Solar Orbiter To Return Earth For Flyby Passing Through Clouds Of Space Debris
Solar Orbiter Will Make Its Closest Pass To The Sun In March. Its First Pass, Called A Perihelion, Took Place In June 2020
Solar Orbiter, a European Space Agency (ESA) spacecraft carrying instruments proposed, designed and built at UCL, is returning to Earth for a flyby passing through clouds of space debris before starting its main science mission exploring the Sun.
The Earth flyby, the riskiest ever undertaken by a space science mission because of the risk of collision, takes place a week on Saturday, on 27 November. At 04:30 GMT (05:30 CET) on that day, the spacecraft will be at its closest approach, just 460 km above North Africa and the Canary Islands. This is almost as close as the orbit of the International Space Station.
The manoeuvre is essential to decrease the energy of the spacecraft and line it up for its next close pass of the Sun but it comes with a risk. Professor Lucie Green (UCL Mullard Space Science Laboratory) said: “Space debris is of increasing concern and the number of near misses, although rare, is on the rise. The recent Russian satellite that was purposely destroyed into thousands of pieces shows how the problem is worsening.
“Solar Orbiter passing close by the Earth should be occasion to celebrate. We should be looking up and waving, marking this milestone in its journey. But instead we are crossing our fingers and hoping for its safe passage.” The spacecraft must pass through two orbital regions, each of which is populated with space debris. The first is the geostationary ring of satellites at 36 000 km, and the second is the collection of low Earth orbits at around 400 km. As a result, there is a small risk of a collision. Solar Orbiter’s operations team are monitoring the situation very closely and will alter the spacecraft’s trajectory if it appears to be in any danger.
Start of main science phase
Solar Orbiter will make its closest pass to the Sun in March. Its first pass, called a perihelion, took place in June 2020, with the spacecraft closing to 77 million kilometres. This time, Solar Orbiter will draw to within 50 million kilometres, a third of the distance between the Sun and Earth – providing a significant boost to the science that can be done. UCL scientists have a leading role in two of the spacecraft’s instruments – the Extreme Ultraviolet Imager (EUI), a suite of telescopes providing images of the hot and cold layers of the Sun’s atmosphere and corona, and the Solar Wind Analyser (SWA).
Professor Chris Owen (UCL Mullard Space Science Laboratory), Principal Investigator on the SWA instrument, said: “The Earth flyby represents the transition of Solar Orbiter’s mission from ‘cruise phase’ into ‘nominal mission phase’ operations. “For this new phase, the Deep Space Network tracking of the spacecraft and download of recorded data increases to daily, but more importantly we have the opportunity to begin observing campaigns in which the entire payload, made up of 10 distinct instruments, will begin to be operated in coordination.
This news was originally published at Mirage News