"Critical divergence from flight path!" the range officer reported.
"Concur. Critical divergence from flight path," the flight dynamics officer reported.
The ascent program was failing as Peter had feared. The computer was pulling the spacecraft out of the necessary flight path it needed to achieve orbit.
"Status... procedure romeo seventeen...," Lipton ordered instantly, sitting bolt-upright in his seat, rigidly following his procedure at once.
"I've got it!" Cartwright reported over the net. In the lander, he grabbed the flight control stick between his legs. He could see the same divergence from the flight path as the monitors at the control center. The display on the computer screen in front of him showed the flight path as a three dimensional corridor in which the lander was depicted, and the lander was falling below the corridor.
Cartwright's wrist twisted decisively and instinctively on the control stick to bring the tiny craft back into the flight corridor. The lander began to buck and vibrate. Beads of sweat materialized instantly on his lip and forehead. His eyes focused quickly on the time remaining. He had two minutes and fifteen seconds to correct the divergence with the fuel remaining. There could be no second chances.
"Lander, BC1, report status," the flight director asked impatiently.
"I said I've got it!" Cartwright replied sharply.
He could see the display responding to the movements of his wrist. This was clearly different from simulations of similar situations. The control was much more difficult. The vibration was too excessive. Something else was going wrong.
Sigourney Michner, sitting in the opposite seat, scanned the instruments quickly with her eyes. She saw the time ticking away and realized the response was too sluggish. Then she saw why. The autopilot had not been disabled from the control console.
"Autopilot disabled!" she said, flipping the switch on the panel in front of them. Suddenly the wild vibration and bucking stopped.
The mistake had been costly. For nearly a minute, the computer and Cartwright had been battling for two different trajectories. The ship was attempting to fly in one direction, Cartwright in another As soon as the autopilot was disabled, the ship began to respond just as it had in the simulators. But Cartwright's reflexes had been fixed by the effort of the seconds just preceding. Suddenly the image representing the ship's trajectory climbed steeply, too high and too quickly above the flight corridor.
"Out of range high!" Michner warned unnecessarily.
Cartwright responded reflexively, again overcompensating and sending the ship out of the corridor too low. The final seconds were ticking away.
"15 seconds to MECO," the flight dynamics officer reported, referring to main engine cut off, when the main engine fuel tanks literally ran dry.
Cartwright struggled to bring the ship back into the corridor. This time his wrist moved slowly, inching the ship back into the correct flight path. He could see the image apparently responding in the proper degree.
Michner was the first to recognize disaster was inevitable. Her trained eyes scanned the instruments. Too much fuel had been used fighting the autopilot. The vehicle did not have enough inertia to stay in orbit.
"Main engine cutoff!" Cartwright replied proudly, watching the projection of the lander finally drift into the corridor.
The feeling of freefall and weightlessness released the eight passengers and two crewmembers. The passengers began to cheer and remove their helmets. Cartwright's smiling eyes met Michner's profoundly troubled visage. In a single second he could read the reality in her face. His eyes shot back to the display of orbital parameters. The flight dynamics officer on the ground voiced it aloud just as he saw it glowing on the screen before him.
"Suborbital parameters: 191 kilometers by zero. Velocity: 4.87 KMS." He could not bring himself to complete the statistics on the impact. They were some 0.16 kilometers per second short of achieving any kind of stable orbit. The orbit's lower parameter of zero kilometers implied inevitable impact.
Cartwright could see his computer display reflect the facts. The image representing the lander had already risen above the line. The ship was destined to arc high over its intended orbital altitude, then fall back to crash on the other side of the planet. They were out of fuel and out of options. He realized, as Michner had, they were all dead. Awaiting their final seconds was only a formality dictated by the rigid laws of physics and flight dynamics. “TIME TO IMPACT” flashed across his screen, counting relentlessly down: minus 22 minutes 33 seconds.
