A NASA spacecraft successfully slipped into orbit around Mars
Friday, joining a trio of orbiters already circling the Red
Planet.
Scientists cheered after the Mars Reconnaissance Orbiter emerged
from the planet's shadow and signaled to NASA's Jet Propulsion
Laboratory that the maneuver was a success.
"Oh I am very relieved," project manager Jim Graf said minutes
later. "It was picture perfect."
The two-ton spacecraft is the most sophisticated ever to arrive
at Mars and is expected to gather more data on the Red Planet than
all previous Martian missions combined.
It will explore Mars in low orbit for four years and is expected
to churn out the most detailed information ever about the planet
and its climate and landscape.
In the fall, the orbiter will begin exploring the Martian
atmosphere, scan the surface for evidence of ancient water and
scout for future landing sites to send robotic and possibly human
explorers.
The US$720 million mission is managed by JPL in Pasadena.
After a seven-month, 310 million-mile journey, the orbiter
arrived at Mars Friday for the risky orbit insertion phase. Project
managers had been nervous because of Mars' reputation of swallowing
scientific probes.
But the Reconnaissance Orbiter performed the move without
problem.
As it neared the planet, it fired its main propulsion engines
for 27 minutes to slow itself down so that the planet's gravity
could pull it into orbit. At one point during the burn, the
spacecraft disappeared behind Mars — as engineers had planned — and
was temporarily out of radio contact with controllers.
Mission control was visibly tense as it awaited word from the
orbiter, which reappeared and signaled that it had entered into an
elliptical orbit around Mars that will swing it as close as 250
miles above the surface.
The spacecraft will spend seven months dipping into the upper
atmosphere to shrink the orbit.
The successful mission was welcome news for NASA, which has a
mixed record of putting spacecraft into orbit around Mars.
In the last 15 years, NASA lost two orbiters back-to-back — the
Mars Observer in 1993 and the Mars Climate Orbiter in 1999 — during
the orbit insertion phase.
The Reconnaissance Orbiter is the fourth eye on the Martian sky,
joining NASA's Mars Global Surveyor and Mars Odyssey and the
European Space Agency's Mars Express, which have been mapping the
planet the past few years. On the surface, the NASA rovers Spirit
and Opportunity, continue their robotic geology missions.
The newest orbiter is loaded with the most advanced science
instruments ever sent to another planet including a telescopic
camera to photograph the surface in unprecedented detail and radar
to probe underground for ice and possible evidence of liquid
water.
The spacecraft won't beam back images or data until November.
Like previous space probes before it, it will seek for evidence of
ancient water and other signs that the planet could have been
hospitable to life.
It will also scan for potential spots to land the next
generation of robotic rovers and determine whether human outposts
can survive on the dusty planet.
Present-day Mars is dry and cold with large caps of frozen water
at its poles, but scientists believe the planet once was warmer and
wetter eons ago — conditions that might have been suitable for
life.
During the mission's second phase, the orbiter will transmit
data between Earth and Mars. It is expected to serve as a
communication relay for the Phoenix Mars Scout, which will explore
the icy north pole in 2008 and the Mars Science Laboratory, an
advanced rover scheduled to launch in 2009.
The Reconnaissance Orbiter's primary mission will end in
2010.
(Chinadaily.com.cn via AP March 11, 2006)
