<div class="pull-right"><img src="https://cdn.steemitimages.com/DQmYSxS8DpBkYNeCUCkEpuFf9sKfDskbJKZQGwF9Fq7vyNw/image.png)"><br><center><sub>U.S. Army Institute of Heraldry <a href="https://commons.wikimedia.org/wiki/File:United_States_Space_Command_emblem.gif">link</a>
Public domain image.</sub></center></div>

On June 18 2018 U.S. President Donald Trump signed into existent the US Space Force which will be a new arm of the American military separate from the Air Force, Army, Marines, Coast Guard and Navy.

So this means that we will all soon be thinking about space in a different way from now on. No longer will space exploration by the sole topic of conversation but space warfare will also be on our minds.

Actual space warfare will be nothing like you see on Star Trek, Star Wars or your favourite TV show. In a space battle the enemy will be very far way and you will not be able to see the enemy except through a high powered telescope, radar screen or some other detection method. 

Space warfare will not be up close and personal. It will be distant, impersonal and automated.

There are of course a number of offensive weapons developed and under development for space warfare but by far the most valuable thing in war is stealth and in space stealth will not be possible.

This post will go into the details why stealth in space will be effectively impossible.

<div class="pull-left"><img src="https://cdn.steemitimages.com/DQmPZniRkrd9NNgXFpDkT8k5wt4LnhGGYC65ugLLHM87bw2/image.png"><br><center><sub>NASA/Sandra Joseph and Kevin O'Connell <a href="https://commons.wikimedia.org/wiki/File:Ares_I-X_launch_11.jpg">link</a>
Public domain image.</sub></center></div>

#### Rocket Exhaust

To move around in space you will need to use either a chemical rocket or an ion engine. Once activated, both of these propulsion techniques are extremely obvious to anyone with even the simplest detection equipment.

The flames from a chemical rocket are hot and bright. The charged atoms emitted by an ion engines are more tenuous but still very hot and will have an easily detectable spectral signature.

You may as well just jump out and yell "Hello, here I am. Please shoot me into oblivion!"

Photons have momentum so maybe, just maybe, someone could develop a light beam engine strong to move a ship or a missile around. The light beam will need to be pointed away from the enemy but even this will not be good enough and I will get into the following sections.

#### Radar Cross Section

In space the enemy will be pinging out radar pulses all the time in the volumes of space it wants to control. A ship or a missile will need to be coated in special materials to reduce its radar cross-section. This will only be effective for hiding the object beyond certain distances. Once a ship or missile gets closer than a certain distance, its presence will become obvious and it will become a target for elimination.

#### Light Signature

If an object is in an orbit near the Earth it will be lit up by the Sun. You can paint it black to make it less visible to telescopes but there are so many more wavelengths of light reflected by objects than just visible light. It will be a massive technological challenge to find a paint or a substance that does not reflect or emit any electromagnetic radiation in any wavelength whatsoever. 

<div class="pull-right"><img src="https://cdn.steemitimages.com/DQmfPQnFJ9XbqndSquoFx7crSfB9hYU5Q9tbmUUJfCLGcbA/image.png"><br><center><sub>NASA <a href="https://scifli.larc.nasa.gov/about/">link</a>
Public domain image.</sub></center></div>

#### Heat Signature

Everything that uses energy will never do so with 100% efficiency. Some of that energy always gets converted into heat. Once a body warms up above absolute zero (and that is everything) it will give off a heat signature (also called blackbody radiation).

The enemy will just need to sit there looking for any thing in the sky that glows with a heat signature. If that object does not identify itself as a friendly or if it simply looks annoying they will just blow it way.

So even if you have coated your ship or missile in the perfect EM absorbing paint, there is no known way to stop it from emitting a heat signature unless it has been chilled down to absolute zero of course. Any object at absolute zero is useless because it cannot move around, change orbit or operate any equipment.

<div class="pull-left"><img src="https://cdn.steemitimages.com/DQmdjcEwewfi4ksX5fEvTxDun7VqdhMq7u5gJa5E4CyhmUL/image.png"><br><center><sub>NASA/JPL-Caltech/UCLA<a href="https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA14723">link</a>
Public domain image.</sub></center></div>

#### Blocking Out The Stars

So, let us say that you have a great paint that absorbs most light, radar and any other frequency of the electromagnetic spectrum. That won't help because now you are now an obvious black dot blocking out the stars and galaxies behind you.

