Tag Archives: Poppy Northcutt

[April 22, 1970] “Houston, We’ve had a Problem Here!” (Apollo-13 emergency in space)

April 22, 2025 Kaye Dee 2 Comments

[New to the Journey? Read this for a brief introduction!]

by Kaye Dee

We all breathed a sigh of relief when the astronauts of Apollo-13 returned to Earth safely a few days ago, after the Apollo programmes’ first (and hopefully last) inflight emergency, but superstitious people are claiming that Apollo-13 was unlucky because of a prevalence of “13s”! After all, the mission was launched at 13:13 Houston time (but somewhere in the world there will always be a place where the time is 13: something!) and the explosion that caused its inflight emergency occurred on 13 April (but only in certain timezones – it was already 14 April in Australia and most of the world east of the United States).

Don’t tell me the Apollo-13 crew were “unlucky”; in fact, they were immensely lucky that when something did go wrong they were a team with the right skills for the situation. As seasoned test pilots, the crew were experienced at working in critical situations with their lives on the line, and their professional skills as astronauts were matched by the “tough and competent” (to quote Flight Director Mr. Gene Kranz) Mission Control teams, backed by highly trained engineers and scientists – all determined to “return them safely to the Earth”, just as President Kennedy committed NASA to do when he set the goal of a manned lunar landing by 1970!

Timeline of major mission events during Apollo-13

Crew Switcheroo
The prime crew for Apollo-13 changed multiple times, the last alteration occurring just days before launch! Instead of rotating the Apollo-10 back-up crew to become the prime crew for Apollo-13 – the normal procedure – Director of Flight Crew Operations, Mr. Deke Slayton, designated astronauts Alan Shepard (Commander), Stuart Roosa (Command Module Pilot) and Edgar Mitchell (Lunar Module Pilot) as the Apollo-13 prime crew. However, although he was the first American in space, Captain Shepard had only recently returned to flight status after a lengthy medical issue. It was felt that he needed more training time, so in August 1969, his crew was swapped with the prime crew for Apollo-14.

The prime crew for Apollo 13 then became US Navy Captain James Lovell, as Commander, civilian Mr. Fred Haise as Lunar Module Pilot (LMP) and USAF Lt. Col. Ken Mattingly as Command Module Pilot (CMP).

Official crew portrait for Apollo-13. L.-R. Jim Lovell, Ken Mattingly and Fred Haise. They are shown with ancient scientific and navigation instruments hinting at the classical elements in the mission patch and callsigns

Unfortunately, just a week before launch back-up LMP Charles Duke contracted German measles (rubella) from a child and accidentally exposed both the prime and back-up crews to the disease. CMP Mattingly was found to have no immunity, and the astronauts’ medical team had serious concerns that he could become too sick to perform adequately during the flight if he began to experience symptoms of the disease.

Normally, NASA policy would dictate that the back-up crew step into the mission. However, since back-up LMP Duke also had the measles, this wasn’t feasible. Just three days before launch, the difficult decision was made to replace Lt. Col. Mattingly with Mr. Jack Swigert, the fortunately-immune back-up CMP. This made the final crew for Apollo-13 Lovell, Haise and Swigert. Astronaut Mattingly will be re-assigned to a later Apollo mission, probably Apollo 16.

The last minute Apollo-13 crew portrait, following the swap of Ken Mattingly to Jack Swigert

Who’s Who?
Although he announced his intention to retire from NASA prior to Apollo-13, 42-year-old Mission Commander James “Jim” Lovell is the world's most experienced astronaut, the record holder for the most time in space, with 572 hours aboard Gemini-7, Gemini-12 and Apollo-8!

Members of the fifth astronaut group, selected in 1966, Captain Lovell’s crewmates may have both been space rookies, but fortuitously they each had specialisations that provided vital knowledge and experience during the in-flight emergency.

Mr. Fred Haise, the Lunar Module pilot (LMP), is a 36-year-old aeronautical engineer, who was both a Marine Corps and Air National Guard fighter pilot. A civilian research pilot for NASA before his selection as an astronaut, Mr. Haise previously served as back-up LMP for Apollo-8 and 11. He is a specialist on the Lunar Module (LM), having spent fourteen months at the Grumman factory where the spacecraft are built.

Mr. John “Jack” Swigert, the Command Module Pilot (CMP), is 38 years old, with degrees in mechanical engineering and aerospace science. He has served in the US Air Force and in state Air National Guards and was an engineering test pilot immediately prior to his astronaut selection. A specialist in malfunctions of the Command and Lunar Modules, Mr. Swigert “practically wrote the book on spacecraft malfunctions.”

Knowledge from the Moon
It’s probably fortunate that, like Apollo-11, Captain Lovell’s original crew made the decision that the Apollo-13 mission patch would not carry their names: when the last minute crew swap occurred, no changes were required to the design. Instead of names, the Apollo-13 patch carries the motto “Ex Luna, Scientia”, Latin for “From the Moon, knowledge”. This references Apollo-13’s intended role as the second ‘H’-class mission, designed to demonstrate precision landing capability so that the crew could explore a specific site on the Moon. As a Navy officer, Captain Lovell derived the motto from that of the US Naval Academy, “Ex scientia, tridens ("From knowledge, sea power").

A powerful image of the Sun rising behind the horses of the god Apollo’s chariot forms the centrepiece of the design. As Apollo is the god of both the Sun and knowledge, this plays upon both the project name and the mission motto. Against the black background of space, the golden horses of Apollo prance over the Moon, their journey from the Earth (in the background) to the Moon depicted by a bright blue path. Artist Lumen Martin Winter, designer of the Apollo-13 mission patch, based the horses on a mural he previously painted for the St. Regis Hotel in New York City (below). Using Roman numerals for the mission number also complements the classical connections of the spacecraft names and callsigns.

