CHAPTER 12
DEEP SPACE RADAR SEARCH
The huge warship clawed her way around Jupiter, surveying its large retinue of moons. On the gas giant’s surface, blustering storms swirled, forming a mosaic of vague images, any one of which could have hung majestically in an art gallery. Raucous winds swept along, singing their own songs, as yet unheard across the vacuum of space.
As Repulse traveled through Jupiter’s thin rings, micrometeorites disintegrated against her hull. In the distance, small craft and merchantmen dotted the horizon. Three flights of Eagle fighters were soaring nearby in a lattice formation.
Nearing the end of JOOD watch, Gallant stood on the bridge of the Repulse. Usually, he savored the grandeur of sunlight illuminating the writhing planetary oceans, but today he was distracted by Kelsey’s delicate silhouette standing between him and the wall-height display.
Refocusing his attention on the current series of radar sweeps, he ordered, “Flights one, two and three, reform into formation bravo.” Then he added to the helmsman, “Hard to port, come to course 180, azimuth up 10 degrees, speed 0.001c, at time 1155.” He felt the ship respond even while the fighters repositioned around her.
“Kelsey,” he bawled, over the din on the bridge. A wave of his hand beckoned her aft.
Balancing herself against the motion of the deck, she made her way to him. She had examined the status board and was prepared to relieve him as JOOD. He said to her, “Conducting mobile radar sweeps around Jupiter and the moons. Our speed is 0.001c, two hundred thousand miles from the planet. There are two merchantmen and several shuttles as listed on the contact board, no maintenance or repair operations. I have the conn. The captain has the deck.”
“No long range sweeps?” she asked.
“That evolution has been left for your watch section,” he smiled, knowing she would be pleased to perform the complex scans facing the outer planets.
“Good,” she said. “I relieve you.” Her eager face showed she couldn’t wait to conn the ship for the upcoming maneuvers.
“I stand relieved,” he said.
Loudly enough that the whole bridge could hear, she said, “This is Midshipman Mitchel. I am the Junior Officer of the Deck. I have the conn.”
“Very well,” said Captain Caine.
“Request permission to remain on the bridge to observe, sir?” asked Gallant, hoping to gain some experience on the long range radar sweep.
“Permission granted, but stay out of the way,” said Caine.
“Yes, sir. Thank you, sir.” Gallant moved to the starboard wing. He relished the few additional minutes available to him.
Captain Caine ordered, “Midshipman Mitchel, prepare for long range sweeps.”
“Aye, aye, sir,” said Kelsey.
Gallant watched Kelsey slide into a casual proficiency as she reviewed the virtual screen displaying the configuration for the lattice. He let his mind wander while the bridge crew busily set up for the maneuver. She was working with the AI to calculate how to reposition Repulse.
Gallant followed her math, accustomed to doing the calculations in his head.
The goal of the long range lattice radar sweeps was to scan the outer planets on a regular basis. They presented minimal planet, or moon, shadows for alien ships to hide behind. Captain Caine had dispersed Jupiter Fleet’s six battle cruises and their fighters to ensure that coverage areas were comprehensive and overlapping.
Captain Caine observed the preparations and checked to see that they would execute on the prearranged schedule. When he was satisfied, he said, “Midshipman Mitchel, commence scan at time 1230.” He waited expectantly.
“Yes, sir,” she replied.
Gallant observed, as Kelsey’s agile mind reevaluated and cross-checked the parameters. Then she broadcast over the fighter channel, “All fighters form lattice formation gamma-seven.” She turned to the helmsman and ordered, “Come right to bearing 122 degrees, azimuth up 010 degrees, velocity 0.001c, course 120, time 1230.” This placed Repulse in the exact center of the lattice formation.
Her astrogation was ‘spot on’ and the exercise proceeded successfully, but the sweep revealed no new sightings. Some bulk information was added to the disposition of ships around Saturn, but the details were poor, given the distance.
A few minutes later, Gallant heard Chief Howard’s voice booming over the ship’s intercom, “Captain, I’m receiving the long range radar results from the rest of the fleet. I am forwarding the data to the bridge.”
