"No, I don't believe in it," she replied simply, to the horror of most of the crew.
Townsend, however, was gratified. "There! That settles it."
"But I think it is a reasonable hypothesis that should be put to the test."
Rebecca's reversal sent the commander mentally reeling. He turned to the historian. "McGee, where do you stand on all this?"
"Let me put it to you this way, Colonel. If you were deciding for yourself alone, and didn't have a crew to be responsible for, what would you decide?
Townsend paused for a moment and looked out the window, then returned to face the crew with a rueful grin on his face. "You got me there, Professor. If I were flying this solo, I'd go for the drill. But there's more at stake now."
McGee was puzzled. "I don't get what you mean."
"The mission." Townsend tried to appear decisive. "If even some of us get back, the mission will count as a success. We can now be sure of that outcome, simply by continuing our current digging effort, scaled back a bit so we can stand it. If we gamble on Luke's theory, we risk not only our own lives, but the success of the mission. NASA, Mission Control, will never agree."
His lack of inner conviction was apparent to McGee. "Do you really care?"
"Yes I do, Professor," Townsend huffed. "For your information, I happen to be a military man and I believe in following orders."
Gwen wasn't fooled. "Come on, Colonel, cut the crap."
"Major, that remark was—" Townsend looked at the skeptical faces surrounding him and gave up the pretense. "All right, so I don't give a damn what anybody on Earth thinks we should do. This is nuts. You people really want to try it?"
Incredibly, they all nodded in agreement.
He shook his head in wonder. "You're all out of your minds. I don't know what you're doing here. You should have been fighter pilots. Major Llewellyn, in the morning, I want you to start rigging the rover for radar sounding. I'll work on a report to explain our new course of action to Mission Control. And Dr. Sherman..."
"Yes?"
"Doctor, I want you to start compiling a psychological dossier on me proving insanity. I'll need it for legal defense at my court-martial."
"Don't worry, Colonel," Rebecca giggled. "If that's your plea, I'm sure I can provide you with an ironclad defense."
"A real sweetheart, isn't she?" the commander muttered to the others.
CHAPTER 16
NEXT DAY, INSTEAD of resuming their digging routine, Gwen, Townsend, and McGee set about assembling a large Yagi antenna out of scrap aluminum stripped from the ERV and Hab lander stages. The antenna resembled an old-style TV rooftop antenna, but larger, designed to transmit "short-wave" radio signals that actually have a much longer wavelength than VHF television. Five meters long, the device was fitted crosswise across the rear of the rover and hooked to an oscilloscope that Gwen mounted on the right seat control panel.
Acting on the basis of a sense of humor unique to engineers, Gwen augmented the retro image of the gear by wiring in an audio oscillator that pinged every time a radio pulse was emitted, and sounded a slightly delayed answering ping if an echo signal was received. This gave the whole setup an operating feel similar to World War II submarine sonar.
Townsend looked at it and frowned. "Why is the audio necessary, Major, when all relevant data from the radar sounder is available in fully interpreted digitized form on the rover's computer display?"
With a wink at McGee, Gwen insisted on the absolute necessity of maintaining a "direct channel analog backup" to the computerized data. The colonel walked away, shaking his head, but the oscilloscope and pinging system stayed in place. Stepping close, Gwen confided to the historian, "Besides, the pinger should make the radar rig a whole lot more fun."
As the construction of the radar set proceeded, Rebecca and Luke spent hours scrutinizing maps, attempting to deduce from available surface geological evidence the most promising locations for underground aquifers. Unfortunately, no locations showed any obvious hints of subsurface water. So where to search?
The rover's maximum speed during sounding would be ten miles per hour, and the sounding data could only be assumed relevant to a quarter mile in either direction from the ground track. This meant that in a ten-hour driving day, they could search fifty square miles. Since the rover's maximum sortie range was 300 miles, a total of about 280,000 square miles was available to be surveyed.
Even at fifty square miles a day, it would take more than fifteen years to scan it all. If the stranded crew were to find water in time to make propellant for the next launch window, they had time to probe only about five percent of the territory available.
While there were no obvious targets, some regions of low-lying topography looked more promising than others. With this in mind, the two scientists drew up a plan for a systematic search of the best five percent their landing zone had to offer.
The search sorties began on July 28, with Townsend driving and Luke at the radar console. Unfortunately, they heard no return echoes that day—or any day in the ensuing three weeks, as various combinations of the crew took turns at radar sounding, tried their luck, and failed.
The radar sounding was not as hard work as digging, though, and as the weeks went by, the crew began to recover from the sheer physical exhaustion of their previous efforts. Nonetheless, as the searches continued to produce only negative results, hope began to fade, and a demoralization even more thorough than before began to settle upon the crew.
Then, early on the afternoon of August 12, with a bored Gwen Llewellyn at the wheel and a daydreaming McGee on radar, an echo was finally returned. The unexpected ping woke the historian out of his stupor. "We got something! We got something! Take a look."
Before Gwen could react, both the amplitude and frequency of the return pulses increased dramatically. She stopped the rover and looked at the oscilloscope trace, then at McGee with wide eyes. "What do you have on digital?"
He punched through several screens of data. "It's great! According to this, the source of the echo is less than a hundred meters down."
The flight mechanic adjusted knobs, kicking in the frequency doubler to increase depth resolution. She stared at the data in amazement and, forcing herself to remain cool, picked up the microphone. "Beagle, this is rover, reporting from map coordinate Delta 62.2, Foxtrot 96.8. We may have found something. It's a fast echo, just seventy meters down. If it's water, it's within range."
There was a crackle of static and then Luke's voice came over the receiver. "Send me the data file from your EM soundings so I can have a look."
Gwen threw a switch, opening the radar log upload. "Sending."
For almost a full minute, they heard nothing but static from the receiver. Then the geologist's voice blared forth, loud and clear. "Hehaa! That's water all right."
Gwen reached out and joyously hugged McGee, taking him by surprise. Embarrassed, she pulled back and covered up by getting back to business, while the professor blinked rapidly. Gwen, is there something going on in your mind that I should know about?
"Water! We found it! Well, don't just sit there staring like a silly old egghead, McGee—break out the drilling rig. We've got work to do."
McGee regarded her for a significant moment, then unbuckled his seat belt. "Aye, aye."
Moving quickly, they broke out the drilling rig, which consisted of sets of concentric tubing that could be extended by means of a rotating screw mechanism, a collapsible tripod to hold the upper end in place, an automole with a superhard drill bit to lead the descent, and an electric motor with a set of gears to turn the toothed exterior of the uppermost of the telescoping tubes. Then they ran a power line out to the motor from the auxiliary generator of the rover engine. The two set up the drill and started it running, then climbed back into the rover to pass the time.