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> Being able to reach space at all is the hard part No its not. Teenagers can get to space with model rockets and simple fuels. You can reach space simply by th

by tekla 3y ago

> Being able to reach space at all is the hard part No its not. Teenagers can get to space with model rockets and simple fuels. You can reach space simply by throwing something really really hard, but it will come right back down. https://www.wired.com/story/a-rocket-built-by-students-reached-space-for-the-first-time/ https://www.wired.com/story/a-rocket-built-by-students-reach... > Orbit seems like a such an arbitrary line It's not. If your super expensive rocket can't reach orbit, why would anyone bother? Can't deploy sats, can't go to the ISS, nothing.

sangnoir 3y ago
> You can reach space simply by throwing something really really hard, but it will come right back down. Is there anything special about boosters, second or third stages or vacuum motors that's tough to crack for an organization that has already managed to reach space under its own steam? Bigger tanks, more engines and/or higher specific-impulse-fuels are tractable problems to organizations that have already reached space - they know how to do R&D, integration and operations. Getting to space ab initio is harder, and is where most - if not all - failed launch companies have failed.
- two_handfuls 3y ago
  You ask whether there is something special about orbit vs reaching space. This is a good question. To be in orbit, a rocket must move extremely fast. The source below says that the energy needed to go to space is only 3% of the energy needed to go to orbit. That means orbit is about 30 times harder than space. And it gets worse than that because of the rocket equation: to get twice as much kinetic energy requires more than twice the amount of fuel, because you are not just accelerating your capsule, but also the fuel it will need along the way. So yes, there is a huge difference between being able to reach space and being able to reach orbital velocity. Source: https://blogs.scientificamerican.com/life-unbounded/basic-rocket-science-sub-orbital-versus-orbital/#:~:text=For%20a%20100%20kilometer%20jaunt%20that%20change%20in,a%20factor%20of%2032%20increase%20in%20energy%20budget https://blogs.scientificamerican.com/life-unbounded/basic-ro....
- philwelch 3y ago
  It took about a decade of work to go from the first suborbital rockets to orbit, and even that was in the context of a competitive arms race. It actually took more than a decade but it’s not completely fair to count all of that time since there wasn’t a continuous effort between the V-2 and the US and Soviet rocket programs.

by tekla 3y ago

sangnoir 3y ago

> You can reach space simply by throwing something really really hard, but it will come right back down. Is there anything special about boosters, second or third stages or vacuum motors that's tough to crack for an organization that has already managed to reach space under its own steam? Bigger tanks, more engines and/or higher specific-impulse-fuels are tractable problems to organizations that have already reached space - they know how to do R&D, integration and operations. Getting to space ab initio is harder, and is where most - if not all - failed launch companies have failed.

two_handfuls 3y ago
You ask whether there is something special about orbit vs reaching space. This is a good question. To be in orbit, a rocket must move extremely fast. The source below says that the energy needed to go to space is only 3% of the energy needed to go to orbit. That means orbit is about 30 times harder than space. And it gets worse than that because of the rocket equation: to get twice as much kinetic energy requires more than twice the amount of fuel, because you are not just accelerating your capsule, but also the fuel it will need along the way. So yes, there is a huge difference between being able to reach space and being able to reach orbital velocity. Source: https://blogs.scientificamerican.com/life-unbounded/basic-rocket-science-sub-orbital-versus-orbital/#:~:text=For%20a%20100%20kilometer%20jaunt%20that%20change%20in,a%20factor%20of%2032%20increase%20in%20energy%20budget https://blogs.scientificamerican.com/life-unbounded/basic-ro....
philwelch 3y ago
It took about a decade of work to go from the first suborbital rockets to orbit, and even that was in the context of a competitive arms race. It actually took more than a decade but it’s not completely fair to count all of that time since there wasn’t a continuous effort between the V-2 and the US and Soviet rocket programs.