Let's Take A Rocketship To Space

 is Swing musical number from "Out to Launch". It accompanies the montage depicting Phineas and Ferb trying to build a rocket-propelled spacecraft to visit a star bought for them by their dad and runs again later during the credits.

Lyrics
Let's take a rocket ship to space

I hear it's a real swinging place

There isn't much air, or gravity there

The stars will make your heart race

Let's take a rocket

Let's take a rocket

Let's take a rocket ship to space

Let's take a saucer to the stars

Look out moon, move over Mars

The Martians all rock

To Basie and Bach

So bring your maracas and your jazz guitars

Let's take a saucer to the stars

(instrumental interlude)

Let's take a rocket ship

A crazy three-stage rocket ship

Let's take a rocket ship to space!

(during end credits)

Let's take a rocket ship

A crazy three-stage rocket ship

Let's take a rocket ship to space!

Voiceover: It's the final frontier, baby.

Soundtrack Lyrics
The lyrics for is a lot different in the Phineas and Ferb Soundtrack. For example when the singer said "Let's take a rocket ship" is shortened down to "Let's Take a Rocket"; and "A crazy three-stage rocket ship" is shortened down to "A Crazy kind of rocket". Also, on the last line, "Let's take a rocket ship to space," the vocal still changes, but gets lower. The song on the Phineas and Ferb Soundtrack is also a little faster then in the show. Here are the soundtrack version of the lyrics:

Let's take a rocket ship to space

I hear it's a real swinging place

There isn't much air, or gravity there

The stars will make your heart race

Let's take a rocket

Let's take a rocket

Let's take a rocket ship to space

Let's take a saucer to the stars

Look out moon, move over Mars

The Martians all rock

To Bassie and Bach

So bring your maracas and your jazz guitars

Let's take a saucer to the stars

(instrumental interlude)

Let's take a rocket

A crazy kind of rocket

Let's take a rocket ship to space!

Voiceover: It's the final frontier, baby.

Background information

 * One of the few songs where the Soundtrack version is shorter than the broadcast.
 * The clips of failed rockets were from the Space Race in the late 1960s and 1970s.
 * On the blackboard we can see Tsiolkovsky rocket equation.

Allusions

 * This song seems to be based on Fly Me to the Moon by Frank Sinatra. The songs are the same style, spoken lyrics, and they both have instrumental interludes. Both songs also feature lyrics about space travel, though Fly Me to the Moon is figurative, and Let's Take a Rocket Ship to Space is literal.

Songwriters

 * Jon Colton Barry
 * Jeff "Swampy" Marsh
 * Martin Olson
 * Dan Povenmire

BMI Work # 10174997, registered under the title Rocket Ship to Space. Listed on the soundtrack as Let's Take a Rocket Ship to Space.