The enemy will just need to set up a high resolution telescope with a sky catalogue of the stars, nebulae and galaxies and just wait for you to blot out a small segment of the sky. 

You can try to mimic the light of the objects you are blocking but you will need to do that in all directions and at all frequencies (gamma rays and x-rays, ultraviolet, visible light, microwaves and black body).

Good luck with that.

<div class="pull-right"><img src="https://cdn.steemitimages.com/DQma1WKE2Qx69eVpY7r9m8XB9cqhq9isg4sYNNdcthnXZoH/image.png"><br><center><sub>Casandro <a href="https://commons.wikimedia.org/wiki/File:Spectrogram-fm-radio.png">link</a>
CC BY-SA 3.0 license</sub></center></div>


#### Move Fast -> Make Radio Waves

Let's say you give up on making your ship stealthy but instead focus on making your missile kind of stealthy and very fast. 

Space near the Earth is a good vacuum but it is not a perfect vacuum. Any fast moving missile will still be colliding with billions of hydrogen atoms every second as well as the solar wind and these collisions will generate radio waves.

As soon as a missile gets going fast enough to be effective its existence will become brutally obvious to all radio detection equipment. The enemy will soon turn this missile into an 'ex-missile' long before it reaches its target.

#### Decoys

What to do. What to do. 

You could set up millions of decoys, each one looking like your ship or semi-autonomous missile. This would be doable but expensive. It may also trigger your potential enemies just to clear out anything that looks like a decoy under the pretext of being belligerent.

Millions of decoys might also make navigation in space a very hazardous affair with commercial space traffic having to dodge all of those hard-to-detect military decoys.

Why defend a volume of space if you cannot live and work in it?

#### Blinding the Enemy

So if war does break out one option you have is to shut down and shield all of your sensors and then set off some nukes. This might blind and overload your enemies detection equipment so that you can rain missile down on them.

However the enemy will also know about this tactic and they will always have shielded equipment that they can bring out after a blast and use as a backup.

No joy there.

<div class="pull-left"><img src="https://cdn.steemitimages.com/DQmY8Uw44cUqeEzPHVMtEfxBMKityx3jtyr3k9adBBhtedv/image.png"><br><center><sub>NASA Orbital Debris Program Office <a href="https://en.wikipedia.org/wiki/Kessler_syndrome#/media/File:Debris-GEO1280.jpg">link</a>
Public domain image.</sub></center></div>

#### The First Space War Means No More Space Launches

If a big, bad space war ever does break out the debris from such a battle will be astounding. There will be millions or billions of pieces of exploded equipment orbiting throughout near Earth space.

This phenomenon is called the [Kessler syndrome](https://en.wikipedia.org/wiki/Kessler_syndrome) and it is the nightmare scenario for space travel.

Once you get large enough numbers of space debris in Earth orbit they will impact with satellites and also with other space debris. Each collision will generate more debris creating a cascading effect and making the situation worse and worse with time.

In only a few weeks or months everything in orbit will be destroyed and turned into debris. Launches from Earth will be impossible except for heavy, armoured and hardened satellites. Human-rated missions will become forbidden as too hazardous.

After the first Space War it does not matter who wins, humanity will become an Earth-bound species.

Oh yeah, there will also be no more weather satellites, satellite communications or GPS. Maybe this is the solution to Fermi's paradox after all.

*Thank you for reading my post.*

#### Post Sources
[Space warfare - Stealth Reconsidered](http://www.rocketpunk-manifesto.com/2009/06/space-warfare-ii-stealth-reconsidered.html)
[Project Rho - Space Warfare](http://www.projectrho.com/public_html/rocket/spacewardetect.php)
[Space Warfare - Isaac Arthur](https://www.youtube.com/watch?v=xvs_f5MwT04)
[Kessler syndrome](https://en.wikipedia.org/wiki/Kessler_syndrome)
[Blackbody radiation](https://en.wikipedia.org/wiki/Black-body_radiation)