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Active Space
Part 5B: More Controversies

More space controversies are listed here with lots of links to related resources.

Space controversies:


Nuclear Power in Space
In deep space, especially past the orbit of Mars, there is not enough sunlight for reasonably sized solar panels to power large space probes like Galileo or Cassini. So instead, these probes used small nuclear power generators, or radioisotope thermoelectric generators (RTGs) to be exact. The RTGs carry a plug of a radioisotope such as plutonium to produce heat, which in turn drives a thermoelectric generator.

Nuclear material on a spacecraft upsets some people because of the danger of contamination from an explosion during launch and because, in the case of Cassini, of the possibility the probe might crash into the atmosphere if it swings back around earth to gain energy to reach its final destination.

However, such devices are heavily shielded and should survive most any incident. For example, the Challenger and Columbia disasters involved catastrophic inflight disassembly but many large components, including the crew compartments, survived to reach the ground.

Actual nuclear reactors are also proposed for future space propulsion and power. It should be noted that such a reactor is not activated until after the spacecraft reaches orbit. This means that the fuel has very low radioactivity until after the reactor is turned on. So the amount of radioactive material dispersed (if the shielded was somehow broken) from a rocket explosion during launch is very low.

Space & the Military
The military has always been a big influence on Space, although today the commercial space business has surpassed the sum of all government Space expenditures worldwide. (See the Investing section.)

The Nazis, for example, took over Wernher von Braun's rocket club in the early 1930s and used it to develop rocket weapons. (This bypassed the Versailles Treaty, which had put severe limits on German conventional weapons development.)

In the Soviet Union, space & rocket development was supported even during Lenin's time both for ideological reasons and for military purposes. (See the nice discussion of early Soviet space developments in William E. Burrows This New Ocean). Rocket artillery, in fact, was a major help to the Soviets in fighting the Germans in WWII.

After the war the US military, which had modestly funded rocket development at JPL since the 1930's, nabbed von Braun and other German rocket scientists. They were brought to the US where they formed the nucleus of the Army's missile program and later the Saturn rocket program.

In the panic-stricken period following the Soviet launch of Sputnik, there was talk of major involvement of the military in space with serious proposals to put nuclear weapons not only in orbit but on the Moon as well. However, both for practical reasons and subsequent treaty commitments, neither nuclear nor conventional weaponry has ever been put into Space (but for some odd exceptions.)

Nevertheless, the US and Soviet militaries relied heavily on Space but primarily for intelligence gathering and communications. (Positioning with the GPS satellite network, created by the US military, has since the 1980s become very important both for military and civilian applications, as well.) Intelligence was gathered with both imaging and telecommunication eavesdropping satellites.

The very first spy satellites showed that there was in fact no missile gap as JFK had claimed in his 1960 campaign. Eisenhower knew this, in fact, before the election, but didn't reveal it for fear of letting the Soviets know the capabilities of US spysats. When JFK discovered the truth after taking office he canceled plans for starting a major missile program. (This is why Lyndon Johnson said later in an off the record speech that spysats alone had paid for the entire space program including Apollo.)

The proposal to develop a defense against missiles, i.e. Star Wars or SDI, in the 1980's required that missile killing weapons, e.g. lasers or kinetic energy devices, reside in Space to stop the missiles as early in flight as possible.

While development of a full shield against a large ICBM attack is no longer taken seriously, a partial shield effective against one or two missiles from a rogue nation, e.g. Iraq, is now receiving major funding.

Another military space issue is the development of antisatellite weapons to destroy enemy spy satellites during times of conflict. Conversely, protecting spysats from anti-satellite weapons is a rising issue.

Here are some sites that involve the issues of Military & Space

See archive for previous article links

Expendable Vs Reusable Launchers
Although the border to outer space lies only about 100 km from us, getting there and staying there remains extremely difficult and expensive.

It was realized early on that rockets would be needed for space travel since they carry their own oxidizers into the airless void. Furthermore, if a rocket could throw away fuel and oxiders tanks when they are empty, reaching orbit with a reasonable payload gets much easier.

The staged, expendable rocket thus became the key enabler for space exploration. However, throwing away most of a complex vehicle, which can cost as much as $100million, after only one use is obviously a major drawback.

If a launcher could be totally reusable, just like a jet airliner, it would seem obvious that costs of reaching space (currently about$10000 per kg) should fall.

However, the Space Shuttle, despite being semi-reusable, actually costs more per kg than expendables. About 10000 people are needed to maintain and refurbish a shuttle after every flight. The shuttles were once predicted to fly 50 times a year but in fact, only about 6-8 flights per year are practical. (Pressure to increase the flight rate led indirectly to the Challenger disaster.)

So clearly, reusability alone will not reduce flight costs. It must be produced by a robust platform that requires low operating costs and minimal refurbishment between flights. A commercial firm must also ensure that development costs can be covered by operational income.

Attempts to develop reusable launch vehicles (RLV) continue with private companies and at NASA (see the RLV Countdown and RLV News sections.) Alternatively, low cost expendable launch vehicles (ELV) are also being pursued.

Virtually everyone agrees that at a very high flight rate, reusables are vastly superior to ELV's. However, at current launch rates, ELV proponents believe the development costs of a RLV could never be recovered.

RLV proponents counter that lowering costs will inspire many new applications and these will in turn drive the launch rate higher.

Exo-biological contamination
This involves two issues:

- Possible dangers in returning samples from Mars, Europa, etc. that could be contaminated with non-earth based microbes. Could such microbes pose a hazard to humans or the earth biosphere?

- Conversely, how extensively should landers be sterilized to avoid contamination of Mars & Europa with earth microbes. This is both to avoid accidentally identifying such microbes as native life and to prevent life there from being overrun by earth species.

The debate over these issues will grow more intense as Mars exploration accelerates. A number of landers will be sent to Mars over the coming decade and sample return missions are included.

Sterilization of space probes adds complications and expense, e.g. light weight composite structures are increasingly popular but they can't be heated to high temperatures, so alternative sterilization procedures must be used. Similarly, quarantine and handling of returned samples poses serious technical problems.

Protecting Historic Extraterrestrial Sites
The prospect that private teams in the Google Lunar X PRIZE might send rovers to visit Apollo landing sites compelled NASA to lay out some guidelines for protecting the sites. The GLXP program later agreed to abide by the rules.

Ownership of space resources, regulation of space commercialization,
and other legal questions

Exactly how the ownership of property by space explorers, miners, and settlers will be legally protected is not yet fully determined. There are treaties, precedents (e.g. fishing and oil drilling in international waters) and national laws that must be reconciled.

There are several companies that claim to offer to the public the right to name a star, buy lunar real estate and so forth. These have no generally recognised legal validity. As long as one knows that it is just for fun, there is no problem.

One-way Trips
Over the years there have been occasional proposals for human missions to space destinations in which there would be no intention of returning to earth. Without the need to carry fuel for the return flight, the transportation systems become much smaller, especially in the case of Mars. The assumption is that the bold explorers would be totally committed to settling the planet and would have no desire to return.

Other Controversies
When sufficient resources are found on each of these topics, they will get their own sub-section.

 

The Art of C. Sergent Lindsey
NewSpace Watch at NSG

 

 

 

 

 

 

 

 

 

 

 

 

 
 
 
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