So when a thing like a room-sized satellite breaks, the fragments, which are now individually lighter than the original whole, start assuming higher orbits...
Am I correct?
debris going into higher and lower orbits
No need to throw out energy conservation just yet.
The remnants would probably shoot off in various trajectories. It wasn’t a bump or a fender bender.
No. Although it sounds reasonable, weight has nothing to do with orbit size. In orbit everything is in free-fall around the earth, and therefore “weightless”.
Parts scatter into new orbits because the kinetic energy of the space craft translates into a big explosion when they collide. That explosion sends fragments out in all directions at high speed, some go up, some down.
All items at a particular altitude speed and direction will follow the same orbit regardless of size and mass (weight).
The reason the debris is going to higher and lower orbits, is that individual fragments have assumed a wide variety of different velocities and directions after the impact.
Also if there were any pressurized gases in tanks on either satellite that exploded, this would have accelerated debris nearby even further in different directions.
Acceleration in this case, means some debris items might have been SLOWED in velocity. This would result in them having an average orbit lower than before the collision / explosion.
SO the net speed and direction from the impact of each debris item will detemine that item's new orbit. AND they will be all over the place.
What a mess...
When you break a coconut in half do the pieces rise?
Has more to do with Mass and acceleration, some particles will go into a higher orbit because they have more energy. Others will go slower, and fall into the atmosphere. Think of it like a marble in a funnel, if you keep swirling or swirl harder the Marble will go higher up in the come. A gravity well is a similar idea.