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STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.


STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.


STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

 Full presentation
 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.


Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

 Full coverage

Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

 Launch | Science

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Laplace & Tandem vie for Cosmic Visions top-spot

Posted: April 4, 2008

Missions to the moons of Jupiter and Saturn are being considered by the European Space Agency. Image: NASA/JPL.

Two missions to the outer Solar System, Laplace (Europa and Jupiter Mission) and Tandem (Titan and Enceladus Mission), are competing against each other for selection later this year; Emily Baldwin summarises the key goals of each ambitious mission as described by the European Space Agency's director David Southwood and the Open University's Professor John Zarnecki in today's lectures at the National Astronomy Meeting.

Laplace and Tandem fall under the European Space Agency's "Cosmic Visions" umbrella, missions that are designed to tackle some of the big scientific questions concerning the evolution of the Solar System and our place in it. The Laplace mission proposal outlines an orbiter that will probe the Jovian environment, with particular emphasis on the Galilean satellite Europa, which may harbour an ocean underneath its icy crust. The key aim, therefore, is to determine whether this tiny world could be inhabitable and to what extent its possible habitability is related to the initial conditions and formation scenario of the Jovian satellites. The mission may even include an impactor that would penetrate into the surface and perform analyses of the icy surface and possible subsurface ocean. "The Europa mission could teach us about the existence of an ocean and its habitability, the conditions of the sea-floor and even the interaction of this proposed ocean with the surface," says Zarnecki.

Laplace is in direct competition with Tandem, a mission designed to follow in the footsteps of Cassini-Huygens in the Saturnian system, with the ultimate destination of Titan, via Enceladus. Enceladus, just 500 kilometres in diameter, is full of big surprises and has already revealed dramatic organic-laden jets of water vapour emanating from the infamous 'tiger-stripes' that feature heavily in the satellite's southern hemisphere. Part of the mission proposal includes plans for a lander or a penetrator, both of which would permit in-situ measurements of the local surface environment. At Titan, an orbiter, aerial platform (a giant balloon that would traverse Titan's hazy, methane-rich atmosphere) and a number of mini surface landers are envisaged. "The Huygens lander mission was a huge success, but we only have three and a half hours of data sent back from the surface," says Zarnecki. "The Tandem mission package would greatly increase what we learnt in that relatively short time."

Both missions have clear aims: to study the potential habitability of outer Solar System satellites that have already proven themselves as viable candidates for conditions favourable to life. As well as the obvious astrobiological advances that would be made, the missions would also provide insight into the interiors and evolution of these outer Solar System worlds, their potential heat sources and interior-surface interaction.

The tough decision as to whether we go back to either Jupiter or Saturn will be made in the autumn of this year, with the selected mission eventually launching in 2018.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


© 2014 Pole Star Publications Ltd.