Classical Callsigns
Captain Lovell drew upon classical mythology in selecting the Command Module callsign “Odyssey” – taken from Homer’s epic Greek poem. Since an “odyssey is “a long voyage with many changes of fortune”, it turned out to be an extremely appropriate choice indeed! The name was also a nod to the classic science fiction film "2001: a Space Odyssey".

For the Lunar Module, the crew selected the callsign “Aquarius”. Although the media have linked the callsign to the song in the musical “Hair”, it is actually meant to reference Aquarius, the cup-bearer of the Graeco-Roman gods, and bringer of water – the only water on the Moon being that carried there by the Apollo crew.

Medieval illustration of Aquarius watering the Earth

Preflight Preparations
Apollo-13’s launcher, AS-508, had some slight modifications compared to earlier Saturn-V vehicles, to prepare for the future J-class missions which will carry heavier payloads. New “spray-on insulation” was used for the liquid hydrogen propellent tanks in the S-II second stage. The rocket also carried additional fuel, as a test for future launches, making it the heaviest Saturn-V yet flown.

The intensive preparation for the Apollo-13 crew included over 1,000 hours of mission-specific training, with a much greater focus on geology, since the intended landing area in the hilly Fra Mauro formation (named for a 15th Century cartographer monk) is of significant geological interest. If rocks from this area could be dated, they might improve our understanding of the early geological history of both the Moon and the Earth. Scientist-astronaut Harrison Schmitt, himself a geologist, was heavily involved in the crew’s geological training.

Jim Lovell and Fred Haise during geology training in Hawaii

Due to the difficulty of distinguishing astronauts Armstrong and Aldrin from each other in Apollo-11 photographs, NASA introducec a means of differentiating crew members from each other on the Moon by adding red stripes on the helmet, arms and legs of the commander's spacesuit. This system will now be implemented on Apollo-14.

Experiments That Might Have Been
A major component of Apollo-13’s lunar surface activities would have been the installation of a new Apollo Lunar Surface Experiment Package (ALSEP), powered by a SNAP-27 radioisotope thermoelectric generator (RTG). This small nuclear generator contains 8.36lb of plutonium oxide. The fuel capsule is intended to withstand the heat of re-entry into the Earth's atmosphere in the event of an aborted mission, which means that Apollo-13’s RTG may have survived Aquarius’ re-entry on return to Earth, splashing down into a remote area of the southern Pacific Ocean.

Mission Commander Lovell practicing the deployment of an ALSEP instrument during training

Like Apollo-11 and 12, Apollo-13’s ALSEP included a seismometer (the Passive Seismic Experiment), which was to be calibrated by the impact of Aquarius’ ascent stage, a Lunar Atmosphere Detector (LAD) and a Dust Detector. New to the Apollo-13 instrument package was a Heat Flow Experiment (HFE), and a Charged Particle Lunar Environment Experiment (CPLEE), designed to measure solar protons and electrons reaching the Moon.

A Shakey Start
Originally scheduled for launch in March, Apollo-13 was delayed for a month while NASA re-considers how it will schedule the remaining Apollo missions out to Apollo-19, now that Apollo-20 has been axed due to President Nixon’s budget cuts.

The mission hit trouble right at the start: five and a half minutes after liftoff on Saturday 11 April (US time). The crew felt “a little vibration”, then the centre engine of the S-II stage shut down two minutes early. This required the remaining four engines to burn and additional 34 seconds longer, while the S-IVB third stage had to burn 9 seconds longer to put the spacecraft into orbit. But with the extra fuel on board for this flight, the engine failure fortunately didn’t cause any major problem.

A successful trans lunar injection burn placed Apollo-13 on course for the Moon, with the CSM and LM docking occurring 20 minutes’ later. Unlike previous lunar missions, after the LM was extracted from the S-IVB stage, the stage was not sent off into solar orbit, but targetted to impact the Moon so the vibrations could be detected by the Apollo-12 seismometer. This would later cause unexpected communications complications after the accident occurred.

Apollo-13's S-IVB stage heading towards the Moon

“We’re Bored to Tears”
With the spacecraft safely on its way to the Moon, the first phase of the flight was uneventful. Approaching 31 hours into the flight, the crew performed a burn to place Apollo 13 on a hybrid trajectory, enabling Aquarius to ultimately land at the Fra Mauro site. This change from the free-return trajectory used on earlier missions would cause later complications for returning the astronauts to Earth: on a free-return trajectory, no further engine burns were necessary to ultimately bring the spacecraft home, but a hybrid trajectory would miss Earth on its return leg, unless further burns were performed.

Apollo-13 White Team Flight Director Mr. Gene Kranz catching up on his paperwork in Mission Control during the calm before the storm

The day after launch, Mr. Swigert became worried by the realisation that, in the rush to replace Ken Mattingly, he had forgotten to file his Income Tax Return, and needed to apply for an extension! Fortunately for him, an amused Mission Control advised that “American citizens out of the country get a 60-day extension on filing; assume this applies to you.”

With Apollo-13’s telemetry showing that the spacecraft was “in real good shape”, on 13 April Capcom Joe Kerwin told the crew “We are bored to tears down here.”—a situation that was soon to change.

The Last Apollo-13 Show
Astronauts Lovell and Haise entered the LM to test its systems about an hour before a major television broadcast, scheduled for 55 hours into the mission.

With Commander Lovell acting as MC, the astronauts put on a lively show, exhibiting some of their gear such as space helmets, sleeping hammocks and newly-designed bags for drinking water inside their spacesuits. From Odyssey, Captain Lovell played tinkly lounge music using a small tape recorder, and he said it was an awesome thing to see the Moon accompanied by the theme to 2001.

