The Spitzer Space Telescope in the Clean Room at Cape Canaveral, Florida.

Spitzer in the clean room at Cape Canaveral, Forida, prepping for the aborted April 18, 2003 launch. Spitzer was ultimately launched on August 25, 2003.

The Spitzer Space Telescope in the Clean Room at Cape Canaveral, Florida.

The Spitzer Space Telescope in the Clean Room at Cape Canaveral, Florida.

The adapter ring that would attach Spitzer to its Delta II rocket, seen here being prepped before the aborted April 18, 2003 launch. Spitzer ultimately launched on August 25, 2003.

The adapter ring that would attach Spitzer to its Delta II rocket, seen here being prepped before the aborted April 18, 2003 launch. Spitzer ultimately launched on August 25, 2003.

Spitzer in the clean room in Cape Canaveral, Florida

Spitzer in the clean room in Cape Canaveral, Florida

Spitzer in the clean room in Cape Canaveral, Florida

Spitzer in the clean room in Cape Canaveral, Florida

Spitzer in the clean room in Cape Canaveral, Florida

Spitzer in the clean room in Cape Canaveral, Florida

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

The second stage of a Delta II rocket intended for Spitzer, but ultimately used for a Mars mission due to a scheduling change.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.

Spitzer in the clean room at Cape Canaveral, Florida.

Spitzer in the clean room at Cape Canaveral, Florida.

Spitzer in the clean room at Cape Canaveral, Florida.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.

A Delta II rocket, initially intended to launch the Spitzer Space Telescope on April 18, 2003. However, due to additional engineering tests that were needed on the rocket, the launch was delayed and the rocket was instead used to launch a Mars mission. Spitzer launched on a different rocket on August 25, 2003.