The Whale Probe was the designation for a probe of unknown origin which visited Earth in 2286. It was given this designation due to the fact that it apparently came to Earth in order to contact members of the humpback whale species.
Dwarfing the Miranda-class Federation starship USS Saratoga and even the Earth Spacedock, the Whale Probe was cylindrical in shape, and carried a small deployable sphere, normally stowed internally, at the front. This sphere was physically detached from the Probe while in use, but connected to it by an energy beam. The sphere's purpose was that of a communications device.
It apparently served to broadcast the message of the Probe, but had the side effect of causing virtually any device that used energy to function to lose its power. It was also capable of ionizing planetary atmospheres, seemingly as another unintended side effect. (Star Trek IV: The Voyage Home)
First contact with the Probe by a Federation starship was made by the USS Saratoga while patrolling the Neutral Zone. The Saratoga was disabled by the probe's powerful communication, as were at least seven other vessels along the probe's route to Earth, including the starships USS Yorktown and USS Shepard and two Klingon vessels. The ships did not recover from their neutralized states even after the Probe had continued on, beyond their ranges.
After disabling both Spacedock and the USS Excelsior, the Probe settled over the planet and directed its transmissions towards its oceans. The sheer amount of energy contained in the broadcast began to vaporize Earth's oceans and ionize the atmosphere, creating a catastrophically thick cloud layer over the entire planet, disabling power and communications over many of Earth's largest cities. One report to the Federation President gave the planetary cloud cover at 73% and rising.
As all planetary power sources began to fail, the Federation President was forced to send out a planetary distress signal, which was picked up by Admiral Kirk, aboard the "HMS Bounty", a captured Klingon Bird-of-Prey. In the signal, the President gravely advised any unaffected space craft to avoid Earth at all costs. Spock, also aboard, noted that the transmission appeared to have been intentionally directed at Earth's oceans, and theorized that the message may have been intended for some aquatic creature.
After listening to what the Probe's transmission sounded like underwater, it was discovered to be identical to the sounds produced by an extinct cetacean species called the humpback whale. Spock theorized that the Probe had been sent by some unknown intelligence that had once been in contact with whales, who had sent the Probe after the whales went extinct to find out why contact had been lost.
Destroying the probe appeared to be out of the question, as any vessel that went anywhere near it immediately lost power. As such, it was determined that the only way to save Earth was to respond to the Probe and hope that it would leave once it had made contact with its intended recipient. However, with no whales left on Earth, there was no way to accurately respond to the Probe, as simply replicating the sounds made by humpback whales would have been useless without knowledge of the language involved.
Kirk determined that the only way to stop the probe was to find some humpbacks who could answer it. Consequently, the Bounty was taken into the past via the slingshot effect, and successfully retrieved two of the species from 1986. Returning to the time shortly after the probe's arrival in 2286, the two whales were able to respond to the probe's call, and it departed for an unknown destination, restoring power to the vessels it disabled along the way. (Star Trek IV: The Voyage Home)
A cylindrical space probe was already envisioned in the reference book Star Trek Spaceflight Chronology (p. 121) of 1979 as "first evidence of extra-galactic civilizations". In the book, it was described as a small probe of unknown origin, measuring 2.0×0.375 meters. Nevertheless, it is highly unlikely to have been the original inspiration for the eventual "Whale Probe".
Described in the script of Star Trek IV: The Voyage Home as "a simple cylinder, non-threatening but huge in size, with odd, eye-like antennae" , no specifics of the Whale Probe were ever given on screen. Yet, Effects Director of Photography Don Dow stated that, as far as in-universe dimensions were concerned, "it was to be five miles long and a mile-and-a-half wide." The Whale Probe was designed by Nilo Rodis, incorporating ideas he had received from The Film-Makers' Cooperative in Los Angeles, that translated into an apparently simple, vaguely whale-like cylinder, transferred onto pre-production storyboards. (Cinefex, issue 29, p. 5)
Deceptively simple as it might have seemed, Industrial Light & Magic did encounter problems while trying to realistically bring the concept of the probe onto the big screen. Model Shop Supervisor Jeff Mann recalled, "There were some difficulties early on with the probe. Trying to get that to have some scale was difficult because it was big and shiny. It had blue-spill problems. Early on, we did a bunch of tests to try to figure out what kind of texture or what we could do to give it that kind of scale that the starships had." ("From Outer Space to the Ocean", Star Trek IV: The Voyage Home (Special Edition) DVD special features) Don Dow elaborated, "I think the probe was the most difficult thing we had to work with on this show, simply because there was nothing to it. Our original instructions from L.A. were to make it 'menacing, military and massive' and it was supposed to be about five miles long and a mile-and-a-half wide. To really do that, we would have had to build a model that was as big as a building. And because it was so devoid of detail, I was afraid it was just going to look like a giant water heater in space." (Cinefex, issue 29, p. 5)
