"Houston, We've Had a Problem"

[AdamSmith]

Just came across this report by astronaut Jim Lovell of the Apollo 13 drama. Familiar story but fascinating to read this firsthand account.

Apollo Expeditions to the Moon

CHAPTER 13.1
"Houston, We've Had a Problem" By JAMES A. LOVELL

In

Mission Control the Gold Team, directed by Gerald Griffin (seated, back of head to camera), prepares to take over from Black Team (Glynn Lunney, seated, in profile) during a critical period. Seven men with elbows on console are Deke Slayton, Joe Kerwin (Black CapCom), Vance Brand (Gold CapCom), Phil Shaffer (Gold FIDO), John Llewellyn (Black RETRO), Charles Deiterich (Gold RETRO), and Lawrence Canin (Black GNC). Standing at right is Chester Lee, Mission Director from NASA's Washington headquarters, and broud back at right belogs to Rocco Petrone, Apollo Program Director. Apollo 13 had two other "ground" teams, the White and the Maroon. All devised heroic measures to save the mission from disaster.

Since Apollo 13 many people have asked me, "Did you have suicide pills on board?" We didn't, and I never heard of such a thing in the eleven years I spent as an astronaut and NASA executive.

I did, of course, occasionally think of the possibility that the spacecraft explosion might maroon us in an enormous orbit about the Earth - a sort of perpetual monument to the space program. But Jack Swigert, Fred Haise, and I never talked about that fate during our perilous flight. I guess we were too busy struggling for survival.

Survive we did, but it was close. Our mission was a failure but I like to think it was a successful failure.

Apollo 13, scheduled to be the third lunar landing, was launched at 1313 Houston time on Saturday, April 11, 1970; I had never felt more confident. On my three previous missions, I had already logged 572 hours in space, beginning with Gemini 7, when Frank Borman and I stayed up 14 days- a record not equaled until Skylab.

Looking back, I realize I should have been alerted by several omens that occurred in the final stages of the Apollo 13 preparation. First, our command module pilot, Ken Mattingly, with whom Haise and I had trained for nearly two years, turned out to have no immunity to German measles (a minor disease the backup LM pilot, Charlie Duke, had inadvertently exposed us to). I argued to keep Ken, who was one of the most conscientious, hardest working of all the astronauts. In my argument to Dr. Paine, the NASA Administrator, I said, "Measles aren't that bad, and if Ken came down with them, it would be on the way home, which is a quiet part of the mission. From my experience as command module pilot on Apollo 8, I know Fred and I could bring the spacecraft home alone if we had to." Besides, I said, Ken doesn't have the measles now, and he may never get them. (Five years later, he still hadn't.)

Dr. Paine said no, the risk was too great. So I said in that case we'll be happy to accept Jack Swigert, the backup CMP, a good man (as indeed he proved to be, though he had only two days of prime-crew training).

The second omen came in ground tests before launch, which indicated the possibility of a poorly insulated supercritical helium tank in the LM's descent stage. So we modified the flight plan to enter the LM three hours early, in order to obtain an onboard readout of helium tank pressure. This proved to be lucky for us because it gave us a chance to shake down this odd-shaped spacecraft that was to hold our destiny in its spidery hands. It also meant the LM controllers were in Mission Control when they would be needed most.

Then there was the No. 2 oxygen tank, serial number 10024X-TA0009. This tank had been installed in the service module of Apollo 10, but was removed for modification (and was damaged in the process of removal). I have to congratulate Tom Stafford, John Young, and Gene Cernan, the lucky dogs, for getting rid of it.

This tank was fixed, tested at the factory, installed in our service module. and tested again during the Countdown Demonstration Test at the Kennedy Space Center beginning March 16, 1970. The tanks normally are emptied to about half full, and No. 1 behaved all right. But No. 2 dropped to only 92 percent of capacity. Gaseous oxygen at 80 psi was applied through the vent line to expel the liquid oxygen, but to no avail. An interim discrepancy report was written, and on March 27, two weeks before launch, detanking operations were resumed. No. 1 again emptied normally, but its idiot twin did not. After a conference with contractor and NASA personnel, the test director decided to "boil off" the remaining oxygen in No. 2 by using the electrical heater within the tank. The technique worked, but it took eight hours of 65-volt DC power from the ground-support equipment to dissipate the oxygen.

With the wisdom of hindsight, I should have said, "Hold it. Wait a second. I'm riding on this spacecraft. Just go out and replace that tank." But the truth is, I went along, and I must share the responsibility with many, many others for the $375 million failure of Apollo 13. On just about every spaceflight we have had some sort of failure, but in this case, it was an accumulation of human errors and technical anomalies that doomed Apollo 13.

