Press. Voanews.
NASA's next Mars
explorer is going to have company all the way to the red planet: a couple of
puny yet groundbreaking sidekicks. Named after the characters in the 2008
animated movie, the small satellites WALL-E and EVE are hitching a ride on the
Atlas V rocket set to launch early Saturday morning from California with the
Mars InSight lander.
Similar in size
to a briefcase or large cereal box, the satellites with pop out from the
rocket's upper stage following liftoff and hightail it to Mars, right behind
InSight. It will be the first time little cube-shaped satellites, CubeSats as
they're known, set sail for deep space. The journey will span 6 1/2 months and
300 million miles (485 million kilometers). A brief look at the $18.5 million
experiment tagging along with InSight:
Mini sats
Miniature
satellites, or CubeSats, have been piggybacking on big-ticket space missions
for well over a decade, providing relatively cheap and fast access to orbit for
students and other out-of-the-mainstream experimenters. Until now, the hundreds
of CubeSats have been confined to Earth orbit. That's about to change with
NASA's Mars Cube One project, or MarCO.
The European
Space Agency, meanwhile, has its CubeSat sights on the moon. A recent
competition yielded two winning proposals: a CubeSat to explore the moon's far
side from lunar orbit, another to probe a permanently shadowed crater near the
moon's south pole, also from lunar orbit. NASA is also looking to send CubeSats
to the moon, as well as an asteroid.
Movie connection
It turns out
that these twin cubes are equipped with the same type of cold gas propulsion
system used in fire extinguishers to spray foam. The movie WALL-E uses a fire
extinguisher to propel through space. Team members couldn't resist the
connection, thus the names WALL-E and EVE for the two mini spacecraft.
Engineers want to test this compact propulsion system for guiding the 30-pound
(13.6-kilogram) cubes to Mars.
Getting to Mars
Once free from
the rocket's upper stage following liftoff, WALL-E and EVE will trail a few
thousand miles (kilometers) behind InSight en route to Mars. The two mini
spacecraft will also be a few thousand miles (kilometers) apart from one
another. That's to prevent any collisions or even close calls. While that may
seem far apart, it's actually fairly close by space standards, according to
Brian Clement, an engineer on the project at NASA's Jet Propulsion Laboratory
in Pasadena, California.
While InSight
will be stopping at Mars on November 26, WALL-E and EVE will zoom past the
planet from about 2,200 miles (3,500 kilometers) out. Don't expect any
Thunderbird pilot-theatrics as the cubes fly by, like a tilting of the solar
wings in salute. ``That would make a great movie, but that's definitely not the
way we're going to do it,'' Clement said.
Extra ears
Besides testing
the cubes' maneuvering system, NASA wants to see if WALL-E and EVE can transmit
data to Earth from InSight during its descent to Mars. If the experiment
succeeds, it should take just several minutes for flight controllers to hear
from the cubes. No worries if they're silent. NASA will rely on the Mars
Reconnaissance Orbiter already circling the planet as the main communication
link with InSight during descent and touchdown. It will take a lot longer,
though, to get confirmation. The beauty of a CubeSat relay system is that it
could provide descent information at planets and other cosmic stop-offs lacking
established communications.
Post-Mars
Once past Mars,
WALL-E and EVE will remain in an elliptical orbit around the sun, together for
years to come. But they won't work for long. Once they run out of fuel, they
won't be able to point their solar wings toward the sun for recharging.
Associated Press
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