Darkness fell over Mare Crisium, ending a daily dose of dazzling images from the Moon. //

Firefly Aerospace's Blue Ghost science station accomplished a lot on the Moon in the last two weeks. Among other things, its instruments drilled into the Moon's surface, tested an extraterrestrial vacuum cleaner, and showed that future missions could use GPS navigation signals to navigate on the lunar surface.

These are all important achievements, gathering data that could shed light on the Moon's formation and evolution, demonstrating new ways of collecting samples on other planets, and revealing the remarkable reach of the US military's GPS satellite network.

But the pièce de résistance for Firefly's first Moon mission might be the daily dose of imagery that streamed down from the Blue Ghost spacecraft. //

Dtiffster Ars Praefectus
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TylerH said:
Given the amount of fuel needed to return to Earth, probably somewhere around the middle.

The prop to lift back off is at least 1.1 times the dry mass + up mass, but 78% of that is LOX which goes in the bottom tank. We don't know if the liftoff prop will just be in the tanks or in some kind of a really large header in the tank (as a boil off mitigation), but I would assume if there are headers they will be at or near the bottom of the of their respective tanks. Thus atleast 41% of the landed mass would be LOX and be very near the bottom. The legs and engine section will also be fairly substantial and very low. The methane for liftoff would be another 11% and only about a third of the way up the rocket. Much of the rest of the mass is tankage, but that center of mass is also probably no more than a third of the way up. The habitat section and equipment is high up, but it's less than 15% of that lift off mass. The CoM of the whole thing on landing/liftoff is probably only 25-30% up from the surface. It is much less tippy than your initial intuition would lead you to believe. //

https://www.youtube.com/watch?v=M2P-z_cXsOs

https://youtu.be/IpA9DORDkeE?si=oNmwnzJs6_UwzjPb

https://www.flickr.com/photos/fireflyspace/albums/72177720313239766/with/54395270843