At five and a half minutes after liftoff, Swigert, Haise, and I felt a little vibration. Then the center engine of the S-II stage shut down two minutes early. This caused the remaining four engines to burn 34 seconds longer than planned, and the S-IVB third stage had to burn nine seconds longer to put us in orbit. No problem: the S-IVB had plenty of fuel.

The first two days we ran into a couple of minor surprises, but generally Apollo 13 was looking like the smoothest flight of the program. At 46 hours 43 minutes Joe Kerwin, the CapCom on duty, said, "The spacecraft is in real good shape as far as we are concerned. We're bored to tears down here." It was the last time anyone would mention boredom for a long time.

At 55 hours 46 minutes, as we finished a 49-minute TV broadcast showing how comfortably we lived and worked in weightlessness, I pronounced the benediction: "This is the crew of Apollo 13 wishing everybody there a nice evening, and we're just about ready to close out our inspection of Aquarius (the LM) and get back for a pleasant evening in Odyssey (the CM). Good night."

On the tapes I sound mellow and benign, or some might say fat, dumb, and happy. A pleasant evening, indeed! Nine minutes later the roof fell in; rather, oxygen tank No. 2 blew up, causing No. 1 tank also to fail. We came to the slow conclusion that our normal supply of electricity, light, and water was lost, and we were about 200,000 miles from Earth. We did not even have power to gimbal the engine so we could begin an immediate return to Earth.

The message came in the form of a sharp bang and vibration. Jack Swigert saw a warning light that accompanied the bang, and said, "Houston, we've had a problem here." I came on and told the ground that it was a main B bus undervolt. The time was 2108 hours on April 13.

Next, the warning lights told us we had lost two of our three fuel cells, which were our prime source of electricity. Our first thoughts were ones of disappointment, since mission rules forbade a lunar landing with only one fuel cell.

With warning lights blinking on, I checked our situation; the quantity and pressure gages for the two oxygen tanks gave me cause for concern. One tank appeared to be completely empty, and there were indications that the oxygen in the second tank was rapidly being depleted. Were these just instrument malfunctions? I was soon to find out.

Thirteen minutes after the explosion, I happened to look out of the left-hand window, and saw the final evidence pointing toward potential catastrophe. "We are venting something out into the- into space," I reported to Houston. Jack Lousma, the CapCom replied, "Roger, we copy you venting." I said, "It's a gas of some sort."

It was a gas-oxygen-escaping at a high rate from our second, and last, oxygen tank. I am told that some amateur astronomers on top of a building in Houston could actually see the expanding sphere of gas around the spacecraft.

http://history.nasa.gov/SP-350/ch-13-1.html

[AdamSmith]

Apollo Expeditions to the Moon

CHAPTER 13.2 ARRANGING FOR SURVIVAL

The knot tightened in my stomach, and all regrets about not landing on the Moon vanished. Now it was strictly a case of survival. The first thing we did, even before we discovered the oxygen leak, was to try to close the hatch between the CM and the LM. We reacted spontaneously, like submarine crews, closing the hatches to limit the amount of flooding. First Jack and then I tried to lock the reluctant hatch, but the stubborn lid wouldn't stay shut! Exasperated, and realizing that we didn't have a cabin leak, we strapped the hatch to the CM couch. In retrospect, it was a good thing that we kept the tunnel open, because Fred and I would soon have to make a quick trip to the LM in our fight for survival. It is interesting to note that days later, just before we jettisoned the LM, when the hatch had to be closed and locked, Jack did it - easy as pie. That's the kind of flight it was.

"There's one whole side of that spacecraft missing," said Lovell in astonishment. About five hours before splashdown the service module was jettisoned in a manner that would permit the astronauts to assess its condition. Until then, nobody realized the extent of the damage.

Vital stores of oxygen, water, propellant, and power were lost when the side of the service module blew off. The astronauts quickly moved into the lunar module which had been provided with independent supplies of these space necessities for the landing on the Moon. Years before, Apollo engineers had talked of using the lunar module as a lifeboat.

The pressure in the No. 1 oxygen tank continued to drift downward; passing 300 psi, now heading toward 200 psi. Months later, after the accident investigation was complete, it was determined that, when No. 2 tank blew up, it either ruptured a line on the No. 1 tank, or caused one of the valves to leak. When the pressure reached 200 psi, it was obvious that we were going to lose all oxygen, which meant that the last fuel cell would also die. At 1 hour and 29 seconds after the bang, Jack Lousma, then CapCom, said after instructions from Flight Director Glynn Lunney: "It is slowly going to zero, and we are starting to think about the LM lifeboat." Swigert replied, "That's what we have been thinking about too."

