Starlink v0.9 1/60

Launch data: Designation  19029 Launch date  24 May 2019 - 02:30 UT Launch site  CC, SLC40 Launch vehicle  Falcon-9v1.2 Mission  Communication Earth orbit: Perigee / Apogee   ~450 x 450 km Eccentricity   Inclination  53.0° Period   min

Spacecraft data: Prime manufacturer  SpaceX Platform   Operator  SpaceX Mass at launch  227 kg Dry Mass   kg Basic shape   Dimension (m)   Equipment  Ku/Ka-band payload, optical inter-satellite link Solar array  Solar arrays Stabilization   Propulsion   DC power   Design lifetime

View of the 60 Starlink Satellites from the May 24, 2019 launch

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.
• Observers in Europe saw the satellites as a spectacular string of mag 2 to 3 objects a few hours after launch. As of May 30 it appears the satellites are mostly in the mag 4 to 7 range with frequent flares to mag 2 and occasional brighter flares, depending on illumination conditions and satellite orientation. (For the nonastronomers: bigger mag is fainter, mag 1 = brightest stars in the sky and mag 6 = barely naked-eye visible at a dark site).
• The brightness of the satellites has raised concerns in the astronomical community - a full constellation of many thousand satellites could interfere with observations and, if they are brighter than mag 5 or so, might dominate the naked-eye night sky in dark locations. However, it is likely to take some weeks before we really understand how much of the time the satellites are bright and whether it′s a real problem. SpaceX have now stated that they will look at ways to reduce the reflectivity of later satellites.
• SpaceX report that 56 of the 60 satellites are working as expected, and 4 have some problems but are in communication with the ground.
• After several months at 550 km the main group of flight 0 (2019-029) satellites have lowered their orbits to 530 km.
  Satellites lowering orbit below 530 km constellation:
  • Starlink 26 (44240/29F) is undergoing rapid orbit lowering and is now at 455 km and falling.
  • Starlink 46 (44246/29M), previously stored in a 390 km orbit, is also lowering and is now at 309 km, lower even than Starlink 67.
  • Starlink 67 (44278/29AV) continues slow decay in an elliptical 300 x 325 km orbit.
  • Starlink 60 (44723/29AQ) continues slow decay in a 416 x 425 km orbit.
  
  Satellites in storage orbit below 530 km constellation:
  • Starlink 29 (44243/29J) in 440 x 448 km
  • Starlink 52 (44259/29AA) in 443 x 445 km
  • Starlink 43 (44257/29Y) in 477 x 479 km
  • Starlink 80 (44282/29AZ) in 492 x 497 km
  • Starlink 48 (44289/29BG) in 507 x 508 km
  
  Satellites lowering orbits toward 530 km constellation:
  • Starlink 37 (44252/29S), 41 (44277/29AU), 22 (44236/29B), 64 (44275/29AS) at 547 to 551 km and descending.
  
  47 of 60 satellites are in 530 km orbit:
  • Starlink 21, 23, 24, 25, 27, 28, 30-36, 40, 42, 44, 45, 49, 50, 51, 53-59, 61, 62, 62, 65, 66, 68-79, 81
  
  
• As of 17 September 2020, most satellites have been deorbited or sent to a much lower orbit.
• Starlink 52 moved down to 280 km August 8 to 14. Starlink 50 halted at 376 km August 7 to 11. Starlink 53, 77 and 81 resumed downward movement August 5. Starlink 81 halted at 350 km August 16 to 27. Starlink 77 halted at 340 km August 17 to 26. Starlink 32 halted at 260 km August 19. Starlink 73 halted at 250 km August 22. Starlink 65 moved down from 435 km to 395 km August 11 to 23. Starlink 70 started moving down from 470 km August 29. (#3-SD574)
• SpaceX is retiring the V0.9 constellation of 60 prototype satellites launched in May 2019.
  As of Oct 7, 2020 39 of the 60 satellites have reentered.
• This is a new kind of reentry: it′s not a normal impulsive deorbit and not a normal orbital decay, but something inbetween. The Starlink satellites are, apparently, retired by continuously lowering their orbit with electric propulsion. Reentry occurs in a way similar to uncontrolled reentry - eventually the satellite is low enough and the ambient density is high enough that the vehicle heats, breaks up and is destroyed. The crucial point here is that the *location* of the breakup on the Earth is unpredictable and uncontrolled, in contrast to an impulsive deorbit where the rapid elliptical-orbit descent from a relatively high apogee means that reentry location is determined relatively precisely by the orbital parameters. These Starlink retirements should perhaps be termed ` propulsion-assisted orbital decay' - they are more like normal uncontrolled orbital decay but speeded up by the thrusters.

External links:

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