Deep
Space 1
Part of the new NASA fleet of "cheaper, faster, better" spacecraft,
Deep Space 1, (DS1) is set to be launched in October of 1998.
Compare DS1 with the Cassini spacecraft launched a year earlier
in October of 1997:
DS1 | Cassini | height
x width (ft.) | 8
x 6 | 22
x 13 | weight
(lbs.) | 1080 | 12
800 | cost
(US$) | $141
million | $2.7
billion |
Part
of the savings is due to the revolutionary propulsion system.
Basic physics still requires an engine that throws mass out
the back and then according to conservation of momentum, the
craft goes forward. Instead of the standard method of throwing
gas exhaust out the back, DS1 throws xenon ions. | With
Ion Propulsion, there is no roar from the engine, just an eerie
blue glow. (0.0K) |
Ion
Propulsion Engine
Ion propulsion has many advantages. For one, it is 10 times
more efficient than conventional chemical propellants, so DS1
saves on weight. However, the DS1 only produces one eightieth
of a pound of thrust. Even though the ions are fired out the
back at 70 000 miles per hour, xenon ions are just not very
massive. As of now, the JPL (Jet Propulsion Lab) scientists
are expecting ion propulsion to power many missions in the new
millennium. |