China is
ramping up for the launch this year of Chang’e 1, a lunar orbiter designed to
set the stage for the nation’s future Moon-bound
missions.
Assembly of
the China National Space Administration (CNSA) Moon probe is complete, with
tests underway of its rocket booster, according to several state media reports
[image].
“If everything
goes well, the Chang’e
1 orbiter is expected to be launched in 2007,” a mission overview, one of
several attributed to Luan Enjie, chief commander of the China Lunar
Exploration Program (CLEP), stated. The multiple mission descriptions are
listed on the CNSA’s lunar program website.
Chang’e 1
is slated to launch atop China’s Long
March 3A rocket from the Xichang Satellite Launch Center in the nation’s
southwestern province of Sichuan, though no official flight date has been given.
The mission is named after a Chinese goddess who, in a popular fairy tale,
lives on the Moon.
Past reports in
China’s official state media pointed to a planned April liftoff.
But recent statements – such as a March 6 report by the Xinhua News Agency
citing Huan Chunping, China’s chief consultant for its manned launch vehicle
program – indicated the mission may be pushed to the latter half of 2007.
Huan was
quoted by Xinhua as stating that China could ultimately succeed the
Chang’e-1 flight with a manned mission the moon in 15 years (by 2022), though
such an effort depends on the steady development of the nation’s Long March 5 heavy-lift
rocket.
Studying
the Moon
Chang’e 1 is
based on China’s Dongfanghong 3 telecommunication satellite platform and reportedly
carries a 280-pound (127-kilogram) payload of science instruments for its planned
one-year mission.
“In terms
of technical configuration, Chang’e 1 is actually a new spacecraft,” Luan wrote
in the CLEP mission overviews.
Luan stated
that Chang’e 1 carries a total of eight primary instruments to photograph and
map the lunar surface, probe its depth, study the regolith’s chemical
composition, and analyze the space environment around the Moon.
According
to the mission description, Chang’1 carries two basic imagers.
A CCD stereo
camera will produce three-dimensional images of the lunar surface by compiling
three separate, two-dimensional views of each target area. Meanwhile, the probe’s
interferometer spectrometer imager is expected to overlay optical measurements
with spectra to depict the regional distribution of resources and materials,
Luan added.
Chang’e 1
will also carry a laser altimeter to take precise elevation measurements of the
lunar surface, as well as gamma/X-ray spectrometers to hunt out and measure the
amount of up to 14 elements – among them iron, potassium, uranium and titanium –
according to Luan’s description.
A microwave
detector will bounce signals down to the Moon’s surface, operating on four
different frequencies to determine the lunar regolith’s depth, while a
high-energy solar particle detector and low-energy ion instrument – Chang’e 1’s
space environment monitor system – measures the solar wind environment,
according to the CNSA mission description.
A payload
data management system rounds out Chang’e 1’s instrument package. Also riding
to the Moon aboard the lunar probe are some 30 songs, among them Chinese folk
songs and “The East is Red” – China’s national anthem – Xinhua reported in November.
In the
past, Luan has told the People’s Daily Online that Chang’e 1 carries an overall
mission cost of 1.4 billion yuan (about $180 million).
The lunar
path
CNSA
officials stated that Chang’e 1 is destined to circle the Moon in a polar orbit
at an altitude of between 62 and 124 miles (100 and 200 kilometers) [image].
“Considering
the abnormality of the lunar gravity field, Chang’e 1 may fall on the lunar surface
within half a year if a 100 [kilometer] orbit is selected,” Luan stated, adding
that a 200-kilometer orbit will be chosen if mission managers decide not to
probe the Moon’s gravitational field.
To reach
the Moon in the first place, Chang’e 1 is expected to launch spaceward into a
highly elliptical orbit that comes within 372 miles (600 kilometers) of Earth at its closest point, according to
the mission overview. Its flight plan then calls for a series of three maneuvers
to gradually climb into ever-higher orbits for the eventual departure for the
Moon.
“Lunar
acquisition is the most essential point in the orbit design in Chang’e Program,”
Luan stated. “If lunar acquisition is not designed perfectly, the satellite
will fly by or impact the Moon, which may lead to grave consequence.”
Beyond Chang’e
1
The Chang’e-1
mission is reportedly
the first of China’s three-phase plan for lunar exploration, which includes
a follow-up lunar lander or rover by 2012, and an ultimate sample return flight
[image]
in 2017, according to past press reports.
China is
the third nation to build and launch spacecraft to ferry astronauts into orbit
following the former
Soviet Union and United
States. The country launched its first astronaut
into space during the 2003
flight of Shenzhou 5, and followed with the two-astronaut
Shenzhou 6 flight in October 2005.
A third
manned spaceflight, Shenzhou
7, is slated
for 2008 and expected to feature China’s first
spacewalk [image],
state media has reported.
Huang told Xinhua
last week that engineers have completed designing the engines for China’s Long
March 5 rocket, which is expected to be able to haul payloads of between nine
and 25 tons into orbit when complete. Intended to launch a Chinese space
station, the booster should be ready in about eight years, Huang told Xinhua.
Last month,
state media reported that China formerly planned to build a new launch
site on Hainan Island in the South China Sea, which some China space
analysts have said would be
required for any new heavy-lift boosters.
But a
Chinese manned mission to the Moon will require substantially stronger rockets
than those currently available, Luan told the nation’s state media last week.
“[A] Moon
landing needs a rocket with 3,000 to 4,000 tons of thrust,” Xinhua
quoted him as saying. “But the most power thrust carrier rocket is at around
600 tons.”
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