess the viability of using such a coating on future Starlink satellites. 

There’s a catch with the darkening treatment.  Because it won’t be reflecting as much light from the sun, it’s going to absorb that solar energy instead.  Which means the components inside the satellite are going to be exposed to more heat. Too much heat could damage those components, rendering the satellite inoperative and making it another piece of space junk.  Additionally, that heat is going to be expressed as infrared radiation because physics. If you damp out or remove one set of wavelengths emitted or reflected by an object, another set of wavelengths will pop up as a result.  You might be wondering what the big deal with that is — the satellite is darker, it won’t interfere as much with observations, right? Wrong! As a reminder, there’s telescopes that perform observations and collect data in the infrared range, so it’s possible that the increased infrared radiation that results from this may still affect astronomers to a certain degree.

The hope is that the increased internal heating and infrared emission will be within operational limits for the payload while still providing a significantly reduced visible signature.  As far as visibility goes, according to Pam Seitzer from the University of Michigan, we won’t know how the coating will affect visibility until the satellite reaches its 500 kilometer operational orbit at the end of February.

More on this mission at:

• Starlink-3 (RocketLaunch Live) https://www.rocketlaunch.live/launch/starlink-3
• Starlink Mission (SpaceX) https://www.spacex.com/news/2020/01/07/starlink-mission
• Starlink Mission January 2020 Press Kit (SpaceX, PDF) https://www.spacex.com/sites/spacex/files/starlink_media_kit_jan2020.pdf