Vengeance 10

‘For instance’ — Bethwig broke in — ‘the alcohol and liquid oxygen mixture we currently use approaches optimum in terms of energy obtainable from chemical fuels. The power, if you will, of a rocket fuel is measured in terms of specific thrust per second, which is simply the push per unit of fuel consumed. Liquid oxygen and alcohol provide a specific thrust of one hundred and eight kilograms per second. We could obtain a greater specific thrust with a combination of, say, liquid oxygen and hydrazine which provides one hundred and seventeen, or even liquid oxygen and liquid hydrogen which provides the greatest specific impulse of all chemical fuels, one hundred and fifty-two kilograms per second. But we do not have the facilities to manufacture or handle liquid hydrogen. Hydrazine would be ideal, but Germany does not produce it in sufficient quantities, and the resulting performance increase would not justify the added cost of developing a manufacturing capability. Above all, an engineer must be practical.’

Heydrich replied, with a trace of annoyance, ‘Yes, yes, I understand.’ He got up to pace the room as von Braun took up the briefing again, but it seemed to Bethwig that his patience was nearly exhausted. The more detailed the explanations became, the more restlessness the reichsprotektor displayed.

‘… will stand fifty-one point eight metres tall. At the base the first stage will measure nineteen point eight metres. The entire rocket will weigh 4,082,331 kilograms, nearly as much as a naval cruiser. We have designed a cluster of twenty-one rocket motors to provide a combined thrust of 3,401,942 kilograms. The motor will consume 3,985,230 kilograms of fuel in less than one hundred and twenty seconds. The second stage will have four motors providing a total thrust of 635,028 kilograms. The third stage will have a single motor providing 158,757 kilograms of thrust and will carry the crew and equipment. It will…’

‘Please, spare me a recital of further facts and figures.’ Heydrich heaved a sigh, then turned and smiled. ‘I really do believe you gentlemen know what you are doing.’

He went to the window, and Bethwig realised the man was posing for them. He was dressed in what the English would describe as ‘country clothes’. Tweeds made in Scotland and probably tailored on Bond Street or wherever that sort of thing was done. Heydrich was, of course, the party’s prototype Nordic — tall, blond, blue-eyed, ruggedly masculine; and standing at the window gazing into the distance as if concerned with all manner of problems affecting the direction of the human race, he certainly looked the part.

‘Gentlemen, it is too beautiful a day to remain cooped up inside. You do both ride, of course?’ Not waiting for a reply, he threw open the windows and stepped on to the terrace, motioning them to follow. ‘I am certain that you will find the course challenging. I laid it out myself.’

Von Braun gave Bethwig a startled look and followed him out. He did of course ride, but it was clear from the set of his shoulders that he would rather have spent the day cooped up in the library discussing the A-10 project, willing audience or not. Bethwig followed both men on to the terrace where the horses waited, thankful that Heydrich had suggested the diversion. It had just occurred to him that he was intensely weary of Peenemunde and the host of new problems that had grown out of Hitler’s refusal to grant overall priority to either the Luftwaffe or the army for the development of advanced weaponry. In that single respect Heydrich had been a godsend.

‘Come, gentlemen. You will enjoy fresh air not filled with the exhaust of rocket engines.’ He laughed at his own joke, swung into the saddle, and, without waiting, urged his mount to a canter. Bethwig waited until von Braun, grumbling and muttering to himself, was safely mounted before following.

Heydrich set a stiff pace, and although it had been four years since he had last sat on a horse, Bethwig found himself falling easily into old patterns. The air was crisp and the sun pleasantly warm. Sunlight glinted on massive chestnuts and oaks in the parklike forest, and not until he noticed the huge trunks did he realise that he was in a medieval hunting park that had belonged to Bohemian kings.