Otros antecedentes generales de las experiencias analizadas

OTHER APPLICATIONS

While this report has exhaustively examined alternate Whipple and Enhanced Stuffed Whipple ballistic limit equations for the U.S. Laboratory Modules, future research is not limited to this module, nor to the International Space Station as a whole. Whipple Shields and the Enhanced Stuffed Whipple Shield can be used in various forms on other earth-orbiting satellites. Protecting multi-billion dollar satellites in space with some form of Whipple shielding would reduce program risks for the commercial industry, scientific bodies, and the U.S. government. Not only could Whipple Shields and Enhanced Stuffed Whipple Shields on satellites protect against the naturally occurring space debris and micrometeoroids, it could also protect against manmade debris. Maintaining satellite functionality after an impact could save industry and government countless millions of dollars in replacement or maintenance costs (for those satellites serviced by the Space Shuttle). For the nominal cost of implementing a multi- stage shield on the bus of many satellites, a satellite may have its usable lifetime expanded considerably, or, at a minimum, may avoid having its usable life terminated abruptly as a result of damage sustained by a debris impact. An opportunity cost study or similar research should be conducted to determine the feasibility of putting the family of Whipple Shields on other earth-orbiting satellites.

In addition to the International Space Station, the shielding could be modified and used on other manned space vehicles too. With a manned mission to Mars a goal of NASA in our lifetimes, some form of shielding will be needed to protect against the heliocentric micrometeoroids that pose a great risk to any mission undertaken. The projectiles have incredibly high speeds and therefore require significant shielding to defeat their destructive power. Some configuration of Whipple or Enhanced Stuff

Whipple Shield is a more viable option than thick, heavy monolithic shields. In fact, this is an area of ballistic research that should be of particular interest to NASA as it prepares to send a man to Mars. Preliminary work should begin in earnest now. It is a logical and an ideal follow-on to the ISS shield analysis work done by JSC HITF.

From the aspect of Space Control, a topic currently of great interest in the Department of Defense, Whipple and Enhanced Stuffed Whipple Shields could provide some protection against attacks upon U.S. and allied satellites by parties using small projectiles aimed at impacting national systems and causing their disruption; reduction or loss of functionality; or outright destruction. Specifics of Space Control and the defense of U.S. satellite systems to guarantee assured access to space are typically classified, so future work in this realm would have to fuse the unclassified shield theory with classified Space Control theory. The Department of Defense would be foolish not to consider implementing some form of shields on its national systems, those satellites that provide military communications, signals-gathering, imagery, and nuclear launch warning. After all, these are strategic assets and are vulnerable enough to space debris that was not placed in space by malice. They are even more susceptible to debris put in space for the sole purpose of denying access to our satellite systems. Unfortunately, those competing states that have the ability to launch debris into orbit are also likely to know the ephemeris data of many of U.S. national asset satellites. In a known orbit, a satellite is particularly vulnerable to a dedicated, targeted attack using space debris as a kinetic kill vehicle.

As a completely theoretical example, one could assume a nation like North Korea that does not have satellites of its own in space and doesn’t concern itself with the political repercussion of damaging other nation’s space-based systems and satellites, could launch a missile into space that is full of ball bearings, which is promptly dispersed and becomes debris upon entering low earth orbit. At this point, North Korea has the perfect space-based weapon – it is indiscriminate, does not require guidance, and can

cause cascading damage if it impacts any manmade satellite in its path. Thus, they can impact other nations’ ability to communicate, spy, or conduct scientific experiments. Such an attack could have negative effects on the entire body of manmade satellites for years to come. While this is a somewhat tenuous chain of events in modern times, it is a frightening possibility of things to come in the near future, when mankind becomes increasingly reliant on space-based systems for national defense and in our everyday lives.

To examine the possibilities of adding some form of shielding to the satellites to avoid such a devastating scenario seems a prudent decision. The work contained in this thesis merely provides an example of the ability of Whipple and Enhanced Stuffed Whipple Shields to mitigate against some of the debris that is orbiting earth. The Department of Defense can independently assess any debris threats to its satellite networks, as well as the threats of orbital debris being introduced for the sole purpose of denying the United States the ability to use space as a strategic asset. In doing so, the government must look at what defensive measures are available to counter the threats. The family of Whipple Shields is just one possible solution that springs from the research in this report. Future hypervelocity impact analysis work could become an interagency project, with NASA and the Department of Defense organizations operating in concert to mitigate against orbital debris threats to national satellite systems.

Outside of NASA and the ISS program, there is a wide customer base of potential Whipple Shield users. Future research into shield performance can and should be tailored to the commercial, civil, and military uses of these multi-stage shields. Such research would introduce this latest technological triumph of NASA into the greater world and would continue the proud tradition of technology marvels springing from the U.S. space program. This would be good for NASA and good for the space-faring community as a whole.

Continuing ballistic limit analysis and further experimentation are the best ways of ensuring all spacecraft are protected against hypervelocity impacts. If NASA is prescient enough to continue its already impressive work in this field, it will revolutionize the way in which satellites are built with debris protection in mind. NASA’s work will further industry’s and government’s risk assessment capabilities, leading to smarter, safer business and engineering decisions on space systems.

VIII. SUMMARY AND CONCLUSIONS

A. SUMMARY OF RESEARCH FINDINGS – REVISED BALLISTIC LIMIT