“Very well,” responded the captain, as he scrambled over to the radar station to see for himself. Gallant craned his neck to catch a peek at a nearby science station. Each of the five battle cruisers sent their data from their long range scans. It was up to Repulse to perform the integrated the analysis.
As Gallant observed the operation, he was reminded of one of Caine’s favorite alliterative sayings: ‘Proper planning; prevents poor performance.’
Captain Caine’s search plan was to optimize his limited Jupiter Fleet radar antennas by using strategically placed arrays along the Jupiter orbit. The fleet radar (radio detection and ranging) used radio frequency electromagnetic waves, supplemented with the optical telescope signals. Each radar system consisted of four main parts - a transmitter, an antenna, a receiver, and a display. The optical equivalent of radar, called lidar (light detection and ranging), used light waves. The fleet’s pulse radars sent radio waves in short bursts, or pulses. The distance to a target was determined by the time it took for the signal to reach the target and for the echo to return. Even at the speed of light this took a significant amount of time.
Gallant recalled from his academy classes that because radio wavelengths are longer than visible light, radio telescopes were necessarily larger in order to achieve the equivalent resolution of the optical telescopes. As part of his training check-off requirements he recently learned that many of Jupiter Fleet’s directional antenna arrays used wavelengths between 3 and 30 meters (10 - 100 MHz). Other radio telescopes operating at wavelengths shorter than 30 cm (above 1 GHz) used antenna of 3 to 90 meters in diameter.
To produce a high quality image over vast distances required the integration of a large number of different telescopes at various separations. The projected separation between two telescopes, as seen from the radio source, formed the baseline. The telescopes arranged in an array created a process called very long baseline interferometry (VLBI). Interferometry increased the total signal collected which increased the resolution by aperture synthesis. This technology superposed the signal waves from many sources. In principle, when the waves coincided with the same phase, they added together, while two waves of opposite phases, cancelled each other.
Caine’s plan spread his ships and their antennas, out into as wide an area as possible. The dispersed battle cruisers, destroyers and fighters scanned outward toward Saturn to produce a huge collective array system that could superimpose their results.
Renown, Remarkable, Retribution, Dauntless, Devastator and seven destroyers were deployed with Repulse along Jupiter’s orbit. Renown, Remarkable, and Retribution, were each fifty million miles apart on the clockwise side of Jupiter’s orbit. Dauntless and Devastator were each fifty million miles apart on the counter clockwise side from Jupiter. Each of Jupiter Fleet’s six battle cruisers were positioned so when their collective radar scans could be analyzed accurately while covering the largest possible sector from Jupiter extending toward the outer planets. Together the scans could look toward Saturn and Uranus and catch any large formation of ships at ranges of several hundred million miles.
In addition, Caine collected supplemental information from his search drones. Their input was integrated with the radar reports. The drones set an early estimate of ship activity at Saturn, and then the collective radar scans were intended to monitor any large ship formations coming toward Jupiter.
While this offered some assurance that Jupiter could not be approached from the direction of the outer planets without detection,
Neptune and Uranus were on the other side of the sun and completely outside the radar search area. Also, if the Titans traveled along the Saturn orbit for several months, they could then turn and travel sunward beyond Jupiter Fleet’s detection range.
The Weapon’s Department head, Lieutenant Stahl, and Operation’s Department head, Lieutenant Mather, were on the bridge reviewing the results. As each battle cruiser reported its findings, Repulse’s CIC analyzed the results. The results showed no significant ship activity coming from Saturn.
Lieutenant Stahl said, “There are no large formations coming from the outer planets. The Titan’s seem to be content to stay in their own backyard.”
“Maybe,” said Caine.
Lieutenant Mather said, “There are still a lot of Titan destroyers patrolling the asteroid belt that might interfere with mining operations or interdict shipping.”
“They haven’t done so yet,” said Caine thoughtfully. Nevertheless, after deliberating with Stahl and Mather, Caine considered the possibility more seriously.
Captain Caine said directly to his communication officer, “Midshipman Gallant, draft an order for Devastator and Dauntless. They’re to move into the shallows of the asteroid belt. Once there they are to evaluate alien ships near the mining settlements.”
“Aye, aye, sir,” said Gallant. He began thinking not only about how he would word the orders in preparation for transmission, but what impact moving two battle cruisers such a distance away would mean to the fleet.