Apollo 9

Apollo 9 was the third crewed mission in the United States Apollo space program and the first crewed flight of the Apollo Lunar Module (LM). Launched on March 3, 1969, the ten-day mission was a critical milestone designed to test the LM's systems in Earth orbit, evaluate the newly developed Apollo spacesuit, and demonstrate the spacecraft's capability to operate independently and rendezvous, thereby proving its readiness for future lunar landing missions.

Background and Objectives

Following the successful circumlunar flight of Apollo 8, NASA needed to verify the performance of the Lunar Module, the specialized spacecraft designed to land astronauts on the Moon. Apollo 9 was tasked with conducting the first crewed test of the complete Apollo spacecraft, comprising both the Command/Service Module (CSM) and the LM, in low Earth orbit. The primary objectives included testing the LM's descent and ascent engines, evaluating the docking and undocking mechanisms between the two spacecraft, and conducting an extravehicular activity (EVA) to test the Extravehicular Mobility Unit (EMU) and its Portable Life Support System (PLSS), which would be essential for lunar surface exploration.

Crew

The prime crew of Apollo 9 consisted of three experienced astronauts:

• James A. McDivitt served as the Commander. A veteran of the Gemini 4 mission, McDivitt was responsible for overall mission command and piloting the LM during its independent flight.
• David R. Scott was the Command Module Pilot (CMP). He had previously flown on Gemini 8 and was tasked with operating the CSM, maintaining orbit, and executing the rendezvous with the LM.
• Russell L. "Rusty" Schweickart served as the Lunar Module Pilot (LMP). Although designated as the LMP, his primary role during the mission's critical LM flight was to operate the spacecraft's systems alongside McDivitt and to perform the mission's spacewalk.

The backup crew, who would later fly on Apollo 12, consisted of Charles "Pete" Conrad (Commander), Richard F. Gordon Jr. (CMP), and Alan L. Bean (LMP).

Spacecraft and Launch Vehicle

The Apollo 9 spacecraft consisted of two main components. The Command/Service Module (CSM-104), nicknamed "Gumdrop" due to its shape and the appearance of its protective ablative coating, served as the crew's primary living quarters and the vehicle for Earth re-entry. The Lunar Module (LM-3), nicknamed "Spider" for its spindly, arachnid-like landing legs, was the first crewed version of the lunar lander. The mission was launched atop a Saturn V rocket (SA-504) from Launch Complex 39A at the Kennedy Space Center in Florida.

Mission Profile

Launch and Docking

Apollo 9 launched on March 3, 1969, achieving a stable low Earth orbit. Shortly after reaching orbit, the CSM separated from the Saturn V's S-IVB third stage, turned around, and docked with the LM. Scott then extracted the LM from the stage, successfully demonstrating the transposition, docking, and extraction maneuver that would be required for future lunar missions. The combined spacecraft remained attached for several days while the crew conducted systems checks and prepared for the LM's independent flight.

Extravehicular Activity (EVA)

On the fourth day of the mission, Schweickart performed an EVA to test the new Apollo spacesuit, which featured an independent backpack life support system rather than relying on an umbilical tether to the spacecraft. While McDivitt and Schweickart depressurized the LM, Scott depressurized the Command Module. Schweickart stepped onto the LM's "porch," testing the suit's mobility and life support capabilities. Although Schweickart had suffered from space adaptation syndrome earlier in the mission, which curtailed a planned transfer between the two spacecraft via spacewalk, his successful test of the PLSS proved the suit was ready for the lunar surface.

Lunar Module Independent Flight

On March 7, McDivitt and Schweickart entered the LM "Spider," undocked from the CSM "Gumdrop," and began the first crewed flight of a dedicated lunar lander. They fired the LM's descent engine, simulating the braking maneuver required for a lunar landing, and maneuvered the spacecraft up to 111 miles (179 kilometers) away from the CSM. Following the successful testing of the descent stage, they jettisoned it and fired the ascent engine, simulating the liftoff from the lunar surface. McDivitt then piloted the ascent stage back to the CSM, where Scott successfully executed the rendezvous and docking. This complex sequence proved that the LM could operate autonomously and safely return its crew to the mother ship.

Return and Splashdown

After transferring back to the CSM, the crew jettisoned the LM ascent stage, which was subsequently tracked by ground radar to simulate a future lunar ascent trajectory. The crew spent the remaining days in orbit conducting Earth resource photography and scientific observations. On March 13, 1969, Apollo 9 fired its Service Propulsion System to deorbit. The Command Module re-entered the Earth's atmosphere and splashed down safely in the Atlantic Ocean, approximately 290 miles (470 kilometers) east of the Bahamas. The crew was recovered by the USS Guadalcanal.

Legacy and Significance

Apollo 9 was an unqualified success, fulfilling all of its primary mission objectives. The mission proved that the Lunar Module was spaceworthy, structurally sound, and capable of supporting human life during independent flight. Furthermore, the successful testing of the Apollo spacesuit and the complex rendezvous procedures provided NASA with the confidence needed to proceed to the next phase of the lunar landing program. By validating the hardware and operational techniques in Earth orbit, Apollo 9 paved the direct path for Apollo 10's lunar dress rehearsal and the historic Apollo 11 Moon landing just four months later.