Down in the radio beam station, Wagner, Ward and a very unsteady Portiz
surveyed each other in stunned dismay for about ten seconds.
Fred Ward was struggling to put into speech that which he felt within.
Here was crisis. Here was an intermingling of human and mechanical
failings which had built up almost to the point of nervous dissolution
in the men concerned. Probably of secondary importance now was the
fact that two terrestrial cruisers were nearing perihelion at the sun;
they depended absolutely on the keyed radio wave which would leap
across their trajectory and crackle in their attentive receivers. But
that keying device was out of commission and in all that great bank
of two hundred keyers there was not another silent. There was not
another which they could safely adjust to the cruisers' course without
imperiling the safety of some other craft.
Over in Pali-Vanyi proper were some of the greatest political minds
of Earth and Venus, closeted within a great hall whose entrance was
barred, whose televisorphonic connections were cut off. It would take
at least fifteen minutes to gain access to that hall, once reached, and
probably another ten minutes to evacuate the great hall and get them to
a place of comparative safety.
Up above a great Martian destroyer was diving down into Venus' mists,
doubtless riding the radio range beam straight down toward the port.
Its objective was obvious: the convention hall.
The radio range beam transmitter could not be cut off since there were
a dozen ships due to hit atmosphere within the next few minutes. Six
of them had bucked a Perseid meteor shower coming out of Earth and
were low on fuel; it was imperative that they follow the beam down to
Pali-Vanyi for a one-try landing. The excessive consumption of fuel
in an atmosphere was prohibitive of their cruising around until the
destroyer could be apprehended by Patrol ships and driven away. The
beam had to be maintained!
As for the human element, Portiz was scarcely able to stand; Wagner had
a fine case of the jitters and could do little more than botch things
up royally if he tried to tackle a complicated task; Ward had gone to
bed after a sixteen hour shift, and after two hours of sleep plus a
dosage of unadulterated Venusian atmospherics had been awakened and
called back to the station.
The nervous tension was terrific. The three inarticulate men stood
there while the seconds sped, Wagner staring around with desperation on
his fat face, Silvy Ward clenching and unclenching his hands, Portiz
leaning his drink-pliant body against the bank of keyers.
Suddenly Ward broke the silence.
"Wagner, get that trajectory keyer going. First check the interlock
beam relay; the circuits seem to be okay, so it must be the relay.
Portiz, get the portable glide beam transmitter unit and drive it out
to the very base of the Hump on the eastern end of the field, and keep
your receiver open on thirty-four megacycles; I'll give you directions
from here. Come on, get going!"
Wherewith Ward spun around to the Pali-Vanyi radio range transmitter.
There was a peculiar smile on his face as he released the controls
on the goniometer unit which governs the direction of the signals by
reducing or increasing the radio frequency in the four range radiators.
They'll be on the beam, he thought; these Martian boys won't take any
chances of missing on the first stab for it would take them so long to
maneuver around for a second attempt that the element of surprise would
be lacking and their prey would have gotten away. They'll ride the
beam in from the west. When they get directly over the range station
they'll get the vertical radio signal from the station location marker
and know that the field lies ten miles to the east and Pali-Vanyi ten
miles south of the field. Switching their course ninety degrees they'll
drop in right over the city and let go with everything they've got.
They're probably on the beam now and four hundred miles to the west.
They're due to hit the strato-winds which any astronaut knows will
buck them around. The thunderheads will make their compass blotto so
the only direction they can be sure of is due east on the beam. If we
shift the beam slowly by rotating the goniometer counter-clockwise, the
quadrants of the beam will be reversed. They'll swerve their course
to follow, and gradually instead of getting the A signal to the south
they'll be getting it from the east, and instead of an N from the
north they'll have an N from the west. They'll come into Pali from the
South--
* * * * *
The radio range at Pali-Vanyi resembled to a great extent the radio
ranges used for centuries before by the Federal airways of the United
States of America, Earth. The increasing use of ultra-high frequency
waves had made obsolete the four towers of the intermediate frequency
range. Small, compact, the new range system had through the long
decades of scientific advancement after the war years of the 20th
century reached a stage of efficiency a hundredfold greater than its
predecessor.
A small antenna array atop the broadcast station consisting of four
vertical radiators mounted at the terminals of a horizontal X replaced
the towers of yesteryear. The four bars of the X pointed northeast,
northwest, southwest and southeast.
The NW and SE radiators sent out a steady N (dash-dot) in Morse code,
the SW and NE a steady A (dot-dash). At thirty second intervals
the identification letters of Pali-Vanyi [dot-dash-dash-dot
dot-dot-dot-dash] were transmitted from all radiators. A ship coming in
from the west, directly on course, heard both N and A simultaneously
and with equal strength so that they interlocked and formed a steady
dash. A swerve to the north of the course meant that the N signal would
be predominant in the ship's receiver; to the south, that the A would
be predominant. Rotating the goniometer counter-clockwise would so
change the radio frequency in the four signal radiators as to cause
all on-course signals to swing similarly, and ships on the beam would
follow it blindly around, especially when their compasses were put
awry by natural causes. A 90 degrees swing would completely reverse
the so-called N and A quadrants; hence the beam would completely lie.
WHAT would the destroyer's speed be? Probably twelve or fourteen
hundred m.p.h. Twenty minutes or less to swing the beam. With one hand
Silvy Ward began to rotate the goniometer, casting an eye at a nearby
chronometer. Ninety degrees, say, in eighteen minutes. Five degrees per
minute. Easy now! With a free hand Ward reached out and snapped on the
shortwave transceiver which was used in communications when testing
experimental equipment. He picked up the microphone and called:
"Portiz, are you in position?"
"Yes, sir!" the answer came promptly.
"Directions, pal. Cut in the glide path transmitter now and stick with
it until further instructions so that nothing goes wrong."
"Yes, sir. But what's the idea, Silvy?"
"No time to explain now, Portiz! I've work to do!"
Ward snapped off, and immediately reached out for the televisorphone.
He dialed Public Service and asked for his good friend Duka Dwane,
Venusian utility magnate.
"Duka," he barked after credentialling his way past a Mr.
Dwane's-in-conference operator, "this is Silvy Ward of the Authority.
There's a Martian destroyer coming in with obvious intentions of
bombing Pali. I want you to black out the city immediately."
"But, Silvy, think of the convention," Dwane protested. "I had to give
them special fluorescent lighting; they'll be angry if I cut them off!"
"If you don't cut them off this time they'll never be cut off again.
Kick that master switch over pronto. The Authority will take all
responsibility!"
"Okay," lisped Dwane. "Okay, _sharnar_!"
Ward cut off wondering if that "_sharnar_" had meant "friend" or
"bigshot"; it meant one thing in Pali and another in Vanyi, the city
across the "tracks".
Four minutes gone. Twenty degrees. The destroyer should be almost
west-south-west now.
"Wagner," Ward barked. "How are you coming?"
"It's the relay, right enough. I should have it clicking in a few mins."
"You've about twenty, so do it right! Buzz Control and tell them that
we're going to cut off the landing beams on the south of the field and
for them to light up all the eastern boundary lights."
"Yes, sir."
Six minutes gone. Thirty degrees.