For the last 16 months a George Washington University team, at the request of the Space Shuttle Children’s Fund , has been reviewing astronaut safety .
Our findings are divided into three main sections that address ways to enhance the safety of the space shuttle, the international space station (ISS) and f uture launch systems. We conducted this study completely independently from NASA. We only had funding for a limited effort that totaled only 1.25 person years of effort, thus we recognize that many concerns may have already been addressed and findings may have been reached without complete information.
Nevertheless many hundreds of documents, Web sites and analyses were investigated and dozens of interviews undertaken to reach these conclusions and findings.
The Space Shuttle
We believe the new Independent Technical Engineering Authority within NASA should assume full oversight of all safety activities including control of waivers and responsibility for the NASA Engineering and Safety Center — that in our opinion should be made more proactive. The more than 7,000 waivers granted for the Columbia should not be considered acceptable.
A replacement crew vehicle system for the shuttle should be accelerated and any financial benefits resulting from shutting down the shuttle at a somewhat earlier date should be reinvested in the earlier development of the replacement vehicle or other system requirements of the new exploration space vision.
In general, robotically controlled cargo vehicles should in the future do the heavy lifting into space to minimize astronaut risk. Specially designed crew vehicles should fly separately or in tandem with cargo vehicles and should provide a full envelope escape mode for the crew.
In addition, s erious consideration should be given to the feasibility of converting and operating one or more of the orbiters as a robotic cargo vehicle, because it could reduce risk to astronauts on missions where crews were not essential and increase cargo-lift capability.
NASA should explore reducing the number of remaining flights for the shuttle by limiting some aspects of ISS construction. This should be considered in concert with the international partners and should not involve reduction of flights related to major international subsystems such as the European Columbus Space Lab and the Japanese CAM and JEM. Simply put, more flights of the shuttle increase the odds of another catastrophic failure. A 28 launch manifest produces about even odds of another shuttle accident — an event for which NASA does not seem to have a viable exit strategy .
Several safety issues and possible improvements to the shuttle, as listed in our full report, were offered as possible ways to reduce risk, although it is recognized that many of these involve considerable expense and many also have been previously considered. We are concerned that with the expenditure of nearly $2 billion, safety concerns remain and the safety gains are not significant in a statistical sense.
We are in general agreement with the findings of the Columbia Accident Investigation Board , the Rogers Commission, the Diaz Committee report and the findings of the BST Inc., and believe these all aid shuttle safety.
The International Space Station
As noted above, a reduction in scope of the space station in concert with international partners could reduce the number of shuttle missions. This also would reduce the probability of a major accident and in theory allow the development of a new replacement manned launch system sooner.
The lack of an effective escape capability from the ISS or the ability to use the space station as an extended safe haven when the shuttle is not available is of major concern. In this regard either the immediate re activation of the X-38/ACRV program or the obtaining of U.S. legislative authority and funding to support obtaining additional Soyuz vehicles (including expanded crew-capacity Soyuz capsules to be used as access and escape systems) is considered to be of prime concern. Upgrading the ATV to support crew missions to and from orbit might be another option.
We list possible ISS improvements in our f ull report as ways to reduce risk, although we recognize many of these involve considerable expense and may also have been previously considered. Observations with respect to the gyro system, the environmental and life support systems and debris hazards are considered among the most important issues.
International components of the space station have certain safety implications. These fortunately do not give rise to any major concerns. The formation of the International Association for the Advancement of Space Safety might well provide new opportunities for a more integrated ISS operational process for safety and emergency procedures that go beyond the national franchises on the ISS.
The Independent Technical Engineering Authority and the NASA Engineering and Safety Center can provide strength to the oversight of ISS safety operations, better control of waivers and address the issue of so-called “risk creep” that has accompanied the current operational procedures that have evolved during the period of the grounding of the shuttle.
The Future Human Space Programs
It is important that we learn historical lessons from the shuttle and apply them to future planning. Key aspects in this regard: D on’t combine too many missions and capabilities; E nsure the ongoing infusion of new technology; P rovide complete full-envelope launch-to-land escape capability; s eek simplicity of design, operation and retrofit (especially of passive systems); D esign in safety at the beginning including sensor warning systems, emergency shutdown & escape; and R ecognize that safety is only as strong as the weakest link (i.e. a highly reliable CEV on top of a launch vehicle that is not as highly rated could still represent a questionable system.)
Cargo systems that can be robotically deployed are not only safer (i.e. no crew) but may very well be more efficient and more economical.
Advanced technology is not necessarily more complex technology. Simplicity of design, such as throttle-able solid-fuel systems or hybrid rockets, and other systems that provide increased performance at lower cost and with few active components might represent the best designs. Input from smaller entrepreneurial organizations should be actively sought in designing future launch systems with a view to increasing safety and simplifying designs.
The coordination and relationship between NASA and defense-related space programs with human crews are not clearly delineated and certainly are not transparent. This could lead to safety issues in terms of key information not being shared. Thus there can be overlap or “underlap” of programs, and best practices observed in one sector might not be applied in another.
Private initiatives to develop new manned space commercialization, space tourism and even private spacehabs are moving forward in response to prize awards , new entrepreneurial capital and new regulatory authority provided to the Federal Aviation Administration. This provides new paradigms with regard to private astronauts and even new approaches to passenger liability, insurance and risk assessment. This may offer NASA new opportunities in the future. It may eventually also allow NASA’s manned space and astronaut programs to work in parallel, or perhaps in competition, with private ventures. This may not reduce risk but nevertheless may help redefine public and private safety definitions and accepted standards for safety performance.
The Crew Exploration Vehicle if launched by an upgraded expendable rocket such as Delta, Atlas or Titan will likely remain limited in its overall systems safety and reliability by this design approach.
Evolution to launch systems that use new technology such as ion engines, tethers, or electrical and nuclear propulsion systems instead of chemical explosions may represent the key to providing safer and more reliable in-space propulsion systems in the longer-term future.
A stronaut safety will evolve so that developing the safest transportation and propulsion systems may not be the greatest challenge. Instead, the prime issues may relate to protecting astronauts in space from debris, micro-meteorites, comets, radiation and zero- or low-gravity environments. New programs to ensure long-term survival in space need to be given higher priority in the new space vision.
All new human space transportation systems should be developed to common international standards that would permit compatibility for emergency crew rescue and contingency capabilities when needed. These standards should be developed in concert with international partners, and the specifications should be made widely available for the public and private sectors for any nation seeking to develop these capabilities to use as they deem warranted. This is a key consideration in making possible, affordable, reliable alternative access by dissimilar redundancy and modular approaches. The sky is no longer the limit, but space safety is.
Joe Pelton is director of the Space & Advanced Communication Research Institute at The George Washington University and was principal investigator on the study “Astronaut Space Safety 2005” The full 243 page report can be found at www.spacesafety.org
