. 24/7 Space News .

Subscribe to our free daily newsletters

Getting On Course For Lunar Capture Took A Smart Move

see details below
Paris, France (ESA) Oct 28, 2004
On 25 October SMART-1 fired, for the last time, the electric propulsion engine. This small correction manoeuvre of about 4 hours was necessary to correct the slight over-performance of the engine during the last long burn of 100 hours (10-14 October) during the 'third resonance".

From now on the spacecraft will proceed unpowered in its journey towards the Moon - where it will arrive on 15 November. In the meantime, SMART-1 will perform another two revolutions around the Earth.

The last time SMART-1 will approach the Earth, the last perigee, will be on 2 November at 07:28 UTC and finally the last part of the Earth orbit will lead to the capture by the Moon and the first perilune on 15 November at 17:56 UTC.

Up to 26 October, and the 289th engine pulse, the SMART-1 electric propulsion system has cumulated a total ON time of nearly 3648 hr, consumed about 58.8 kg of Xenon and imparted to the spacecraft a velocity increment of about 2737 ms-1.

The electric propulsion firing will be resumed only in lunar orbit on 15 November at 05:28 UTC for a 4.5 days long burn, to reduce the lunar orbit.

Orbital/Trajectory information

In this diagram the osculating orbits at launch (GTO) and at different times are plotted. It can be seen now the huge effect of the combination of the operations of the electric propulsion together with the last Moon encounter have on the orbit expansion. The moon effects is now mainly in the increase of the perigee altitude, in the rotation of the line of apsides (change in argument of perigee) and in the orbital inclination.

Since the start of the mission the orbital elements have been changed by the ion-engine and the lunar resonances as follows:

  • The semi-major axis from 24 626 km to 242 466 km
  • The perigee altitude from 656 km to 173 339 km
  • The apogee altitude from 35 880 km to 300 000 km
  • The orbital period from 10 hours 41 minutes to nearly 14 days

    Also note the change in the orbit inclination, which has now reached 20�. As explained in the last report, it was mainly the task of the last resonance to shift the orbit plane of the spacecraft towards the the lunar orbit plane, which is inclined at 28� with respect to the Earth equator (it varies between 28�35' and 18�21' with a period of 18.6 years).

    Related Links
    SMART-1 at ESA
    Search SpaceDaily
    Subscribe To SpaceDaily Express

    Moon Shadows
    Moffett Field CA (SPX) Oct 27, 2004
    Skywatchers are about to be treated to a total lunar eclipse, just in time for Halloween. For more than an hour Wednesday night, the Earth's shadow will completely cover the moon - making it glow orange like a pumpkin.

    Thanks for being here;
    We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

    With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

    Our news coverage takes time and effort to publish 365 days a year.

    If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
    SpaceDaily Contributor
    $5 Billed Once

    credit card or paypal
    SpaceDaily Monthly Supporter
    $5 Billed Monthly

    paypal only

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.