‘They may not be yours,’ said Hazel, ‘but they are my grandsons, I’m sure of that. Hallelujah, here I come! Anybody coming with me?’
Dr Stone said quietly, ‘You know, dear, I don’t much care for Venus, either. And it would give you leisure for your book’
The Rolling Stone shaped orbit from Phobos outward bound for the Asteroids six weeks later. This was no easy lift like the one from Luna to Mars; in choosing to take a ‘cometary’ or fast orbit to the Hallelujah the Stones had perforce to accept an expensive change-of-motion of twelve and a half miles per second for the departure maneuver. A fast orbit differs from a maximum-economy orbit in that it cuts the orbit being abandoned at an angle instead of being smoothly tangent to it… much more expensive in reaction mass. The far end of the cometary orbit would be tangent to the orbit of the Hallelujah; matching at that point would be about the same for either orbit; it was the departure from Phobos-circum-Mars that would be rugged.
The choice of a cometary orbit was not a frivolous one. In the first place, it would have been necessary to wait more than one Earth year for Mars to be in the proper relation, orbit-wise, with the Hallelujah Node for the economical orbit; secondly, the travel time itself would be more than doubled — five hundred and eighty days for the economical orbit versus two hundred and sixty-nine days for the cometary orbit (a mere three days longer than the Luna-Mars trip).
Auxiliary tanks for single-H were fitted around the Stone’s middle, giving her a fat and sloppy appearance, but greatly improving her mass-ratio for the ordeal. Port Pilot Jason Thomas supervised the refitting; the twins helped. Castor got up his nerve to ask Thomas how he had managed to conn the Stone in to a landing on their arrival. ‘Did you figure a ballistic before you came aboard, sir?’
Thomas put down his welding torch. ‘A ballistic? Shucks, no, son, I’ve been doing it so long that I know every little bit of space hereabouts by its freckles.’
Which was all the satisfaction Cas could get out of him. The twins talked it over and concluded that piloting must be something more than a mathematical science.
In addition to more space for single-H certain modifications were made inside the ship. The weather outside the orbit of Mars is a steady ‘clear but cold’; no longer would they need reflecting foil against the Sun’s rays. Instead one side of the ship was painted with carbon black and the capacity of the air-heating system was increased by two coils. In the control room a time-delay variable-baseline stereoscopic radar was installed by means of which they would be able to see the actual shape of the Hallelujah when they reached it.
All of which was extremely expensive and the Galactic Overlord had to work overtime to pay for it. Hazel did not help with the refitting. She stayed in her room and ground out, with Lowell’s critical help, more episodes in the gory but virtuous career of Captain John Sterling — alternating this activity with sending insulting messages and threats of blackmail and/or sit-down strike to her producers back in New York; she wanted an unreasonably large advance and she wanted it right now. She got it, by sending on episodes equal to the advance. She had to write the episodes in advance anyhow; this time the Rolling Stone would be alone, no liners comfortably near by. Once out of radio range of Mars, they would not be able to contact Earth again until Ceres was in range of the Stone’s modest equipment. They were not going to Ceres but would be not far away; the Hallelujah was riding almost the same orbit somewhat ahead of that tiny planet.
The boost to a cometary orbit left little margin for cargo but what there was the twins wanted to use, undeterred by their father’s blunt disapproval of the passengers-in-cold-sleep idea. Their next notion was to carry full outfits for themselves for meteor mining — rocket scooter, special suits, emergency shelter, keyed radioactive claiming stakes, centrifuge speegee tester, black lights, Geiger counters, prospecting radar, portable spark spectroscope, and everything else needed to go quietly rock-happy.