CAPE CANAVERAL, Fla. — NASA’s Apollo 13 lifted-off fifty-years ago on Saturday to begin the third crewed mission to land on the Moon, but quickly became an odyssey of survival in deep space.
The flight of Apollo 13 has been called “a successful failure”. It was successful in how the crew worked with mission control to return home, but a failure in that the lunar landing was aborted.
A veteran of three previous spaceflights, James (Jim) Lovell commanded the flight. Command Module pilot John (Jack) Swigert and Lunar Module Pilot Fred W. Haise, both rookie astronauts, rounded out the crew.
On the ground, mission control’s wealth of engineers, astronauts, and spacecraft designers worked long hours to get the crew home. They designed a new flight plan to save on electricity to power the spacecraft home.
For many not alive in 1970, the odyssey of Apollo 13 has today become a flight of inspiration. The 1995 movie Apollo 13, directed by Ron Howard and co-written by Lovell, has kept this modern day Homer-epic fresh for new generations.
“Apollo 13 has been one of my all time favorite movies as it shows the courage and determination of Lovell, Haise, and Swigert to overcome the odds and return home,” said Bob Hennelly, who has viewed the movie over 200 times since his college days. “Jim Lovell is a hero of mine — he is the epitome of courage.”
The Flight of Apollo 13 Begins
Apollo 13 launched a top a Saturn V rocket from the Kennedy Space Center at 2:13 p.m. EDT, on April 11, 1970, and darted out over the Atlantic waters. Minutes later, the spent first stage separated and the second stage took over to increase the rocket’s velocity.
As the five engines fired, the center engine abruptly shutdown two minutes early. Controllers decided to burn the remaining four engines 34 seconds longer to stay on its orbital target. The third stage engine also burned for a few seconds longer.
The crew spent the next two days preparing the two docked spacecraft — command module Odyssey and lunar module Aquarius — for lunar orbit. In mission control, the flight was very quiet.
They also beamed to Earth a live 45-minute TV show for the public on day three — 55 hours into the flight. It was never broadcast by the networks.
“Okay Houston, We’ve Had a Problem Here”
Minutes after the broadcast, Swigert was asked by mission control to flip switches to stir the fans in an oxygen tank housed inside the service module. Controllers had seen a failure in one of the tank’s pressure sensor.
About 100 seconds later, the number two oxygen tank ruptured. That explosion on April 13 at 10:08 p.m., shook the entire spacecraft and caused oxygen tank 1 to also fail over 209,000 miles from Earth.
Swigert radioed seconds later, “Okay Houston, We’ve Had a Problem Here”. The crew then reported of hearing a large bang. Thoughts of a meteor impact had crossed Swigert’s mind.
“Looking over the instrument panel that became very clear that the pressure meter, the temperature, and the quantity meter needles for one of the oxygen tanks was down in the bottom of their gauges,” Fred Haise said in a recent NASA interview. “These are different sensors, so it was unlikely that this was false. So it effectively told me we had lost one oxygen tank.”
The command module was dying, loosing power and water supply. The crew quickly worked to power up the lunar lander Aquarius for the crew to move in to. Aquarius became a life boat upon the vast ocean of space.
“My emotions at that time went to just a sick feeling in the pit of my stomach, because I knew by mission rules, without reference, that that meant the cancellation of the lunar mission,” Haise added. “Within probably the first two minutes, I knew we had lost the mission.”
Oxygen for the crew was never an issue as Aquarius carried a plentiful amount. Carbon dioxide did become an issue inside the lifeboat as the crew of three lived inside a spacecraft designed for two.
Aquarius’ oxygen scrubbers were a different size and shape then those used by Odyssey. The ground worked to have one of Odyssey’s CO2 filters work with Aquarius by using hoses and plastic materials. Jack and Fred constructed what the ground designed, and it worked perfectly.
“The most critical consumable I didn’t consider was the lithium cartridges,” Haise discussed. “The people on the ground subsequently worked out the way of implementing the use of the square cartridge from the command module, which there were an abundance of, to deploy in in the lunar module.”
The Cold Flight Around the Moon
As Aquarius housed the three astronauts, cold temperatures inside the cabin dropped down to nearly 35 degrees F. The spacecraft was running on only a few amps to run the computer and communications.
“We did not have adequate clothing to handle that situation. We did put on every pair of underwear we had in the vehicle,” Haise noted. “Jim Lovell and I wore our lunar boots, the boots we would normally put over our spacesuit boots on the lunar surface.”
There was little for the freezing astronauts to due except for course corrections and to look out the window. The timeline allowed for the crew to observe and photograph as they rounded the backside of the Moon.
Haise and Swigert studied and commented on the lunar geography, including their intended landing site at Fra Mauro. Lovell, who had flown in lunar orbit in December 1968, carried a feeling of disappointment for not landing.
“Probably the best high point was to view the Moon as we went by, which is quite a different variety body than the Earth, and to get to see the backside, which is quite different from the front,” Haise recalled. “Mountainous, very hilly, only a very few small mares or seas, the so-called smooth areas. And that was exciting. Jack Swigert and I both had cameras out and shot quite a number of pictures while we passed by briefly.”
It was on the backside of the Moon that Apollo 13’s crew set a record not yet broken for the furthest human distance from Earth. The flight’s free return trajectory caused them to travel 60 miles further from the lunar far side than past crewed flights. The record is a distance of 248,577 miles from Earth.
As they lost communications with mission control on the backside, Lovell pulled the rookies away from the windows. It was time to prepare for a critical engine burn by the lunar module’s descent stage.
The Safe Return Home
The two docked spacecraft flew with the service module’s engine cone in the direction of travel. This allowed the crew to use the lunar module’s descent engine for course corrections. Controllers determined that the explosion could have damaged the service module’s core engine.
As the Earth grew larger in the windows, Swigert returned to Odyssey to begin powering up the frozen craft. Once ready, the crew loaded into the command module to separate the lunar lander safely away. They were 90 minutes away from landing.
“We pressurized the tunnel between the two vehicles,” Haise continued. “So when we separated the lunar module, and it was quite a jolt, it actually projected (Aquarius) away from us out to the side.”
Odyssey reentered the Earth’s atmosphere and successfully splashed down in the southern Pacific Ocean on April 17.
Apollo 13 Accident Investigation
According to NASA, Apollo 13’s No. 2 oxygen tank, serial number 10024X-TA0009, was first installed into Apollo 10’s service module. It was then removed and damaged in the process. The O2 tank was repaired and tested before it was installed in the service module for Odyssey.
In addition, the voltage to the heaters inside the oxygen tanks had been upgraded from 28 to 65 volts DC. The thermostatic switches, however, were not upgraded.
During the Apollo 13 countdown test with the Saturn 5 in March 1970, heaters inside the oxygen tank were on for a long time. This caused the nearby wiring to reach temperatures near 1000 degrees F, causing the wiring’s teflon insulation to degrade.
NASA’s investigation board noted the thermostatic switches had begun to open, but were welded shut by the nearly eight hours of high heat during the countdown test. The investigation board then said, “The tank was a potential bomb the next time it was filled with oxygen. That bomb exploded on April 13, 1970.”
(Charles A. Atkeison reports on aerospace and technology. Follow his updates via social media @Military_Flight.)