Comments by "ke6gwf - Ben Blackburn" (@ke6gwf) on "Why hasn't SpaceX's Falcon Heavy flown much?" video.

@nopenope9023 , you need to get out more man! lol Crew Dragon is the SpaceX capsule at the ISS right now, designed to carry crew instead of just cargo. The Dragon capsule is the one designed for the Falcon rocket, and has the cargo and now crew versions.
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Joe Chang , once you get out of the atmosphere, you use mass ejection to reach the desired speed, and then you coast. Since it is a vacuum, there is nothing to slow you down, so you can travel as far as you want. That's why the space station can keep orbiting at 17,000 mph, because there is nothing to slow it down. You are correct that in the atmosphere things are limited by air resistance and need constant fuel consumption just to keep moving, but even things like icbm missiles work by getting out of the atmosphere, orbiting around to the right location, and then reentering the atmosphere.
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@naufalfarras1556 , but no one else can handle the larger payloads either, so someone is going to have to design a way to do it, and since SpaceX is so much cheaper to begin with, they can build a custom fairning or nose cone and still be cheaper than anyone else. So if it is light enough for FH, just larger than the fairing, they change the fairing. But that's still a small market, with no loads like that currently. And then we have the BFR on the way, which will be able to handle those loads lol
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Joe Chang , an icbm can reach anywhere on the globe, since it goes into orbit, thus has unlimited range. Short and medium range ballistic missles etc never leave the atmosphere, so they are limited by how much fuel they carry, because they can't just coast in the vacuum of space. Do you see how things change when you get out of the atmosphere and no longer have air resistance?
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@naufalfarras1556 , for large bulky items such as ISS modules, you either make a custom shroud around them for launch and include it as part of the payload rather than part of the rocket, or you build the module to be able to handle launch, and just put a nose cone on it. Compared to the complexity of building the rocket, building a custom nose cone or fairing is peanuts. The existing fairing is the one designed for Falcon 9, based on the average size of most of the payloads, so they have never even built one for the Heavy, because so far they haven't needed anything larger. But offer them a payload too large to fit in the standard fairing, and see how quickly they can modify it to fit or design a new one.
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Joe Chang , what do you mean that we can't measure space craft speed yet? Considering that we can measure it in many ways in many reference systems, I don't know what you are talking about.
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@naufalfarras1556 , there are currently no options to fly anything much larger than what the Falcon can carry, so except for that small market of heavy and slightly bulky satellites, anything larger is going have to have those things figured out anyway. There is currently no system with the capability of the Shuttle Bay, so anything that would be that size is going to need a custom solution, and SpaceX is the fastest option to make it happen. And if someone is going to all the work and planning to build a giant module going to space, running some aerodynamic calculations and planning a custom fairing is well established rocket science. And with the ability that Falcon has for thrust vectoring and throttle control and such, it can handle minor aerodynamic problems easier than a solid rocket system etc
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Joe Chang , there are many ways to measure spacecraft speed, from radar, to lasers, to Astral navigation (measuring the angles to stars), and in the vicinity of the earth, GPS provides accurate speed reference. I can go into detail on any one of those methods if you want.
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Joe Chang , when they are closer to earth they have a military grade GPS receiver that measures the time radio signals take to travel between the GPS satellites and the rocket and calculates position and speed, just like your phone, but much more accurate. If it is headed away from earth, they use a radar transponder, and send a signal from earth and measure how long it takes to return, and then calculate speed from rate of change. If they want to be really precise, they can put a prism reflector on the rocket and shoot a pulsed laser beam at it and measure the time it takes to reflect back. They can measure to the accuracy of a photon this way. When a rocket is in visual range, just launched, or like a military short range rocket, they often use high speed cameras and measure how far it moved per frame. They can also use multiple tracking cameras like you see for nasa launches, and by feeding the exact angles of several cameras into a computer, they can triangulate the exact position, and calculate the speed. And while a rocket is still in the atmosphere, they just use a regular air speed indicator like a plane would use. So there are many ways to measure a rocket's speed, and most of them are more accurate than your car's speedometer!
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Joe Chang , GPS, radar, measuring time of travel of radio waves to the ship, laser reflectometry, measuring speed with high speed camera, uhh, did I miss any?
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