Israeli robotic lunar lander

[JayUtah]

Isn't that known as the Oberth Manoeuvre?  You get more bang for your buck at high velocity than low.

Yep.

[ka9q]

Incidentally, how is it that multiple short burns to raise the apogee are more efficient than a single longer one? Is it that the efficiency of the burn is greatest when the spacecraft is closest to perigee, and this efficiency drops off considerably even minutes either side of perigee?

This assumes an instantaneous burn. If the required burn time is too long, it might be more efficient to split it up to a bunch of shorter ones.

[ka9q]

I haven't studied the Beresheet trajectory, but another consideration is that it is more efficient to do plane changes at apogee. If one is necessary along with apogee raising, it might be more efficient to establish an intermediate apogee to do the plane change.

[bknight]

First burn was successful raising the perigee to 600 Km.

https://spacenews.com/spaceil-lunar-lander-makes-first-post-launch-maneuvers/

[bknight]

A second burn successfully completed after a aborted attempt on Monday.  The new Apogee is 131000 Km.

https://www.space.com/israel-moon-lander-beresheet-engine-firing.html

[bknight]

A final burn has been completed for the craft to enter an orbit of the Moon.

https://www.israelnationalnews.com/News/News.aspx/260690

[raven]

A final burn has been completed for the craft to enter an orbit of the Moon.

https://www.israelnationalnews.com/News/News.aspx/260690

"Israel’s first spacecraft performed a special maneuver Wednesday night, aimed at putting the lunar lander into position to achieve a stable lunar orbit."
"Israel’s first spacecraft."
***
To quote Miss Clavel of Madeline fame, "Something is not right."

[ka9q]

The article says it was a plane change. That's as I had expected, since a plane change is more efficient at a high apogee where the orbital velocity is lowest. They can be extremely expensive in low orbit.

[bknight]

Beresheet Gears up for Lunar Rendezvous

As of Thursday, 28 March, Beresheet is making its final orbit around the Earth. On 30 March, it will hit perigee, buzz past its home planet one last time, and head towards the Moon, roughly 405,000 kilometers distant. SpaceIL senior engineer Yoav Landsman said the spacecraft will make a small trajectory correction on 1 April. The duration of the lunar insertion burn on 4 April, as well as the parameters of the initial lunar orbit, have yet to be decided, but SpaceIL was originally planning for an orbit roughly 10,000 by 300 kilometers. Landing won't happen for another week, on 11 April.

http://www.planetary.org/blogs/jason-davis/beresheet-gears-up-for-lunar.html

[Dalhousie]

At least one web user I know at ATS is frothing at the mouth that there is Israeli government money involved so it can't be private, and, well, you know, Jews.

Since it is built by a company that is heavily underwritten by the Israeli government the hype about it being the first private missions is a bit excessive.

[bknight]

From yesterday
Israel’s Beresheet lander arrives in lunar orbit

https://spaceflightnow.com/2019/04/03/israels-beresheet-lander-heads-for-make-or-break-maneuver-to-enter-lunar-orbit/

Landing attempt n the 11th still.

ETA:  LO, I realize that this is in the hoax forum, if you want to move it to an appropriate thread.

[JayUtah]

ETA:  LO, I realize that this is in the hoax forum, if you want to move it to an appropriate thread.

I was going to ask about that.

[bknight]

ETA:  LO, I realize that this is in the hoax forum, if you want to move it to an appropriate thread.

I was going to ask about that.

I freely and openly confess an error on my part in the OP. 

[LunarOrbit]

LO, I realize that this is in the hoax forum, if you want to move it to an appropriate thread.

No problem.

[bknight]

Some images of the far side of the Moon.

https://www.space.com/israeli-lander-moon-far-side-photos.html?utm_source=sdc-newsletter&utm_medium=email&utm_campaign=20190406-sdc