of them. It makes me boiling mad to hear anyone sneer at them. Why, I'll bet those two couldn't qualify for permanent visa even under our present "open door" policy! Feeble-minded- But I do hope Clark hasn't done anything too drastic. I wouldn't want Clark to have to spend the rest of his life on Titan; I love the little wretch.

Sort of.

We've had that radiation storm. I prefer hives. I don't mean the storm itself, it wasn't too bad. Radiation jumped to about 1500 times normal for where we are now-about eight-tenths of an astronomical unit from the Sun, say 120,000,000 kilometers in units you can get your teeth in. Mr. Savvonavong says that we would have been all right if the first-class passengers had simply gone up one deck to second-class passenger country-which certainly would have been more comfortable than stuffing all the passengers and crew into that maximum-safety mausoleum at the center of the ship. Second-class accommodations are cramped and cheerless, and as for third class, I would rather be shipped as freight. But either one would be a picnic compared with spending eighteen hours in the radiation shelter.

For the first time I envied the half-dozen aliens aboard. They don't take shelter; they simply remain locked in their specially conditioned staterooms as

0')

usual. No, they aren't allowed to fry; those X-numbered rooms are almost at the center of the ship anyhow, in officers' and crew's country, and they have their own extra layer of shielding, because you can't expect a Martian, for example, to leave the pressure and humidity he requires and join us humans in the shelter; it would be equivalent to dunking him in a bathtub and holding his head under. If he had a head, I mean.

Still, I suppose eighteen hours of discomfort is better than being sealed into one small room for the whole trip. A Martian can simply contemplate the subtle difference between zero and nothing for that long or longer and a Venerian just estivates. But not me. I need unrest oftener than I need rest-or my circuits get tangled and smoke pours out of my ears.

But Captain Darling couldn't know ahead of time that the storm would be short and relatively mild; he had to assume the worst and protect his passengers and crew. Eleven minutes would have been long enough for us to be in the shelter, as shown later by instrument records. But that is hindsight ... and a captain doesn't save his ship and the lives depending on him by hindsight.

I am beginning to realize that being a captain isn't all glorious adventure and being saluted and wearing four gold stripes on your shoulders. Captain Darling is younger than Daddy and yet he has worry lines that make him look years older.

QUERY: Poddy, are you sure you have what it takes to captain an explorer ship?

ANSWERS: What did Columbus have that you don't? Aside from Isabella, I mean. Semper toujours, girl!

I spent a lot of time before the storm in the control room. Hermes Solar Weather Station doesn't actually

warn us when the storm is coming; what they do is fail to warn us that the storm is not coming. That sounds silly but here is how it works:

The weathermen at Hermes are perfectly safe, as they are underground on the dark side of Mercury. Their instruments peek cautiously over the horizon in the twilight zone, gather data about Solar weather including running telephotos at several wave lengths.

But the Sun takes about twenty-five days to turn around, so Hermes Station can't watch all of it all the time. Worse yet. Mercury is going around the Sun in the same direction that the Sun rotates, taking eightyeight days for one lap, so when the Sun again faces where Mercury was, Mercury has moved on. What this adds up to is that Hermes Station faces exactly the same face of the Sun about every seven weeks.

Which is obviously not good enough for weatherpredicting storms that can gather in a day or two, peak in a few minutes, and kill you dead in seconds or less.

So the Solar weather is watched from Earth's Luna and from Venus' satellite station as well, plus some help from Deimos. But there is speed-of-light lag in getting information from these more distant stations back to the main station on Mercury. Maybe fifteen minutes for Luna and as high as a thousand seconds for Deimos ... not good when seconds count.

But the season of bad storms is only a small part of the Sun's cycle as a variable star-say about a year out of each six. (Real years, I mean-Martian years. The Sun's cycle is about eleven of those Earth years that astronomers still insist on using.)

That makes things a lot easier; five years out of six a ship stands very little chance of being hit by a radiation storm.

But during the stormy season a careful skipper (the only sort who lives to draw a pension) will plan his orbit so that he is in the worst danger zone, say inside

the orbit of Earth, only during such time as Mercury lies between him and the Sun, so that Hermes Station can always warn him of coming trouble. That is exactly what Captain Darling had done; the Tricorn waited at Deimos nearly three weeks longer than the guaranteed sightseeing time on Mars called for by the Triangle Line's advertising, in order to place his approach to Venus so that Hermes Station could observe and warn-because we are right in the middle of the stormy season.

I suppose the Line's business office hates these expensive delays. Maybe they lose money during the stormy season. But three weeks' delay is better than losing a whole shipload of passengers.

But when the storm does start, radio communication goes all to pieces at once-Hermes Station can't warn the ships in the sky.

Stalemate? Not quite. Hermes Station can see a storm shaping up; they can spot the conditions on the Sun which are almost certainly going to produce a radiation storm very shortly. So they send out a storm warning-and the Tricorn and other ships hold radiation-shelter drills. Then we wait. One day, two days, or a whole week, and the storm either fails to develop, or it builds up and starts shooting nasty stuff in great quantities.

All during this time the space guard radio station on the dark side of Mercury sends a continuous storm warning, never an instant's break, giving a running account of how the weather looks on the Sun.

and suddenly it stops.

Maybe it's a power failure and the stand-by transmitter will cut in. Maybe it's just a "fade" and the storm hasn't broken yet and transmission will resume with reassuring words.

But it may be that the first blast of the storm has hit Mercury with the speed of light, no last-minute

warning at all, and the station's eyes are knocked out and its voice is swallowed up.in enormously more powerful radiation.

The officer-of-the-watch in the control room can't be sure and he dare not take a chance. The instant he loses Hermes Station he slaps a switch that starts a big clock with just a second hand. When that clock has ticked off a certain number of seconds-and Hermes Station is still silent-the general alarm sounds. The exact number of seconds depends on where the ship is, how far from the Sun, how much longer it will take the first blast to reach the ship after it has already hit Hermes Station.

Now here is where a captain bites his nails and gets gray hair and earns his high pay....ecause he has to decide how many seconds to set that clock for. Actually, if the first and worst blast is at the speed of light, he hasn't any warning time at all because the break in the radio signal from Hermes and that first wave front from the Sun will reach him at the same instant. Or, if the angle is unfavorable, perhaps it is his own radio reception that has been clobbered, and Hermes Station is still trying to reach him with a last-moment warning. He doesn't know.