Discovery and MRO
Discovery was due to return to Earth today but, due to bad weather at the landing site, this has been postponed to tomorrow. Fingers crossed for a safe return to Earth for the shuttle and its crew.
This is a busy week for NASA as Wednesday will see the launch of the Mars Reconnaissance Orbiter aboard an Atlas V rocket. This probe is designed to orbit Mars at a height of around 450 km, looking for evidence of the history of water on the planet by taking close-up photographs of the surface, analysing surface rocks to look for certain minerals associated with water and examining the content of the atmosphere. The mission page has this list of science objectives:
- Characterize the present climate of Mars and its physical mechanisms of seasonal and interannual climate change
- Determine the nature of complex layered terrain on Mars and identify water-related landforms.
- Search for sites showing evidence of aqueous and/or hydrothermal activity.
- Identify and characterize sites with the highest potential for landed science and sample return by future Mars missions.
- Return scientific data from Mars landed craft during a relay phase.
MRO will accomplish all this using an array of science instruments: a high resolution camera, a spectrometer working in the optical and near-infrared parts of the spectrum, a "context imager" (wide-field camera), subsurface radar to look for signatures of ice below the surface, an atmospheric probe to investigate temperature, dust and water vapour variations with height, and another imager to observe clouds and watch dust storms.
MRO will transmit its data back to Earth using powerful radio transmitters which will be available for future missions to Mars. This (according to NASA) is the start of an interplanetary internet, which really means that they want to transmit lots of data. This probe will use a part of the spectrum known as the Ka-band at frequencies around 32 GHz. Most of the transmissions using the current Deep Space Network (DSN) use X-band at frequencies around 8 GHz. Ka-band is four times higher in frequency, so it can carry around four times as much information. MRO will use both as the Ka-band system is still being tested, so this mission is also an experiment in communications.