SpaceX launched 60 more Starlink satellites this week – EarthSky

After two weeks of delays, SpaceX delivered its 13th batch of controversial Starlink satellites to low-Earth orbit this week (October 6, 2020).There are now 775 Starlink satellites in orbit. The 60 satellites launched this week are equipped with a sunshade called VisorSat in an effort to reduce their brightness. They were carried to orbit by a two-stage Falcon 9 rocket, which blasted off from Pad 39A at NASAs Kennedy Space Center at 7:29 a.m. Eastern Time (11:29 UTC) on October 6. The Falcon 9 boosters first stage came back to Earth, landing on one of SpaceXs drone ships in the Atlantic Ocean, nine minutes after launch.

Poor weather conditions at Falcon 9s ocean recovery site had initially forced SpaceX to stand down from its first attempt to launch this particular Starlink mission one of multiple missions designed to provide satellite Internet access on September 17, 2020. Weather concerns also thwarted launch attempts on September 28 and October 5, while ground systems issues prevented the rocket from flying on October 1. However, the fifth time was the charm, and weather conditions finally cooperated for a smooth launch on October 6. Onlookers cheered as the Falcon 9 rocket leapt off the pad, signaling an end to the series of launch aborts and weather scrubs that have recently plagued the Space Coast.

The booster powering the October 6 launch is a previously flown Falcon 9 first stage that the company has identified as B1058.3. This booster, now with three flights under its belt, previously carried two NASA astronauts to the International Space Station on May 30 as part of SpaceXs historic first crewed mission. The rocket then lofted a communications satellite for South Koreas military in July. Emblazoned with NASAs iconic worm logo, still visible underneath the boosters scorched appearance from its two trips to space and back, B1058 made its landing on the deck of the SpaceX drone ship Of Course I Still Love You, which was waiting out in the Atlantic Ocean.

The successful launch and landing marks SpaceXs Falcon 9s 94th flight to date and 61st recovery of a Falcon first stage booster since SpaceX recovered their first one in 2015.The launch also came amid World Space Week 2020, which is celebrating the impact satellites have on everyday life.

SpaceXs Starlink megaconstellation is designed to provide global broadband coverage for high-speed internet access, particularly for people across the world in rural and remote areas. Its download speeds are currently going through a private beta-testing phase, but are now able to be extended to the public with broader participation. SpaceX founder and CEO Elon Musk tweeted

Once these satellites reach their target position, we will be able to roll out a fairly wide public beta in northern U.S. and hopefully southern Canada.

Other countries to follow as soon as we receive regulatory approval.

Starlink controversy within the astronomy community. Despite the promise of high-speed broadband internet, SpaceX has taken criticism within the astronomical community for its Starlink satellites, due to their brightness and potential to disrupt observations of the night sky. The National Science Foundation and the American Astronomical Society released a report on the situation in August 2020. Discussions among more than 250 experts at the virtual Satellite Constellations 1 (SATCON1) workshop expressed concern that the bright train of satellites marching across the sky will hinder their observations.

In response, this is the third batch of Starlink satellites now that are outfitted with a blackened sunshade called VisorSat that the company hopes will reduce the satellites apparent brightness by reducing the amount of sunlight thats reflected. This is just one of the six suggestions proposed by the SATCON1 team. Initial efforts at mitigating the spacecrafts impact involved launching a prototype Starlink satellite later dubbed DarkSat earlier this year, which features a black antireflective coating. Recent ground-based observations of DarkSat in orbit found it half as bright as a standard Starlink satellite, which is a good improvement, according to experts, but still far from what astronomers say is needed. Jeremy Tregloan-Reed, a University of Antofagasta astronomer on the observational team that assessed the prototype, commented:

I would not consider DarkSat as a victory but instead a good step in the right direction.

The team compared DarkSat with a typical Starlink sibling using a 0.6-meter telescope at the Ckoirama Observatory in Chile and found that although DarkSats antireflective coating rendered it invisible to the naked eye, it remains far too bright to avoid interfering with the Vera C. Rubin Observatory now under construction in Chile and other major telescopes. Additionally, DarkSats darker color retains too much heat, so the company is sticking with the visor alternative instead.

Astronomers are hoping to observe VisorSat and compare it with DarkSat once observatories reopen following the Covid-19 shutdown. The Federal Communications Commission has currently granted SpaceX permission to launch as many as 12,000 of the flat-panel broadband satellites, but have indicated goals to send up to 30,000. With those plans as well as Amazons Project Kuiper aiming for 3,236 satellites and OneWeb, a now-bankrupt company recently acquired by the United Kingdom government, perhaps striving for 2,000 the scale of astronomys satellite-constellation problem will only increase.

A time-lapse image shows the passage of a Starlink satellite cluster, creating bright streaks through a telescopes field of view at the Cerro Tololo Inter-American Observatory of Chile in November 2019. Image via CTIO/ NOIRLab/ NSF/ AURA and DECam DELVE Survey.

Bottom line: After 2 weeks of delays, SpaceXs Falcon 9 rocket blasted off October 6, 2020, hauling a full stack of 60 Starlink VisorSat satellites. The rocket successfully landed at sea aboard a drone ship, just minutes later.

Read more:Astronomers Issue Report on the Effect of Satellite Constellations on Astronomy

Read more: SpaceX launches 60 starlink satellites and lands rocket at sea

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SpaceX launched 60 more Starlink satellites this week - EarthSky