ARDENT QUESTIONS !

[sky-high]

1. What progresses have been made recently (last 15 years) in new propulsion system research ? Rockets and their principle, that's 1500 years old, at least ! True that the Chinese were using them mainly for fireworks and the Europeans for weapons (what else ? ...), still to my knowledge nothing really new was applied to the present day. There was some talk in the 70-es about an atomic engine called "Nerva", then in the 80-es some scientists forgot themselves and talked about reasearch involving an ionic engine...and denied everything next day, I bet their wrists were kind of red . The present system sounds impressive at Earth scale only. At 20 km per second (meaning 72,000 km/hr), speed enough to get around the world in 2000 seconds (36 minutes) it still takes 3 years to go to Mars and back. That's crawling, man ! Decency (lower level) begins at 100 km/sec and with 200 km/sec, well, you can hope to start in May and be back by Thanksgiving, or Christmas at the outmost, without too many microG side effects.

2. Earth radioactivity is monitored from Space from years. (This is not a question). IS SUCH INFORMATION AVAILABLE ONLINE ? IF YES, WHERE? (This IS a question). I'm talking about a map display with constant readings of the local radioactivity, especially artificial sites, like power plants, research facilities, weaponry.
If not as a map, is the information available in text, like listing the abnormal only and the respective places ?

[rocketa]

Nerva was a successful program until it was cancelled. My guess is due to much negativity around nuclear reactors.

Ion propulsion has been around since the 50's. I built an ion propulsion system in 1958.

Laser initiated bursts by vaporizing a plastic material has worked in testing. Takes a mean ground based laser to make it work. Any aircraft flying through the beam would be in great jeapardy!

Solar sails also, ECHO demonstrated that possibility again in the 50's. (it was perterbed in orbit by solar radiation, being a giant balloon in space)

Then there are resistojets, arc-jets, plasma propulsion systems. None of which are great lifters.

I wish there was something new and fantastic to report.

[sky-high]

Thanks man !

How about my idea (it was orriginal but I bet I'm not the first to think of it) recently posted under "propulsion" topic, as a reply? (I saw yours ... it was too daring and metaphysical even for me. Probability generator, huh ?)

It started with the fact that an electric engine uses the principle of an elecric conductor in a magnetic field, I mean the fact that it moves, perpendicular to the field. Now a metal space-ship could be suitably electrified and the Sun has a suitable big magnetosphere, don't you think ? I mean could this be a propulsion system or what ?

Remember those magneto-hydrodynamic prop for sea-ships in the 80-es? Well, something similar.

So what do you say, would it work or not?

[Duane]

There are 2 types of propulsion that seem to get overlooked alot in discussions like these--magnetic rail launchers (so called "rail gun") and the "space cannon".

While the concept of the space cannon has been around for many years (I think it was first proposed in the late 1800's, & was mention by Jules Verne in one of his books (From Earth to the Moon I think--written in 1865&#33), the magnetic rail gun has only been seriously looked at since the seventies. I nod here to Robert Heinlein who mentions a system similar to a rail gun in his book "The Man who Sold the Moon" from the 50's.

It seems the cannon would be unlikely to launch humans, given the forces involved in accelerating an object to escape velocity by means of a chemical "explosion", it is certainly an idea that could work for low-cost launching of supplies and material into low-earth orbit. This could become important if and/or when there becomes a need for large amounts of materials to be launched into space for use aboard orbiting construction platforms.

The rail gun seems to have some potential, although the technology is still very experimental.

I also think the laser accelerator is an interesting concept.

[megaquark]

Personally I like the improbability drive on the spacecraft Heart of Gold!