WHAT WILL AMERICA DO IN SPACE NOW?

Transcription

1 WHAT WILL AMERICA DO IN SPACE NOW? William Ketchum AIAA Associate Fellow 28 March 2013 With the Space Shuttles now retired America has no way to send our Astronauts into space. To get our Astronauts to the International Space Station (ISS) we now have to pay Russia to ride on Russian rockets, at more than $60 million per flight. There is no current plan for a replacement for the Shuttles, and plans for future missions to space are mired in confusion and uncertainty. How has this happened? To answer this requires going back 40 years to the end of the Apollo Moon landing program when NASA was trying to figure out what to do next. Three options were then being considered, a manned mission to Mars, an Earth orbiting space station, and a reusable space shuttle. Having developed the capability to land Americans on the Moon only seven years after putting John Glenn into Earth orbit, NASA had achieved the most impressive technological accomplishment in the history of the human race, and developed a completely new and vast space infrastructure. But with the Vietnam war now taking billions of dollars, and the lives of American servicemen, money for continued space efforts was short. Therefore, a mission to Mars that would have cost a lot more than the $25 Billion (1970$) spent in the Apollo landings on the Moon ($150 Billion in today's 2013 dollars) was dropped from further consideration. This left the other two options, a space station and a space shuttle, but since a space station needed a way to get there, the space shuttle was selected for development. But what kind of space shuttle? The Saturn V rockets used in landing Apollo Astronauts on the Moon were one shot deals and after sending Astronauts on their way the rockets were not recovered. Furthermore, on its return to the Earth from the Moon, the Apollo manned space capsule had to land in the ocean, requiring an immense task force of U.S. Navy ships and personnel, obviously not the way to go for routine trips to space and back. -1-

2 So designers and engineers (I was one of them) came up with a fully reusable rocket concept that would be expected to permit routine, low cost, safe access to orbit and back, similar to operating an airline. All the technologies needed, rocket engines, propellant tanks, guidance and control, life support systems, escape systems, recovery, etc, had been been proven out in the Apollo program by the end of the 1960s, and we even got airline companies involved in our discussions to be sure we considered their operations requirements. At the same time, a reusable spacecraft, the X-15, piloted by both NASA and military test pilots, had already routinely reached speeds of over 4500 mph and altitudes of 67 miles, and was capable of even higher speeds and altitudes. And the X-20 "Dyna-Soar", a manned reusable orbital space vehicle, was under advanced development by the U.S. Air Force for the Manned Orbiting Laboratory program (both later canceled). With all this knowledge in hand, work started in the late 1960s on designing the Space Shuttle, a much larger fully reusable space vehicle, having a seven person crew, capable of placing up to 65,000 pounds of cargo into low Earth orbit, to satisfy both civilian and military space requirements. FULLY REUSABLE SPACE SHUTTLE DESIGN CONCEPT

3 Extensive engineering and economic studies by many Aerospace companies resulted in several variations being defined and presented to NASA for consideration with the preferred concept of a booster and an orbiter resembling two airliners attached alongside each other, vertically launched, with each one capable of horizontal landing on existing airport runways. However, cost estimates for developing a completely reusable space shuttle were considered too high, and cheaper development concepts were sought largely because Congress and the Office of Management and Budget had determined that limiting the up-front funding was more important, and as a result by 1972 the Space Shuttle design had ended up becoming a compromise, cheaper to initially build, but more costly to operate. SPACE SHUTTLE It should also be remembered that the military requirement for heavier and larger size payloads, in addition to more cross-range landing capability, had a significant impact on the selected design (and on the willingness to risk the crew). Combining NASA and military requirements was possibly the biggest mistake ever made in the American space program. The taxpayer-citizen who would pay for everything was never asked what they would have preferred, and if asked to choose a space vehicle that they would personally ride in, most people would choose the safest one, not necessarily the cheapest one. -3-

4 Unfortunately the chosen Space Shuttle design experienced two tragic failures killing a total of 14 Astronauts needlessly. Challenger was destroyed in 1986 shortly after launch because of a failure of one of the solid rocket boosters. Columbia was destroyed in 2003 because a piece of insulation/ice falling off the external tank during launch punctured a hole in the wing of the orbiter letting hot gasses penetrate and burn up the orbiter upon re-entry from orbit. Both of these failures need not have happened if warnings from the engineers had been heeded. Neither the orbiter vehicles themselves, or their main engines (the most complex system in the Space Shuttle), ever experienced a failure in their 30 year history of 135 flights, and to their credit are the launch and servicing of the Hubble Space Telescope which revealed the Universe as never seen before, and the construction of the International Space Station (although the space station would have been more spacious and less costly if it had been launched in fewer but larger sections like Skylab, which was launched by an unmanned Saturn V booster following the Apollo program). Ironically, while the orbiters are now retired, never themselves having ever failed, the two systems that caused the Challenger and Columbia to fail are slated for continuation in the new Space Launch System (SLS) being mandated by Congress. SLS COMPARISON TO SATURN V AND SPACE SHUTTLE -4-

