4 ms·

I always find it funny in sci-fi: "their missiles have locked on to us!"

by Chris2048 7y ago

leetcrew 7y ago
even if the missile isn't using active guidance (ie laser/radar), it's pretty easy to detect anything with an engine in space. there aren't a lot of other explanations for a small object on an intercept course for your ship at high acceleration.
- krapp 7y ago
  Obligatory link to the "There Ain't No Stealth In Space" article at Project Rho[0]. [0]http://www.projectrho.com/public_html/rocket/spacewardetect.php http://www.projectrho.com/public_html/rocket/spacewardetect....
- saberdancer 7y ago
  I'm not sure if this is true, if the missile is coming head on. If it is made in a stealthy way, the "head" of the missile could obscure the engine area and make the plume invisible to the target. Having low RCS alongside with hidden plume could make a passively targetted missile relatively stealthy to the target. Ofcourse, anyone with enough offset to the target would be able to easily detect the engine and thermal release but the target could be unaware. Another method to hide it is if missile uses some kind of obstacle in order to accelerate behind, for example you fire your missiles and they accelerate when a moon or a planet break line of sight from the target to the missiles. This would make their acceleration burn invisible to the target and could get them very close without being noticed.
  - leetcrew 7y ago
    if you're curious about this topic, I highly recommend checking out the webpage linked in the sibling comment, "There Ain't No Stealth in Space" if you're curious about this topic. tl;dr: it's exceedingly difficult to hide anything that consumes power in space. the rcs thrusters would either be too weak to achieve the delta v to hit the target, or the friction from the thrust against the nozzle would unstealth the missile. even the radiation from the onboard computer would likely stand out against the cosmic background. a missile like you describe could potentially evade current detection systems, but would almost certainly be detected by any civilization where ship-to-ship space combat is feasible. and not in a handwavy future tech way, but just from extrapolating current tech. I highly recommend checking out that page. it makes for a great read.
    - saberdancer 7y ago
      I've read it and mostly agree. The article even talks about the "solution" I mentioned (they call it cold plate). Stealth in space is impossible if you use constraints they used (solar system coverage with sensors and need to hide a ship with life support). What I've talked more is about a missile. Missile can fly "cold", it could even be multistage so that after it's acceleration burn it can drop of a hot lower stage and continue to the target completely cold. If you add a cold plate and "terrain masking" you could effectively use a missile stealthily. Ofcourse if there is a full system sensor coverage this is not possible, but I've said that in my initial comment as well. You may be able to hide the heat from your target, but not from everyone.
lolc 7y ago
Granted this works only for active radar-guided missiles, but those can easily be detected by their radar shining right at you. Maybe all the missiles in sci-fi are radar-guided?
- Chris2048 7y ago
  They "lock on" before the missile if fired.
  - lolc 7y ago
    How would the target know it was locked upon?
    - Chris2048 7y ago
      That's my point. Maybe a notification protocol? Seems to be used as a warning sometimes..
      - lolc 7y ago
        Ah sorry I misunderstood your comment. I thought you wanted to say it was obvious for the target to know. Haha yes a notification protocol would be a weird thing to have. It would be gamed the millisecond things went beyond friendly warnings.
      - saberdancer 7y ago
        Others have already commented, but normal surveillance radar is like a spotlight from the tower. It goes around and scans the area. If they determine that you are important, the radar can "lock on" to you which means that it will no longer scan around but would shine the light on you constantly. If they want to shoot at you, they turn on another even stronger more focused light to improve accuracy. Military today have ability to detect enemy targetting radars and when they lock on so having such a thing in SciFi does not seem strange to me.
    - magduf 7y ago

I always find it funny in sci-fi: "their missiles have locked on to us!"

even if the missile isn't using active guidance (ie laser/radar), it's pretty easy to detect anything with an engine in space. there aren't a lot of other explanations for a small object on an intercept course for your ship at high acceleration.

krapp 7y ago
Obligatory link to the "There Ain't No Stealth In Space" article at Project Rho[0]. [0]http://www.projectrho.com/public_html/rocket/spacewardetect.php http://www.projectrho.com/public_html/rocket/spacewardetect....
saberdancer 7y ago
I'm not sure if this is true, if the missile is coming head on. If it is made in a stealthy way, the "head" of the missile could obscure the engine area and make the plume invisible to the target. Having low RCS alongside with hidden plume could make a passively targetted missile relatively stealthy to the target. Ofcourse, anyone with enough offset to the target would be able to easily detect the engine and thermal release but the target could be unaware. Another method to hide it is if missile uses some kind of obstacle in order to accelerate behind, for example you fire your missiles and they accelerate when a moon or a planet break line of sight from the target to the missiles. This would make their acceleration burn invisible to the target and could get them very close without being noticed.
- leetcrew 7y ago
  if you're curious about this topic, I highly recommend checking out the webpage linked in the sibling comment, "There Ain't No Stealth in Space" if you're curious about this topic. tl;dr: it's exceedingly difficult to hide anything that consumes power in space. the rcs thrusters would either be too weak to achieve the delta v to hit the target, or the friction from the thrust against the nozzle would unstealth the missile. even the radiation from the onboard computer would likely stand out against the cosmic background. a missile like you describe could potentially evade current detection systems, but would almost certainly be detected by any civilization where ship-to-ship space combat is feasible. and not in a handwavy future tech way, but just from extrapolating current tech. I highly recommend checking out that page. it makes for a great read.
  - saberdancer 7y ago
    I've read it and mostly agree. The article even talks about the "solution" I mentioned (they call it cold plate). Stealth in space is impossible if you use constraints they used (solar system coverage with sensors and need to hide a ship with life support). What I've talked more is about a missile. Missile can fly "cold", it could even be multistage so that after it's acceleration burn it can drop of a hot lower stage and continue to the target completely cold. If you add a cold plate and "terrain masking" you could effectively use a missile stealthily. Ofcourse if there is a full system sensor coverage this is not possible, but I've said that in my initial comment as well. You may be able to hide the heat from your target, but not from everyone.

lolc 7y ago

Granted this works only for active radar-guided missiles, but those can easily be detected by their radar shining right at you. Maybe all the missiles in sci-fi are radar-guided?

Chris2048 7y ago
They "lock on" before the missile if fired.
- lolc 7y ago
  How would the target know it was locked upon?
  - Chris2048 7y ago
    That's my point. Maybe a notification protocol? Seems to be used as a warning sometimes..
    - lolc 7y ago
      Ah sorry I misunderstood your comment. I thought you wanted to say it was obvious for the target to know. Haha yes a notification protocol would be a weird thing to have. It would be gamed the millisecond things went beyond friendly warnings.
    - saberdancer 7y ago
      Others have already commented, but normal surveillance radar is like a spotlight from the tower. It goes around and scans the area. If they determine that you are important, the radar can "lock on" to you which means that it will no longer scan around but would shine the light on you constantly. If they want to shoot at you, they turn on another even stronger more focused light to improve accuracy. Military today have ability to detect enemy targetting radars and when they lock on so having such a thing in SciFi does not seem strange to me.
  - magduf 7y ago