5 ms·

As amazing as space technologies are, we are in the stone ages when it comes to spaceflight: > Earth moves around the sun faster than Voyager 2 is traveling fr

by josho 10y ago

As amazing as space technologies are, we are in the stone ages when it comes to spaceflight: > Earth moves around the sun faster than Voyager 2 is traveling from Earth, the distance between Earth and the spacecraft actually decreases at certain times of the year. We don't even have the technology to escape the sun's gravity without needing a gravitational slingshot from other planets, and that still leaves us with a space craft moving slower than the earth.

civilian 10y ago
Nitpicky but.... we'd still want to use gravitational slingshots even if we had more deltaVs to burn.
- hcrisp 10y ago
  Yes, in fact per Mark Adler [0] you'd use a Jupiter flyby to fly back to the sun and then do a high thrust burn at closest approach to maximize your speed into interstellar space (Oberth effect). [0] https://www.quora.com/Can-we-use-the-gravity-of-the-sun-to-slingshot-spacecraft-into-interstellar-space-or-to-other-stars https://www.quora.com/Can-we-use-the-gravity-of-the-sun-to-s...
rm_-rf_slash 10y ago
Problem is we don't really know where to go next. Jeff Bezos' Blue Origin tried to cook up alternate space travel methods for years and still couldn't come up with anything better than the same basic rocket model that put Gagarin into space. Most theorized "warp drives" either require more energy than humanity is capable of producing or necessitate breaking a law of physics or two just to move anything organic or larger than a postage stamp. Then again, the answer could be right under our noses. There's a Sci-fi story - I forget the name - where space travel is actually quite simple if you know the math to make it happen, and when a peaceful alien race visits Earth, the humans - with their thousands of years of armed conflict - kill the aliens and take their spaceships. Makes me wonder that if we treat the rest of the universe the way we have treated our planet, do we truly deserve the right to roam the stars?
- Normal_gaussian 10y ago
  It would be nice, and is certainly the result I hope for (with all the good wishes do), as I'm not sure we will work very well with slow and expensive growth. Reading 'Against a Dark Background' was certainly interesting as it considers a system which essentially has its growth capped by the distance between itself and the rest of the universe.
  - pavel_lishin 10y ago
    Something I noticed in that novel is that they still had incredibly advanced technology. The Lazy Guns alone hint at what they lost! Maybe there's a reason Golter is where it is, and maybe it wasn't always there.
    - zipwitch 10y ago
      I read _Against A Dark Background_ as a teen an thought of it as a pretty fun sf, almost space-opera adventure story. Then I read it again as an adult and... wow. Bank's SF work is very good, but the quiet existential horror that lurks behind the scenes in that novel really merits the title. Makes good old Lovecraft seem like a piker by comparison.
- meric 10y ago
  You write a good comment, I don't know why you were down voted.
- macintux 10y ago
  I recall the story too: if I recall correctly, it was actually a branch of chemistry we had missed, not a math problem per se. The aliens stormed off the ships with muskets and we slaughtered 'em.
  - bitJericho 10y ago
    Not doing any kind of reconnaissance before a conflict would be crazy! But I guess maybe they didn't think of it! It's also my working theory of why we won in Independence Day the movie :) Aliens were never warring among themselves and/or allowing any kind of a hacking culture, so didn't think to secure their systems!
Diederich 10y ago
> we are in the stone ages when it comes to spaceflight Indeed, only 59 years since we first put something into earth orbit. We're just getting warmed up!
- kevin_thibedeau 10y ago
  But that was only 54 years after figuring out powered flight.
  - Retra 10y ago
    It turns out that "getting off the ground" is also the hard part when it comes to space exploration.
    - agjmills 10y ago
      "getting off the ground and staying there"
- kaybe 10y ago
  > We're just getting warmed up! Literally, sadly.
  - Diederich 10y ago
    Sigh..I see what you did there.
sien 10y ago
We could build something nuclear powered that would be able to do it. Project Orion or Project Daedelus would be able to escape the sun's gravity without needing a gravitational slingshot. But we have decided for now not to build something like that. Maybe in the next century at some point a nuclear powered spacecraft could be built in space that could start exploring other star systems.
- sandworm101 10y ago
  >> nuclear powered spacecraft. The voyagers are nuclear powered. They have RTGs powering their electronics and heat from those devices has changed their trajectories. The concept of a nuclear reactor powering an electric thruster isn't very far fetched. If we were going to go anywhere outside the solar system, that is the sort of nuclear power we would use.
  - mjevans 10y ago
    Sein is probably referring to something running quite a bit hotter and likely exciting hydrogen atoms or other expendable fuel sources. I think these might have been looked at for purely interplanetary/solar travel in the past, but written off for the dangers of lifting cargo to orbit (think about the failure cases!) and also the general cost compared to alternatives. If we had mining in lower gravity well areas (such as the asteroid belt) yielding that kind of fuel it might make a lot more sense.
    - supergarfield 10y ago
      Specifically, projects Orion and Daedalus are based on nuclear pulse propulsion[0], which is essentially detonating thermodynamic bombs behind the spacecraft. It's one of the only realistic options we currently have to do interstellar exploration. There was a discussion on HN not too long ago[1]. [0] https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion [1] https://news.ycombinator.com/item?id=12705705 https://news.ycombinator.com/item?id=12705705
Sanddancer 10y ago
Keep in mind that the Voyager probes weren't designed to go as fast as possible, they were designed to do planetary surveying while taking advantage of a rather favorable set of planetary alignments [1]. They could have been set on a much faster course if we were just concerned about getting them as far out into space as fast as possible. Voyager 1, for example, had its path altered away from Pluto to do a more in-depth survey of Titan. Regardless, using planets to help speed things is just good sense. Think of going on a long trip in a car. You don't hook a trailer full of all the fuel you'll need to get to your destination, you stop at gas stations along the way. Using planets is a lot like that. [1] https://en.wikipedia.org/wiki/Grand_Tour_program https://en.wikipedia.org/wiki/Grand_Tour_program
peterwoo 10y ago
New Horizons was launched directly into a solar escape trajectory. It's going slower than Earth but that is no indication of how advanced the technology is. The whole goal was to get a close encounter with Pluto-Charon. What's the point in flying off into nothingness any faster after that?
angusp 10y ago
Not really, earth is waaaay closer to the sun, so goes faster in its orbit but has a lot less energy (when normalised for mass) than any of the voyagers. They are going way faster than Earth in the sense that we're they to suddenly to telephone to Earth's perihelion, they'd be going ridiculously fast relative to Earth

