How far could we detect a rocket in space?

In summary: The article claims that "directing your waste heat (and making some part of your ship colder, a related phenomena) requires more power for the heat pump - and every W of power generated generates 4 W of waste heat."
  • #1
GTOM
955
64
For exact example, the Apollo rocket, that carried Armstrong to the Moon?

Yes i read atomic rockets, but that happened : http://en.wikipedia.org/wiki/Chelyabinsk_meteor

It looks like to me, they were a bit over optimistic about how far can we detect a simple heat radiating object. Ok that meteor came from the direction of the Sun (isnt an impossible stealth option for a rocket neither), but still, if such faint objects can be detected only in the last few hours, that seems to me a scale below the ranges suggested by that site.
Maybe they underestimated infrared background clutter, or i misunderstood something?
 
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  • #2
hi there

Not sure what atomic rockets has to do with it ?

dont forget it wasnt radiating any significant heat before atmospheric entry ... it seems that you think it was ?

they can only really be detected by either radar or optically

Dave
 
  • #4
"dont forget it wasnt radiating any significant heat"

Does that mean it doesn't warmed up by sunlight, to a degree similar to lunar average?
With 200K i still calculated millions km detection range, based on their equitation.
 
  • #5
Asteroid J002E3, detected in high Earth orbit near the L1 point (~1.5 million km), turned out to be the Apollo 12 third stage. It was rediscovered in 2003 when it re-entered Earth orbit from heliocentric orbit.
 
  • #6
Remember that Atomic Rocket makes a very important(and reasonable) assumption. Any polity which can launch large spacecraft on a regular basis can afford to spread huge numbers of observation satellites throughout the solar system. We don't have very many of those right now.
 
  • #7
Bandersnatch said:
He means this site: http://www.projectrho.com/public_html/rocket/
and this section in particular: http://www.projectrho.com/public_html/rocket/spacewardetect.php#nostealth
There's a lot of nonsense and misinformation in that latter link.

Those telescopes could spot Voyager because the operators already knew where to look. Suppose they had no clue where to look; which is what the situation would be if one were looking for invaders. Suppose they took two seconds to take an image and only took another couple of seconds to move the telescope to the next area of the sky. Let's ignore the fact that there will have to be some overlap in images to get a full scan of the sky. How long would this full sky scan take with the Green Banks Telescope? The answer is almost a year. Not four hours.

Voyager is of course aiming it's antennas straight toward the Earth. Would intruders be broadcasting their presence and aiming their antennas straight at the place they are about to attack? No. They are not going to come in sending signals straight at us, or firing thrusters straight at us. Even if we were looking at exactly the right spot in the sky we might never see them.

Think of it this way: An alien intruder did exactly that last February over Chelyabinsk. We never saw that meteor coming. After the fact, astronomers looked at previously gathered images to see if it had ever been seen. It hadn't.
 
  • #8
In Rise of Leviathan there were some stealth ships, described as strategical instead of tactical weapon.
I know that due to the laws of thermodynamics you can't contain your waste heat forever, let alone hide the flames of the thrusters. (Magnetic sails would have pretty big radar cross-section on the other hand.)

However, is that true, what is written on that not so reliable atomic rockets link?
"Furthermore, directing your waste heat (and making some part of your ship colder, a related phenomena) requires more power for the heat pump - and every W of power generated generates 4 W of waste heat."

What if they use liquid helium and magnetic cooling instead of the traditional method of compressing gases?
Would that be more efficient for containing or beaming away waste heat?
 

1. How far can we detect a rocket in space?

The exact distance at which a rocket can be detected in space depends on various factors such as the size of the rocket, the type of sensors used for detection, and the surrounding environment. Generally, current technology allows us to detect rockets up to a few hundred thousand kilometers away.

2. What types of sensors are used to detect rockets in space?

There are various types of sensors used for detecting rockets in space, including optical sensors, radio telescopes, and radar systems. Each type of sensor has its own strengths and limitations, and scientists often use a combination of these sensors to accurately detect and track rockets.

3. Can we detect rockets in deep space?

Yes, we can detect rockets in deep space. However, the detection range may be limited due to the immense distances involved. For example, the Voyager 1 spacecraft, which is currently the farthest human-made object from Earth, can only be detected up to a distance of about 22 billion kilometers.

4. How does the distance of the rocket affect its detectability?

The farther a rocket is from the detection sensors, the weaker the signals it emits will be. This means that as the distance increases, the detection range decreases. Additionally, the size and speed of the rocket also play a role in its detectability, as larger and faster rockets can be detected from farther away.

5. Is it possible to detect a rocket in space without using any sensors?

No, it is not possible to detect a rocket in space without using sensors. Since space is a vacuum, sound waves are unable to travel through it, making traditional methods of detection, such as sound waves, ineffective. Therefore, specialized sensors and technologies are necessary for detecting rockets in space.

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