Shields always up?

[Velocity]

Starships are always zipping around the galaxy at extreme speeds, so shouldn't they always have shields engaged at some level, for protection from running into space detritus, runabouts, escape pods, crystalline entities, etc, not just when they need to repel enemy weapons? Should they be saying instead Raise MORE Shields!

 

[1001001]

Deflector vs Shields

 

[JirinPanthosa]

The plot device is that you can not have shields up and do other stuffs, like use the transporter, cloak and go to warp.

 

[Velocity]

So there is a difference between deflectors and shields...

 

[Vger23]

Navigational deflectors (like the main dish on most starships) handle the issues you've brought up here.

The shields draw a lot more power and would not be practical to keep constantly engaged.

 

[GNDN18]

Neither deflectors nor shields for me. “The meteorite beam has not deflected it, Captain.”

Next thing you know they’ll be switching to rockets.

 

[Timo]

It's an enduring and complex mystery, that - why don't starships always have their full combat shields up? Why are they only raised in the nick of time even in clear-cut combat situations, with invisible opponents potentially lurking left and right?

Starships have energy resources to burn: there's never a concern about fuel consumption when a ship whimsically goes to warp at arbitrary speed (although impulse flight does appear to consume fuel in "Doomsday Machine" at least). Why not burn it for protection in anticipation of combat? Shields can be raised without warp power, so they aren't that copious consumers.

Since no rationale is ever stated on screen, speculation abounds. Is it for stealth, with raised shields shining across lightyears? Does it confuse early warning sensors, so the best protection is instead obtained by having those sensors automatically trigger the raising of shields?

Timo Saloniemi

 

[Forbin]

Maybe there are "normal" shields up for cruising around, but "battle" shields for battle. So when the captain dramatically yells "SHIELDS!!!" and drops his tea, it's the additional battle shields they're raising.

 

[Timo]

With TOS, it's extra redundant with repeat: the ship itself is supposed to turn on the shields in face of danger or mystery. Which might explain why Kirk utterly fails to utter the "shields up" bit in the whole of the combat engagement in "Balance of Terror"...

Or then we can use that ep for the shields-hamper-sensors theory and decide that Kirk deliberately kept his shields down so that Spock could track the invisible ship.

Timo Saloniemi

 

[Bry_Sinclair]

In "The Outrageous Okona" Riker comments about 'navigational shields' and how they would be more than enough defence from laser fire.

 

[Timo]

Which then makes one wonder about the transporters. The writers want to say "shields means no transporters". Having variety to shields sort of thwarts that. Especially if we want to believe in a variant that's always up.

Although there are so many cases of transporters having little problem with shields that we probaby would be better off believing that only "shields from certain level up" are a problem.

Timo Saloniemi

 

[feek61]

In the book "The Making of Star Trek" it explains the difference between shields and screens and the power consumption of both. From memory, basically deflectors screens are always on when the ship is at warp to divert dust, etc. and the shields on when there is danger.

 

[Spot261]

With TOS, it's extra redundant with repeat: the ship itself is supposed to turn on the shields in face of danger or mystery. Which might explain why Kirk utterly fails to utter the "shields up" bit in the whole of the combat engagement in "Balance of Terror"...

Or then we can use that ep for the shields-hamper-sensors theory and decide that Kirk deliberately kept his shields down so that Spock could track the invisible ship.

Timo Saloniemi

Kirk just likes to live on the edge.....

I always thought the navigational deflectors effectively provided the role of routine protection against space debris, etc, whilst shields proper are for tactical purposes. We could suggest that they would be highly energy intensive to an extent that surpasses warp drive, (which after all doesn't actually have to propel a million ton starship using newtonian mechanics) or that components are subject to rapid deterioration during prolonged use.

It could be simply that the tendency to only operate them as required is primarily a diplomatic policy, with keeping them down being a convention which signals peaceful intent, but the fact we are often shown ships in wartime operating with shields down until danger presents makes this problematic

 

[Tenacity]

why don't starships always have their full combat shields up?

Maybe it's not a question of power, but of the operational service life of the shield emitters? You only get a certain number of hours of use, and then you have to physically replace or overhaul several hundreds of them all over the ship.

 

[Vger23]

Maybe it's not a question of power, but of the operational service life of the shield emitters? You only get a certain number of hours of use, and then you have to physically replace or overhaul several hundreds of them all over the ship.

It's likely to be a combination of both factors, actually.

Well that, and the fact that it would suck if various characters didn't get to yell "SHIELDS UP!" at various points throughout the series and films.

 

[JesterFace]

Perhaps some form of shielding is on all the time.

Then when someone screams "shields up!" combat shields pop up.

 

[ZapBrannigan]

Regarding the main deflector dish that Roddenberry envisioned for rocks and dust, in real space it would have another use as well. Interstellar space contains about one hydrogen atom per cubic meter.

As you fly through space, you slam into those floating atoms. The faster you go, the more of them you hit, and the harder you hit them. At a certain speed, the hydrogen atoms you are hitting become exactly like high-speed radiation hitting you. If the ship doesn't have some kind of deflector system, or tons of lead in the hull, this pseudo-radiation would be deadly.

 

[Balok's Decoy]

I always figured that energy isn't free and a defensive shield constantly turned on would be a drain on resources.

 

[Retu]

It's an enduring and complex mystery, that - why don't starships always have their full combat shields up? Why are they only raised in the nick of time even in clear-cut combat situations, with invisible opponents potentially lurking left and right?

Starships have energy resources to burn: there's never a concern about fuel consumption when a ship whimsically goes to warp at arbitrary speed (although impulse flight does appear to consume fuel in "Doomsday Machine" at least). Why not burn it for protection in anticipation of combat? Shields can be raised without warp power, so they aren't that copious consumers.

Since no rationale is ever stated on screen, speculation abounds. Is it for stealth, with raised shields shining across lightyears? Does it confuse early warning sensors, so the best protection is instead obtained by having those sensors automatically trigger the raising of shields?

Timo Saloniemi

Starships might have excess energy to spare, but thermodynamics can still throw a spanner into the works. If we go by the dialog, then heat dissipation is one of the limiting factors in shield operation:

TASHA: Deflector shield technology has advanced considerably during the war. Our heat dissipation rates are probably double those of the Enterprise-C, which means we can hang in a firefight a lot longer. (Yesterday's Enterprise)

 

[Tim Thomason]

AIUI, deflectors "deflect" physical objects, i.e. asteroids, debris, atom bombs. But shields shield the ship from non-physical energy beams (phasers, lasers, disruptors, plasma cannons). By the time of TNG they even have navigational shields for, I guess, solar flares or maybe as a backup from sucker punch strikes (not as good as 100% shielding, but the ship won't go down in one hit).

 

[Blamo]

I thought that deflectors, screens, shields and forcefields were largely interchangable.

Hence why it's called a navigational deflector and not just deflector.

As for why they aren't always on.... No idea. I mean some systems won't work with them on, but the show never really bothered to address the power drain on systems.

To be honest, if there was ever a reboot, I'd like them to have a limit on how many systems they can run at the same time. I mean shields, transporters/replicators, holodecks, warp drive should be huge crazy power drains, yet they don't seem to ever have a problem with it.