Oxygen tank No. 2 overheated and blew up because its heater switches welded shut during excessive prelaunch electric currents. Interior diagram (above) of three-foot-tall oxygen tank No. 2 - whose placement in bay 4 of SM is indicated below - shows vertical heater tube and quantity measurement tube. Heater tube contains two 1800-rpm motors to stir tank's 320 pounds of liquid oxygen. Note thermostat at top. Two switches were supposed to open heater circuit when temperature reached 80° F, but spacecraft power supply had been changed from 28 to 65 Vdc - while contractors and NASA test teams nodded - so switches welded shut and heater tube temperature probably reached 1000° F.

A lot has been written about using the LM as a lifeboat after the CM has become disabled. There are documents to prove that the lifeboat theory was discussed just before the Lunar Orbit Rendezvous mode was chosen in 1962. Other references go back to 1963, but by 1964 a study at the Manned Spacecraft Center concluded: "The LM [as lifeboat] . . . was finally dropped, because no single reasonable CSM failure could be identified that would prohibit use of the SPS." Naturally, I'm glad that view didn't prevail, and I'm thankful that by the time of Apollo 10, the first lunar mission carrying the LM, the LM as a lifeboat was again being discussed. Fred Haise, fortunately, held the reputation as the top astronaut expert on the LM- after spending fourteen months at the Grumman plant on Long Island, where the LM was built. Fred says: "I never heard of the LM being used in the sense that we used it. We had procedures, and we had trained to use it as a backup propulsion device, the rationale being that the thing we were really covering was the failure of the command module's main engine, the SPS engine. In that case, we would have used combinations of the LM descent engine, and in some cases, for some lunar aborts, the ascent engine as well. But we never really thought and planned, and obviously, we didn't have the procedures to cover a case where the command module would end up fully powered down."

Top of Apollo 13's fuel tank No. 2 (bottom part is below shelf), photographed before it left North American Rockwell plant. Tank was originally installed in Apollo 10's SM, but was removed for modification and in process was dropped two inches (skin of tank is only 0.02 inch thick). Then it was installed on Apollo 13 and certified, despite test anomalies. In raging heat, it burst and the explosion was ruinous to the SM.

Nestled amid crinkled metal foil used for thermal insulation, oxygen tank No. 2 was mounted above and close to a pair of hydrogen tanks in spacecraft bay.

To get Apollo 13 home would require a lot of innovation. Most of the material written about our mission describes the ground-based activities, and I certainly agree that without the splendid people in Mission Control, and their backups, we'd still be up there.

They faced a formidable task. Completely new procedures had to be written and tested in the simulator before being passed up to us. The navigation problem was also theirs; essentially how, when, and in what attitude to burn the LM descent engine to provide a quick return home. They were always aware of our safety, as exemplified by the jury-rig fix of our environmental system to reduce the carbon dioxide level.

However, I would be remiss not to state that it really was the teamwork between the ground and flight crew that resulted in a successful return. I was blessed with two shipmates who were very knowledgeable about their spacecraft systems. and the disabled service module forced me to relearn quickly how to control spacecraft attitude from the LM, a task that became more difficult when we turned off the attitude indicator.

[AdamSmith]

Apollo Expeditions to the Moon

CHAPTER 13.3 FIFTEEN MINUTES OF POWER LEFT

With only 15 minutes of power left in the CM, CapCom told us to make our way into the LM. Fred and I quickly floated through the tunnel, leaving Jack to perform the last chores in our forlorn and pitiful CM that had seemed such a happy home less than two hours earlier. Fred said something that strikes me as funny as I read it now: "Didn't think I'd be back so soon." But nothing seemed funny in real time on that 13th of April, 1970.

Blast-gutted service module was set adrift from the combined command module and lunar module just four hours before Earth reentry. Mission Control had insisted on towing the wrecked service module for 300,000 miles because its bulk protected the command module's heat shield from the intense cold of space. The astronauts next revived the long-dormant command module and prepared to leave their lunar module lifeboat.

There were many, many things to do. In the first place, did we have enough consumables to get home? Fred started calculating, keeping in mind that the LM was built for only a 45-hour lifetime, and we had to stretch that to 90. He had some data from previous LMs in his book -- average rates of water usage related to amperage level, rate of water needed for cooling. It turned out that we had enough oxygen. The full LM descent tank alone would suffice, and in addition, there were two ascent-engine oxygen tanks, and two backpacks whose oxygen supply would never be used on the lunar surface. Two emergency bottles on top of those packs had six or seven pounds each in them. (At LM jettison, just before reentry, 28.5 pounds of oxygen remained, more than half of what we started with.)

