Starlink v1.0 2-1/60

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Spacecraft data:

Description:

• Starlink is SpaceX′s 4425-satellite low earth orbit constellation to provide broadband Internet access.
• The mass-produced spacecraft carry a communications payload using the Ku and Ka frequency bands. The satellites will employ optical inter-satellite links and phased array beam forming and digital processing technologies.
• The Starlink satellites feature a flat panel design with a single solar panel and have a mass of about 227 kg. The satellites are stacked for launch without the need for an dispenser. As a propulsion system for orbit adjustion and maintenance as well as deorbiting, they use krypton-fueled Hall thrusters. The Startracker navigation system is based on the heritage of Dragon. The satellites are designed autonomously avoid collisions based on uplinked tracking data. At the end of life, the Starlink satellites are to be actively deorbited, leading to reentry. 95% of the material is expected to burn up.
• The first 1584 Starlink satellites are to operate from a 550 km orbit. Later sub-constellations are planned for 1200 km and very low 340 km orbital altitude, bringing the final constellation size to nearly 12000 satellites.
• The initial 75 satellites, called Block v0.9, are prototypes without inter-satellite links and Ka-band antennas. These are to be used for extensive testing of deployment and operation and also of deliberate deorbiting.
• For launch, 60 satellites are stacked on top of each other without the need of a massive deployer. 60 satellite is the maximum possible to fit inside the Falcon-9 v1.2 (Block 5), although a future enlarged fairing will allow launches of more than 60 satellites per mission.
• The unexpected brightness of Starlink satellites has caused widespread concern among astronomers. Thousands of such satellites could dominate the visible view of the night sky in dark areas; the bright satellites crossing the field of view of astronomical detectors could cause bright streaks, electronic cross-talk and `ghost images' compromising deep exposures of faint objects. At a meeting of the American Astronomical Society in January, SpaceX representatives seemed confident they would be able to reduce the brightness of future satellites so that they would no longer be naked eye objects, and expressed committment to iterative improvements to address the concerns of professional astronomers.
• The latest launch includes a modified satellite, Starlink 1130, with a special dark coating on the bus to reduce its brightness. This satellite will be used to improve SpaceX′s models of satellite light scattering, allowing engineers to evaluate design improvements for future versions of the satellite.
  It will be important to get visual magnitude estimates of Starlink 1130 once it reaches its operational orbit.

Mission details:

• SpaceX launched its first batch of 60 Starlink Ku-band internet satellites on May 24, 2019. The Falcon 9 rocket placed the satellites in a 434 x 442 km x 53.0 deg. Each one is about 200-250 kg (the press kit says 227 kg, but this is suspiciously close to the metric equivalent of 500 pounds, so it′s possible they really mean 500+-50 lb = 227 +- 23 kg). The satellites are a flat panel with krypton-propellant electric thrusters and a single deployable solar panel.
• The second batch of 60 SpaceX Starlink satellites were launched on Nov 11, 2019.
  The Falcon 9 launch vehicle used first stage B1048 on its fourth flight; the stage landed on the OCISLY drone ship and the second stage was deorbited south of Australia, leaving the 60 payloads and four deployment rods in orbit. The new satellites have both Ka and Ku band antennae.
  This time the payloads were deployed in a 298 x 303 km x 53.0 deg orbit; the deployment rods seem to have been ejected in a retrograde direction and are in a 275 x 288 km orbit.
• As with V1.0 Batch 1, the 60 satellites were split into three groups, with orbit raising of two of the groups pausing at 350 km to precess to different orbital planes.
• Stage 2 of the Falcon 9 was deorbited south of Australia, reentering at approximately 0448 UTC Jan 7 after 1.6 orbits.
• Recent observations by Richard Cole (Res.Notes.AAS, in press) and Tregloan-Reed et al (arxiv2003.07251) show that in the days after reaching its operational orbit at the beginning of March 2020, Starlink-1130 (Darksat - Starlink 2) was indeed about a magnitude fainter than other Starlink satellites, indicating that the special coating has been reasonably successful.

External links:

• SPACE-X: Satellite Information
• SPACE-X: Starlink mission
• AmericaSpace: Starlink launch
• AmericaSpace: Starlink launch
• AmericaSpace: Starlink launch video
• Wikipedia: Starlink mission
• Satellite tracking (n2ya.com): Real time satellite tracking