Slide 12 of 100
Notes:
The ”Pegasus” was a Saturn V-class intercontinental rocket capable of transporting
170-260 passengers and 13-33.5t of cargo at 25,000km/h, or 90t to a 560km low Earth orbit.
It would have been available in the 1980s and reduced the travel time from New York to Bombay
from 22 hours to only 40 minutes. In Phil Bono's words: “the SST would be just a small
step in the direction of reducing transit time, whereas rocket-propelled vehicles would provide
the ultimate in sub-orbital speed for transportation on the Earth's surface. The space age has
equipped us with the technology for transporting emergency equipment to any disaster area on
Earth in the time it would take for a bus ride across town, despite the conditions of aircraft
runways upon arrival. In addition, diplomats, heads of state, chiefs of staff, as well as
business executives, could be transported in person to consult, confer, inspect, decide and to
lead in a manner currently impossible from distant shores, even with the aid from
television.”
Pegasus would have carried most of its hydrogen fuel in expendable drop tanks; hardly advisable
for a low-cost suborbital launcher but necessary in order to improve the maneuvrability of the
rocket during reentry and landing since the vehicle then could be made much lighter and smaller.
The projected gross liftoff mass was 1520t and the landing weight only 148t. This illustration
depicts the emergy landing procedure, where all eight tanks are jettisoned before the vehicle
makes an emergency landing on inflatable pontoons. Pegasus would have carried sixteen 1170KN
thrust aerospike rocket modules so the engine-out safety would have been fairly good since only
four engines were required for landing. The expected landing accuracy was only
1.6 * 3.2 kilometers so the spaceport would have to be located in a 5km wide uninhabited area
for safe launch and landing operations.
Pegasus atmospheric reentry. The combined heatshield + plug nozzle rocket engine would
be cooled by circulating liquid hydrogen fuel at the base of the vehicle. The intercontinental
passenger version would incorporate fins between the external liquid hydrogen tanks to restrict
reentry decelerations to a safe maximum of 2.5-3 g's. Pegasus would have been launched from
spaceports which, by the 1980s, were expected to be established near most key cities throughout
the world. Off-shore launch platforms were another possibility. Douglas estimated that the
Pegasus would cost $3 billion [1964 $s -- $16.1B at 1999 rates] to develop, and the operational
vehicles would cost $34M (=$183M in 1999 )per copy if two dozen were built. The first operational Pegasus would
have cost $63 million (=$338M in 1999) to produce. According to Phil Bono, “we cannot afford to dismiss the rocket
transport as a far-fetched impractical pipe dream. We must design today as if the next 10
years had already passed...”
"Pegasus" -- Space World 1964/December/p.20
