NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
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Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#2Given how SpaceX has landed things on a drone ship, presumably they're considering launching from a rocket that's been lifted above the bulk of the atmosphere using a balloon of some sort.
You'd probably save a ton of fuel if you could launch from 40 or even 100K feet.
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#3Given how SpaceX has landed things on a drone ship, presumably they're considering launching from a rocket that's been lifted above the bulk of the atmosphere using a balloon of some sort. You'd probably save a ton of fuel if you could launch from 40 or even 100K feet.
Eh, not really. It's not getting to altitude that's expensive, it's speed. Orbit is blisteringly fast.
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#4Given how SpaceX has landed things on a drone ship, presumably they're considering launching from a rocket that's been lifted above the bulk of the atmosphere using a balloon of some sort. You'd probably save a ton of fuel if you could launch from 40 or even 100K feet.
Eh, not really. It's not getting to altitude that's expensive, it's speed. Orbit is blisteringly fast.
It's expensive to build up speed while fighting through the lower atmosphere. Density drops pretty fast[1], so you don't need to fight it with the rocket if the launch vehicle has already paid the cost.
[1] https://upload.wikimedia.org/wikipedia/commons/d/de/Atmosphe...
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#5I worked on the software for the star trackers in these. Glad to hear they have already made contact. :-)
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#6I worked on the software for the star trackers in these. Glad to hear they have already made contact. :-)
Great! You didn't fuck it up than right? Or does it take some time to tell? I guess we will see soon. I will come back to you and this comment if they go down!
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#7Lifting a rocket that high before firing it carries another benefit besides the (small) altitude gain and lower fuel requirements due to drag: Max Q, the maximum dynamic pressure that has to be sustained by the rocket usually happens at a lower altitude than that (depending on the mission).
This means your rocket has to sustain a far lower structural load, making it safer and lighter.
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#8Given how SpaceX has landed things on a drone ship, presumably they're considering launching from a rocket that's been lifted above the bulk of the atmosphere using a balloon of some sort. You'd probably save a ton of fuel if you could launch from 40 or even 100K feet.
Eh, not really. It's not getting to altitude that's expensive, it's speed. Orbit is blisteringly fast.
It's a lot easier to get up to speed if you don't have to deal with cutting through a heavy chunk of atmosphere on the way up. Plus, rocket designs could vary, be less concerned about aerodynamics, if they were starting from a launch platform already in very thin air.
A wider, shorter rocket might work better in thin air, for example, but that would be impractical launching from sea-level as is tradition.
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#9Just an FYI, NASA live streams mosts of these launches here: https://www.nasa.gov/multimedia/nasatv/#public
Re: NASA just launched 8 satellites from a rocket dropped from a plane at 40,000ft
#10Earlier quoted context omitted.
Eh, not really. It's not getting to altitude that's expensive, it's speed. Orbit is blisteringly fast.
It's expensive to build up speed while fighting through the lower atmosphere. Density drops pretty fast[1], so you don't need to fight it with the rocket if the launch vehicle has already paid the cost. [1] https://upload.wikimedia.org/wikipedia/commons/d/de/Atmosphe...
Why aren't space ports then at higher altitudes but mostly at sea-level like cape canaveral? At the beginning the rocket flies comparably slow, so the lower atmosphere density is not that important, its the speed that is hard.