#sta-099

Rockwell International workers install the left-hand forward payload bay door onto the Structural Test Article (STA-099) at Palmdale, California. After being used to test the launch stresses and verify the Space Shuttle design, it was later refurbished as an operational orbiter and named Challenger.

Date: February 1978

The Space Shuttle Structural Test Article (STA-099) being returned to Rockwell International's Palmdale Facility from Lockheed. STA-099 was used to test the launch and orbital stress an operational orbiter would experience. In January 1979, it was decided to convert the space frame into Challenger (OV-099), taking the operational orbiter slot intended for Enterprise (OV-101). There were many reasons NASA chose it over Enterprise, the major reasons were it was stronger, lighter and most importantly, there was less to disassemble.

Date: November 7, 1979

The Structural Test Article (STA-099) and a Lockheed L-1011 TriStar in the test rig at Lockheed facility in Palmdale, California.

The Space Shuttle Structure Test Article (STA-099) (later converted Challenger (OV-99)) being moved into the Lockheed facility for vibration stress testing.

The frame was tested for a year simulating all of the loads an operational orbiter would experience.

Date: February 14, 1978

Posted by Bill Roberts on the "STS-The Space Shuttle Legacy" Facebook group page: link

source, source, source

STA-099 and Columbia (OV-102) under construction at Rockwell International's Plant 42 Site 1 in Palmdale, California.

Date: January 17, 1978

Enterprise (OV-101) and STA-099 at Rockwell International's Plant 42 Site 1 in Palmdale, California. Parts from Enterprise were transferred to STA-099 for the conversion into the second operational orbiter, Challenger (OV-099).

Over the next several months the elevons, vertical stabilizer, payload bay doors, body flap, aft-fuselage, RCS module, and upper forward-fuselage were sent back to their respective factories for modifications.

Note: her forward fuselage is covered with a silver Mylar Insulation Blanket.

Date: November 8, 1979

Posted by Bill Roberts on the "STS-The Space Shuttle Legacy" Facebook group page: link

STA-099 under construction at Rockwell International's Plant 42 Site 1 in Palmdale, California.

Date: January 19, 1978

STA-099 and Columbia (OV-102) under construction at Rockwell International's Plant 42 Site 1 in Palmdale, California. This was shortly after the Vertical Stabilizer was installed on Columbia and before STA-099 was completed. STA-099 was later converted into the second operational orbiter Challenger.

Date: January 25, 1978