Hank.Walker@UNH.CS.CMU.EDU (02/18/86)
The discussion of the manned space program can be broken down into 3 areas: past, near future (10 years), and farther future (> 10 years). The discussion of the past has centered on why the shuttle is bad since it is neither optimized for carrying people or cargo to orbit. First, it is not clear to me that the presence of people substantially increases costs. The main drawback is the cockpit and life support weight compared to more computers. In any case this discussion is irrelevant. Liberals like Walter Mondale tried their damnedest to kill the shuttle, and it was the military's support that kept the shuttle alive. Hence it had to meet their requirements. The choice was more like this shuttle or no shuttle, so no use crying about it. The discussion of the near future has tended to ignore the fact that a lot of the payloads for the next 10 years have already been planned. They need a replacement for Challenger lifting capability NOW, not 20 years from now. The choices are either another shuttle, or unmanned rockets like Delta, Altas/Centaur, and Titan/Centaur. Some payloads can only go by shuttle. Unmanned rockets have been on the market for a few years now with no sales, due to the heavy subsidies of the shuttle and Ariane. NASA could buy rockets and subsidize them, but I doubt that they will. Alternatively, the US could put extreme pressure on France to cut subsidies, making commercial offerings more attractive. Shuttle subsidies are already scheduled to fall (in 1988?). Or else NASA could just tell those who can't get a ride on the 3 existing shuttles to fend for themselves. The discussion of the farther future has been somewhat divorced from reality. A Transatmospheric Vehicle (TAV, Orient Express) will barely be available to the military in 10 years. Shuttle quality service is probably much farther away. Consequently if a new shuttle is built, it will see plenty of use before something better comes along. Those discussing teleoperators might want to wander down to the lab some day and look at the manipulators available, and the current rate of progress. People are going to be needed for a good long time for many tasks. On almost every SpaceLab mission, equipment repairs were necessary. On the last mission, the JPL scientist doing some suspended fluid experiments in equipment he designed had to spend the better part of a day upside down inside the machine fixing it. It is silly to talk about manned versus unmanned as an either/or proposition. Both have their good and bad points. Machines are cheap but not too flexible. They can handle all the simple tasks. Men are expensive but very flexible. They can handle the messy cases, which are unfortunately not all that rare. As I pointed out in a New York Times letter a while ago, one reason for having a space station is the cost of launches. It might be cheaper over the long run to have a space station with infrequent launches compared to no space station and more frequent launches.
space@ucbvax.UUCP (02/21/86)
In article <8602180507.AA06619@s1-b.arpa> you write: >The discussion of the farther future has been somewhat divorced from >reality. A Transatmospheric Vehicle (TAV, Orient Express) will barely be >available to the military in 10 years. Shuttle quality service is probably >much farther away. Consequently if a new shuttle is built, it will see >plenty of use before something better comes along. Those discussing >teleoperators might want to wander down to the lab some day and look at the >manipulators available, and the current rate of progress. People are going >to be needed for a good long time for many tasks. On almost every SpaceLab >mission, equipment repairs were necessary. On the last mission, the JPL >scientist doing some suspended fluid experiments in equipment he designed >had to spend the better part of a day upside down inside the machine fixing ^^^^^^^^^^^ Did you really mean that or was it a Freudian slip? I mean after all, how does one determine up or down without gravity? >it. It is silly to talk about manned versus unmanned as an either/or >proposition. Both have their good and bad points. Machines are cheap but >not too flexible. They can handle all the simple tasks. Men are expensive >but very flexible. They can handle the messy cases, which are unfortunately >not all that rare. As I pointed out in a New York Times letter a while ago, >one reason for having a space station is the cost of launches. It might >be cheaper over the long run to have a space station with infrequent >launches compared to no space station and more frequent launches. Kim Althoff ihnp4!pesnta!kima