.: Low Cost Access to Space

For decades, mankind has dreamed, written books, created films and video games and invested billions of dollars to explore the unique environment of earth orbit and outer space. The appeal of space is broad and universal, leading some to inquire about their origins and the earliest moments since creation of the universe and others to envision their future in space, to gain a better understanding of the universe and to imagine becoming a voyager or inhabitant on some distant colony or star.

Most of the benefits of the past and current space programs are attributed to advanced technologies or products which are spin-offs from the attempts to develop strong light-weight structures or the means of launching men and materials from the surface of the earth to space.

But the direct benefits of space are quite different and much more spectacular. Many of our current and future global challenges can be met by innovative use of space. For example:

  • Global Communications - a network of low cost nano- communication satellites can provide instant communication (and perhaps imaging) to any place on earth.
  • Global Warming and Climate Change - solar Power Satellites located in geosynchronous orbit could beam energy to any place on earth.
  • Exploration and Colonization - habitats in space to provide launching points for deep space exploration or settlements with an abundant source of energy.
  • Space industry - zero gravity manufacturing to make new materials or products not possible on earth.
  • Precious metals - recovery from asteroids, other planetary bodies.
  • Global Protection - deflection of earth crossing asteroids.
  • Availability of Helium-3 for fusion energy

So what is preventing us from experiencing these direct benefits?

Cost of Access to Space

To date, all satellites have been launched to space using chemical rockets. Usually less than 1 % of the total rocket/satellite system actually goes into orbit. The rest goes into the fire and brimstone which make rocket launches such a spectacular event. A fascinating description and an excellent analysis of the cost of reaching orbit is an article published in Space Policy by Prof. Jonathan Coopersmith. He points out that launching a satellite costs roughly $20,000/kg and “that figure is the major challenge facing space flight: until the cost of reaching orbit drastically decreases, the large-scale exploration and exploitation of space will not occur.” (Coopersmith, 2011)

Although there are numerous industrial and government projects to reduce launch costs, the technology is much the same and any cost reductions will most probably be underwhelming.

Science fiction writers have envisioned large guns that would be able to shoot capsules into space and imaginative engineers built large guns that were able to accelerate projectiles to an altitude of 180km. But none of these alternative launch technologies received sufficient support to become a viable competitor to chemical rockets. Jules Verne captured the idea in his 1865 book “From the Earth to the Moon” and Northrup described the technology for a “coilgun” in his 1937 book “Zero to Eighty”.

In the early 1980s, NASA Lewis investigated the feasibility of launching materials to space using railguns. At each of the IEEE International EML Symposia since that time, there has usually been at least one paper discussing electromagnetic launchers as an alternative means of launching materials to space. Unfortunately, none of them has been able to make a compelling case that the EM technology was feasible and affordable. Consequently, there was never sufficient interest on the part of the Government funding agencies to develop the necessary research program to establish the feasibility.

It is ironic that the keynote address at the 4th International EML Symposium ( H. Fair, P. Coose, C Meinel and D Tidman, “Electromagnetic Earth to Space Launch”, Trans on Magnetics, Vol 25, PP 9-16, 1989), advocated:

“If we consider where we were at our first EML Symposium at San Diego in 1983, Dick Marshall and a few others had successfully performed isolated experiments with electromagnetic launchers (mainly launching grams of lexan to hypervelocity). What we have managed to accomplish was to provide a focus which created an incredibly talented technical community and pulled together a serious effort to develop electromagnetic launcher and pulsed power technology. This community is at the forefront of being able to apply its resources and energies to the problem of launching material to space. We can make a valuable and unique contribution to truly opening the frontier of space. As a first step, The University of Texas is planning to host a workshop this fall which will provide a forum for serious discussion of EM earth- to-space launch issues. As this develops, we welcome your participation and are confident that the same high level of technical talent, energy, and enthusiasm will lead to the development of a new, credible program of international importance.”

The workshop was held but the results were not published. There was interest, but no compelling credible path forward.

From 1989 to the mid 1990s, there were significant advances in EML technology including an improved understanding of plasma armatures . All the Army and Navy applications involved launching projectiles which would transit through the atmosphere, so to eliminate concerns about aerodynamic heating, they limited their efforts to about 2-3 km/s. On the other hand, SDIO envisioned railguns in space and had programs such as “Have Sting” with a launch velocity requirement of 16 km/s. But following a political decision by the White House NOT to put weapons in space, the SDIO railgun efforts were terminated as was research on plasma armature railguns.

Since that time, Nano-electronics has emerged as a rapidly growing technology enabling small nano-satellites. The solid state electronics naturally lend themselves to compact, dense, g-hardened devices. Thus, nets of nano-satellites weighing several to 10 kg may provide much more capability than the large redundant 100 ton satellites of previous years. Some of the fastest growing small business ventures involve the design of nano-satellites. But they still face the same physical limits of cost of access to space!

Can alternative launch technologies provide a possible means of resolving this issue?

There are a number of candidate technologies for launching materials to space including railguns, coilguns, Superconducting MAGLEV in a tube( STAR TRAM) Light gas guns, Slingatrons, etc.

For Example- star tram was discussed at the most recent EML Symposium in San Diego.

In principle, velocities of 8 km/s can be achieved leading to direct access to space.

What is the Status of these alternative technologies to achieve the Ultra-High Velocity required for launch to space?

The technology is in much the same status as was the EML technology prior to 1980.

  • Some excellent independent technical efforts- mainly theory and computations
  • Few experiments to demonstrate the required velocity at any scale

No alternative launch technology has received the minimum of support to seriously evaluate its potential and associated challenges and to develop the technology:

  • Scale to appropriate velocity( 7-10 km/sec) and mass(minimum 5-10 kg)
  • High acceleration of payload
  • Aero thermal heating
  • Atmospheric drag