5 The SLS as presently configured by NASA is an expendable rocket similar to the old Saturn V from the 1960s Apollo era and is intended to launch very heavy (130 metric tons) payloads into low Earth orbit and beyond, with the capability of launching Astronauts in a recoverable capsule (Orion) similar to the old Apollo concept (parachuted to an ocean recovery). Developing the SLS is estimated to cost many tens of billions of dollars and it will not be available until 2017, more than six years after the retirement of the Space Shuttles. Understandably, the companies that manufacture the solid rocket boosters and the liquid propellant tanks want to continue building these things and are hard at work lobbying Congress, however, there is no planned or funded mission for this rocket such as a manned mission to Mars or anywhere else. One has to question why to build such a rocket now, especially when there are several existing launch vehicles that routinely put heavy payloads into orbit (Delta IV, Atlas V, Falcon 9, etc), and with further upgrading these rockets could launch even heavier payloads (and Astronauts) for much less cost than developing a new SLS system. Instead, it would seem that there is a need to develop a new and better replacement for the Space Shuttles that can offer routine, low cost, and safe access to orbit. An updated version of the originally proposed fully reusable Space Shuttle would take advantage of the lessons learned from the Space Shuttle program, and would use liquid propellants (internal tanks) and multiple engines (capable of shutdown) for safety, and reusability of all stages for lower recurring costs and rapid turnaround (frequent launch). It will not be cheap to develop, but it will be much cheaper (and safer) to operate than the Space Shuttle was. The only question remains, does America want to regain our preeminence in space? I believe that we do, based on my discussions with the general public on the space program in a series of five lectures that I gave recently at the University of California San Diego during which the audience expressed regret that the Space Shuttles are no longer flying, and that America has no real plan for further space exploration in the future. When a recent poll (Phillips) of Americans was taken, a majority (75%) said that they would support doubling NASA's budget from the current $17 billion per year, to 1% of the total federal budget, or $35 billion per year, to accomplish a human mission to Mars. At this rate of spending for the next 10 years we could see humans walking on Mars by the year 2023 and do it the right way as NASA did in landing humans on the Moon, and not by cutting corners with a low cost but risky flyby (no landing) mission to Mars as recently proposed by several private wealthy individuals and eager space enthusiasts. We should be taking advantage of NASA's vast experience and infrastructure to develop second generation fully reusable Space Shuttles, space-based Orbit Transfer Vehicles, and free-flying human-tended orbital facilities for assembly, maintenance, and re-fueling, and for future basing of nuclear powered upper stages to reduce human travel times to other planets. -5-

6 SPACE BASED ORBIT TRANSFER VEHICLE FACILITY With such new capabilities we could start to seriously and permanently move into Space, to do such things as building space-based solar power stations to supply electricity for our future energy needs on Earth, to send humans beyond Earth to other places such as Mars, and to do many other things as yet unforeseen. Besides further opening up Space for all mankind this will benefit people on Earth by inspiring people to create many new technologies and jobs, just as the Apollo Moon landing program did. This was stated more eloquently by former NASA administrator James Fletcher

7 for more information contact WILLIAM J. KETCHUM William Ketchum is an Associate Fellow of the American Institute of Aeronautics and Astronautics. He holds a Bachelor of Science degree in Aeronautical Engineering, and a Master of Science degree in Aerospace Systems Management from the University of Southern California. He started his Aerospace career in 1956 at Edwards Air Force Base in Flight Test Engineering. He then worked for General Dynamics Space Systems Division specializing in cryogenic liquid propellant rocket propulsion systems, developing the Atlas and Centaur space launch vehicles. He participated in designing the Fully Reusable Space Shuttle, Space-Based Orbit Transfer Vehicles, and NuclearThermal rockets for human interplanetary missions. His military experience was in the U.S. Army Missile Command at Redstone Arsenal testing the solid propellant NikeZeus Missile Defense System. His work is in Astronautics and Astrodynamics. He is a consultant for the next generation of Space Launch Systems, and he is developing a small reusable personal spaceplane. He has written many technical reports and papers and lectured on the history of the space program at schools and public events nationwide. He lives in San Diego, California.