Radiation Canopy

The Radiation Canopy is a ship part in Pikmin and Olimar's Shipwreck Tale of, acting as the cockpit cover of the S.S. Dolphin. The Radiation Canopy turns the harsh radiations of space into soft infrared rays that aren't harmful to the body, making it necessary for space travel. In Pikmin 2, the Decorative Goo treasure is in the Radiation Canopy's corresponding location from Pikmin, and the Blue Onion replaces the Armored Cannon Beetle that guards the ship part. After being collected, it is installed on top of the cockpit, completely covering it.

In Pikmin
From the landing site, go through the gate that needed bomb-rocks to be destroyed. Throw at least 30 Pikmin on a ledge and then proceed through a second gate located in a small body of water, therefore requiring Blue Pikmin to destroy it. Climb to where the Pikmin are and command them to destroy another gate. Though not required, beating the Armored Cannon Beetle will produce a safe path to carry the Radiation Canopy back to the ship. The part itself is located in a small area in the top left corner of the arena.

While speed running, it is advisable to use bomb rocks to destroy the white gate. This can be done by throwing a Yellow Pikmin with a bomb rock on the ledge to the gate’s right. If done correctly, the Pikmin will walk on the top of the bridge, set down the rock, and jump into the water, after which it can be saved with the drowning reset glitch. Repeat the process, and the wall will be destroyed, without needing Blue Pikmin.

In Pikmin 4
The part is inside a Baldy Long Legs in the northeast of the area. Moss' jumping ability is required to reach the boss as it walks on top of a hill. Yellow Pikmin are the best type for fighting the Baldy Long Legs and are simultaneously needed to carry an Ionium Jet which lies nearby.

Be aware that after you kill the Baldy Long Legs, a swarm of Mitites will scatter around the Radiation Canopy and make Pikmin and Moss panic unless you wait for them burrow into the ground. Panicking Pikmin and Moss may run off the hill, potentially forcing you to waste time gathering them before you can transport either ship part.

Trivia

 * It is possible to get this part without Blue Pikmin, by throwing Yellow Pikmin carrying bomb-rocks on the ledge to the right of the gate, thus making them throw the rocks directly onto the top of the gate, taking it down.