To the stars

There is a double Marxist principle: double because it is associated with both Karl and Harpo.

The Karl variant made the wise planners of East Germany import coal From Astrakhan (on the Caspian Sea), the coal-fired locomotives of the trains burning up somewhere around half [?] of the coal they were hauling. In Harpo's version, the good guys (the Marx Brothers) have to make it to some town in a train before the bad guys racing them in a car. When they run out of coal they start burning the carriages, Harpo grinding his axe on the wheels. They make it just in time, arriving with only the engine pulling about a dozen undercarriages of what used to be Pullman cars.

The Karl-Harpo principle is this: For transportation without refueling the fuel load must rise with distance, until at some point it is so large that there is nothing left for hauling the payload. Nowhere is this principle more important than in space. To borrow Theodore Roosevelt's expression, it is the "mankind though, alas, not necessarily of the USA. Here is a basic figure (IEEE Spectrum, Dec. 1984) that I have printed before and may print again: it shows the Karl-Harpo limits of the tree possible fuels on a log-log scale. For example, one can use chemical fuels (as propellants or for internal electricity generation) at about 5 MW for one hour, or at 100 W for about 2 months. Anything more powerful or of longer duration than shown by the curve for chemical fuels exceeds the Karl-Harpo limit and is physically impossible. For solar energy, higher power needs bigger collector areas, which increase the weight until the collectors become so unwieldy that the Karl-Harpo limit is exceeded.

Beyond these limits only nuclear reactors will do for propulsion. For example, to keep a modest 10 MW going for a mere month (a manned mission to explore Mars would take about 3 years) only a nuclear reactor can be used.

That is not propaganda, ideology or opinion, but hard, inexorable physics.

Then came an unexpected break: after the collapse of the Soviet Empire (mainly due to inability to compete with the high-tech SDI), the Russians offered to sell their space nuclear reactor Topaz 2, which can be used for the high-powered and long-lasting radar missions of SDI missile detectors, and possibly even for a nuclear propulsion system, e.g., expelling electrically charged particles rather than chemically heated gases to achieve the rocket propulsion effect. The US Air Force purchased one and may purchase another.

Well now. Solar Max was used to measure the ozone concentration at a time when the average of its wild fluctuations was (very slightly) decreasing. Are we to conclude that all those ozone measurements and alarms were for the birds?