October 22, 2010
Buzz Aldrin: We Need a ‘Space Taxi’
Most people are familiar with the space shuttle as the current primary means for NASA to carry astronauts into space. However as the final flights of this complex and impressive machine are prepared, the design of the next space transportation system is being debated. The original purpose of the space shuttle was to be a convenient way to launch large payloads and crew into space. By reusing parts of the system and flying often, the cost of launches would be reduced. But the complexity of the shuttle and risk associated with carrying crew and cargo together prevented it from achieving this goal of reducing launch costs. That is why I believe the next vehicle we use to bring astronauts to and from space should be a dedicated space taxi.
This vehicle would be much smaller than the space shuttle. It could launch a crew of six to eight people by sitting on top of an existing expendable launch vehicle. After delivering crew to the ISS, or other transfer stations for deep space missions, the vehicle is able to re-enter Earth's atmosphere and land back at or near the launch site. This vehicle will operate at a fraction of the cost of both the space shuttle and the proposed Orion capsule.
Water recoveries are expensive and introduce risk to the astronauts. In addition, dropping these complicated machines into salt water makes it very difficult to create hardware that is reusable. Looking at the "reusable" solid rocket boosters that are currently recovered from the ocean, we know that this is a complicated procedure that requires stripping components down to bare metal. This is not the sort of design that makes for a launch system we can turn around and launch again on a weekly basis in a cost-effective manner. Rather than returning to the "Apollo on steroids" philosophy, a space taxi will land either on a runway or vertically (using airbags or propulsion) to minimize the time and work required to prepare for the next launch.
A specialized crew transportation vehicle as I've described above is not a new idea. In fact NASA already spent about a billion dollars over seven years developing one. The HL-20 was a NASA Langley space taxi concept for the original Space Station Freedom. However after partnering with Russia on the ISS, the Soyuz was selected as the vehicle of choice for its significant heritage and strong safety record. The HL-20 concept was at a high level of development but unfortunately work was stopped before flying a complete prototype. Now, the concept has been taken up by a private company.
Another option is a vertically descending capsule that is designed to return to land. This is a difficult task compared to a water landing because of the difficulty of having a soft landing. However the benefit of creating a system that really is reusable and allows for a high flight rate will outweigh these extra propulsion or airbag systems.
Without the space shuttle, we must invest in a reusable crew vehicle "“ a "space taxi" "“ to establish a reliable and cost effective space transportation system into Earth orbit. Reducing cost and risk burdens where possible is essential to a sustainable spaceflight infrastructure. The image of the space shuttle has become an icon representing the great achievements we've made in space. It has carried our astronaut heroes for the past few decades. Let's invest in a vehicle that will be able to carry many more people into space and increase our capabilities in a way that will make space accessible to the next generation of explorers of the solar system.
Since retiring from NASA and the Air Force, Col. Aldrin has remained at the forefront of efforts to ensure America's continued leadership in human space exploration. He devised a master plan for missions to Mars "“ the "Aldrin Mars Cycler" "“ a spacecraft transportation system with perpetual cycling orbits between Earth and Mars. Dr. Aldrin has received three US patents for his rocket systems and schematics.
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