Mission Control during the Apollo-13 broadcast. Astronaut Fred Haise can be seen on the big screen

Disappointingly, American television viewers had become, it seems, even more bored than Mission Control with now-“routine” missions to the Moon. None of the major US networks carried the broadcasts, although they were seen in Australia and, I believe, other countries. Marilyn Lovell and Mary Haise had to go to the Mission Control VIP viewing room to see their husbands’ half hour broadcast on television.

“Houston, We’ve had a Problem Here!”
Just nine minutes after the conclusion of the television broadcast, at 205,000 miles from Earth, an incident occurred that turned Apollo-13 from a routine mission into an emergency situation: one that the media and anxious communities in the US and around the world would intently follow as soon as the news broke!

At the request of Mission Control, Mr. Swigert stirred the cryogenic hydrogen and oxygen tanks that powered the fuel cells in the Service Module (SM). This action was followed by a “pretty large bang”, felt as a jolt through the spacecraft, accompanied by fluctuations in electrical power, attitude control thrusters firing automatically and a brief loss of communications and telemetry to Earth.

Diagram of the Service Module showing the location of the fuel cells and oxygen tanks that must have been damaged by the explosion, based on the available telemtry

CMP Swigert quickly reported "Okay, Houston, we've had a problem here," confirmed moments later by the Mission Commander, "Houston, we've had a problem. We've had a Main B Bus undervolt”. This meant that the SM’s three fuel cells were not providing sufficient voltage to the second of the Service Module’s two electrical power distribution systems

Captain Lovell momentarily thought that LMP Haise had activated Aquarius’ cabin-repressurisation valve (which Haise could have done as a joke, since its bang would startle his crewmates); CMP Swigert initially thought that a meteoroid might have struck the LM, though there was no atmospheric leakage. But voltage was dropping in both electrical buses, one oxygen tank was empty, and the other leaking, and two of the three fuel cells were failing!

Headline from Australian newspaper "The Sun" just a few hours after the accident. It references Lovell's description of gas venting from the Service Module

Looking out Odyssey’s hatch window, seeking a cause for the spacecraft thrusters to be firing erratically and affecting their course to the Moon, Captain Lovell saw “gas of some sort” venting into space. Some kind of physical rupture had definitely occurred: whatever had caused the problem, the situation was serious.

Mission Control Swings into Action
Although the Flight Controllers in Houston initially assumed that their bizarre anomalous readings from Apollo-13 had to be the result of instrumentation issues, it quickly became obvious, judging from the reports from the crew, that they were dealing with a genuine emergency.

The Mission Control White Team, led by Flight Director Gene Kranz, was on duty when the incident occurred and had to deal with the initial hours afterwards. With extensive Flight Director experience going back to the Mercury programme, and including critical phases of the Apollo-11 mission, Mr. Kranz played a crucial role in the rescue of the Apollo-13 crew.

Flight Director Gene Kranz (seated) and senior Flight Controllers during the tense period following the Apollo-13 accident

With telemetry data providing some insight into the condition of the spacecraft, and support from “backroom” teams of technical specialists, White Team worked to diagnose the problems and prioritise recovery and rescue actions.

The fuel cells needed oxygen to operate, but it was rapidly leaking away. Attempting to stem the leak, they shut down the two failing fuel cells. This immediately meant the loss of the lunar landing, as mission rules prohibited going into orbit around the Moon unless all three fuel cells were functioning. With oxygen still being lost, Mr. Kranz ordered the isolation of a small oxygen supply within the Odyssey, to retain it for use with the last remaining fuel cell, which would be needed for the final hours of the mission. The CM's batteries would be needed to power the craft during re-entry, so they were also shut down to conserve power.

Lifeboat Aquarius
Ninety-three minutes after the accident, oxygen pressure in the Command Module was dropping and Mission Control determined that the last fuel cell would soon fail as oxygen ran out, leaving the CM effectively dead. Aware of training simulations that had used the LM as a “lifeboat”, Mission Control ordered the crew to transfer to Aquarius.

Lovell, Haise and Swigert had themselves already realised that Aquarius would be needed as a lifeboat, and had commenced to power-up the Lunar Module, transferring necessary information to the LM’s guidance system. They bagged up as much water as possible from Odyssey’s supply (needed for equipment cooling as well as drinking), storing the water and food supplies in Aquarius.

The Apollo-13 crew's only view of their lifeboat Aquarius in space, drifting after it was cast loose shortly before re-entry

It was going to be a tight fit for three astronauts in a spacecraft meant for two, but the crew were fortunate that the emergency occurred when they had a fully-powered and supplied Lunar Module attached to the Odyssey. Had the explosion occurred after the lunar landing, with Aquarius jettisoned, the CM would not be able to provide enough life support to keep the astronauts alive until they returned to Earth.

Apollo-13 was being surrounded by a cloud of debris from the explosion. Communications were weak and erratic, due to probable antenna damage from debris, as well as interference from the S-IVB stage also on its way to the Moon. Its tracking beacon was operating on the same frequency as the Lunar Module, as it had not been anticipated that the LM and S-IVB stage would be communicating at the same time. (I’ll cover this situation in more detail in an article in May).

Flight Controllers conferring on how best to bring Apollo-13 safely home. Note the lack of data usually present on the big screens

“Returning Them Safely to the Earth”
Apollo-13’s new mission goal became the safe return of the crew to the Earth. Vital consumables (oxygen, electricity, and water) were assessed and rationing plans devised. Calculating the best way to get the spacecraft back to Earth before supplies were exhausted became a priority, with the mindset that “failure is not an option”.

Ultimately, the safest course of action was deemed to be putting Apollo-13 back on a free-return trajectory, firing the LM’s descent engine so that the spaceship would loop around the Moon and head back to Earth. Using the large Service Module engine was ruled out, since it was uncertain if it had been damaged by the explosion.

