Now, the commercialisation of launch capabilities, most notably SpaceX, is one way to combat these launch costs - and in the next few years we will find out if this approach is going to be viable in the long term (Personally I think it will, but thats not why I'm writing this short post).
However, one of the threats we face is technological complacency. SpaceX and their Falcon launch vehicles use Liquid propellants, which is (to a broad definition) the same technology being used 50 years ago. Just like modern cars still employ the internal combustion engine, technology which has existed for well over a century, the space industry risks becoming stale with old technology. Many alternate launch mechanisms have been proposed over the years and its time we start investing more heavily in their development.
Last Friday, we had a visiting lecturer to the SSP, one Michael Wright from NASA's Goddard Spaceflight centre, speak to us about the idea of Electromagnetic Launch Technology (EML). Utilising the concept that the interaction between electric and magnetic fields will induce a force, this technology aims to accelerate projectiles at high velocity. The projectiles (or vehicles) are magnetically suspended above a fixed track, whose length determines the final velocity - which can become very high indeed. The beauty of EML is that it is easily and quickly repeatable and could allow many launches per day and hence also allow a vehicle which initially failed a launch test to launch as soon as that problem is fixed. This is in stark contrast to the long delay between rocket launches, which usually aren't completely recyclable. Not only that, but EML could be a 'green technology' and be powered by renewable energy sources. However, EML does have it's limits. As mentioned, the velocity is determined by the length of the track and it require dozens of kilometers of track to launch an object into orbit
Sending an object into orbit requires an extremely large velocity (Greater than 11.2km per second) and has always been the principle challenge to spaceflight. One proposed solution is to use EML to accelerate a launch vehicle to greater that the speed of sound and then to use conventional rocket technology for the remainder of the journey - this approach would significantly cut down on the amount of fuel required by a rocket.
Particular interest in EML revolves around its use on the moon. The moon has a gravitational attraction which is 1/6th of Earths, so it is significantly easier to launch objects off of the lunar surface than it is from Earth. In the coming decades, lunar development and settlement is going to become a reality and with the vast amount of resources on the moons surface (Helium-3, water, rare Earth metals to name but a few) we are going to need a method of sending objects off the lunar surface. Numerous site locations for an EML station have been proposed for the moon and all have their merits. Personally, I believe an ideal site would be on the south pole of the moon, in particular the Shackleton Crater. By using the slope of the crater, the EML track could be inclined to propel objects at a greater angle. Moreover, the crater is the site of extreme temperature differences; the bottom of the crater is in constant shade whilst the crater rim is bathed in constant sunlight. These temperature differences can be used as an energy source, especially when combined with solar panels along the rim which would generate significant energy. Plus, the chilling temperatures within the crater could help maintain the superconductivity of the magnets required in EML.
Michael Wright has been involved with EML for a long time and had some very interesting points to make. One troublesome thing he brought to our attention is that continuous NASA budget cuts have led to a considerable lack of funding for EML technology even though it has already proved its effectiveness. Perhaps it is time for a commercial enterprise to take the reigns on the use of EML?
Regardless of where it used and by whom, EML is definitely an effective launch mechanism and I expect to see it being employed within the next decade or so. Furthermore, this technology is easily applied to terrestrial transportation (it is already being looked at by the military to launch aircraft) and I look forward to it revolutionising our transport industry.
Michael Wright enlightened me to this fascinating Edison quote which is definitely appropriate:
"There is a way to do it better - find it." - Thomas Edison
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