© 2006 by Donald F. Robertson.
E-MAIL: DonaldFR@DonaldFRobertson.com.
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by
Donald F. Robertson
I have always been a staunch defender of the Space Shuttle. Almost as far back as I can remember, observing, studying, and advocating for this project has been an important part of my life. It is difficult for many in my generation to even imagine a future without the shuttle project.
The time has finally come to dust off our imaginations and envision just such a future.
Like most good things, the Shuttle is a vehicle for promises only partially fulfilled. Those who fly the Shuttle attest that, once in space, it is a craft of amazing grace and power. Astronauts state it is rock-solid stable and can be positioned with near-perfect precision. The trouble is, too many compromises were made to get the design off the drawing boards and none of that grace is apparent getting into, or out of, orbit.
Along with many others I argued that, in the long term, reusability was the key to lower launch costs. As a first generation vehicle, it is not surprising that the Shuttle failed to fulfill all of its promises. It provided valuable operational experience, it kind-of worked, and there was no replacement on the political horizon. We should persevere and, if we only try hard enough, we can _make_ the Shuttle perform.
In the days before Columbia was lost, I was writing an article proposing the use of surplus Shuttle capacity to start a lunar base. The Shuttle launch system, I argued, was capable of maybe ten flights per year and we were using it less than five. If we were maintaining the Shuttle anyway, the unused capacity of some 150,000 kilograms of payload to orbit each year could go a long way toward testing a new lunar transportation system and pre-positioning some equipment for future missions on Earth’s moon -- without developing any new launch vehicles. Since the majority of the shuttle’s cost was involved in maintaining the orbiters and infrastructure, and not in actual flight operations, the additional flights would not add all that much to the total cost of the Shuttle program. The only new developments would be a trans-Lunar stage and a lander, both of which would be needed later when the lunar base was being fully deployed.
Like the Shuttle program itself, now that article will never be completed.
With the loss of Columbia, circumstances changed, and the Shuttle was given a 2010 death sentence in order to avoid the high costs of “re-certifying” these ancient vehicles for continued flight. It made more sense to invest the money “going forward to the past”, as space analyst Tim Kyger put it. NASA would finish the Space Station with the last Shuttle flights while developing a “quick-and-dirty” Apollo-like capsule to return to Earth’s moon and prepare to go to Mars. After decades following the ever-receding mirage of inexpensive access to orbit, it was time to refocus on the reason for it all: to “explore strange new worlds and go where no one has gone before.”
With the latest problems safely launching the Shuttle, circumstances have changed yet again. If the fix to prevent the External Tank from shedding insulation is not obvious and quick -- and possibly even if it is -- it is finally time to give up on the Shuttle.
There, I said it: maybe the Shuttle should never fly again. It is very hard to write those words, but truth and ease are rarely synonymous. We have learned to do many things from this rickety vehicle -- and how not to do many more -- but we have learned all we can from the Shuttle.
Where does that leave the Space Station?
I believe that the Space Station -- or something else in space that requires regular deliveries of cargo -- is vital if we are to have a near-term future as a spacefaring people. Without a base in space, there is no near-term market to justify new rockets and the launch industry could wither. With no launch industry, obviously, there is no spaceflight. Since the Space Station is already built and partially deployed, it makes no sense at this point to start over.
Discovery’s problems may turn out to be a blessing in disguise. By taking the Shuttle -- a vehicle that clearly has no future -- and its giant payload out of the loop, the Space Station may become entirely dependent on SpaceX, Kistler, the Evolved Expendable Launch Vehicles, Ariane, and others yet to come along. All these vehicles could have a future – but only if they have a market.
It is unfortunate that the Shuttle project ran out of steam with much of the Space Station’s hardware still on the ground. While the current Station configuration is clearly capable of long-term flight, and thus of being the market commercial rockets need, it is time to revisit the idea of getting at least the European and Japanese hardware into orbit on the EELVs.
The empty European Columbus module weighs some 10,300 kilograms, about half the 21,892 kilogram payload of a Delta-IV Heavy to the Space Station’s orbit. In the configuration that was to be launched by the Shuttle, Columbus weighs 12,000 kilograms. At 4.477 meters, the widest diameter is comfortably smaller than the advertised five-meter diameter of the largest Delta-IV payload shroud. Much the same is true of the Japanese Kibo module, which has a dry weight of 15,900 kilograms and a size of 4.4 x 4.2 x 11.2 meters. The most significant problem would be presented by Japan’s external experiment platform for the Space Station, which measures 5.0 x 4.0 x 5.6 meters but only weighs four tons. It is true that these modules were designed to be mounted horizontally in the Shuttle’s payload bay, but even on the Shuttle they would be launched vertically; they have to be capable of significant vertical loads.
If most or all of the remaining Shuttle payloads could be launched on existing expendable rockets, the Shuttle program could be shut down tomorrow, or possibly after one more repair mission to the politically and scientifically important Hubble Space Telescope. Much of the $5 billion a year the Space Shuttle costs could be funneled into the Crew Exploration Vehicle, developing a Shuttle-derived heavy lift vehicle, deep space propulsion, and early work on a lunar base -- and probably still have money to spare.
NASA does seem to have caught the religion. NASA Administrator Michael Griffin was quoted in the trade journal Space News: “It is in our interest to sponsor commercial development [of launch vehicles] by providing the only market I have for the next few years, which is cargo delivery to the Station.”
If he means it, and if the storied Space Shuttle really is down for the count, maybe all the years and dollars entrepreneurs have bet on innovative launch vehicles will finally pay off.
The death of a great dream is bound to be painful, but when new life follows death it usually starts out small. Spring is in the air. Let one rocket die so that a hundred rockets can fly. . . .