Why did Anakin and Obi-wan need to blow up Invisible Hand’s hangar shield to land inside?

Question

In Star Wars: Episode III – Revenge of the Sith, Obi Wan tells Anakin that the shields are still up and Anakin destroys them before going into the hangar of the Invisible Hand. Why does it matter that the shields are up if it is a hangar shield that fighters regularly go in and out of?

I looked in the cross section and it says that Anakin blew up the “Atmospheric Containment Shield”, which doesn’t really explain why they couldn’t land while it was on. Why didn’t Obi-wan and Anakin just land inside the Invisible Hand (name of Grievous’ ship here)?

Why did they need to blow up the shield? Did the shield need to be turned off for vulture droids to exit? Was it a one way shield? We see in clone wars shields being left on with ships leaving from republic ships. Was it like the droidika’s shield and they were traveling too fast to make it in?

I would like a in-universe answer that can be canon or legends.

Answer 1

Per the script, the ship lowered its ray-shields (shields capable of repelling incoming energy and matter) to allow the droid tri-fighters to leave the hangar. It presumably raised them again shortly afterward, necessitating Anakin to blow up the generators before they can land.

7 INT. ODD BALL'S FIGHTER COCKPIT-SPACE

ODD BALL: We're on your tail, General Kenobi. Set S-foils in attack position.

[The protective ray shield lowers on the main hangar of the TRADE FEDERATION CRUISER, and six new DROID TRI-FIGHTERS emerge and join the DROID VULTURE FIGHTERS heading toward the Jedi. The JEDI STARFIGHTERS extend the stability foils on the ends of their wings].

As to what would have happened had they not lowered the shields, the official novelisation gives us a fair indication.

Reaching into the Force, his mind followed the starfighter’s mangled circuitry to locate and activate the sublight engines’ manual test board. With a slight push, he triggered a command normally used only in bench tests: full reverse.

The cometary tail of glowing debris shed by his disintegrating starfighter shot past him and evaporated in a cascade of miniature starbursts on contact with the hangar shield. Which was exactly what was about to happen to him.

The only effect of full reverse from his failing engines was to give him more time to see it coming.

Answer 2

There are two types of shields in star wars

• Particle shields which deter projectiles and physical objects at sufficient velocity
• Ray Shields, stopping energy and high velocity impact.

Yes the shields on the Invisible hand were up, but were hybrids of the two to keep the hangar bay atmosphere in. At the speed they were going they'd crash into the shields, Only by slowing down could they enter, but doing so would render them vulnerable to enemy fire.