Exploration Platform Depot
Space Shuttle External Tank

ABSTRACT Construction of a Space Shuttle External Tank structural berth appropriately covered with a radiation reflective material can create an effective thermos bottle for propellant storage. The berth, itself reconfigurable as cranes, drilling rigs, grading equipment and other structural members, would support cryogen maintenance equipment, provide for mating a set of Space Shuttle Main Engines in another structural section and be combined into depots or exploratory freighting platforms. Configurable as vertical thrust units, each with its own engines, it would be able to support a Space Shuttle thereby affording it vertical takeoff and landing capability on many objects of our Solar system. Forward thrust would be provided by the Space Shuttle re-attached to a replenished ET, or horizontally mounting an ET and engine combination without the Space Shuttle to form an autonomous freighting platform.

TECHNICAL OBJECTIVES Now that the International Space Station (ISS) is a sufficient presence in space, it is time to reconsider the wasteful disposition of the Space Shuttle's external tank (ET). Since the first launch of the Space Shuttle (SS) surely many have thought it a waste of launch dollars to plunge the ET back into the atmosphere for a fiery dispersion of aluminum particles into the upper portion and a residual deposit into the Indian Ocean. I can remember as a boy building a box to save all the plastic parts hangers that accompanied the many model boats and airplanes that I built, in hopes of melting it down to build other models. Not thinking much of anything as being waste, I have always believed the adage "One man's trash is another's treasure."

This proposal suggests the construction of cryogenic and other fuel storage depots with multipurpose uses at the ISS and beyond and requests the funding to begin the design and research necessary for this endeavor. With the ISS functioning as a space based assembly, maintenance and operations facility, instead of discarding the ETs, it is proposed to bring the ETs along to the ISS and store them there until residual cryogens or fuels brought for the purpose adequately prepare a tank depot (TD) for use on a mission. If ETs accumulate too rapidly, attach a freight rocket, brought by the shuttle, to the empty tanks firmly lashed together with woven, high-strength, industrial straps commonly used by manufacturing plants. The autonomous freight rocket could resemble a reduced scale version of the DC-X with similar landing capabilities. Take the excess empty tanks to Luna or to some other orb for use as water storage, habitat, fuel, etc. or simply leave them in Earth orbit or at a Lagrangian point, bringing back the freighter for additional use, perhaps by a less demanding propulsion system or a solar sail.

Assembly of truss type structures for TDs would be by mechanical means wherever possible. Lunar welding of aluminum should be highly efficient in vacuum. Of course, methods of welding would be perfected on Earth under simulated space circumstances to the extent possible.. Welding in free space, without sufficient gravity, could be extremely dangerous if a molten, radiative, cooling drop should impact a spacesuit; however, vacuum welding on a gravity generating moon should be an efficient enterprise. Newly developed techniques using charged getters and globule processors may enable welding safely in free space. This is another issue, but will need resolution for determination of the best methods of assembling the TD.

ET housings should be constructed of a rectangular, gangable structural berth, appropriately lined with a radiation reflective material. When combined with a reloadable ET, an effective thermos bottle for propellant storage is created. This TD should have capability for re-attachment to the SS for exploratory manned expeditions. It should also be attachable to another structural section housing a number of Space Shuttle Main Engines (ME) that would provide an autonomous freighting platform. It would. ferry supplies autonomously preceding or following a human expedition and or for emergency purposes. A multiple TD and engine module combination might also be used for extended voyages or accelerated access. The two principal platform combinations are then the TDSS and the TDME. Naturally the ISS would be able to utilize a TD for its own purposes and ISS operations would include maintaining and constructing the TD.

TDME sections, say four, arranged properly to form a platform for the SS, would use the SSME for forward thrust and the TDME combination for vertical landing and take-off. Using on-orbit, hydrazine engines to provide initial thrust and acceleration necessary to feed the fuels from the SS ET, ignite the MEs and go to Luna or Mars or elsewhere. Initially, a simpler scenario might consist of a TD refurbished SS carrying a DC-X type manned lander to lunar orbit where the lander then descends to the surface while the SS orbits overhead or returns to the ISS, a somewhat familiar scenario. A more robust exploration would be achievable with the SSTD vertical take-off combination. The SS would carry a habitation module returnable or transferred off to remain on the surface. Perhaps the TD berthing structure could be designed in such as way as to provide reconfiguration as construction cranes, drilling platforms, habitat structure and grading equipment. Empty tanks for use with indigenous materials, or even full ones could be left there. Think about it. We could take a shuttle to the ISS and leave it parked there, outfitted with a vertical launch and landing DC-X type (VLL) vehicle in the cargo bay. The shuttle doubles as a Crew Return Vehicle (CRV), eliminating the need for a sole purpose CRV. An additional shuttle could go to the ISS with adequate supplies for base operations. One would remain at the ISS while the other made the trip to Lunar facilities. A small processing plant would be constructed and could begin work on the ETs that were freighted there from the ISS. What an excellent dress rehersal for planetary exploration. Solar tracking sun shades would also be of benefit to the TD containing cryogens in space or at a base.

Constructing a lunar base doesn't seem like a far cry from existing capabilities. A Mars expedition should gain much practice and expertise by building a Luna base or two on that much more accessable body. The same principles can be applied for a Martian excursion, although several fueled ETs may be desired and more than one shuttle. Maybe we should build a few more shuttles.

It is re-emphasized that the purpose of this proposal is the construction of the Tank Depot or TD which combines the spent External Tank, from the Space Shuttle mission to the International Space Station, with a structural ET housing noting that the designs are done with the aforemention considerations.

COMERCIAL APPLICATIONS POTENTIAL If there is going to be any commercial exploration and development of space, this is believed to be the correct path. It is also believed that this pursuit, placed on a front burner, has potential to give the rest of the world a unifying purpose thereby enabling funding enhancements. The area of a ground floor from the 100 External Tanks thus far discarded is significant. Considering the number of floors that might be constructed in these, a sizeable outpost has been discarded.

The International Space Station thus fulfills its true destiny.

REFILLING THE SPACE BASED EXTERNAL TANK

Tubular Light Conveyor
Gathering Gases on Orbit


Jeepers, would I like to get or see this moving. Oh, please write dates correctly. We'll get there sooner and safer.


Ronald W. Cook
12915 Alton Sq., #117 -- 703-471-7226
Herndon, VA 20170-5802 -- rwc@cowaro.com

2001/05/26 19:28:27 Sat 146 990919707 2002/02/28 18:39:58 Thu 059 1014939598 last updated