Though the fourth Star Trek film was supposed to be light on ILM where starship studio models were concerned, no less than three models of the Whale Probe were constructed in the end. Jeff Mann recalled, "Since Nilo's concept was that the probe looked similar to a whale, we built a prototype that was a cylinder shape with barnacles and whale-like coloring – but still basically just a tube. We capped the ends of a piece of irrigation pipe and installed a mechanism to turn the ball-like antenna that jutted out from the bottom." (Cinefex, issue 29, p. 5)
Eventually, the bullet was bitten and a model was constructed, about which Jeff Mann stated, "Basically, it's a cylinder that started off to look like a section of a whale. We used a barnacle type of texture for it, and it was originally painted with a crusty-textured white on a blue background. It was sort of organic looking, and that was the design we originally settled on. We built several versions of this monolithic probe that threatens the Earth. The main model we used was an eight foot long cylinder about two feet in diameter, and it had a hole at one end through which an antenna ball emerges on a shaft of light and sort of searches around." (American Cinematographer, October 1982 ed., p. 68) Also constructed were a "smaller version to scale for the distance shots, and then we built a large section of the ship – just a third of the side of it – and it was tapered for a shot where the ship is heading towards camera and then flies overhead. Like a takeoff on that first shot in Star Wars. We also built some large antennas for close-ups," as reported by Mann. (American Cinematographer, October 1982 ed., p. 68) More to the point, Mann stated, "Our primary probe was eight feet long, but we also made a small one for the long-distance shots and another big section that was a forced perspective model – about twenty feet long and really wide at one end and the tapered back at the other." (Cinefex, issue 29, p. 5)
In order to save as much financially as post-production opticals were concerned, Jeff Mann decided to have his new Whale Probe models, as much as possible, have self-illuminating capabilities. Mann elaborated, "The Probe had a hole on the bottom that the ball jutted out from. Inside it, we put six halogen bulbs that emitted a general glow down onto the ball and out the hole. Then, down the center we had a tube of plexiglass that was about two inches in diameter that attached to the ball. Inside of that was a long tube lamp – like a refrigerator lamp – which was just screwed into a 110 socket. So the stage crew could do several light passes on the probe." (Cinefex, issue 29, p. 5)
The whale-colored probe did not quite work out on screen, and after several shoots, a decision was made to alter the color scheme of the model as was recalled by Don Dow; "We had to give it some texture. After brainstorming it for a while, Ken Ralston came up with the idea of painting it shiny black and then backlighting it so there would be reflections coming off of it. We also ended up pock-marking the surface a little so that the backlighting would pick up some hills and valleys. Then we shot it with fog filters which helped to give it an awesome, mysterious quality." (Cinefex, issue 29, p. 6) Jeff Mann gave an additional reason from a different point of view; "We worked for quite a while on these models with a specific color and texture on mind, but then we reached a point where they just didn't look right. It wasn't exciting, because it was blue, like a whale. Also, the antenna originally didn't move and it didn't have a light source in it, so we made the antenna move and added an interior light to the ball. For the antenna's beam of light, we added a hot shaft of light in the center and put a much milder glow around that. I think it was Ken Ralston who came up with the idea to paint the probe black and eliminate all the color from it so we could use light and reflections on it to create interest and mystery." (American Cinematographer, October 1982 ed., p. 68)
No matter what the original intent was, lighting the ball-shaped antenna presented its own set of additional problems, as ILM's Optical Supervisor Ralph Gordon recalled; "The spherical antenna underneath the probe was originally shot so that it was orange, which unfortunately made it look very much like a spinning basketball. So we pulled mattes off of that that one element to drop it out – the ball itself had been shot separately from the probe – and then we made high-con elements that allowed us to expose blue light over that same area. We threw in all sorts of diffusion and filters on it to break up the image and give it a glow that looked like it was coming from the inside. That took a lot of finagling. We put diffusions on both the main projector head of our optical printer and on the aerial head, the back projector. We'd find a diffusion that worked somewhere, lock that off and then move the back head around trying to figure out where the best placement of the diffusion was. Like always, it was just a matter of trial and error." (Cinefex, issue 29, p. 6)
A sequel novel to Star Trek IV, Probe, accounted another run-in with the Probe during proposed peace talks/joint archeology-survey with the Romulans. Kirk and his crew later discover that the Probe was created by beings that resembled Earth cetaceans, and that it was damaged thousands of years earlier by what it described as "mites" in cube-shaped vessels, which implies that it encountered the Borg at some point before coming to Earth.
In the Myriad Universes novels, in an alternate timeline with both Kirk and Spock dead, the Probe did indeed decimate Earth, leading Doctor Carol Marcus to attempt to use the Genesis Device to fix it.