by josho 10y ago

civilian 10y ago

Nitpicky but.... we'd still want to use gravitational slingshots even if we had more deltaVs to burn.

hcrisp 10y ago
Yes, in fact per Mark Adler [0] you'd use a Jupiter flyby to fly back to the sun and then do a high thrust burn at closest approach to maximize your speed into interstellar space (Oberth effect). [0] https://www.quora.com/Can-we-use-the-gravity-of-the-sun-to-slingshot-spacecraft-into-interstellar-space-or-to-other-stars https://www.quora.com/Can-we-use-the-gravity-of-the-sun-to-s...

rm_-rf_slash 10y ago

Problem is we don't really know where to go next. Jeff Bezos' Blue Origin tried to cook up alternate space travel methods for years and still couldn't come up with anything better than the same basic rocket model that put Gagarin into space. Most theorized "warp drives" either require more energy than humanity is capable of producing or necessitate breaking a law of physics or two just to move anything organic or larger than a postage stamp. Then again, the answer could be right under our noses. There's a Sci-fi story - I forget the name - where space travel is actually quite simple if you know the math to make it happen, and when a peaceful alien race visits Earth, the humans - with their thousands of years of armed conflict - kill the aliens and take their spaceships. Makes me wonder that if we treat the rest of the universe the way we have treated our planet, do we truly deserve the right to roam the stars?

