Apollo 9: an “all‑up” test

Apollo 9 was an “all‑up” test of the combined Command Service Module (CSM) and Lunar Excursion Module (LEM) flown by Jim McDivitt, Rusty Schweickart and Dave Scott. Aldrin:

At exactly 11:00 am on March 3, Apollo 9 lifted off with Jim McDivitt commanding, Dave Scott as command module pilot, and Rusty Schweickart sitting in the center couch as lunar module pilot. This would be the first manned test of the lunar module. Once again the huge crowd assembled at the Cape was physically and emotionally overpowered by the thunder of the booster.

For the crew however the first stage S‑1C burn was very smooth – “an old lady’s ride,” McDivitt called it. But staging to the S‑II was a real bumper‑car jolt. Violent pogo oscillations developed seven minutes into the second‑stage burn. The jolting continued through the third‑stage ignition, but less than 12 minutes after liftoff the linked S‑IVB and Apollo spacecraft became the heaviest object ever placed in orbit.

McDivitt’s crew wanted to prevent spacesickness. Frank Borman’s crew had had it, so they tried to control their head movements and took Dramamine. These precautions helped, but they still felt dizzy and nauseous as they moved about the spacecraft.

A couple of hours later they were feeling better and had separated the CSM from the S‑IVB third stage. Scott then deployed his command module’s docking probe and thrust the spacecraft neatly around to line up with the conical drogue that was nestled at the top of the lunar module. The latches all snapped properly into place. Just over three hours into the mission, they were hard‑docked with the LM. Dave Scott then backed the two docked spacecraft away from the third stage and thrust well clear of the slowly tumbling white booster.

As they worked through their long flight plan, dizziness came in waves. But they had plenty of work to keep them occupied. They had to equalize the pressure between the CSM and LM cabins and prepare the connecting tunnel that would allow McDivitt and Schweickart to move from the CSM into the lander. At one point on the night side of their third orbit, Rusty glanced out and shouted, “Oh, my God, I just looked out the window and the LM wasn’t there.”

Dave Scott began laughing and kidding his crewmate. Dave reminded Rusty that Jim McDivitt was already up in the tunnel and the missing LM was simply hidden by the absolute darkness of orbital night. When Scott fired the SPS engine to boost the combined spacecraft to a higher orbit, he commented, “The LM is still there, by God!”

They were all surprised at how slowly the spacecraft accelerated, but that was understandable because it was carrying almost 16 more tons of mass – the fully fueled LM. Over the next several hours, they repeatedly fired the engine, moving the docked spacecraft through the complex orbital maneuvers that would be needed for the LOR.

The crew was so confident in their spacecraft that they all slept during the same “night” period. On waking, however, Rusty Schweickart was hit by a sudden bout of nausea. He and Jim McDivitt were putting on their spacesuits for the transfer over to the LM. Luckily, Rusty found a nearby barf bag. Pulling on the bulky pressure suit was no fun in the weightless cabin, and Jim McDivitt also went through some dizzy spells as he tugged at all the tubes and Velcro tabs.

Rusty then experienced brief vertigo as he floated up through the tunnel into the LM and ended up staring down at the lander’s flight deck. When he recovered he began flipping switches to power up the lander preparing it for free flight. Jim McDivitt joined him soon after. The LM was noisy with chattering fans and strange, gonglike rumbles. Unlike the command module, the lander was ultralightweight. Jim McDivitt later said it felt like tissue paper.

With no warning, Rusty Schweickart vomited again. McDivitt became alarmed because Rusty was due for an EVA on the porch of the LM later that day. If he got spacesick while wearing a bubble helmet, he could choke on his own vomit. Jim did the right thing and called for a private medical consultation on a “discreet” radio channel to Houston. The hundreds of reporters at the center had a field day making up sensational rumors when they were cut out of the loop.

Now that McDivitt and Schweickart were aboard the LM, the lander began to feel like a separate spacecraft, not just an impersonal hunk of hardware. They referred to it by the name they’d chosen for this mission, Spider; the command module became Gumdrop, an evocative description of its shape.

The crew spent almost two days, while the two spacecraft were still linked, checking out the LM’s many redundant systems and making sure the thrusters were in working order. Then Rusty and Jim crossed over to the lander once more and connected both their portable life support system (PLSS‑pronounced “pliss”) backpacks and the LM’s oxygen hoses to their suits, before depressurizing their spacecraft, Jim McDivitt opened up the waist‑high forward door – which took a lot of muscle – and Rusty crawled out onto the porch on the edge of the descent stage. From that porch he could see almost a quarter of Earth’s blue‑and‑white surface – quite a view.

The crew now had three radio call signs: Scott in Spider, Jim in Gumdrop, and Schweickart, the EVA man, now known as “Red Rover.” Rusty used the same golden slipper foot restraints I had used on Gemini XII. With these and the handrails on the outside of the LM, he had no trouble moving around.

The next day the crew put the LM through its most crucial task: fully testing the LM’s two engines and the spacecraft’s rendezvous radar, guidance computers, and docking system. Despite the playroom names they bantered with during the mission, there were real hazards involved in free‑flying Spider up to 90 miles away from Gumdrop. If any of the LM’s components failed, McDivitt and Schweickart could be marooned in the LM. Spider had no heat shield, so they could not reenter Earth’s atmosphere.

In the CSM, Dave Scott flipped a switch to release the latches gripping the LM, but they hung up. It wasn’t a good start. He flipped the button back and forth – “recycling” in NASA‑ese – and finally the LM broke free. Now came the test of the descent engine. Jirn McDivitt stood on the left side of the flight deck, and Rusty Schweickart occupied the similar place on the right. Ignition and the throttle‑up to 10 percent were smooth. But suddenly there was a harsh chugging at 20 percent. After several loud thumps, Jim released the throttle hand grip and the noise stopped. When he opened the throttle again, the problem had gone away.

Now they were completely on their own. The spacecraft’s four dangling legs, braced by shorter angular struts, actually did make the LM look like a spider.

I was at Mission Control, standing behind the flight directors as they bent over their consoles, monitoring this critical maneuver as Gumdrop changed orbit to simulate its position during an actual lunar rendezvous. Many of these maneuvers were near repeats of the rendezvous exercises I’d helped develop during Gemini. Next, Jim and Rusty “staged,” breaking the Spider into two separate sections. Now the part of the spacecraft they were in was only the bulbous cabin of the LM ascent stage, perched atop its squat engine nozzle. When they ignited that engine, they felt the sudden sagging weight of their limbs as they left Zero G.

Approaching Gumdrop in the darkness, McDivitt fired his thrusters to maneuver, “illuminating the LM cabin like the Fourth of July.” Dave Scott watched the fireworks, carefully matching what he saw with the radar data on his computer display. The final approach and docking went smoothly as Spider and Gumdrop were joined again, and the two men in the LM had completed their most critical maneuver. The lunar module, which had been the program’s bottleneck for years, had just performed flawlessly in space.