RIP, John Houbolt

John Houbolt, former employee of NASA, died a few days ago.  He was 95.

Most Americans do not have a clue as to who he was.  Frankly, until today I didn’t either.

That’s a shame.  Because Houbolt is arguably the individual most responsible for the US moon landing on July 20, 1969.

During the early 1960s, NASA debated the various options for landing humans on the moon.  There were three:

• Direct ascent – which would fly a craft directly to the moon from the earth’s surface.
• Earth orbit rendezvous – which would assemble the lunar vehicle in low earth orbit, but would require the successful launch 2 or more rockets for each lunar mission as well as assembly in space;
• Lunar orbit rendezvous – the option ultimately selected for the Apollo program (orbiter orbits moon while smaller module descends to moon, returns, and rendezvous with orbiter to allow crew to return to earth).

Houbolt was a very vocal proponent of the Lunar rendezvous option.  He took the unusual step of going around his management to present the concept directly to senior NASA officials.    He held that it was the only viable option to succeed prior to 1970.  He bluntly asked, in a 1961 letter to NASA Associate Administrator Robert Seamans, “Do we want to go to the moon or not?”

Houbolt was at the time ridiculed by many of his peers.  Some went as far as to claim he was lying, or to imply that he was professionally incompetent. (In truth, though Houbolt was in general correct, some of his initial estimates did turn out to be substantially off-the-mark.)

But Houbolt stood his ground, and in the end was proven right.  The risks associated with the earth orbit rendezvous option were too large; initial studies showed up to 15 initial-design Saturn launches might be required (final studies and Saturn design refinements allowing larger payload finally showed that two redesigned Saturn-III vehicles might possibly work).  The direct ascent option would require the development of rockets even larger than the Saturn V (the never-built Nova) – which simply couldn’t be done in time, as development and production would require construction of new facilities to build them.  And both direct ascent and earth orbit rendezvous missions would require landing massive, complex vehicles on the moon – inherently a risky operation – which in the end was also deemed too risky.

NASA’s internal debates and final decision are documented here.  The story is fascinating reading – and clearly illustrates Houbolt’s critical role in the decision.  Without his persistent advocacy, the decision process would have stretched out far longer, delaying the US moon mission – and given the rising demands of Vietnam in the 1960s and the economic downturn of the 1970s, the delay perhaps would have been permanent.

In the end, NASA selected the concept Houbolt championed, and developed a final Saturn modification (the Saturn-V) that would perform the mission with a single launch.  And on 20 July 1969, mankind’s long dream of humans walking on the moon became reality – courtesy of the USA.

Without John Houbolt, that reality might still be a dream.

Rest in peace, Dr. Houbolt.

Many thanks.

Category: Blue Skies, Historical