We had 2181 ampere hours in the LM batteries. We thought that was enough if we turned off every electrical power device not absolutely necessary. We could not count on the precious CM batteries, because they would be needed for reentry after the LM was cast off. In fact, the ground carefully worked out a procedure where we charged the CM batteries with LM power. As it turned out, we reduced our energy consumption to a fifth of normal, which resulted in our having 20 percent of our LM electrical power left when we jettisoned Aquarius. We did have one electrical heart-stopper during the mission. One of the CM batteries vented with such force that it momentarily dropped off the line. We knew we were finished if we permanently lost that battery.

The jettisoning of elements during the critical last hours of the Apollo 13 mission is shown in this sequence drawing. When the lifesaving LM was shoved off by tunnel pressure about an hour before splashdown, everyone felt a surge of sentiment as the magnificent craft peeled away. Its maker, Grumman, later jokingly sent a bill for more than $400,000 to North American Rockwell for "towing" the CSM 300,000 miles.

Water was the real problem. Fred figured that we would run out of water about five hours before we got back to Earth, which was calculated at around 151 hours. But even there, Fred had an ace in the hole. He knew we had a data point from Apollo 11, which had not sent its LM ascent stage crashing into the Moon, as subsequent missions did. An engineering test on the vehicle showed that its mechanisms could survive seven or eight hours in space without water cooling, until the guidance system rebelled at this enforced toasting. But we did conserve water. We cut down to six ounces each per day, a fifth of normal intake, and used fruit juices; we ate hot dogs and other wet-pack foods when we ate at all. (We lost hot water with the accident and dehydratable food is not palatable with cold water.) Somehow, one doesn't get very thirsty in space and we became quite dehydrated. I set one record that stood up throughout Apollo: I lost fourteen pounds, and our crew set another by losing a total of 31.5 pounds, nearly 50 percent more than any other crew. Those stringent measures resulted in our finishing with 28.2 pounds of water, about 9 percent of the total.

Carbon dioxide would poison the astronauts unless scrubbed from the lunar module atmosphere by lithium hydride canisters. But the lunar module had only enough lithium hydride for 4 man-days - plenty for the lunar landing but not the 12 man-day's worth needed now. Here Deke Slayton (center) explains a possible fix to (left to right) Sjoberg, Kraft, and Gilruth. At left is Flight Director Glynn Lunney.

Fred had figured that we had enough lithium hydroxide canisters, which remove carbon dioxide from the spacecraft. There were four cartridge from the LM, and four from the backpacks, counting backups. But he forgot that there would be three of us in the LM instead of the normal two. The LM was designed to support two men for two days. Now it was being asked to care for three men nearly four days.

[AdamSmith]

Continued here: http://history.nasa.gov/SP-350/ch-13-4.html

[RA1]

^{Fascinating first hand account. I have of course seen the movie and the History Channel version of this and lived through it "live" at the time. I have always thought space exploration to be very risky and this is just one example. However, else how will we progress? Flying was certainly very risky for 10-20-40 years after the Wright Bros. but please regard how relatively safe it is now.}

^{I won't live long enough for space exploration to be as safe as aviation is today, especially without more political positive input, but I am willing to assume things will improve, sooner or later.}

^{Thanks for posting this.}

^{Best regards,}

^RA1

[AdamSmith]

If you have not read it, just occurred to me that a book you might really like is Michael Collins's autobiograpy Carrying the Fire. http://en.wikipedia.org/wiki/Carrying_the_Fire:_An_Astronaut%27s_Journeys

It illustrates something you have remarked on here before -- that Mission Control attitudes (and thus much press coverage) do not always give full shrift to all the work that the astronauts have to do in flight to make the mission go. Collins gives a riveting account of that work, specifically of the extent to which their survival is very much in their own hands. Continually taking star sightings to make sure the guidance platform stays properly aligned, programming and monitoring the engine burns for midflight course corrections, staying on top of equipment "funnies" which vary with every individual spacecraft, etc., etc. In contrast to the impression we often get that most everything is either pre-programmed or controlled from the ground.

[RA1]

Yes, astronauts are not Monkeys, although their missions have sometimes seemed as though Monkeys could have completed them.

Without a doubt missions are completed with holding hands between crews in flight and those on the ground. Airlines operate this way, using a dispatcher and captain for assessing the trip ahead and how to safely deal with it.

Is co-operation the key to Earth's survival? Yes.

Best regards,

RA1