Recently, the news that the 40 "Starlink" satellites that have just been successfully launched have encountered geomagnetic storms and re-entered the atmosphere has been fired, and Musk has suffered a loss of tens of millions of dollars, and it is not known how many rockets and fairings to recycle and reuse to save it. The main reason why he has this "robbery" is that he is too "slamming the door". Don't worry, listen to the editor slowly.
The photo quoted by the media is actually a picture of the Falcon 9 rocket re-entry
The so-called geomagnetic storm, to the effect that the solar particle eruption intensifies, acting on the Earth's atmosphere, in addition to interfering with the Earth's communication, the increase in charged particles will also heat the Earth's atmosphere. Although this heating is very weak, it can cause the Earth's atmosphere to expand, even slightly deformed.
Geomagnetic storms are also called solar storms
Unlike the traditional impression of many people, space stations and satellites running in low Earth orbit at an altitude of two or three hundred kilometers have not completely escaped from the Earth's atmosphere, and they can still feel a certain amount of air resistance when flying, so after the expansion of the Earth's atmosphere, they feel more air resistance, which may lead to crashes. For example, the Soviet Union's "Salyut" space station and the United States' "Skylab" are all caught in an irreversible re-entry process for this reason. It is said that the "Starlink" satellite, which flew at an altitude of 210 kilometers, suddenly encountered a 50% increase in resistance.
That's how Skylab, america's first space station, crashed
Seeing this, people familiar with the orbit of the "Starlink" may think, is the deployment orbit of the "Starchain" satellite not 550 kilometers, 1150 kilometers, and the lowest 340 kilometers? For example, the 49 "Starlink" satellites launched on February 3 have an altitude of 550 kilometers, so how can they run into an orbit with greater atmospheric resistance of 210 kilometers?
The deployment orbit of the Starlink satellite is not 210 kilometers
The reason is that Musk is too "cutting the door", in order to save costs, the "Falcon" 9 rocket that performs the "StarChain" launch mission is not above, that is to say, after entering space, it can no longer push to help the satellite enter the final deployment orbit, but at an altitude of 210 kilometers, it will "sprinkle potatoes", and the subsequent upgrade will rely on the "Starchain" itself.
Falcon 9 does not have an upper level when it launches Starchain
One sprinkle of "potatoes" is done
And this 210-kilometer orbit, Musk named it a test orbit, the "Starlink" satellite here to test the status OK, will start the engine for uptrack. Yes, the new generation of "Starlink" satellites now has its own propulsion system, but because of its small size, a single satellite only weighs more than 200 kilograms, so it is impossible to use a traditional chemical rocket engine, but like our space station, it uses a "black technology" Hall thruster.
Hall thrusters for starlink satellites
This would have been a good thing, but here Musk's "door-slamming" nature is shown for the second time. Although the Hall thruster is small and saves fuel, the thrust at this stage is generally only a few niu, the largest American X3 Hall thruster and the mainland HET-450, the thrust is only 5.4 Niu and 4.6 Niu, still in the laboratory stage.
American X3 Hall thruster
Suspected of being a continental HET-450 Hall thruster
However, at this stage, the practical Hall thrusters also have a thrust of 1 to 2 ox, such as the core module of the continental space station "Tianhe" equipped with 4 such Hall thrusters. In order to save costs, Musk equipped the "Starlink" satellite with Hall thrusters, the input power range is only 1.35 kilowatts to 10 kilowatts, the thrust is 40 to 600 millinius, probably only 1/2 to 1/15 of ours.
The Continental Space Station Hall thruster ignites instantaneously
Such a small Hall thruster, Musk and SpaceX are precisely calculated, it is just enough to offset the air resistance in the low Earth orbit at a height of 210 kilometers, not much at all, but this time due to the influence of the geomagnetic storm, the air resistance in low Earth orbit suddenly increased by 50%, so 40 "star chains" were GG, even if the "star chain" satellites put away the "small wings" to reduce the resistance at that time. The remaining 9 "Starlink" satellites launched by this batch are estimated to be unable to be saved.
This is really GG
It is worth mentioning that even without the impact of this geomagnetic storm, from the orbit of 210 kilometers to 550 kilometers, with the "StarChain" hall thruster that can not even blow a piece of paper, the whole process takes about one or two months, and the entire orbit change process needs to occupy a lot of orbital resources, and this is one of the reasons why the aerospace industry criticizes the "Starlink" satellite, not that it is too numerous and occupies the low-Earth orbit space. In fact, in Musk's own words, Earth's low-Earth orbit space is large enough to accommodate trillions of satellites, which may sound reasonable, but he avoids the risk that the "starchain" orbit change process is too long, and if something is not flexible enough, it will pose an unknown threat to other spacecraft operating in this orbit, just like our space station encountered not long ago.
Unleash the satellites of the Starlink
Finally, I would like to say that Musk's "door-cutting" is the main reason for the success of his space business empire, and saving launch costs is beyond reproach and worth learning. But nothing can go to the extreme, too late, in addition to the pursuit of economic profits, enterprises must also take the initiative to assume social responsibility, our "Tiangong-2" space laboratory when decommissioned, are actively derailed, this is the responsibility of a big country.
SpaceX needs more enterprise responsibilities