Europe Rediscovers The Moon With SMART-1

MOON DAILY

When a spacecraft orbits around the Moon, as SMART-1 does, it is doomed by the law of gravity. Tugs from the Sun, the Earth, and irregularities in the Moon itself, all disturb its orbit. Sooner or later, any lunar orbiter will impact the Moon surface unless it has very big amounts of fuel left to be re-boosted and escape the lunar gravity.

by Staff Writers
Paris, France (ESA) Aug 17, 2006
Now Europe too can say it has been to the Moon. Watch the Moon up close in the early morning of 3 September (at around 07:40 Central European Summer Time, as currently estimated) and you may just see a European satellite land on its surface.

The story began in September 2003, when an Ariane 5 launcher blasted off from Kourou, French Guiana, to deliver the European Space Agency's lunar spacecraft SMART-1 into Earth orbit. SMART-1 is a small unmanned satellite weighing 366 kilograms and roughly fitting into a cube just 1 metre across, excluding its 14-metre solar panels (which were folded during launch).

After launch and injection into low Earth orbit, the gentle but steady push provided by the spacecraft's highly innovative electric propulsion engine forcefully expelling xenon gas ions caused SMART-1 to spiral around the Earth, increasing its distance from our planet until, after a long journey of about 14 months, it was 'captured' by the Moon's gravity.

To cover the 385,000 km distance that separates the Earth from the Moon if one travelled in a straight line, this remarkably efficient engine brought the spacecraft on a 100 million km long spiralling journey on only 50 litres of fuel.

The spacecraft was captured by the Moon in November 2004 and started its scientific mission in an elliptical orbit around its poles. ESA's SMART-1 is currently the only spacecraft around the Moon, paving the way for the fleet of international lunar orbiters that will be launched from 2007 onwards.

The story is now close to ending. On the night of Saturday 2 to Sunday 3 September, looking at the Moon with a powerful telescope, one may be able to see something special happening. Like most of its lunar predecessors, SMART-1 will end its journey and exploration of the Moon by landing in a relatively abrupt way. It will impact the lunar surface in an area called the 'Lake of Excellence', situated in the mid-southern region of the Moon's visible disc at 07:41 CEST (05:41 UTC).

The story is close to ending

After 16 months harvesting scientific results in an elliptical orbit around the Moon's poles (at distances of between 300 and 10 000 km), the mission is almost over. The spacecraft has now dropped below an altitude of 300 km from the lunar surface and will get a closer look at specific targets on the Moon before landing in a controlled manner on the moon surface (controlled, that is, in terms of where and when). It will then 'die' there.

With a low speed at impact (2 km/sec), SMART-1 will create a crater of 5 to 10m in diameter with a depth in the order of one metre; a crater no larger than that created by a 2kg meteorite on a surface already heavily affected by natural impacts.

Mission controllers at the European Space Agency's Operations Centre (ESOC) in Darmstadt, near Frankfurt, Germany will monitor the final moments before impact step by step.

Final milestones of SMART-1 flight operations

In June and July, SMART-1 mission controllers at ESOC had initiated a series of thruster firings aimed at optimising the time and location of the spacecraft's impact on the Moon's surface. Disposal via impact is a method adopted by many previous missions and will provide an opportunity to gather scientific results related to impact effects.

The manoeuvres and changes in velocity have shifted the time and location of impact, which, before the manoeuvres, was due to occur in mid-August on the far side of the Moon; impact is now set to occur on the near side and current best estimates show the impact time to be 07:41 CEST (05:41 UTC) on Sunday 3 September.

"Mission controllers and flight dynamics engineers have analysed the results of the manoeuvre campaign to confirm and refine this estimate," says Octavio Camino-Ramos, SMART-1 spacecraft operations manager at ESA/ESOC. "Important adjustment manoeuvres are planned for 25 August, which may still have a consequence on the final impact time, as well as smaller ones in the night of 1 to 2 September", he added.

Large ground telescopes will be involved before and during impact to make observations of the event, with several objectives:

+ To study the physics of the impact (ejected material, mass, dynamics and energy involved) To analyse the chemistry of the surface by collecting the specific radiation emitted by the ejected material ('spectra')

+ To help technological assessment: understand what happens to the impacting spacecraft to know better how to prepare for future impactor experiments (for instance on satellites to intercept meteorites menacing our planet)

Email This Article

MOON DAILY

NASA Provides Further Update On Apollo 11 Tapes

Washington DC (SPX) Aug 16, 2006
NASA personnel continue to sift through 37-year-old records in their attempt to locate the magnetic tapes that recorded the original Apollo 11 video in 1969. The original tapes may be at the Goddard Space Flight Center, which requested their return from the National Archives in the 1970s, or at another location within the NASA archiving system. Despite the challenges of the search, NASA does not consider the tapes to be lost.

SPACE TRAVEL Scientists Study Pioneer Anomalies Voyager 1 Hits 100 AU Marker Nearly 14 Hours Out Pioneering Astrophysicist James Van Allen Dies Space Travel Will Take Off In Five Years	MARSDAILY Rovers Look Forward to A Second Martian Spring Gas Jets Spawn Dark Spiders And Spots On Mars Icecap AMASEing Mars Volunteers Sought For Four-Month Arctic Mars Mission Simulation
NUCLEAR SPACE Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear NASA plans to send new robot to Jupiter Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission Boeing Selects Leader for Nuclear Space Systems Program	EXO WORLDS Astronomers Discover Twin Planemos Three-Telescope Interferometer Shows Patchy Red Giants Common Fate Of Sun-Like Stars Ultraviolet Stripping Creates Super Earth Sized Planets FUSE Finds Young Solar System Awash In Carbon
NANO TECH Purdue Engineers Lay Groundwork For Vertically Oriented Nanoelectronics Nano Helps Keep Cells Alive Blueprint For Nanotechnology Risk Profile Proposed Sharply Tuned Nanostrings Work at Room Temperature	SPACE MEDICINE A Lack Of Gravity Can Make Us Dangerously Lightweight NASA Modifies Image Technology To Fight Diabetes NASA To Orbit Fruit Flies To Test Immune System Researchers Make Progress With Robotic Telesurgery
LAUNCH PAD Ariane 5 Is In The Launch Zone With JCSAT-10 And Syracuse 3B Russia To Launch European Weather Probe In October ATK Receives $90M To Supply Motors For Missile Defense And Satellite Launch Vehicles Second Ariane 5 ECA Launch Campaign Is Underway At The Spaceport	ROCKET SCIENCE Why so SMART SpaceDev Awarded Patent For Hybrid Propulsion Technology Scrap The Stick Now Purdue Research Helps Advance New Rocket Technology

The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement