Each explosion in each particular duct can really economical in coarse changing..
You are talking about a rocket thruster... the problem is velocity.
To be able to use the rocket thruster a lot it is very important that the material ejected is very light so you can carry lots of it. Because you want it to be light for it to be effective you need to eject it very fast.
Think of it in terms of a bullet from a gun.
Using a simple bolt action rifle with no muzzle brake to deflect the gas to reduce recoil and no reloading mechanism to soften the recoil when you fire a gun you are accelerating a small metal weight (the projectile) with a large volume of gas (which is the burnt propellent) and you are also accelerating that gas as well.
The energy calculation on the ground is effected by the atmosphere and gravity but in orbit those effects are eliminated. There is gravity in orbit of course but because everything in orbit is "falling" at the same rate is can be ignored.
The energy calculation in orbit... say during an EVA, is the mass and velocity of the bullet plus the mass and velocity of the gas is generating energy in one direction. As it is a balanced system... for every action there is a reaction, using the mass of the rifle you can determine how fast in the opposite direction to the bullet and the gas that the gun will travel under recoil.
Lets say you throw the gun muzzle forward perfectly so that it doesn't spin in any direction and you have fitted the trigger with a small mechanism that after a period of time will pull the trigger and fire the round in the chamber. So you throw the rifle at... say 10m/s... when the rifle fires the equation starts as the weight of rifle times its speed is its forward momentum, but the new force of the bullet and gas mass plus velocity combined which also has a momentum which opposes the momentum of the rifle when it fired. These forces are directed in exactly opposite directions and so counter each other.
What I am trying to say is that the momentum of the bullet and gas is high because its velocity is much higher than the momentum of the rifle even though the rifle is much heavier.
Rockets use separate stages to minimise weight because when you are accelerating an object weight is the enemy to a limit. On earth you can throw a cricket ball further than you can throw a helium filled ballon because a large very light object doesn't push its way through the air very efficiently. You can however throw a cricket ball further than a shot put because the cricket ball has the balance of being heavy enough to move through the air efficiently but not being so heavy it is hard for you to accelerate it to high enough speed to go somewhere.
With more power the result changes... instead of your arm accelerating the object if you use powder propellent like in a cannon that heavy shot put will be better than a cricket ball because the cannon will be able to accelerate the shot put without destroying it and with the high speed the heavy shot put will be much less effected than the cricket ball and so will retain its speed better and travel further.
Reshaping the shot put into a bullet shape and spinning it will further increase its range.
Based on all of this what I am saying is that to stop an object in orbit and make it turn 90 degrees is impossible.
In orbit there is no air to push against so wings or control surfaces don't work... the only way to slow down is to point a rocket engine or gas engine in the direction you are travelling and fire material forward so that the equal and opposite reaction is to slow you down.
Travelling at 7km/s in orbit will take a lot of very high speed material to slow you down.
Remember it took a three stage rocket with up to 60 tons of fuel or more to get 2-5 tons up to orbital speed.
Obviously once in orbit it is easier to slow down but this normally involves slowing down enough to re enter the earths atmosphere which does the rest. A 5 ton object might need 60 tons of fuel to get into space and up to orbital speed, but when it is launched it weighs 60-70 tons so it needs powerful rockets and lots of fuel to get this airborne and moving. Once it is moving as it drops stages it needs less power and less fuel to keep on accelerating. Once it is in orbit it doesn't need a huge powerful engine to slow down or speed up because it is much lighter... however because it is much lighter there is less energy available to speed up or slow down too.
To manouver in space while in orbit you can turn a rocket motor sideways to change your orbital path, but to gain height you need to go faster and to descend you need to go slower.
If you were in a stable orbit and you wanted to climb if you directed your rocket engines downwards and fired them for 10 seconds you would go up... till you ran out of momentum and then you would fall back down and eventually you would end up at the same height you were before you fired your engines.
To climb to a higher orbit and stay there you need to be going faster so to climb you turn your rocket engines backwards and fire them for 10 seconds to accelerate and that will make you climb to a higher orbit.
To turn 90 degrees... well the thing about acceleration force is that it is just like gravity... it is actually measured in units of gravity, so a high speed turn might be 6gs or 9gs.
The g of a turn is determined by its angle and the speed you are travelling at.
Try it with your car... somewhere safe.
Drive at 10km/h and turn rapidly 20 degrees and then straighten up. No big deal really at such a low speed.
Accelerate to 50km/h and turn rapidly 20 degrees and then straighten up... you felt the difference?
The faster you are travelling the more you want to keep going in the same direction.
In the first test you probably felt nothing but at 50km/h you will have felt your body wanting to continue straight with the car seat and steering wheel pulling you 20 degrees off course.
Modern fighter jets can turn at about 16 degrees per second at high subsonic speed which probably equates to about 9 g.
The effect of gs is proportional so doubling the speed more than doubles the g force.
At 7km/s the g forces would rip anything man made to pieces in a 90 degree turn.
To do it with a rocket you pretty much have to swap the gun for the ammo... in other words the bullet and gas is the satellite and the gun is the rocket used to stop the projectile... the problem is that there is not enough matter left to then accelerate what is left to orbital speed.
To turn 90 degrees in orbit would take hours at least and would burn an enormous amount of fuel with a side thruster burning for a very long time... in the 3-5 minutes it is visible overhead the turn would be very difficult to see as the rotation of the earth makes the flight path appear curved anyway.