NASA’s “Return to Earth” trajectory specialist, Miss Poppy Northcutt, calculated a new course to carry Apollo-13 around the Moon and safely home. Anxious to assist in any way they could, other astronauts arrived at Mission Control, including Lt. Col. Mattingly, who still had not developed German measles! Some would spend time in the Apollo simulators, helping to work up needed procedures, such as powering up the Command Module for re-entry with limited electricity available.

NASA Contollers and astronauts gathered in Mission Control to assist the rescue of Apollo-13. Seated, left to right, Guidance Officer Raymond F. Teague; astronaut Edgar D. Mitchell, Apollo 14 prime crew lunar module pilot; and astronaut Alan B. Shepard Jr., Apollo 14 prime crew commander. Standing, left to right, are scientist-astronaut Anthony W. England; astronaut Joe H. Engle, Apollo 14 backup crew lunar module pilot; astronaut Eugene A. Cernan, Apollo 14 backup crew commander; astronaut Ronald E. Evans, Apollo 14 backup crew command module pilot; and M.P. Frank, a flight controller

Sixty one and a half hours after launch, Aquarius’ descent engine burn put Apollo-13 back on a free return trajectory. As it looped around the Moon, Apollo-13 captured the Guinness World Record for the farthest distance from Earth attained by a crewed spacecraft – 248,655 miles.

The Moon's far side photographed by the Apollo-13 crew. The shut down CM Odyssey can also be seen in the foreground of this view from Aquarius

I’m sure you recall the tension during those 25 minutes of radio blackout when Apollo-13 was behind the Moon. People around the world tuned into television and radio, or gathered in public spaces, eager for news, now engrossed in the gripping drama being played out in space. Would the astronauts survive? Religious leaders led congregations in prayer for their safe return.

On Their Way Home
Mission Control determined that a burn following trans-Earth injection would shave 12 hours off the flight time back to Earth and land Apollo-13 in the Pacific, where the main US recovery fleet was located. Thirteen nations (another number 13!), including the USSR, offered to provide rescue ships or aircraft for emergency recovery, should the spacecraft come down off course in the Pacific, Indian or Atlantic Oceans.

When this crucial burn took place, the debris cloud surrounding the spacecraft made it impossible to use stellar navigation to check the accuracy of the firing. However, the crew were able to use the positions of the Sun and Moon to confirm that the trajectory was on target. They were going home!

The astronauts then shut down most LM systems to conserve consumables, making for a miserable return flight: in Aquarius it was extremely cold (38 °F), dark and damp, with moisture condensing out on every surface, including the windows. The same issue occurred in Odyssey, raising concerns of short-circuits occurring when it was powered back up. Fortunately, lessons learned from the Apollo-1 fire prevented that from happening.

Mission Commander Lovell tries to sleep in the extreme cold and semi-darkness of the Lunar Module

The crew slept poorly, eating and drinking little (cold frankfurters and water for dinner, anyone?). They lost weight, with Mr. Haise developing a urinary tract infection, apparently from dehydration.

Putting a Square Peg in a Round Hole
A new problem arose during the return journey – with three astronauts in the LM, dangerous levels of carbon dioxide were building up in Aquarius. They were running out of lithium hydroxide canisters, designed to scrub it from the air, and the square canisters used in Odyssey were not compatible with the round openings in Aquarius!

Jack Swigert, with assistance from Jim Lovell (just out of frame) assembles the connections for the makeshift CO2 scrubbing device nicknamed "the mailbox", which is box shaped object beside Swigert

NASA engineers fortunately found a way to fit “a square peg in a round hole,” using only items available on the spacecraft. After the instructions for building the device were radioed up, Swigert and Haise constructed it and carbon dioxide levels began dropping immediately.

The Final Leg
Apollo-13 showed a tendency to drift slowly off course, and two more mid-course correction burns were needed to keep the spacecraft within the safe re-entry flight path. Just after 138 hours into the mission, the crew jettisoned the SM from the command module, allowing the astronauts to see and photograph the explosion area for the first time. They were shocked by the extent of the damage they saw and concerned that the explosion might have damaged the heatshield.

The astronauts' only view of the Service Module, showing the extent of the damage caused by the explosion, which blew out an entire side panel.

Moving back into Odyssey, the astronauts then reactivated its life support systems, while retaining Aquarius until about 70 minutes before entry. With no heatshield of its own, the LM could not safely re-enter, but as it drifted away, watched sadly by the crew, Capcom Kerwin offered an epitaph from Mission Control: “Farewell Aquarius, and we thank you”.

There's no place like home! Earth taken from Apollo-13 in the final stages of its return from the Moon

Home at Last!
At last, on April 17 (US time),142 hours after launch, Apollo-13 re-entered Earth’s atmosphere. Its shallow re-entry path lengthened the usual four-minute radio communications blackout to six minutes, causing Mission Control to briefly fear that the CM's heat shield had failed. But Odyssey had survived and splashed down safely in the South Pacific Ocean south-east of American Samoa, just four miles from the recovery ship, USS Iwo Jima: total flight time: 5 days, 22 hours, 54 minutes and 41 seconds. Mission Control erupted in cheers!

While the world rejoiced at their safe return, the exhausted Apollo-13 crew stayed overnight on the recovery ship, without undergoing quarantine since they did not land on the Moon.

Exhausted but elated, the Apollo-13 crew are formally welcomed aboard the recovery ship, USS Iwo Jima as returning heroes after their space ordeal

The astronauts flew to Pago Pago in American Samoa the next day, then on to Hawaii, where they were re-united with their wives and President Nixon awarded them the Presidential Medal of Freedom, the highest US civilian honour. The Presidential Medal of Freedom was also awarded to the Apollo-13 Mission Operations Team, for their efforts in ensuring the safe return of the Apollo-13 crew. After staying overnight in Hawaii, Capt. Lovell, Mr. Haise and Mr. Swigert have now returned to Houston to be re-united with their families.