Normal_gaussian 10y ago
It would be nice, and is certainly the result I hope for (with all the good wishes do), as I'm not sure we will work very well with slow and expensive growth. Reading 'Against a Dark Background' was certainly interesting as it considers a system which essentially has its growth capped by the distance between itself and the rest of the universe.
- pavel_lishin 10y ago
  Something I noticed in that novel is that they still had incredibly advanced technology. The Lazy Guns alone hint at what they lost! Maybe there's a reason Golter is where it is, and maybe it wasn't always there.
  - zipwitch 10y ago
    I read _Against A Dark Background_ as a teen an thought of it as a pretty fun sf, almost space-opera adventure story. Then I read it again as an adult and... wow. Bank's SF work is very good, but the quiet existential horror that lurks behind the scenes in that novel really merits the title. Makes good old Lovecraft seem like a piker by comparison.
meric 10y ago
You write a good comment, I don't know why you were down voted.
macintux 10y ago
I recall the story too: if I recall correctly, it was actually a branch of chemistry we had missed, not a math problem per se. The aliens stormed off the ships with muskets and we slaughtered 'em.
- bitJericho 10y ago
  Not doing any kind of reconnaissance before a conflict would be crazy! But I guess maybe they didn't think of it! It's also my working theory of why we won in Independence Day the movie :) Aliens were never warring among themselves and/or allowing any kind of a hacking culture, so didn't think to secure their systems!

Diederich 10y ago

> we are in the stone ages when it comes to spaceflight Indeed, only 59 years since we first put something into earth orbit. We're just getting warmed up!

kevin_thibedeau 10y ago
But that was only 54 years after figuring out powered flight.
- Retra 10y ago
  It turns out that "getting off the ground" is also the hard part when it comes to space exploration.
  - agjmills 10y ago
    "getting off the ground and staying there"
kaybe 10y ago
> We're just getting warmed up! Literally, sadly.
- Diederich 10y ago
  Sigh..I see what you did there.

sien 10y ago

We could build something nuclear powered that would be able to do it. Project Orion or Project Daedelus would be able to escape the sun's gravity without needing a gravitational slingshot. But we have decided for now not to build something like that. Maybe in the next century at some point a nuclear powered spacecraft could be built in space that could start exploring other star systems.

sandworm101 10y ago
>> nuclear powered spacecraft. The voyagers are nuclear powered. They have RTGs powering their electronics and heat from those devices has changed their trajectories. The concept of a nuclear reactor powering an electric thruster isn't very far fetched. If we were going to go anywhere outside the solar system, that is the sort of nuclear power we would use.
- mjevans 10y ago
  Sein is probably referring to something running quite a bit hotter and likely exciting hydrogen atoms or other expendable fuel sources. I think these might have been looked at for purely interplanetary/solar travel in the past, but written off for the dangers of lifting cargo to orbit (think about the failure cases!) and also the general cost compared to alternatives. If we had mining in lower gravity well areas (such as the asteroid belt) yielding that kind of fuel it might make a lot more sense.
  - supergarfield 10y ago
    Specifically, projects Orion and Daedalus are based on nuclear pulse propulsion[0], which is essentially detonating thermodynamic bombs behind the spacecraft. It's one of the only realistic options we currently have to do interstellar exploration. There was a discussion on HN not too long ago[1]. [0] https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion [1] https://news.ycombinator.com/item?id=12705705 https://news.ycombinator.com/item?id=12705705

Sanddancer 10y ago

Keep in mind that the Voyager probes weren't designed to go as fast as possible, they were designed to do planetary surveying while taking advantage of a rather favorable set of planetary alignments [1]. They could have been set on a much faster course if we were just concerned about getting them as far out into space as fast as possible. Voyager 1, for example, had its path altered away from Pluto to do a more in-depth survey of Titan. Regardless, using planets to help speed things is just good sense. Think of going on a long trip in a car. You don't hook a trailer full of all the fuel you'll need to get to your destination, you stop at gas stations along the way. Using planets is a lot like that. [1] https://en.wikipedia.org/wiki/Grand_Tour_program https://en.wikipedia.org/wiki/Grand_Tour_program

peterwoo 10y ago

New Horizons was launched directly into a solar escape trajectory. It's going slower than Earth but that is no indication of how advanced the technology is. The whole goal was to get a close encounter with Pluto-Charon. What's the point in flying off into nothingness any faster after that?

angusp 10y ago

Not really, earth is waaaay closer to the sun, so goes faster in its orbit but has a lot less energy (when normalised for mass) than any of the voyagers. They are going way faster than Earth in the sense that we're they to suddenly to telephone to Earth's perihelion, they'd be going ridiculously fast relative to Earth