Roger Hanson: Moon fly-by missions come with unexpected issues
On February 27, Elon Musk, the head of private space company Space X, announced that the company planned to take two fare paying passengers, each paying tens of millions of dollars, on a fly-by trip to the Moon late next year.
The last manned mission to fly-by the Moon was 49 years ago. The Space X mission will come with plenty of risk. If there was no financial cost to you, would you go?
Technology has moved on considerably since the 1960s but that hasn't stopped Space X experiencing problems.
Three of its unmanned Falcon 9 rockets have exploded during launch or whilst attempting to land – in one of these incidents a $200 million satellite payload was destroyed.
However, Space X has had several notable successes and is working closely with NASA on its proposed manned fly-by mission to the Moon.
Details of the Space X flight are unavailable but perched on top of the enormous, yet to be tested Falcon Heavy rocket, will be the Dragon 2 space capsule, home to the only people on board, the two fee paying passengers.
The flight is to be entirely computer controlled, but as any astronaut will testify, every flight comes with problems.
A mission similar to the proposed Space X flight was conducted in 1968 – Apollo 8 in which a crew of three flew a figure of eight trajectory to the Moon and back.
They returned safely but the mission was full of surprises and technical hiccups.
Once in space the only means of motive power on Apollo 8 were several tiny thruster engines. Ninety nine per cent of the trip required no engine power – the gravitational pull of the Moon and Earth did all the work.
The rear engines on the module were required to be fired in a number of key "burns" at precise times and for precise durations.
Failure of an engine or incorrect timing would spell disaster – the spacecraft would either have drifted into deep space or plunged at hypersonic speed to be smashed into the Moon or Earth.
The side thrusters were used to rotate the module, one revolution per hour, to prevent temperature extremes, 200C on the Sun-facing side and minus 100C away from the Sun.
The necessary attitude (angle) of the spacecraft meant that it wasn't until they actually reached the Moon, three days after launch, that the crew first saw the Moon.
One of the engine burns lasted five minutes 18 seconds and was required to take the spacecraft out of Earth orbit and send it towards the Moon.
Another, lasting four minutes, seven seconds was required to ensure the spacecraft was put into Moon orbit – this was conducted on the far side of the Moon out of radio contact – misfiring of any of these burns would have meant disaster.
The crew spoke of the latter burn being the longest four minutes, seven seconds of their lives. Finally, the angle of re-entry to Earth, under computer control, had to be precise – within two degrees – any more and the craft would have burnt up on entry, any less and it would have bounced off the atmosphere into deep space – never to return.
Examples of unexpected events during the mission included the highly trained commander, Frank Borman, being violently sick, leaving the two other crew members to clean up vomit and faeces floating inside the module.
It was a requirement that at least one member of the Apollo 8 crew could navigate using the stars and sextant – this was in case the computer navigation system failed.
Two of the three windows fogged-up due to out-gassing of window sealant oil – this made star sightings extremely difficult.
During the mission a crew member inadvertently deleted a section of the computer programme from the guidance system - thankfully the data was recovered, but during this incident some highly skilful manual steering of the capsule was required.
The Space X passengers will undergo significant training but just what they will do if confronted with major system failure or how they will handle the inevitable technical hiccups in flight, isn't known, which once again raises the question, would you go?