Returning heroes after their space ordeal. the Apollo-13 crew stand proudly with President Nixon after being awarded the Presidential Medal of Freedom

At present, the cause of the explosion that crippled Apollo-13 is unknown, so I will leave the speculation until my follow-up article in May, talking more about Apollo-13’s epic journey. I’d like to end here with the words of President Nixon, during the Presidential Medal of Freedom presentation: “You did not reach the Moon, but you reached the hearts of millions of people on Earth by what you did.”

The astronauts only learned about the extent of the pubic reaction to their emergency after they returned to Earth!

[New to the Journey? Read this for a brief introduction!]

Follow on BlueSky

2 Comments Leave A Comment

Science / Space Race

[September 28, 1969] Apollo’s New Muses (Women Behind the Scenes in the Apollo Programme)

September 28, 2024 Kaye Dee 4 Comments

Seven years ago, the Journey published an article on the Women Pioneers of Space Science. At long last, Kaye offers a much-needed update, this time focusing on the women who helped make Apollo 11's trip to the Moon possible…

by Kaye Dee

Classical literature tells us that the god Apollo was associated with the Nine Muses, the goddesses who inspired the arts, literature and science.

Our modern Apollo program also has its Muses – trailblazing women working behind the scenes in critical areas of the programme. They deserve to be better known, not just for their own impressive careers to date, but also as role models, inspiring girls and young women who might be interested in science, technology, engineering, mathematics or medicine, but are diverted away from them by the prevailing view that careers in these areas are for men, not women.

The famous ‘Dance of Apollo and the Muses’ by the Italian architect and painter, Baldassare Tommaso Peruzzi

As someone who has had to contend with these stereotypes myself, trying to establish a career in the space sector in Australia, I thought it might be interesting this month to delve into the stories of four of the women working behind the scenes in the Apollo programme: modern-day daughters of Urania, the Muse of Astronomy, Mathematics and the “exact sciences”.

The “Return to Earth” Specialist: Frances “Poppy” Northcutt

Every aspect of a lunar voyage involves moving objects – the Apollo spacecraft, the Earth and the Moon. Calculating the trajectories required for an Apollo mission to meet and go into orbit around the Moon at a particular date and time, is a mind-bending feat. But getting astronauts safely home from the Moon is even more important!

NASA’s specialist in the incredibly complex and precise calculations required to determine the optimal trajectories for the return to Earth from the Moon, minimising fuel and flight time, is Miss Frances Northcutt, who goes by the nickname “Poppy”. She is, perhaps, the only one of these ladies that you might have heard of (at least those of you in the United States), as she was such a “curiosity” during the press and television coverage of the Apollo-8 mission that she has been interviewed many times (and more on this below).

Born in 1943, Miss Northcutt earned a mathematics degree from the University of Texas, then commenced working at TRW in 1965 as a “computress”! Yes, that was her actual job title, although in Australia we’d have just called her a "computer" (a term applied here and in Britain to both men and women doing this kind of intensive calculating work). Miss Northcutt was placed at NASA’s Langley Research Centre, calculating spacecraft trajectories for the Gemini missions. She proved to be so talented in this area that within just six months TRW promoted her to engineering work with its Return to Earth task force, helping to design the computer programmes and flight trajectories to return an Apollo spacecraft from lunar orbit to Earth.

A simplified version of the Apollo lunar free return flight trajectories

Poppy Northcutt became the first woman to work in this type of role and was soon undertaking the intricate calculations involved in enabling the Apollo astronauts to travel around the Moon and come safely home. The Moon’s lower gravity changes parameters such as fuel usage, as well as the timing of manoeuvres, so the calculations are particularly tricky. Poppy identified mistakes in NASA’s original trajectory plan, performing calculations that reduced the amount of fuel used to swing around the Moon.

When NASA decided that Apollo-8 would become a lunar orbiting mission, the task force team, including Miss Northcutt, moved to Mission Control to instruct the flight controllers on the trajectory calculations and be available to make real-time calculations and course corrections in the event of unexpected incidents during the flight. Assigned to Mission Control's Mission Planning and Analysis room, Miss Northcutt and her team have been an integral part of Apollo-8, 10 and 11 and are now preparing for Apollo-12. She is the only female engineer in the teams that work in the backrooms of Mission Control in Houston, providing support to the flight controllers.

Poppy Northcutt working in the Mission Control support room during Apollo-8

Working Like a Man (but not being paid like one!)

“Computresses” in Miss Northcutt’s original position are classed as “hourly workers”, with their wages capped at working 54 hours per week (in other words, five nine-hour days). Their male counterparts were not only paid more (as we all know, female workers are generally paid between about half and two-thirds of the wages for a man doing the same job), they were also on salaries and paid overtime.

As an ambitious young woman, Miss Northcutt quickly realised that to earn the respect of her male colleagues and be considered a peer, she would have to work the same long hours they did – even if this meant that she was essentially working 10 or more hours a week for no pay!

A NASA promotional photo of Miss Northcutt at work in March this year. She presents herself as a diligent professional

Her talent and diligence paid off with her promotion to engineer, but, ironically, even though she was still being paid less than her male colleagues, Miss Northcutt tells the story that there was no normal mechanism to approve the pay rise she received with this jump from Computress! Her manager had to keep scheduling the highest possible raise as frequently as he could to bring her up to the full female rate of her new salary.

