to you, and I've
got tools."

I could see him shake his head in the dim light from the instrument
panel. "You know those fuels ignite on contact with each other," he
pointed out. "If we spill a couple drops of each in here, and they
vaporize, we'll blow this kite to pieces!"

"Then we'll get outside to make the switch," I insisted. "It won't
hurt anything if a few grams burn up out there, will it, with nothing
to confine the expansion."

"But then I won't be able to come after you if anything goes wrong,"
he pointed out. "No dice."

"You're grasping, Stein," I growled. "At this stage I'm in charge
around here. I'll take my chances on getting back."

* * * * *

With the cabin light on I went as far as possible in dismounting both
our tanks. After a couple rehearsals to make sure that at least one of
us would always have a glove on a handhold, we both climbed out the
hatch and I made the switch. Just as Sid suspected, we spilled a few
drops. They vaporized, and again as we had feared, combined in what
would have been an explosion in a confined space. The soundless flash,
dim but real, said we had released quite a little energy uniformly all
around us. I never felt a thing except a faint warmth from infrared
through my helmet.

Best of all, my jets worked. We both climbed back aboard _Nelly_,
dogged the hatch, and started after Telstar Two.

The second bird was about fifteen thousand miles ahead of us. I slept
most of the time, for after Sid gave us a jolt of added velocity, we
had to settle down to about six hours of drifting. I woke up as the
belt cut me when he fired the retros. We went through the radar and
searchlight bit, and had the devil's own time finding our bird. But at
last I got the flash of reflection and went to work.

I won't say the second job was any easier, except for the fact that I
removed only one part to make room to do my bit with the insulation,
and thus had very few screws to replace. My navigating in space was a
lot better, and I didn't use steering fuel as wastefully as the first
time. Still, when we dogged down to chase after the final bird, the
cabin gauge said that I had less than half my load of steering fuel
left. Equally glum, _Nelly_ herself was even lower on steering fuel.
Neither Sid nor I had been as expert as we were supposed to be.

Nevertheless, we took off after the third bird, and found it
glistening in bright sunlight without the help o