Lipton sat back in his seat, completely dazed and ineffectual. He watched as his career was following the exact same trajectory as the lander. It was now absolutely over. As soon as communications with earth were reestablished, he would be recalled in disgrace on the next ship out. Above him, due largely to his relentless, even imperious demands, ten people were about to die a horrible death.
The reality of the situation took a little longer to catch on in the dining hall. There was considerable applause and cheering when the main engines cut off and not everyone understood the full implications of "suborbital parameters of 191 by zero". Yet, within short minutes, the reassurance was supplanted by the impending certainty of mass death.
In space, Cartwright was not giving up so easily. He and Michner were busily scheming possible ways to survive. All they needed was to boost their velocity by 0.16 meters per second. But they had to act quickly. Once they reached the high point of their orbit, or perigee, the mechanics would change and even more velocity would be required to recover.
"Interrogate the OMS energy boundaries," he ordered Michner, but she had already pulled them up on the computer screen. With a few deft strokes of her fingers over the keyboard the answer arose: there was not sufficient fuel remaining in the orbital maneuvering engines to give them enough velocity.
"That's it, unless you can dream up another miracle," Cartwright stated to her flatly. He was a fighter, but knew his ship well. There just was not enough energy on board to raise the velocity. Using up the orbital maneuvering fuel would only serve to delay the inevitable; perhaps boost them around the planet a few hundred more kilometers. But the end would be the same.
The passengers were completely unaware of their predicament. None of them could hear the flight dynamics officer report on the orbital parameters, and had they heard, none of them on this flight would have fully understood. Hicks and several others had unfastened their seat belts and were floating about the already crowded compartment. Their lighthearted noise had risen to the point where hearing was difficult.
Michner unbuckled herself, stood up on her seat and turned to face them. "Okay, okay, listen up!" she shouted. The passengers all stopped to listen. She resisted the urge to be nasty. "Please take your seats immediately," she said as pleasantly as she could. "Please fasten your harnesses tightly around you, place your helmets back on and pressurize your suits. Do it immediately!"
"Is there a problem?" Hicks asked, floating just below her.
"Do it now!" Cartwright exploded. Hicks quickly complied.
Michner returned to her own seat, now trembling, wondering if she had made a mistake by ending the last sounds she would ever hear of other human beings enjoying themselves. Cartwright looked at her and placed his hand on hers giving it a reassuring squeeze.
The activity on the ground was frantic. The flight director shouted orders at the flight dynamics officer who was both tracking the ship and doing energy exchange calculations as fast as his fingers could move.
"Approaching apogee, minus 43 seconds," the flight dynamics officer reported, watching the last moments of possible solutions tick by, waiting powerlessly while ten souls counted their final minutes of life as they approached the highest point of their orbit. "Cartwright, invert and fire your OMS immediately!" he ordered as a last resort.
"Negative," Cartwright replied.
"Then what's your plan, Commander?" he asked briskly. There was no response.
In orbit two hundr
ed kilometers behind and below the lander, Kerry could hear and clearly understand their predicament. But he had an idea.
"Twenty two seconds to apogee," the ground intoned, counting off the seconds till the lander reached the top of the orbital hill.
"Ian, listen up," Kerry said to Cartwright. "Use your reaction and control system to keep your nose pointed at an angle to the atmosphere. We're going to skip you back into space like a rock. Raise your altitude... give it all you've got!"
Cartwright felt a surge of energy. Yes, this was their only chance. If he could gain enough speed to impact the edge of the atmosphere at just the right angle, they could use the heat shield to absorb the energy from the atmosphere and bounce back off into orbit. They might be able to gain enough energy from the long fall back toward the planet to pull it off. It was the longest of long shots, but it represented their only hope. The question was one of whether they would have enough altitude and initial velocity to get the boost they needed at the bottom of the gravitational hill.
"Ten seconds to apogee."
"Siggy, fire the OMS engines now!"