During Apollo missions, when shifts last around 12 to 13 hours a day in Mission Control, Miss Northcutt usually commences her duty shifts for each mission around the time that the Apollo spacecraft, coasting towards the Moon, prepares to enter the lunar sphere of gravitational influence. During lunar orbit insertion she stands by to assist with new calculations, in the event of an emergency abort, and she reports for duty at Mission Control every day of the lunar phase of the mission and until the astronauts have returned safely to the Earth's sphere of influence. No one can say Poppy Northcutt isn’t pulling her weight, just like a man!

Sexism, Celebrity and Activism

As the only female engineer in Mission Control during the Apollo-8 mission, Miss Northcutt was such a “curiosity” that she received a lot of attention from journalists. While much of this coverage was not seen in Australia, from what I have heard from friends in America, I understand that many of the questions that she received were quite sexist – and even silly.

Miss Northcutt is a very pretty woman and dresses fashionably, so apparently ABC reporter Jules Bergman thought it was more important to ask about her potential to distract her male colleagues from the mission, than to ask about her crucial role: “How much attention do men in Mission Control pay to a pretty girl wearing miniskirts?” Would they have asked a male flight controller if the suit he was wearing turned the heads of the typing pool?! I gather that she gave him a polite brush off response.

A friend in the US took this photo from her television screen, giving me a glimpse of Mr. Bergman's interview with Miss Northcutt

It is bad enough when reporters focus on her appearance and ask her such inane questions, while she operates at the level of her male colleagues, for far less monetary reward. But Miss Northcutt has also reported an instance in which she discovered that the other flight engineers were covertly watching her on a video feed, from a camera trained on her while she was conducting equipment flight tests.

As a result of her personal experiences with sexism, Miss Northcutt has become a strong advocate for women’s rights, and has joined the feminist National Organisation for Women. Even in her early days at TRW, she worked to improve the company’s affirmative action and pregnancy leave policies. “As the first and only woman in Mission Control, the attention I have received has increased my awareness of how limited women’s opportunities are”, she has said. “I’m aware of the issues that are emerging. Working in this environment I can see the discrimination against women.”

TRW is happy to use Miss Northcutt's minor celebrity to promote itself, but not happy enough to pay her the same salary as her male colleagues!

However, while she is not pleased that much of the attention she has received has been focussed on her appearance, or treating her as a rare exception to the male-dominated world of spaceflight, Miss Northcutt has said that she recognises that being a woman visibly occupying a critical position in the space programme does send a very positive message to women and girls: a career in science and technology is possible if you want it – and are prepared to work for it!

Miss Northcutt has received letters and fan mail from around the world (including several marriage proposals, it seems!) She has said that she is motivated to continue to advocate for women’s rights in the workplace by the letters she has received from young women, who have said how much she has inspired them.

Whoever Heard of a “Software Engineer”? Margaret Hamilton

The Apollo missions not only need precise trajectories for their lunar voyages – they also need software for their onboard flight computers, which control so many aspects of the flight. If you’re not familiar with this term, “software” describes the mathematical programmes that tell a computer how to carry out its tasks, and a “software engineer” applies the engineering design process to develop software for those different tasks.

The Director of Apollo Flight Computer Programming is Mrs. Margaret Hamilton Lickly, who prefers to be known professionally as Margaret Hamilton.I've heard that women in the United States who prefer not to be categorised by their marital status, are now starting to use the designation "Ms.". I don't know if Margaret Hamilton is using this new honorific, but it seems to me appropriate to apply it to her in this article.

33-year-old Ms. Hamilton is another woman playing a crucial role in NASA’s lunar program. Not only is she a pioneer in software engineering, she even coined the term!

Like Miss Northcutt, Ms. Hamilton is also a mathematician, having studied at the University of Michigan and Earlham College. Shortly after graduating in 1958, she married her first husband, James Hamilton, and taught high school mathematics and French, before taking a job in the Meteorology Department at the prestigious Massachusetts Institute of technology (MIT) in 1959, a few months before the birth of her daughter.

Ms. Hamilton developed software for predicting weather, and in 1961 she moved to MIT’s Lincoln Lab for the Semi-Automatic Ground Environment (SAGE) Project, adapting weather prediction software into a programme used by the U.S. Air Force to search for potential enemy aircraft. At the Lab, she was the first person to get a particularly difficult programme, which no-one had been able to get to run, to actually work! While working on SAGE, Ms. Hamilton began to take an interest in software reliability, which would pay dividends during Apollo-11’s lunar landing.

A Calculated Move

When Margaret Hamilton learned about the Apollo project in 1965, she wanted to become involved in the lunar programme, and moved to the MIT Instrumentation Laboratory, which was developing the Apollo Guidance Computer. She was the first programmer hired for the Apollo work project at MIT and has led the team responsible for creating the on-board flight software for both the Apollo Command and Lunar Modules. She also serves as Director of the Software Engineering Division at the Instrumentation Laboratory.

The Apollo Guidance Computer was installed on both the Command and Service Modules. Astronauts communicated with it using a numeric display and keyboard

While working on the Apollo software, Ms. Hamilton felt that it was necessary to give software development the same legitimacy as other engineering disciplines. In 1966, she therefore coined the term “software engineering” to distinguish software development from other areas of engineering. She believes that this encourages respect for the new field, as well as respect for its practitioners.

A page from the software for the Apollo Guidance Computer

On one occasion when her young daughter was visiting the lab, the little girl pushed a simulator button that made the system crash. Ms. Hamilton realised immediately that the mistake was one that an astronaut could make. While Ms. Hamilton has said that she works in a relationship of "mutual respect" with her colleagues, when she recommended adjusting the software to address the issue, she was told: “Astronauts are trained never to make a mistake.” Yet during Apollo-8, astronaut Jim Lovell made the exact same error that her young daughter had!

