Friday, August 12, 2005
BBC NEWS | Science/Nature | New launch window for Mars probe New launch window for Mars probe
The US space agency's new Mars probe is set for launch on Friday, during a two hour window running from 1243 BST (1143 GMT) to 1443 BST (1343 GMT).
The $500m (£276m) Mars Reconnaissance Orbiter (MRO) was due to launch on Thursday, but controllers called a halt just a few minutes before blast-off.
It will arrive in March to look for evidence of water and hunt for landing sites for future manned missions.
MRO can transmit 10 times more data each minute than previous Mars probes.
The spacecraft is the size of a small bus and weighs about 2,000kg; it will carry some of the most sophisticated instruments ever taken to the Red Planet.
Once in orbit around Mars, the spacecraft's cameras will send back the clearest images yet of the planet from any orbiting spacecraft. This will enable scientists to study Mars' composition and structure and search for surface features related to water.
MARS RECONAISSANCE ORBITER
1) 3m High-gain antenna
2) High-resolution Imaging Science Experiment
3) Electra UHF communications relay
4) Mars Climate Sounder
5) Compact Reconnaissance Imaging Spectrometer for Mars
6) Orbit insertion thrusters
7) Shallow subsurface radar
9) Optical Navigation camera
10) Low-gain antennae
A radar sounder will look for liquid water reservoirs that may exist beneath the surface of Mars.
"A prime goal of ours is to achieve higher spatial resolution in our observations of the surface and of the atmosphere and of the sub-surface by radar," said Richard Zurek, MRO project scientist.
"When you increase your resolution and you still want to cover adequate areas of the planet what you have to be able to do is return much more data than previous missions have done."
As such, MRO is also equipped with the largest communications antenna ever sent to the Red Planet. This will allow it to serve as a powerful communications relay for future missions to the surface.
Nasa has adopted the mantra "follow the water" in its approach to the robotic exploration of the Red Planet, since water is an essential ingredient for life. One of the scientific objectives of the mission is to investigate whether Mars could once have supported microbial life forms.
British scientists hope the US space agency mission will also reveal what happened to the lost Mars probe, Beagle 2.
Professor Colin Pillinger, from the Open University, who led the Beagle 2 mission, said: "If we could just see some trace of it on the surface then at least we could see how far it got - the not knowing is the worst bit.
"It will be a very difficult thing to do, but this is our best chance of finding out what happened and we will be watching the progress of the mission with great interest and anticipation."
The launch marks the first use by Nasa of the powerful Atlas V rocket, which is manufactured by Lockheed Martin.
A scheduled launch on Wednesday was scrubbed after a gyroscope of the type used in the Atlas V failed while being incorporated into a rocket unrelated to the MRO mission. The problem was not found to have affected this launch vehicle, a Nasa spokesman said.
Thursday's launch was also abandoned because, during loading of the hydrogen fuel tank, sensors showed a "dry" reading when they should have been reading "wet".
A similar problem forced Nasa to scrub the launch of the space shuttle Discovery from Cape Canaveral on 13 July.
MRO will join two operational US orbiters - the Mars Global Surveyor and Mars Odyssey - and one European orbiter, Mars Express, at the Red Planet.
Two US robotic rovers, Spirit and Opportunity, have been on the Martian surface for the past 18 months, investigating the geology of Mars.
Nasa is planning two further Mars missions this decade: the Phoenix module, set for launch in 2007, and Mars Science Laboratory in 2009.
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