Holt seated himself beside Hubbard in the Oberth's landing boat's copilot seat, while the others floated into the well-packed cargo space. Then the boat was cast off and hauled by two busy bees some 300 meters to the side of the orderly column of space ships. The three hundred meters increased the boat's distance from Mars above that of the column of the convoy, and the bees had to reduce slightly the boat's velocity around the planet to keep the orbit exactly circular. Since Oberth had been number two ship near the head of the line, the boat now passed in review beside the circling vessels, drifting slowly astern of them, while their crews floated in their astrodomes and waved farewell. Then the boat hung solitary above the vast Martian surfaces.
Deceleration for descent was to take place at the southernmost point of their orbit.
They would then make a half circle of Mars to enter his atmosphere just before reaching the point where their northing flight would again turn southward. Detailed computations had shown that the boat could then glide down to the selected landing spot near the south pole in a long, gentle right hand spiral and with minimum alteration of course. Hubbard brought his flywheels up to speed and turned the boat to maneuvering position. The rocket nozzles were now opposed to the direction of the satellite orbit. Hubbard glanced at the clock and signaled the passengers to strap down. He touched the ignition switch and the jet roared into space, snapping the accelerometer to lg. Slowly it climbed to 1.03 -1.05 — 1.07 — 1.08g. At 17.2 seconds, the thrust cut off. It had reduced their orbital velocity by 173 m/sec. Quiet again reigned in the boat.
Hubbard again rotated his vessel to coincide with the flight direction, occasionally correcting to keep their centerline coincident with the line of flight.
"That must be Lucus Solis," he remarked to Holt, pointing at a geometrically circular, large green area in the desert just below them. "Even with all the study of this scenery and the many months in the simulator, it still looks pretty strange when you actually see it."
"Ahead of us must be Aurorae Sinus," said Holt with a glance at his knee-held chart.
"Then the Margaritifer Sinus. Who do you suppose doped out all these crazy Latin names? I'll bet the Martians name them differently."
"Maybe they call it Greenland because it's green," ventured Hubbard.
"Hardly," grinned Holt. "If their logic works the way logic works on Earth, Greenland would be white!"
They had been coasting for half an hour without power when night fled below them across the planet's wastes. In their control room it remained bright for 15 more minutes, then they too were shrouded in blackness. Their radar altimeter, sending its pulses to ground and measuring the time of return, had begun to register, showing their altitude as 200 kilometers. There were no responses to Hubbard's control movements, nor did the wing temperature indicators even flicker.
"What a queer atmosphere this planet has," remarked Hubbard. "Near Earth, we wouldn't even be expecting any air at this height. But if the scientific boys are right, we'll have stratospheric conditions right at the surface when it comes to the landing."
"According to the sounding bomb," answered Holt, "you ought to feel something when the altimeter reads 180 kilometers. That's quite amazing when you remember that we're moving much slower than we would be this high over Earth."
"That's right," said Hubbard. "If this were a landing from Lunetta, we'd have a velocity of 8.27 km/sec at the perigee of our landing ellipse. Here it's only 3.67 km/sec, notwithstanding this perigee's being 155 kilometers high, while the one from Lunetta is only 80. Hmm… seems to me I can feel something…"
As he twisted the wheel to and fro, the wide wings began to rock slightly under the influence of the elevons and there began the first audible signs of the passing air in the shape of a gentle hissing.
The pressure altimeter's hand began to kick around the dial which had been covered with a rough, hand-drawn scale computed from the results radioed back by the sounding bomb. It went from 165 to 160 to 159 kilometers and then settled at 158. Hubbard thrust the control wheel ahead.
"We seem to have gotten into this funny stuff a little high," he remarked. "I'd better nose down a little so as not to sail right out of it again."
They were lifted softly out of their seats by the negative lift of the great wings.
"The ship's doing all right," said Holt with an eye on the altimeter. "Here we go down again."
The wing temperature began to rise. 100 — 200 — 300 degrees registered in succession. Then it stopped at 370 degrees Centigrade.
"Wing temperatures are no problem here," said Hubbard. "What with our low wing loading and low speed, we won't even get to 400 degrees."
"Do you remember how Dick Peyton wanted to skin those things with dural instead of steel? He might almost have gotten away with it so far as the temperature's concerned.
But discretion's the better part of valor."
Holt kept an anxious eye on the leading edge, but the familiar glow of a landing on
Earth failed to materialize. This was less ghostly than a return home from Lunetta. The tiny light ray from the cabin lost itself along the length of the somber wing surface. There was no tendency to float out of their seats now.
Harry Brooks handed up a radio chit from his cubby hole. "Hope you are doing fine — Tom," it read.
Holt wondered whether Knight, circling above them, was worrying while they sat as comfortably as in any airliner and split the air of the second planet to feel the foot of man… Here they went, through a mad sort of atmosphere, which nevertheless reacted to controls as if their aircraft were in the familiar air of their home planet.
Showing Hubbard the chit, he scrawled upon its reverse the familiar words: "Having wonderful time. Wish you were here," and gave it to Brooks. Doubtless the very banality of the response would help to quiet any undue nervousness in the distant space ships.
Hubbard now cut in the automatic pilot, setting the ship in a long, right-hand gliding turn, carefully worked out beforehand. It would steer them out of the plane of the ecliptic and towards the south polar cap, the aiming point of their descent.
Holt kept looking out at the dark surface below them in the hope of discovering some gleam of light similar to what he had seen through Bergmann's telescope. At times he felt that it had again appeared, but on each occasion the enveloping darkness swallowed it before he could be sure, or the wide wing interrupted his vision.
Finally the first livid glare of the solar corona came up over the dark edge of the horizon. The heavy boat's speed had been reduced only to 3,400 m/sec by the tenuous Martian air, despite the 20 minutes which had elapsed since the perigee of their landing ellipse. They were still 150 kilometers high, and the electric and pressure altimeters coincided almost exactly, thanks to the calibration of the latter permitted by the sounding bomb readings.
The first rays of the Sun penetrated the bow windows of their cabin, although the darkness still spread its mantle over the scene below. Slowly, very slowly, the dawn crept toward them, revealing vague outlines on the surface. Holt consulted his watch, the chart and what he could see through his port.
"That elongated area ahead and to the right must be the Mare Cimmerium. Our flight time corresponds with our passage across the 220 th meridian and the equator."
"Yes," answered Hubbard, "and that broad canal just under us must be Cyclopus."
Still at vast altitude, they followed the Antaeus Canal from northwest to southeast, and passed Mare Chronium, looking like a fertile, green meadow, fifteen minutes later.
There was a broad bridge of vegetation joining the bleak deserts of Thyle I and Thyle II, and after they had whipped across it, the glistening white of the south polar snows rose over the horizon.