While Ms. Hamilton’s team was able to rapidly correct the problem, for future Apollo missions protection was built into the software to prevent a recurrence. With her interest in software reliability, Margaret Hamilton insisted that the Apollo system should be error-proof. To achieve this goal, she developed a programme referred to as Priority Displays, that recognises error messages and forces the computer to prioritise the most important tasks, also alerting the astronauts to the situation.

In Part 2 of my series of Apollo-11 articles, we saw how, during the descent to the Moon’s surface, the Lunar Module’s computer began flashing error messages, which could have resulted in Mission Control aborting the landing. However, the Priority Displays programme gave Guidance Officer Bales and his support team confidence that the computer would perform as it should despite the data input overloads that it was experiencing, and that the landing could proceed.

Ms. Hamilton with this year's printout of the entire Apollo Guidance Computer software

Ms. Hamilton and her 100-strong team continue to work on developing and refining the Apollo flight software, and I’m sure that they will contribute to whatever future spaceflight projects NASA develops, stemming from Vice-president Agnew’s recently-delivered Space Task Group report to President Nixon.

“I’ve Got Rocket Fuel in my Blood”: JoAnn Morgan

Mission safety and reliability are, of course, critical, but Apollo-11 could not even have made the historic lunar landing if the mission had been unable to launch in the first place! When Apollo-11 lifted off, there was one lone woman in the launch firing team at Kennedy Space Centre’s (KSC) Launch Control Centre, who helped to ensure that would happen – Instrumentation Controller JoAnn Morgan.

JoAnn Morgan watching the lift-off of Apollo-11 from her station in Launch Control

Mrs. Morgan, who was born in December 1940, has described herself as a “precocious little kid” who loved mathematics, science and music, and wanted to become a piano teacher. However, after her family moved to Florida from Alabama, she was inspired by the launch of the first American satellite, Explorer-1, in January 1958, and its significant discovery of the Van Allen Radiation Belts. It was the “opportunity for new knowledge” that space exploration represented that filled the teenager with a desire to be part of the new space programme.

Young JoAnn with one of her favourite books. As a child she loved to read and play with her chemistry set

Soon after, JoAnn saw an advertisement for two (US) Summer student internship positions, as Engineer’s Aides with the Army Ballistic Missile Agency at Cape Canaveral. As we know, job openings are often advertised separately for males and females, but this ad only referred to “students” (not “boys”), so she took the chance, decided to apply, and was successful thanks to her strong marks in science and mathematics.

So, at just 17, JoAnn Hardin, as she was then, began working as a University of Florida trainee for the Army at Cape Canaveral Air Force Station. “I graduated from high school on the weekend and went to work for the Army on Monday. I worked on my first launch on Friday night” is how Mrs. Morgan describes the beginning of her NASA career. The Army programme she was working with became part of NASA when it was established in October 1958.

Supportive Male Mentors

While undertaking her degree in mathematics at Jacksonville State University, Mrs. Morgan continued her Summer internships with the NASA team launching rockets at Cape Canaveral. The young student’s potential did not go unnoticed, and she acknowledges that she received significant support in furthering her career from several senior NASA personnel, including Dr. Wernher von Braun, the chief architect of the Saturn V rocket, Dr. Kurt Debus, the first director of Kennedy Space Centre and Mr. Rocco Petrone, Director of Launch Operations at KSC.

Mentors Kurt Debus, left, and Rocco Petrone, right, during the Apollo 7 flight readiness test in the blockhouse at Complex 34

Dr. Debus provided Mrs. Morgan with a pathway to becoming an engineer, and she gained certification as a Measurement and Instrumentation Engineer and a Data Systems Engineer, which enabled her to be employed as a Junior Engineer on the launch team. “It was just meant to be for me to be in the launching business,” she says. “I’ve got rocket fuel in my blood.”

As a young woman joining an all-male group, Mrs. Morgan was fortunate that (unbeknownst to her at the time) her immediate supervisor, Mr. Jim White, insisted that the men on the launch team address her professionally, not be “familiar”, and reportedly told them that “You don’t ask an engineer to make the coffee”! (Which, of course, is often a task that falls to the women in any office).

Professional Disrespect

Despite Mr. White’s efforts to create an environment of respect for his first female engineer, Mrs. Morgan has still described experiencing sexism and harassment, treatment similar to the experiences of Miss Northcutt. With no female restrooms in the launch blockhouses at Cape Canaveral, when she needs to use the restroom, she has to ask a security guard to clear out the men’s room so that she can enter. She has reported receiving obscene phone calls at her station (which disappointingly could only have come from colleagues).

However, like Miss Northcutt, while she has said that she sometimes feels a sense of loneliness as the only woman in the team, Mrs. Morgan “wants to do the best job she can” and works the same long hours as her male colleagues. In 1967, as the Apollo programme was ramping up, her dedication to her work had tragic consequences. The stress and long hours of her job contributed to her miscarrying and losing her first child.

The crowded interior of the blockhouse at Launch Complex 34, where Mrs. Morgan has often worked

Perhaps the most shocking example of professional disrespect and harassment (which could be considered an assault) that Mrs. Morgan has experienced was during a test being conducted at the blockhouse for Pad 34, where the first Apollo missions were set to be launched. When preparing to acquire some test results, she was actually struck on the back by a test supervisor, who aggressively told her that “We don’t have women in here!” She had to appeal to her own supervisor, Mr. Karl Sendler (who developed the launch processing systems for the Apollo programme) to confirm that she could remain. He told her to disregard the test supervisor and continue with her work (though it’s not clear if any action was taken against the offending supervisor).

On Console for Apollo-11

The unpleasant incident with the test supervisor prompted many of Mrs. Morgan’s colleagues and senior managers to come forward in expressing acceptance and respect for her as part of the team. Nevertheless, even though she has worked launches for Mercury, Gemini and Apollo, received an achievement award for her work during the activation of Apollo Launch Complex 39, and been promoted to a senior engineer, Mrs. Morgan has frequently found herself rostered for the inconvenient evening shifts. Since her husband is a school teacher and band-leader, this hasn’t always allowed them a lot of time to be together.

