The test "raft" centered in the Gate was a dummy structure half the size of the Shapieron, containing an instrument and sensor platform, and a duplicate installation of the Shapieron's intended on-board M-wave gear. It also carried a selection of plant and animal specimens for ascertaining the effects on biological processes. Hunt sat in the MP3 Control Center at MP2, taking in the situation from screens commanding the floor, plus VISAR-supplied avco visuals. He was here physically once more. There was no nonexistent observation room, complete with virtual bar, this time.
Almost a year had passed since the group's first arrival at Thurien. However, with acceptance of the new mission that Calazar had called for in his dramatic presentation to the Thurien Grand Assembly, the workload had not only intensified but widened, as everything that had been pieced together concerning Lunarian Minerva suddenly became relevant. On top, there had been Eesyan's insistence on reverifying the engineering from the ground up. Without Thurien methods and the computational resources of VISAR to back them up things, things would never have gotten even close to progressing this far.
All the same, most of the group had managed to fit in at least one trip back to Earth during this time. Sandy and Duncan had broadened the interpretation of their role of assisting Danchekker and Hunt to involving themselves with the Thuriens in analyzing as much as was known of Minervan history in the period leading up to its destruction, but at the same time managed to fit in a couple of weeks skiing in the Andes as well. Danchekker had spent most of the interim at Thurien immersed in his biological and philosophical pursuits, returning once or twice in response to summonses from Ms. Mulling involving official duties that he was unable to evade. Sonnebrandt was currently back there, having been called home on some family affair, and when he would be returning was as uncertain. Mildred had completed her researches and returned to Earth to work on her book, while Chien had not been back at all, but stayed on to follow the progress of construction at the MP3 Gate. She was the only other Terran present with Hunt at MP3 to observe the test.
In fact, Hunt's work had taken him back to Earth the most, involving long sessions with Caldwell to redefine Tramline's part in the new overall strategy. Caldwell was patched into the proceedings too, coming through from Earth in an avco window. Hunt was pretty sure that more had gone on behind the scenes to all this that involved Caldwell somehow. Caldwell was showing more interest in the day-to-day details than was usual for his kind of management style. Hunt had picked up rumors among the Thuriens that the vision with which Calazar had dazzled the Assembly owed much to Caldwell in its earliest stages of conception. But when Hunt tried to raise the subject out of curiosity, Caldwell had been evasive. Hunt knew from long experience that when Caldwell decided he didn't want to talk about an issue, that was the end of the matter.
Since Minerva at the time the mission was aimed at had been inhabited by human Lunarians, it had been agreed humans should be included in the team to be sent on it. Anyone suggesting otherwise would have had a tough time dealing with Hunt and the others who had been there from the beginning, in any case. Caldwell had made it clear that no one among them needed to feel any commitment to the new mission, but the thought of not going hadn't entered any of their heads. As was to be expected, when the news went around back on Earth, various other interests had made their presence felt, wanting to get in on the act and send people too. But they would have been negative assets, resented as an intrusion into the team. Caldwell was alive to the mood, and since disruptions at this point would have compromised the effectiveness of his people who were on the spot, he took it as part of his business to mount defenses on the home front. Hunt could only conclude that in this Caldwell was fully successful, since none of the wrangling and background politics had percolated through to Thurien.
The object of the present experiment was to send the test raft to a marked alternate reality of the Multiverse, and then bring it back-a pretty important prerequisite to have mastered if they were going to be sending Thuriens and Terrans. It was still not possible to "map" the Multiverse in terms of the attributes pertaining to a particular reality, for example, "A universe where Genghis Khan wasn't recalled after defeating the Prussian defenders of Europe, overran the West, and the dominant civilization that arose to colonize the world was Asiatic." No ready way had been found to connect "change," as perceived subjectively in the countless directions making up the Multiverse, with anything that could be measured as physics; indeed, whether such a connection existed at all was by no means certain. VISAR had been trying to refine the concept of "affinity," which yielded rough measure of how far a different reality was from the familiar one, but it could be notoriously unspecific when it came to indicating how they were different. A universe where Earth had no Moon, one in which Mars still possessed oceans, and another where Jupiter was missing two of its principal satellites all registered comparable affinity indexes. Why this should be, nobody even had a theory. At this stage it was impossible to say if sense would ever be made of it.
The affinity index was useful nevertheless in that it provided a crude way of marking off the swathe of Multiverse in which realities possessing a certain family resemblance-the Minerva of fifty thousand years previously, for example-were likely to lie. The approach was a bit like highlighting a newspaper ad with a tar brush, but in a situation where it reduced possible solutions numbered at "almost-infinity" by an amount "almost-infinity-minus something," the result was a problem that VISAR could generally find manageable. In short, while it wasn't possible to hit a specific target by its characteristics, they could usually lob a shell onto more or less the right continent.
Given some indication by the data fed back of where and when they were within those limits, the technique then was to try and hop the device closer by sending it a series of corrections. The corrections didn't always have the expected effect, but correlating the directives sent with the result returned was producing the fragments that it was hoped would one day connect together into a map. But nobody yet knew what the scale was, and to make matters worse the scale seemed to vary in every one of innumerable directions. VISAR said it was nice to have something challenging to do.
The voice of the Thurien supervisor directing the operation came over the local circuit. "Beacon lock-on is holding steady. Bell distributor drawing h-input and charging. Drone wave function registering on all matrixes. Pilot beam synched." An exchange of numbers and status checks with VISAR followed. It meant that the raft out in the Gate was ready to go, and the array of projectors positioned in space around it was almost up to power. The "beacon" was for VISAR to home the raft on-a probe that had been sent through about thirty minutes previously to a fairly "nearby" location in the Multiverse that could be identified with some confidence. A fix from the returned astronomical observations and intercepted Thurien communications signals put it about a half million miles from an unremarkable planet of one of Gistar's neighboring systems, and several months in the past.
"Well, with luck we'll soon know if you were right," Hunt said to Chien. The test involved an aspect of the return-wave that she and some of the Thuriens had been investigating. An object was brought back by reversing the projection process-effectively creating a progression of wave representations in the return direction. It had been demonstrated successfully with a series of small objects sent via the old MP2 chamber. The raft would be the first attempt with a larger body, using the Gate.