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New concept may enhance Earth-Mars communication   An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a six-month journey, and has been investigating the planet since early 2004.  This artist's impression shows the trajectory of ESA SMART-1 spacecraft in the final phase of its mission, due to end through a small impact on the lunar surface.
After two weeks of manoeuvres started on 19 June and concluded on 2 July 2006, the impact is now set to occur on the near side and most probably at 05:41 UT (07:41 CEST) on 3 September 2006. Q1. What is special about the orbital positions described in your paper?  Johannes Kepler (27 December 1571 – 15 November 1630) was a German mathematician, astronomer and astrologer, and key figure in the 17th century scientific revolution. This image is a copy of the 1610 original in the Benedictine Monastery, Krems. Q3. Why not simply use the thrusters that most satellites already have, like those on Mars Express or Venus Express?  The need for GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) to fly in a low orbit means it has to be equipped with a system to compensate for the atmospheric drag it will experience at this exceptionally low altitude. The animation shows a close-up of the ion-propulsion assembly, which keeps the satellite in a smooth trajectory – free from all effects except the gravity field itself. Two winglets provide additional aerodynamic stability.  End-on view of an alternative Mars – Earth communication relay architecture option, looking into the Ecliptic plane. Q5. Could such a double-spacecraft, 'continuous-thrust' mission be launched today?  Artist's impression of humans on Mars Release date: 2 November 2009 |