Until Apollo-11, Mrs. Morgan was also not selected to be part of the firing room personnel for a launch, usually being stationed at a telemetry facility, a display room or a tracking site for launch. She found this very disappointing, as she always wanted to feel the vibrations from a launch that her colleagues described.

But her desire to experience the incredible shockwave vibrations of a Saturn-V lift-off was finally achieved with the launch of Apollo-11. Recognising that Mrs. Morgan is his best communicator, Mr. Sendler quietly obtained permission from Dr. Debus for her to be the Instrumentation Controller on the console in the firing room for Apollo 11! (This achievement also had the bonus of working day shifts, so that she has been able to spend more time with her husband).

Can you spot the lone woman in a sea of men? In this picture of the Launch Control firing room during Apollo-11, Mrs. Morgan is in the third row, just to the left of centre.

A successful launch is critical to each mission and Mrs. Morgan believes that her prime role in the launch of the historic mission will help to further her career within NASA. Although she has not received the same level of press and television attention as Miss Northcutt, she does hope that even the photos of her in Launch Control – a lone woman in a sea of men – will help to inspire young women to aspire to careers in the space programme, so that, at some time in the future, photos like the ones she is in now “won’t exist anymore.”

Making Packed Lunches for Astronauts: Rita Rapp

You could say that the astronauts are the most fragile component of each Apollo mission. Nutrition is important in keeping crews healthy and functioning during a flight, so space food has to be as appetising as possible, within the constraints of spaceflight and the weightless environment – especially as missions to the Moon, and future space stations and lunar bases will keep astronauts in space for longer and longer periods.

Physiologist Miss Rita Rapp, head of the Apollo Food Systems team, has been looking after the astronauts' bodies – and stomachs – since she joined NASA in 1960. For the Apollo programme, she has developed the space food and food stowage system designed to keep the astronauts supplied with the right mix of calories, vitamins, and nutrients to enable them to function well in space. One of her goals has been to ensure that crews have something worth eating during their spaceflights.

Rita Rapp with some of her space food innovations that have greatly improved the space food menu for Apollo astronauts

Born in 1928, Miss Rapp studied science at the University of Dayton and then took a Master’s in anatomy at the St. Louis University Graduate School of Medicine. She was one of the first women to enrol in this school. Graduating in 1953, she took a position in the Aeromedical laboratories at Wright-Patterson Air Force Base, where she began assessing the effects of high g-forces on the human body, especially the blood and renal systems, using centrifuge systems.

In 1960 Miss Rapp joined NASA’s Space Task Group preparing for the Mercury manned spaceflight programme, later transferring to the Manned Spacecraft Centre in Houston. For the Mercury program, she continued her work on centrifugal effects on the human body. She also designed the first elastic exercisers for Mercury and Gemini missions, devised biological experiments for the astronauts to conduct in-flight, and developed the Gemini medical kit.

The first Gemini biological experiment, designed by Miss Rapp

From Aeromedicine to Space Food

In 1966, as the Apollo programme was ramping up, Miss Rapp joined the Apollo Food Systems team. Although she has continued to work on space health and hygiene projects, in her new role her primary focus became looking at systems for storing food onboard the Apollo spacecraft. Working with dieticians, and commercial companies, she has investigated the ways space food could be packaged and prepared, and become the main interface between NASA’s Food Lab and the astronauts.

Although she tries to use as much commercially available food as possible, Miss Rapp and her team are also continually experimenting with new recipes in the food lab, gradually replacing the earlier “tubes and cubes” style of space food used in Mercury and Gemini with meals that are closer to an everyday eating experience.

She has developed improved means of food preservation, such as dehydration, thermostabilisation, irradiation and moisture control, which allows for a wider range of foods to be suitable for spaceflight, and I have no doubt these useful technologies will find their way into commercial food preparation and onto our supermarket shelves in the not-too-distant future.

Working with the Whirlpool Corporation, Miss Rapp has developed new forms of food packaging for Apollo, such as the spoon bowls, “wet packs” and cans for thermostabilised food. These containers enable astronauts to eat with more conventional utensils, instead of sucking food out of a tube or plastic bag. Creating a more natural, homelike eating experience is good for the astronauts’ morale and psychological health during missions. You can discover more about Miss Rapp's space food developments in my articles on the various Apollo missions.

Miss Rapp takes great pride in providing the Apollo crews with the flavours and comforts of home. “I like to feed them what they like, because I want them healthy and happy,” she says. She takes note of their individual food preferences, often devises new recipes and prepares the individual meals of each Apollo astronaut separately. Her home-made sugar cookies, that she bakes herself, are a special favourite of Apollo crews, and additional supplies are included as snacks in the onboard food pantries of the Command and Lunar Modules. She also likes to provide the crews with special food “surprises”, such as the turkey dinner enjoyed by the Apollo-8 crew in lunar orbit on Christmas Eve last year.

Just the Beginning

The women of Apollo who I’ve discussed in this article are trailblazers for women’s participation in mathematics, engineering, and other technical aspects of spaceflight. While they are not the only women in professional roles in the space sector, female participation in space careers, and in science, engineering, and technology more generally, is still very low.

I hope that by highlighting the exciting Apollo-related careers of the four women above, it will plant a seed in the minds of young girls reading the Journey that they, too, can aspire to careers in scientific and technological fields that are generally thought of only as careers for men. I also hope that growing levels of female participation in the workforce, together with feminist activism, will eventually consign the sexism, discrimination and harassment that women working in all careers experience at present, to the history books—though I won’t hold my breath on it happening any time soon.