Lesson 5 of 6 · Missions & decisions
Landing—and coming home
9 minute lesson · 3 checks along the way · Optional video
Your goal for this lessonCompare Apollo 11’s completed landing with Apollo 13’s changed mission, using the spacecraft and teamwork you have learned about.
Follow a linked name to explore their archive card. “Back to your lesson” brings you to the same part of the reading.
The landing brought the preparation together
On July 20, 1969, Apollo 11’s lunar module Eagle landed on the Moon. Neil Armstrong and Buzz Aldrin had descended while Michael Collins stayed in lunar orbit aboard Columbia. Near the surface, Armstrong guided Eagle beyond an area of rocks to a suitable landing spot. The mission joined specialized spacecraft, trained crews, and decisions supported from Earth.
On the surface, the moonwalkers collected samples, photographed their surroundings, and deployed experiments. President Richard Nixon spoke with Armstrong and Aldrin from the Oval Office during their Moonwalk. These tasks had to fit within the time and supplies available. The familiar photograph of Buzz Aldrin therefore captures one moment in an operating mission: the crew still had scientific work to do and a carefully prepared route back to Collins.
Buzz Aldrin on the lunar surface, photographed by Neil Armstrong on July 20, 1969. Michael Collins remained aboard Columbia in lunar orbit.
Look closely
Look for footprints, the edge of the lander, and the reflection in the visor. What evidence shows this moment is part of a larger operation?
See what to notice
Bootprints mark movement around the landing site, part of the lunar module enters the lower right of the frame, and the visor reflects the photographer and nearby equipment. Buzz Aldrin is the subject, but Neil Armstrong is taking the photograph, while Michael Collins remains in lunar orbit. The crew’s work is spread across different places.
Finish the round trip
Eagle’s ascent stage lifted the moonwalkers into lunar orbit, leaving its descent stage behind. After rendezvous and docking, the astronauts transferred themselves and their samples into the command module. The reunited crew could then depart for Earth. Every transfer depended on the spacecraft roles you traced earlier in the course.
Near Earth, the service module separated. Columbia entered the atmosphere with its heat shield protecting the crew; parachutes then slowed the final descent. On July 24 it splashed down in the Pacific, completing the safe return. Recovery ships, aircraft, and divers were part of that ending. The mission’s commitment reached all the way from launch to the crew’s arrival home.
Check 1 of 3
10 pointsUse the reading above. You can try again without losing points.
Apollo 13’s plan breaks apart
Apollo 13 launched in April 1970 for another lunar landing. During the outward journey, an oxygen tank in the service module ruptured. The loss threatened more than breathing supplies: the service module’s fuel cells used oxygen to generate electricity. Jim Lovell, Jack Swigert, and Fred Haise faced a linked power and life-support emergency far from Earth.
The landing had to be abandoned. The team now needed a new plan based on equipment that still worked, the supplies remaining, and the time required to return. Remember the earlier distinction between a goal and a method: preserving the crew’s lives remained essential even though the intended surface exploration was no longer possible.
Use the lander as a temporary shelter
The LM, Aquarius, had separate systems that could support the astronauts while they traveled home. It became a lifeboat, a role very different from its planned surface visit. Crew members and ground teams reduced electrical use, conserved water, and planned engine burns. Keeping three people alive for the return required close attention to what the lander could sustain.
Aquarius could not perform every job. It had no command-module heat shield, so the crew still needed Odyssey, their command module, for Earth entry. They shut down much of Odyssey to conserve its resources, then prepared to bring it back into operation near home. An emergency solution had to protect both immediate survival and the capabilities needed at the end.
Check 2 of 3
10 pointsUse the reading above. You can try again without losing points.
Work through a decision
Work the decision: solve today without losing tomorrow
Suppose you can keep more equipment running now, but doing so uses batteries needed for entry. The choice cannot be judged only by present comfort or convenience. Apollo 13’s team had to budget power across the remaining journey, preserving the command module’s ability to function when its heat shield and entry systems became indispensable.
Carbon dioxide posed another problem. The command module had usable removal canisters, but their shape did not fit the LM’s system. Ground teams developed an adapter using materials aboard the spacecraft and relayed assembly instructions to the crew. This was practical teamwork: identify a specific constraint, test a workable response, and communicate it clearly enough to be carried out in space.
Compare outcomes through the decisions
Apollo 13 splashed down safely on April 17, 1970. Its survival did not turn the abandoned landing into a completed scientific mission. It showed how the crew and ground teams could revise their priorities and use the remaining spacecraft capabilities to bring everyone home. The recovery photograph marks the end of that changed journey.
Compare the two flights using the same questions: what was the objective, what equipment was available, and what decision came next? Apollo 11 carried out the planned landing and return. Apollo 13 required a different path to safety. With those connections in mind, the final lesson follows another return journey: how samples became evidence in laboratories on Earth.
Apollo 13’s command module is recovered on April 17, 1970. The crew was already safely aboard USS Iwo Jima when this photograph was taken.
Look closely
Compare this small capsule with the vehicles that left Earth. Which Apollo spacecraft has made it all the way back?
See what to notice
The conical command module is being lifted beside the recovery ship. The service module and lunar module are absent: neither was designed to carry the crew through Earth’s atmosphere. The ship, crane, and recovery team also show that getting home required a final operation at sea.
Check 3 of 3
10 pointsUse the reading above. You can try again without losing points.
Put it together
Your lesson progress
Each check connects to a part of the story. Complete all 3 to earn your 25-point lesson bonus.
Go to the source
Explore the evidence behind this lesson. These optional readings and videos open in a new tab.
- Watch: Watch: Apollo 11’s restored moonwalkOptional NASA+ archive video (3 hours). Watch about two minutes beginning when Armstrong steps off the ladder. Notice how he tests the surface and describes it to Mission Control.
- Read: NASA: Apollo 11 mission overviewFollow the sequence after the moonwalk. Name the spacecraft stage used at each step from lunar liftoff to splashdown.
- Read: NASA: Apollo 13 mission detailsFind the power-conservation and carbon dioxide problems. Explain how solving each protected a different requirement for returning the crew safely.