Jupp reprogrammed the computers for the delay and fired the rockets. Wahlquist rotated the boom during the firing. Cosmos was now at ten o'clock out Jupp's window, and the boom and mirror shaft extended at almost right angles to the axis of the shuttle. They were particularly vulnerable because the mirror could protect the cabin or the tail, but it was not big enough to shield both when they presented their side to Cosmos as they now did. By previous decision, Wahlquist adjusted the boom forward so the crew was shielded. Jupp rushed through another programming sequence.
Too late!
No human could time the beam of energy that leapt from a portal in the Cosmos. No need to lead the target with this cannon, just point and shoot. Nor was there a mote of dust in space to mark its passage to any eye not in the line of fire. In less than a tenth of a second an intense beam of light crossed a distance greater than that between the poles of the earth and slammed into the upper tail of the shuttle.
The beam delivered heat but little impulse so there was only the faintest jolt and a tiny crackling carried not by the vacuum of space, but through the metallic walls of the craft itself. The three men in the cabin sensed the brief blue— white flare from the change in shadows and odd reflections, as if someone had struck up a welding torch out of their line of sight. The radio crackled to life as the man in the rear seat made his first overt move. With a single motion, smooth despite the constraint of his vacuum suit, he pushed a button on his wrist. To one side of his helmet visor, visible but not in his normal line of sight, the green luminous display of an electronic stopwatch leapt to life, its quickest digits whipping by at dizzying rate. He pushed another button and the display was once again that of a standard chronometer.
'Control to shuttle! Control to shuttle! Cosmos has fired. Repeat, Cosmos has fired! Are you hit? Come in shuttle.'
The battle was on! Jupp felt a calm of adrenalin-charged tension settle over him. He rammed the control thrusters, slewing the craft around to present a smaller, tail-on target to the Cosmos, as Wahlquist adjusted the boom until the mirror shielded them in the rear. Then he responded in his best Chuck Yaeger drawl.
'Aaaah, that's affirmative, control. We have taken a hit in the aft section. We've covered our rear and are having a look now.'
Jupp flipped a finger sign at Wahlquist who hit a switch to relay the image on the cabin monitor to the ground. Wahlquist adjusted the position controls on the boom camera and watched the image play awkwardly on the monitor until he was oriented and began to scan around. The boom extended directly to the rear so that the shaft lay against the right side of the tail with the mirror beyond. Everything seemed normal as he scanned across the base of the tail and then around the bay.
'Look higher up on the tail,' growled Colonel Newman from the rear seat.
Wahlquist gritted his teeth, turning stiffly in his suit until he could see Newman seated behind Jupp. He glanced quickly at him and then for a longer instant at Jupp. He turned back and fingered the controls to tip the camera upward and then let out an audible gasp.
'Son-of-a-bitch,' said Jupp slowly.
The upper third of the tail section was missing. A scorched crescent marked the damage, beyond which there were random ends of wires and shafts, and beyond them nothing, their intended connections vaporized. The lower part of the rudder that remained intact hung at a skew angle, its upper pinions blasted away.
'Aaah, you copy that control?'
'We've got it, shuttle. Evaluation is underway. Mandatory, repeat mandatory, shuttle, you must complete orbital adjustment with greatest speed.'
'Roger.'
Jupp nodded to Wahlquist who swivelled the boom so that the mirror was abeam them, clear of the rockets, but once again exposing their tail. Jupp played with the thrusters and rapidly fed data to the computer. He hit the rockets again, and they felt the thrust of the final burst that would bring their orbit into alignment with that of the Cosmos. When they finished the manoeuvre, they were orbiting directly towards the Cosmos, but going sideways, their side exposed. Jupp rotated the craft until they were pointing towards the Cosmos, and Wahlquist rotated the mirror to the front, protecting them to the maximum extent. They were behind and slightly below the Cosmos, but orbiting more quickly so they would slowly catch up. Wahlquist sticky-footed his way over and budded himself into the copilot's seat.
At a critical point they would fire the rockets and rise into the higher, less rapid orbit of the Cosmos. In orbit, one could not simply fire rockets and catch up. You only went faster than the other guy if you were in a lower, quicker orbit. If you fired your rockets, you would be flung into a higher, slower orbit, a maddening reversal of fighter pilot instincts. If you wanted to go faster, you flipped ass over end and fired the rockets in the direction of your travel. Then you dropped into a lower orbit where your speed was higher.
They settled in to wait. The manoeuvre had taken fourteen minutes. In twenty-seven they would begin the final firing sequence that would raise them to within docking range of the Cosmos. Seventeen minutes had passed since the Cosmos had fired at them. Another six minutes passed in silence.
The intense white hot glow erupted in front of them, accompanied by static on the radio. Both Jupp and Wahlquist jerked, startled, in their seats. Newman punched a button on the wrist of his suit again, and a small satisfied smile creased his features.
'Shuttle, Cosmos has fired again! Please report!'
'Whoa, that one caught us by surprise. Scared the bejesus out of me. The mirror took that one head on, and it seems to be intact.'
'Roger, shuttle, that's satisfactory. You may proceed.'
Newman's voice croaked from the rear.
'The repetition time is twenty-three minutes and thirty— seven seconds, even a little slower than we guessed. We've got them now.'
Jupp looked at him in the small mirror mounted above the window.
'Twenty-three minutes.' He turned his head to see a count-down timer, and then looked back at the man in the rear. 'We'll be in the middle of the final lift.'
'They'll get one more shot at us. That can't be helped. But if it's just before we close on the bastard, we'll have the maximum time to get in and get it disabled.'
Jupp settled back into his chair and stared out the cockpit window at the thin mirror surface that shielded them from a fiery death. He understood the logic, but he was not at all happy about sticking out his chin and giving the satellite one more freebie punch.
They coasted in silence for five, ten, fifteen minutes. Without the obstructing mirror they might have been able to make out the pinpoint of light that was Cosmos 2112, hovering somewhere above and beyond them. Then as Jupp programmed the final burn, the radio crackled alive again.
'Shuttle, there has been a new development. This could be a problem.'
There was a delay during which a mumbled conversation could be heard. Harsh whispers of troubled voices.
'Shuttle, the Cosmos has gone into rapid rotation mode. We can't be sure but we suspect the purpose is to spread the next shot over the surface of the mirror.'
'Roger, control,' Jupp replied. 'What's the matter with that? Doesn't that just lessen the intensity in any particular spot?'
'A little,' came the concerned voice from the ground. 'but more important is that it increases the chance that some of the power will fall in the interstices. The cracks between the mirror segments. The reflection will be imperfect there, a lot more absorption of energy, and the chance for some real damage. You'll be a lot closer, so the power will be more concentrated anyway.'