The Mammoth Book of Space Exploration and Disasters

By 6 January, the total cumulated thrust was more than 1,500 hours. It had consumed 24 kg of Xenon which provided a velocity increment of about 1070 ms-1 (equivalent to 3,850km per hour, 2,406.25 mph). The electric propulsion engine’s performance, periodically monitored by means of the telemetry data transmitted by the spacecraft and by radio-tracking by the ground stations, showed a small overperformance in thrust varying from 1.1 per cent to 1.5 per cent over the previous week.

At first there was a little degradation of the electrical power produced by the solar arrays, however this ceased and the power available has remained virtually constant since November 2003. The communication, data handling, on-board software and thermal subsystems all performed well.

By 23 February 2004 Smart 1 had already reached its top speed and slowed down. The milestone occurred during the first orbit, about 10 hours after launch, when the craft hit about 22,400 mph (10 kilometres per second). After that it fluctuated dramatically between 3,800 and 19,900 mph (1.7 and 8.9 kilometres per second) depending on its distance from Earth.

As with any object in an elliptical, off-centre orbit, Smart 1 travels fastest when it is close to Earth and slower on the outer reaches of its path.

The craft will spiral outward in ever-widening ellipses around Earth for another two months. Ion thrust will then carry it to a special spot in space, about 37,300 miles (60,000 kilometres) from the moon, called Lagrangian point L1. Lagrangian points are locations where gravity from two objects balances out. A craft at a Lagrangian point is free to go either way with very little thrust.

“It is kind of a gateway for the entrance into moon orbit, almost free of charge,” Racca said.

Smart 1 will enter lunar orbit in March 2005, when it will look for clues to the moon’s origin and try to confirm that there is frozen water hidden at the lunar poles.

Storm of stardust threatens satellites

On 19 August 2003 Mark Henderson reported in The Times:

A cosmic dust storm is heading for the Earth, threatening to damage the solar panels of satellites and spacecraft.

The cloud of dust particles has already penetrated the Solar System, which is usually protected by the Sun’s magnetic field, the European space probe Ulysses has discovered.

Although the stardust is too small to have any direct effect on the Earth, being 100th of the width of a human hair, it is likely to rip chunks off the sides of asteroids. This will increase the amount of debris in the Solar System, creating a hazard for spacecraft and satellites. It is unlikely to knock out craft completely, but could damage solar panels, reducing their lifespan.

The dust storm, details of which are published in the Journal of Geophysical Research, could increase the number of meteors entering the Earth’s atmosphere.