[quote=Apollo26]
Why wouldnt it work in space? not arguing ( way past arguing on here) just curious. Covering thermal and radar signatures will render you almost nonexistent to anything short of a visual compromise. Unless someone can pick up the latent radiation residue on your ship? Also would it be an instant detect if anything was broadcasted from a "stealthed" ship or detectable from the source? ( given that the source didn't move)
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Because on a planet, aircraft, vehicles and even people equipped with adequate IR stealth systems can radiate their diminished heat signature into the surrounding medium so that they better blend in with everything else; environmental characteristics such as terrain and weather (storms/fog) must be taken into consideration as well. Stealth isn't about becoming completely and literally invisible, it's mostly about 'fitting in'--for lack of a better phrase or term. 

This doesn't translate well into an environment like space, which is notorious in fiction and nonfiction alike for being exceedingly frigid in areas where a star is not present. This does not bode well for spacecraft trying to hide their heat signatures, because their multi-terrawatt/gigawatt engines and reactors will put out enough waste heat to make them visible from an entire planetary system or star system away; even if you're using a megawatt-range reactor or engine system, you'd still stick out like a sore thumb. When you activate something as simple and low-powered as a faint radio signal of a mere 20 watts, [url=http://www.projectrho.com/public_html/rocket/spacewardetect.php#nostealth]you can literally be detected from 18 billion kilometers away[/url].

Acquiring visual confirmation of a starship in space is also not viable. Space is too dark and too large for that.

Trying to hide the radar signature of a starship displacing hundreds of thousands/millions of tons is more or less a pipe dream; bigger objects have bigger radar signatures.

[url=http://tvtropes.org/pmwiki/pmwiki.php/Main/StealthInSpace]Tv Tropes sheds some light on this topic as well.[/url]

Stealth in space, like FTL, is handwavium---though there are a number of things you can do to hide from someone in space, such as taking cover behind a planet or a very large asteroid or maintaining 'close' proximity to a star or other hot source. 

Personally, I don't run stealth spacecraft, so the vul'kruun do not have them in any shape or form. With how their FTL and space tactics works, space stealth isn't required, and may even be a liability to a star crawler (large spaceship), star cutter (huge spaceship) or star mauler (titanic spaceship) due to these vessels being suited more for rapid assaults and delivering vicious, crippling blows to xeno population centers. Stealth systems would just get in the way of that. Plus, I have no idea how you'd hide an operating Orion drive; detonating nuclear bombs behind yourself isn't exactly something that you sweep under the rug.