Then, there was the possibility of using the increased gravitor-field efficiency in radio communications. This was right up his alley, but the implications went so far and so deep that only a thoroughly experienced and trained scientist could trace all of them. He hadn't been an engineer long enough to have acquired that much training and experience; he wasn't a renowned scientist in the field. He couldn't always be sure where he was right or wrong in his computations. This was pure research; no book had ever been written for it. He couldn't look up all the answers. But it appeared that a small radio set would have the power to reach anywhere in the Solar System, not to mention the extensive refinements of any television and/or radar set-up. The possible refinements of chemical catalysts and electro-chemical processes were extensive, too. Staring at his diagrammatical results, Morrow wondered if mechanisms couldn't be perfected to measure the taste of foodstuffs as the taste-buds in the human mouth did, to measure the smell of odors as the human nose did, to convert carbon-dioxide into oxygen as plants did--even mechanisms which would react selectively to the electrical impulses generated by the cells of the human brain! But he wasn't a chemist. He could only guess at the possibilities. Finally, there was the possibility of applying the gravitors directly to the problem of transporting the human body by air. Part of this, he could answer: a gravitor strapped to a man's back would more than replace the conventional parachute for emergency bail-outs. The gravitor could be hooked into alternate power-circuits with alternate field-transmission coils, so if it failed to work on one setting the wearer could switch it to another, the equivalent of wearing a second parachute in case the first failed to open. And unlike a parachute, the wearer would have complete control over his rate of fall: he could descend gently to the ground or, if he wished, he could stop and hover in the air or even reverse his descent and rise upward. That was part of it. Morrow had discussed it with Smitty and they'd decided to incorporate it into their project. In addition to having the ship look like something from outer space, there was also the problem of having to make a forced-landing somewhere. They might be seen on the ground, repairing their ship. The gravitors could be built into a tank carried on their backs, and fastened to a special harness costume complete with transparent helmet fitting over their heads. The helmets would protect their faces from the wind in a bail-out. Also, their appearance would be altered just enough to make them seem to be visitors from another planet, beings who did not breathe Earth's atmosphere. But that still didn't give the human body a means of transportation by air. A small, portable propulsion unit was needed for that, and Morrow wasn't at all sure he could design such a unit. He was not a jet engineer.