SSI External Tank Report

VII – Conclusions

VII. ET Project – Conclusions and Recommendations

As has been discussed in the previous pages, the External Tank is a very large, very inexpensive enhancement of the American space effort. For almost no additional cost, the STS can deliver an ET complete with residual cryogenics to a space station orbit. This 69,000-pound object could become a multi-billion dollar investment in the future of our space program. Typical figures for aluminum mass alone a yield net worth over $20 billion after 250 launches. This does not include the previously discussed economic advantages of cryogenics scavenging, aluminum fueled rockets, ACC additional volume, and the resulting elimination of the volume limit for STS launches.

With the external tank, we have the potential for achieving an extremely high return if the tanks are take to orbit today and stored for later use. This is something that can be used to leverage the growth of industry into space at a very low cost and will provide the nation with the advantages of industrial growth, national preeminence in space utilization, jobs, and tax revenues. It is also an enabling technology that will enhance the safety in potentially dangerous research in genetics, pharmaceuticals, and industrial chemicals by stationing the ‘lab’ in orbit. The existence of large inexpensive space platforms opens the field for space based research on more risky and less well known subjects. This widens the possible avenues of both commercial and governmental research and allows additional approaches to be made with the corresponding potential increase in new discoveries.

The space station can be enhanced by flying a fleet of additional stations in close proximity. The multiple stations could include DOD, Corporate, and Foreign platforms both manned and unmanned. The actual enhancements of the station itself include elbowroom, storm shelters, experimental volumes, fuels scavenging and storage, to name just a few. The addition of the ET or the ET/ACC to the space station will be a welcome answer to those critics of the space program that want low costs and high returns on investments.

As with any other suggestion that paints a very rosy picture, the use of the ET does have its problems. These include the lack of a current market for a large number of tanks, the maintenance of the tanks in an orbit high enough not to decay to an uncontrolled reentry, and the problems of SOFI outgassing. The information used by the author in this report indicates that none of these problems are insoluble. Indeed, the most difficult question to answer is the one concerning the present or future market for the ET. It has been demonstrated that there are myriad uses of the ET in almost every area of space endeavor. All that remains is the decision to use the tank or to allow it to be used.

Recommendations for the use of the ET are:

1. Quickly fly the ET and store it in a permanent storage facility in relatively high earth orbit.

2. Arrive at a pricing policy that covers the cost of orbital storage and maintenance of the tank. Sales should be based only on average storage costs. If a tank is purchased for orbital use, the purchase cost and agreement can be determined prior to launch. The only stipulation should be that the buyer be able to physically do something with the ET in a specified period of time.

3. Design and offer the ACC as an enhancement of the STS itself. The ACC is initially thought of as a secondary cargo carrier. This need not be the case if the ACC payload is the primary payload for that flight.

The External Tank is simply too flexible and valuable a resource to continue throwing away in the upper atmosphere. We as a nation are fortunate that such a great opportunity for program advancement exists at so little cost. The use of the ET is well within our current capabilities and would be a welcome addition to the future of the United States in space. We recommend that the tank be flown early and often.


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