Japanese Startup Wants To Rain Down Man-Made Meteor For Tokyo Olympics (sciencealert.com)
A startup called Star-ALE wants to create a man-made meteor shower over the city of Tokyo for the 2020 Olympics opening ceremonies. The pyrotechnics show, Star-ALE says, will be visible from an area 200km across Japan, and the pyrotechnics will actually shower from space. Starting next year, Star-ALE will begin sending a fleet of microsatellites carrying 500 to 1000 specially-developed pellets that ignite and intensely glow as they re-enter the earth's atmosphere. ScienceAlert reports: But wonderment comes at a cost, and in this case, that cost isn't cheap. Each combustible pellet comes in at about $8,100 to produce, and that's not including the costs involved in actually launching the Sky Canvas satellite. The company has tested its source particles in the lab, using a vacuum chamber and hot gases to simulate the conditions the pellets would encounter upon re-entering Earth's atmosphere. In its testing, the particles burn with an apparent magnitude of -1, which should ensure they're clearly visible in the night sky, even in the polluted skyline of a metropolis like Tokyo.
It saddens my heart to see the billions spent on these sporting events that today have nothing to do with the spirit of the events but everything to do with bolstering ego's of politicians and piss away money. Imagine if this kind of money was used to build infrastructure, provide solutions for clean water and food where needed, I imagine that would be a world less stricken by suffering, poverty and war. It would be a world with fewer refugee crisis as people generally like to live where thwy were born, and if the resources for a decent life existed migration would be for the few adventurous souls rather than for the suffering masses... wake up!!!
should ensure they're clearly visible in the night sky, even in the polluted skyline of a metropolis like Tokyo.
Unless it's cloudy.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
One thing that bugs me about this summary:
At orbital velocity (LEO) an object has a potential energy of around 30MJ per kilogram, an energy density higher than ethanol. Black powder, by contrast (common in fireworks) has 1/10th that energy density. The various colours, with the exception of white, are generally from rather weakly combusting compounds. There's a lot more energy to be had for producing "glow" from the orbital energy rather than whatever they want to burn to produce a coloured glow. And the colour of the thermal radiation from reentry will depend on the surface temperature, and that's customizeable for red, orange, yellow, and white (no green, blue or purple, though) just through simple blackbody emission, customizeable if specific ions are being ablated that tend to radiate in certain bands. The blackbody colour can be varied over the course of reentry by changing the drag coefficient as the surface ablates.
Perhaps "combustion" is the wrong term, perhaps they're just talking about ablation?
Honestly, you don't need special pellets to make a neat fireworks display, rockets can do that themselves ;) In fact... hmm... now that I think about it, the most cost-efficient way to get strange atmospheric effects might be barium clouds. They only require sounding rockets, the glow comes from the below-horizon sun itself, they show effects of the solar wind on the atmosphere (sort of like artificial auroras), and are often mistaken for UFOs and can look like slow fireworks when they expand.
Friends! Help! A guinea pig tricked me!