Good heavens! he could see it!

A great gleaming star against the black of space... growing growmg!

"Mind your scope, son," said Hazel. "Nineteen seconds."

He put his eye back to the scope; the images were steady. Hazel continued, "It seems to be drawing ahead slightly."

He had to look. As he did so something flashed up and obscured the starboard port and at once was visible in the portside port - visible but shrinking rapidly. Stone had a momen­tary impression of a winged torpedo shape.

"Whew!" Hazel sighed. "They went that-a-way, podnuh!" She added briskly, "All hands, brace for acceleration - five seconds!"

He had his eye on the star images, steady and perfectly matched, as the jet slammed him into his pads. The force was four gravities, much more than the boost from Luna, but they held it for oniy slightly more than one minute. Captain Stone kept watching the star images, ready to check her if she started to swing, but the extreme care with which he had balanced his ship in loading was rewarded: she held her attitude.

He heard Hazel shout, "Brennschluss!" just as the noise and pressure dropped off and died. He took a deep breath and said to the mike, "You all right, Edith?"

"Yes, dear," she answered faintly. "We're all right."

"Power room?"

"Okay!" Pollux answered.

"Secure and lock." There was no need to have the power room stand by, any correction to course and speed on this leg would be made days or weeks later, after much calculation.

"Aye aye, sir. Say, Dad, what was the chatter about a blip?"

"Pipe down," Hazel interrupted. "I've got a call coming in." She added, "Rolling Stone, Luna, to Traffic - come in, Traffic."

There was a whir and a click and a female voice chanted:

"Traffic Control to Rolling Stone, Luna - routine traffic precautionary: your plan as filed will bring you moderately close to experimental rocket satellite of Harvard Radiation Laboratory. Hold to flight plan; you will fail contact by ample safe margin. End of message; repeat – " The transcription ran itself through once more and shut off.

"Now they tell us!" Hazel exploded. "Oh, those cushion warm­ers! Those bureaucrats! I'll bet that message has been holding in the tank for the past hour waiting for some idiot to finish discussing his missing laundry."

She went on fuming: ""Moderately close!" "Ample safe margin!" Why, Roger, the consarned thing singed my eye-brows!"

""A miss is as good as a mile"."

"A mile isn't nearly enough, as you know darn well. It took ten years off my life - and at my age I can't afford that."

Roger Stone shrugged. After the strain and excitement he was feeling let down and terribly weary; since blast-off he had been running on stimulants instead of sleep. "I'm going to cork off for the next twelve hours. Get a preliminary check on our, vector; if there's nothing seriously wrong, don't wake me. I'll look at it when I turn out."

"Aye aye, Captain Bligh."

First check showed nothing wrong with their orbit: Hazel followed him to bed - "bed' in a figurative sense, for Hazel never strapped herself to her bunk in free fall, preferring to float loosely wherever air currents wafted her. She shared a stateroom with Meade. The three boys were assigned to the bunkroom and the twins attempted to turn in - but Lowell was not sleepy. He felt fine and was investigating the wonderful possibilities of free fall. He wanted to play tag. The twins did not want to play tag; Lowell played tag anyhow,.

Pollux snagged him by an ankle. "Listen, you! Weren't you enough trouble by being sick?"

"I was not sick!"

"So? Who was it we had to clean up after? Santa Claus?"

"There ain't any Santa Claus. I was not sick. You're a fibber, you're a fibber, you're a fibber!"

"Don't argue with him," Castor advised. "Just choke him and stuff him out the lock. We can explain and correct the ship's mass factor tomorrow."

"I was not sick!"

Pollux said, "Meade had quite a bit of sack time on the leg down. Maybe you can talk her into taking him off our hands?"

"I'll try'."

Meade was awake; she considered it. "Cash?"

"Sis, don't be that way!"

"Well ... three days' dishwashing?"

"Skinflint! It's a deal; come take charge of the body." Meade had to use the bunkroom as a nursery; the boys went forward and slept in the control room, each strapping himself loosely to a control couch as required by ship's regulations to avoid the chance of jostling instruments during sleep.

VIII - THE MIGHTY BOOM

Captain Stone had all hands with the exception of Dr. Stone and Lowell compute their new orbit. They all worked from the same. data, using readings supplied by Traffic Control and checked against their own instruments. Roger Stone waited until all had finished before comparing results.

"What do you get, Hazel?"

"As I figure, Captain, you won't miss Mars by more than a million miles or so."

"I figure it right on."

"Well, now that you mention it, so do I."

"Cas? Pol? Meade?"

The twins were right together to six decimal places and checked with their father and grandmother to five, but Meade's answer bore no resemblance to any of the others. Her father looked it over curiously. "Baby girl, I can't figure out how you got this out of the computer. As near as I can tell you have us headed for Proxima Centauri."

Meade looked at it with interest. "Is that so? Tell you what let's use mine and see what happens. It ought to be interesting."

"But not practical. You have us going faster than light."

"I thought the figures were a bit large."

Hazel stuck out a bony forefinger. "That ought to be a minus sign, hon."

"That's not all that's wrong," announced Pollux. "Look at this – " He held out Meade's programming sheet.

"That will do, Pol," his father interrupted. "You are not called on to criticise Meade's astrogation."

"But -"

"Stow it."

"I don't mind, Daddy," Meade put in. "I knew I was wrong." She shrugged. "It's the first one I've ever worked outside of school. Somehow it makes a difference when it's real."

"It certainly does as every astrogator learns. Never mind, Hazel has the median figures. We'll log hers."

Hazel shook hands with herself. "The winnah and still cham­peen!"

Castor said, "Dad, that's final? No more maneuvers until you calculate your approach to Mars?"

"Of course not. No changes for six months at least. Why?"

"Then Pol and I respectfully request the Captain's permission to decompress the hold and go outside. We want to get to work on our bikes."

"Never mind the fake military-vessel phraseology. But I have news for you." He took a sheet of paper out of his belt pouch. "Just a moment while I make a couple of changes." He wrote on it, then fastened it to the control room bulletin board. It read:

SHIP'S ROUTINE

0700 Reveille (optional for Edith, Hazel, & Buster)

0745 Breakfast (Meade cooks. Twins wash dishes)

0900 School C & P, math

Meade, astrogation, coached by Hazel

Lowell, reeling, writhing, and fainting in coils - or whatever

his mother deems neces­sary

1200 End of morning session

1215 Lunch

1300 School C&P, math

Hydroponics chores, Meade

1600 End of afternoon session

1800 Dinner - All Hands initial ship's maintenance schedule.

SATURDAY ROUTINE - turn to after breakfast and clean ship, Hazel in charge. Captain's inspection at 1100. Personal laundry in afternoon.