Starlink v1.0 5-1/60

Int. spacecraft nº:

US spacecraft nº:

Launch data:

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.

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.
• On Mar 18, 2020 SpaceX launched the sixth batch of satellites, A single burn of the upper stage placed the satellites in a 209 x 366 km orbit.
  The Falcon 9 first stage, on its fifth flight, suffered one engine shutdown during ascent, and failed to land on the droneship on descent. This did not affect the successful orbit insertion of the second stage. The second stage was deorbited over the eastern Pacific.
• Nr launched:
  • Starlink 1207
  • Starlink 1213
  • Starlink 1255-1260
  • Starlink 1262-1268
  • Starlink 1272-1293
  • Starlink 1295-1313
  • Starlink 1316-1319
• 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, Starlink-1130 (Darksat - Starlink 2) was indeed about a magnitude fainter than other Starlink satellites, indicating that the special coating has been reasonably successful. The analysis (Jonathan′s Space Report No.777) of the astronomical impact of Starlink has been published as https://iopscience.iop.org/article/10.3847/2041-8213/ab8016 (Astrophysical Journal Letters, v. 892) and https://arxiv.org/abs/2003.07446
• As of Mar 10, 2020 there were 20 sats from launch 3 and 39 sats from launch 4 undergoing orbital plane drift at the 350 km `pause' altitude, with 40 of the launch 5 satellites reaching or paused at that altitude. On Mar 11 to 13 all 99 of these sats abruptly began raising their orbits again, without waiting for their target orbital planes to be reached. Jonathan speculate that the plane-relocation process requires extra personnel and the abrupt orbit raising towards the operational 550 km orbit is a contingency activity in response to COVID19.

External links:

• Jonathan C. McDowell: Astrophysical Journal Letters, v. 892
• SPACE-X: Satellite Information
• SPACE-X: Starlink mission
• Wikipedia: Starlink mission
• Satellite tracking (n2ya.com): Real time satellite tracking