Michner did not fully understand why she should fire the engines, but she did as she was told, instantly. She knew by training and discipline that her life often depended on instant obedience. Her fist smashed against the firing plunger.
The lander lurched forward. They had enough fuel remaining to boost them some 0.08 kilometers per second faster. The firing ended all too quickly, just nine seconds later.
The flight director was temporarily disoriented. He had not listened to Kerry's broadcast. The flight director's plan was to invert the orbiter and fire the engines to round out the orbit, giving them a slower reentry profile and a better chance at surviving the reentry heat, never mind the crash landing. Cartwright had just fired the engines with the lander aimed in the direction of flight, which would have the opposite effect. The lander would now achieve a higher apogee, a longer fall to the planet and a higher reentry velocity.
The new orbital figures flashed on the screen: “Suborbital: apogee 223 kilometers by zero. Apogee minus 2 minutes 06 seconds.” They had bought themselves a few more minutes.
"What's your plan Commander?" the flight director inquired once more.
"Standby," Siggy replied briskly. They were too busy to offer narratives. That could come later if they were successful.
Kerry was busy calculating orbital limits. The plan was painfully simple and relied on the ability of the lander to preserve enough of its initial velocity, plus that added by the planet's gravitational tug downward, minus the energy lost by the glancing blow with the upper atmosphere when they skipped off; provided they could skip off at all.
It was an exceptionally crude variation of the slingshot effect used by planetary probes. But unless everything was just right, they would burn up on reentry instead of skipping. Being the crew of a manned meteor was not Cartwright's idea of a good flight.
"Ian, I've got some good stuff," Kerry reported. "Adjust your attitude to minus 32 degrees and hold it there. Report your altitude and I'll give you a signal to raise the nose. Prepare to recover at plus seven degrees on my mark. Whatever you do, maintain your azimuth!"
Kerry's voice was now being broadcast throughout BC1. Every individual crowded around a screen, eyes glued to the drama unfolding around them. Lipton sat catatonically, not daring to move or speak. Peter had removed enough skin from his lower lip that it was beginning to bleed.
"Ian, have you got any fuel left in the OMS?" Kerry asked.
"No."
"Then use your RCS, sparingly, to recover your angle of approach. I want you to arc over apogee. Don't crest or you'll lose momentum. We're going to need all we can get."
"Roger," Cartwright said and swung the ship to change his trajectory just slightly. Now he was aimed toward the horizon.
"Good; now we wait," Kerry said forthrightly.
"Thank you Commander," Cartwright replied.
"I'm just a lowly Lieutenant, remember?"
"Not if this works," Cartwright replied drolly.
The minutes to apogee dragged by. The flight dynamics officer calculated Kerry's plan out to the third decimal. He found it barely had a chance to work, but every maneuver would have to be executed perfectly.
"Now at apogee," the Flight Dynamics Officer confirmed sharply.
Siggy gave Cartwright a hopeful look and a weak smile. They had crested the hill and were now accelerating toward Mars. The finesse with which they now flew their ship would determine whether they would live to see another hour. Cartwright reflected on the only positive side he could envision from such a death: it would come quickly.
"Time to interface: 8 minutes 49 seconds," the flight dynamics officer reported. In that time the spacecraft would encounter the Martian atmosphere where, with any luck, they would bounce off with added gravitational energy and glide with all the grace of a wounded goose back into space.
While the minutes drifted by, Cartwright and Michner discussed and struggled with the piloting techniques they would use when encountering the atmosphere. Meanwhile, Kerry slaved over new and radically different rendezvous equations. He was beginning to understand that even if they achieved some kind of bizarre orbit with this technique, it may put them out of range of an eventual rendezvous. He discovered that their angle of skip was most important.
He explained this to Cartwright who appreciated not only the realities of space and aerodynamic flight, but was astonished at the instant creativity and gushing but controlled energy of Kerry. He had always thought of Kerry as quite an oddball.
"Two minutes to interface."
