In "Star Trek" (2009), how did the Enterprise collide with debris while the shields were on?

Question

Re-watching the 2009 movie for the first time after answering this question about shield collisions, I noticed the following:

Enterprise is about to drop out of warp in Vulcan space.

Captain Pike: Raise shields, red alert.

Enterprise drops out of warp, encounters the debris field of the other star fleet vessels and suffers hull damage due to a low velocity graze against a piece of debris even though its shields are up and fully charged.

The shields are capable of pushing interstellar dust out of the way at high impulse (which is relativistic), and surviving photon torpedo detonations.

So what happened?

Answer 1

I think the shield technology is a little different than the later ellipsoid ones. It is an energy field applied to the hull that deflects energy weapons. In Star Trek 6 you can see torpedoes hitting the hull even though the shields are up, but they cause little damage compared to later when the shields are down.

Answer 2

I'd have to watch that scene again - but it could be that the debris was already inside the shield's surface area.

In other Star Trek material (particularly TNG, but other series, too), shields appear to be ellipsoid shells around the ship, so it is possible that the debris was already inside as the shield was powering up.

An alternative explanation is that the shield technology at the time of the movie isn't as good as the other time periods we see in Star Trek (it is set prior to TOS).

Answer 3

The exact behavior of shields varies through the canon. It's generally accepted that shields block high-energy transmissions (phasers, disruptors, transporter beams), and "high-velocity" physical objects (photon torpedoes, asteroids, even smaller ships). However, there are also instances of a ship's shields holding back powerful but slow-moving physical barriers, such as the gate into the Dyson's Sphere in the TNG episode "Relics". So, one would think with shields at full that a collision with a piece from another ship would leave the debris worse off than the shielded ship.

In addition to deflector shields, most Federation ships have a deflector array. This array is highly configurable, and so can do basically anything the scriptwriters need, but its primary purpose is to push away large physical objects while the ship is underway; it's the ship's "icebreaker", shoving aside particulate matter, asteroids, etc while the ship is moving, especially at warp. It's supposed to work in much the same way as the full shields, but is generally lower-power in "shield" form, requiring a "beam" to push higher-mass objects. It's logical, given the difficulty involved in locking transporters on to a moving target, that the deflector array would simply be overwhelmed. The very large ship remnant that Enterprise specifically has to dodge is also half the size of the Enterprise herself; at some point the act of using any sort of beam to shove away a hunk half as heavy as yourself without any change in your direction or velocity would offend our Newtonian-oriented sensibilities.

The in-universe answer would probably be that the deflectors, both the full shields and the array, is simply overwhelmed by the sheer size and number of debris objects that must be shunted aside. Why they're still effective at near-full power after that, to absorb one of the Narada's missiles, is anyone's guess. The out-of-universe answer is that it's more visually engaging to see a piece of flotsam the size of an aircraft carrier gouge out a few panels of the brand-new Enterprise's saucer, with or without shields. Typical Rule of Cool.

Answer 4

I don't believe there are canonical examples of starships plowing through fields of ship-sized debris and expecting the shields to handle it for them. Maybe this is just because captains prefer to preserve their shield power, but it's certainly plausible that shields just aren't meant to handle that sort of thing.

Answer 5

I've always attributed this to the size of the debris that collided with the ship. As you mentioned, the shields (augmented by the navigational deflector) are capable of deflecting interstellar dust, even at high velocities.

But dust has a relatively low mass, meaning the energy required to move it out of the way is not very high (relatively speaking). The destroyed starship debris on the other hand, IIRC, was a large section of a secondary hull, a piece of the saucer section. The energy required to deflect this would have been orders of magnitude greater. Also, we don't know what velocity the Enterprise was traveling at, whether it was moving at full impulse or some fraction. This would have played a large part in how effective the shields would have been as well.

Finally, remember back to the movie Nemesis. In the final battle the Enterprise is struck by a large section of a Romulan ship. It is not unreasonable to assume that the Enterprise-E from the 24th century, built to battle all the baddies of its age, would have had vastly superior shielding technology. Yet even with that advantage, the shields were only just able to deflect that piece of debris.

Answer 6

The Enterprise in this episode is a new and untried ship with an inexperienced crew.

The shields are designed to protect the hull of the starship, so a piece of another starship of the same design could possibly breach the shields, as the shields are designed to protect against energy weapons and foreign materials, Another Federation starship could pass through this, theoretically.