Although there's no shortage of communication gaffes attributed to BP chief Tony Hayward, for some NASA vets the most rankling has been his likening of the oil spill recovery to the Apollo 13 crisis.

"Like the astronauts aboard Apollo 13 who had to build a CO² filter from whatever was available in their capsule under the direction of engineers back on Earth, we are forced to innovate in real time," Hayward wrote in a recent op-ed piece.

The message from some Apollo-era space vets: Hayward, we have a problem.

"The response after an oxygen tank explosion in the Apollo 13 spacecraft on its way to the Moon illustrates how complex technical accidents should be handled," responded Harrison Schmitt, an Apollo 17 astronaut, in a letter. "It stands in sharp contrast to the Gulf fiasco."

Difficulty factor

Yet Hayward isn't alone making the connection. Thad Allen has done it too.

Responding to the Deepwater Horizon oil rig accident is "closer to Apollo 13 than the Exxon Valdez" because of the well's remote location and complexity, the Coast Guard admiral overseeing federal response to the disaster recently said.

Hayward, Allen and others are comparing the technical challenge of working deep underwater, on the fly, with doing so in space.

That's one question, whether it's more difficult to work in space or a mile beneath the sea.

Another objection of the NASA vets is whether the responses of BP and NASA to their respective crises are comparable.

"I don't think that's a fair comparison at all," said Jerry Bostick, a flight dynamics officer for the Apollo 13 mission.

Vacuum, pressure

Let's tackle the issue of space versus sea first.

In one sense, outer space and the deep water site of the blowout could not be more different. Space is a vacuum, with zero air pressure.

The water pressure at the Deepwater site a mile beneath the ocean's surface is 150 times greater than the pressure at the surface.

It would crush a submarine. In fact, most submarines only go about 1,000 feet or so beneath the ocean.

But in another sense, the regions are comparable. They're both cold, with the deep Gulf several degrees above freezing and space a few degrees above absolute zero. And they're dark.

In space its dark when the Earth or moon blocks the sun, and no sunlight penetrates a mile beneath the sea.

Dealing with tremendous water pressure is more difficult than working in a zero-pressure environment, said Larry Bell, a professor of space architecture at the University of Houston. So score one for BP.

And the astronauts of Apollo 13 had another advantage: They were on site and could work with their hands. All work at the BP site must be done with robots.

"If you're using mechanical hands or claws, they have to be specially designed for that function, and they can be very clumsy," said Mahlon Kennicutt II, a professor of chemical oceanography at Texas A&M University.

Yet working deep in the Gulf has one key advantage: the ability to resupply in a timely manner.

"In space, you can't go back to the hardware store and get a tool," Bell said. "In the Gulf there's ready access by helicopter or ship. If one tool doesn't work, you can get a replacement."

A question of planning

And what of the response to the spill?

NASA vets say the space agency does not deserve to be saddled with BP comparisons because it thought proactively about failures, building in multiple back-up systems if a component of the Apollo spacecraft failed.

While the space agency did not specifically prepare for the oxygen tank explosion aboard Apollo 13, Bostick said, it did run an exercise with the crew during which, in an emergency situation, the three astronauts got into the lunar module, which was designed for two people.

This is what the Apollo 13 crew did to survive.

Another NASA engineer, Jerry Woodfill, agrees that failure planning sets NASA apart from BP. Woodfill still works at NASA and served as the caution and warning system engineer for both the Apollo Command Module and Lunar Module Spacecraft.

It was Woodfill's alarm that first alerted the crew to a problem.

"My assessment of what made the rescue a success, besides the real-time contributions, was the proactive design and operational rules already in place when the accident happened," Woodfill said.

Facts, not fault

There's also the contrast in the response of BP and the federal government to the oil spill — critics have accused BP of delays and the Justice Department has launched a criminal inquiry - to that of NASA to the Apollo 1 launch pad fire. Instead of assigning blame, NASA focused on identifying the problem and fixing it, Bostick said.

During a pre-launch test in February 1967, a fire destroyed the command module and killed astronauts Virgil "Gus" Grissom, Edward White and Roger Chaffee.

A day after the late-afternoon fire, a NASA-appointed review board arrived at Kennedy Space Center, Bostick said.

When board chairman Floyd Thompson, director of Langley Research Center, arrived in Florida, Bostick recalled, Thompson said he was there to find facts, not faults.

The panel eventually found a number of design and construction flaws. Apollo 11 launched two years later.

"It was a horrible thing to happen," Bostick recalled. "It was by far the worst thing that had happened to NASA up until that time. But the way it was handled, someone should teach a course on that. It was handled ... very, very professionally, and it solved the problem."

eric.berger@chron.com