Those on the ground and in the two spacecraft literally held their breaths as the seconds ticked away to the inevitable resolution.
"Minus one minute."
The first encounter with an atmosphere for space travelers is a pink glow around the nose of the spacecraft as it ionizes the thin atmospheric gasses. This particular reentry was far and again faster than the craft was designed for, so the glow began immediately. For the first time in their careers, pilot and commander felt the lander bump against the thickening layers of the high atmosphere, alarming Cartwright.
"We've already got turbulence!" he reported.
"It's too early," the flight dynamics officer reported. "You're half a minute from interface."
Kerry responded instantly. "Start your skip profile early. Start it now!" He understood that the atmospheric limit calculations varied from sol to sol and that with the increased speed, the effect from a radical density change came sooner than predicted by the nominal approach calculations. Together they were working against the calculated limits and eating up the energy of the spacecraft.
Cartwright's sweaty hands gripped the stick and gently eased it back to a positive inclination. They could feel the rising G-forces pull them back and down into their seats. This distressed Cartwright who correctly interpreted these forces as deceleration forces, pulling them toward the surface of Mars.
"I've got a rising G-load," Cartwright warned, his voice obviously alarmed.
"Stay with it, Ian; this is the most critical time. Keep your nose at 12 ‘till I order otherwise," Kerry said. He, too, was afraid. He was flying the lander by intuition from hundreds of kilometers away, feeling the G-load by instinct, moving his hand on the stick by sympathetic emotions alone. It was not by-the-book flying or even sane flying, but it was all they had.
"Move it to 17.5 now, Ian. 17.5; stay with it pal," he said evenly. “And for God’s sake, mind your azimuth!”
The brilliant radiance of the lander had increased. They were glowing even brighter than under normal reentries. This was to be expected. Yet, the temperature was rising in the vehicle and now both Cartwright and Michner were sweating profusely.
Cartwright kept an eye on the glow. Nothing else mattered. If they were going to survive, the glow would start to decrease, and that would have to happen in the next 45 seconds or less.
The flig
ht dynamics officer on the ground had quit trying to figure it all out and just sat in silence in his seat watching the show. The orbital data was appearing and revising itself so quickly on his screen that it was an unintelligible blur.
"Ian, you still with me?" Kerry asked.
"Still alive, Commander Kerry. And I’m happy to report the glow is diminishing."
"Stay with it, buddy. Ease your angle up to parabolic at 24 and hold it steady. You're on your way back into orbit!"
The cheers in the control center and BC1 were deafening. It was hard to find anyone not hugging or slapping someone’s back. Lipton was the sole exception. He sat stoically, still staring at his monitor.
Finally the flight dynamics officer had a good number. "Elliptical orbit: 55 by 117 kilometers!" The orbit was stable. The low end was very low, but could last another few sols. The applause and back slapping began anew.
But Kerry began feverishly working out a new set of calculations: rendezvous. The flight dynamics officer began with the same calculations instantly. The answer came quickly.
"Are you certain of your tracking data?" Kerry asked the ground.
"Plus or minus half a klick," flight dynamics answered confidently.
There was a protracted silence.
"What solution do you have, flight?" Kerry asked worriedly.
"No nominal solutions," responded a quiet voice.
"Would somebody please tell me what the hell...," Cartwright asked, his voice rough and agitated.
"We don't have a solution for the rendezvous, yet," Kerry replied, knowing the chances were very good there would not be one at all.
Orbital rendezvous depends on several conditions including the same angle of motion relative to the ground. Changing such orbital angles, called inclination, determined entirely by the three dimensional plot of not just altitude but flight angle or azimuth, was extremely difficult and energy intensive when attempted from orbit. After a given degree of separation, none were even possible at all. The flight computers both in space and on the ground had already cranked through all the possible calculations and found "no nominal solution", which was so much technical jargon for "impossible".
Mars Wars - Abyss of Elysium Page 18
