Back in 2008, Richard Branson outlined his vision for Virgin Galactic’s future. Once tourists are taken into Earth orbit, it seems possible that space hotels could be developed for longer stop-overs in space. He then went on to mention that short “sight-seeing” tours to the Moon could be started from these ultimate hotels. If we are to make travel to the Moon routine enough to send tourists there, the trip would need to be as short as possible.
So how long is the commute from the Earth to the Moon anyway? Human beings and machines have made that trip on several occasions. And while some took a very long time, others were astonishingly fast. Let’s review the various missions and methods, and see which offers the most efficient and least time-consuming means of transit.
Many missions have arrived in lunar orbit and landed on the lunar surface, but the means of getting there are widely varying. Whether a mission uses a rocket to blast its way there, or a subtle ion engine to slowly edge its payload closer, we have many options open to us when we travel to the Moon in the future. To this end, I’ll give a quick rundown from slowest to fastest flights to Earth’s natural satellite 380,000 km away.
The slowest mission to fly to the Moon was actually one of the most advanced technologies to be sent into space. The ESA’s SMART-1 lunar probe was launched on September 27th, 2003 and used a revolutionary ion engine to propel it to the Moon. SMART-1 slowly spiraled out from the Earth to arrive at its destination one year, one month and two weeks later on November 11th, 2004.
SMART-1 may have been slow, but it was by far the most fuel efficient. The craft used only 82 kg of xenon propellant for the entire mission (ending with a lunar impact in 2006). The SMART-1 mission is an oddity as it is by far the longest mission to the Moon, the rest of the missions took a matter of days to reach lunar orbit.
China’s Chang’e-1 mission was launched from Xichang Satellite Launch Center on October 24th 2007 but sat in Earth orbit til October 31st when it began its transit to the Moon and arrived in lunar orbit on November 5th. The mission therefore took five days to cover the distance, using its rocket boosters. This was followed up by the Chang’e 2 orbiter, which launched on Oct 1st 2010 and arrived in lunar orbit within 4 days and 16 hours.
More recently, Chang’e 3 probe and lander launched on Dec. 1st, 2013 at 17:30 UTC and arrived in Lunar orbit on December 6th at 9:53 UTC. It was therefore the fastest of the Chang’e missions, taking 4 days, 12 hours, and 23 minutes to reach the Moon before deplyoing its lander to the lunar surface.
However, it was the first-even unmanned mission to the Moon that was the fastest. This mission was known as the Soviet Luna 1 probe, which completed a flyby of the Moon in 1959. This basic, but pioneering probe was launched on January 2nd and flew past the Moon by a few thousand kilometers on January 4th. It only took 36 hours to make the trip, therefore traveling an average speed of 10,500 km/hr.
The Apollo missions, which were the only manned Lunar mission, were fairly quick in reaching the Moon. Naturally, it was the Apollo 11 mission, where Neil Armstrong and Buzz Aldrin became the first men to walk on the Moon, that made the greatest headlines. This mission began on July 16th, 1969, where a Saturn V multi-stage rocket took the astronauts from Kennedy Space Center into orbit.
They reached lunar orbit after only 51 hours and 49 minutes in space, arriving on July 19th, 1969. The famous “One small step for man…” speech would not take place until July 21st, roughly 109 hours and 42 minutes into the mission. After dusting off from the Lunar surface, the Lunar Module spent another 2 days, 22 hours and 56 minutes getting back to Earth. So in addition to be the first manned mission, Apollo 11 was also the fastest trip to the Moon where astronauts were involved.
By far, the fastest mission to fly past the Moon was NASA’s New Horizons Pluto mission. This mission had a speedy launch, with its Atlas V rocket accelerating it to a a speed of about 16.26 km per second (58,536 km/h; 36,373 mph). At this rate, it only took 8 hours and 35 minutes for it to get to the Moon from Earth. Quite a good start for this probe, which was on its way to Pluto and the Kuiper Belt at the time.
Although this is impressive, it’s worth keeping in mind that New Horizons was not slowing down to enter lunar orbit (as was the case all of the manned and unmanned mission to the Moon mentioned above). Hence, it was probably still accelerating long after it had placed the Moon in its rear view mirror (assuming it had one).
Mission concepts like the Space Launch System and Orion Multi-Purpose Crew Vehicle (MPCV) will also come into play in the near future. On December 5th, 2014, an unmanned test of the Orion capsule took place, officially known as Exploration Flight Test 1. Having launched atop a Delta IV Heavy rocket, the capsule reached Low Earth Orbit, achieved two orbits of the Earth, and then splashed down again 4.5 hours later.
During the course of the flight, EFT-1 reached speeds of up to 8.9 km/s (32,187 km/h; 20,000 mph). At this velocity, an Orion mission could conceivably make it to the Moon (at an average distance of 384,400 km) in nearly 12 hours. Obviously, adjustments will have to be made for weight (since it will need a crew), and deceleration. But still, that’s not a bad framework for a tourist flight.
So, when space tourism begins mounting sight-seeing tours or missions to the Moon, they will have a few options. They could offer long cruises, gently gliding to the Moon using ion engines to slowly let the tourists take in the views. Or they could opt for the exhilarating rocket ride of a lifetime, blasting tourists off into space and whipping them back in just a day or two. Hard to say which one people would prefer, but surely there are many who would pay handsomely for the opportunity.
We Have written many interesting articles about the Moon here at Universe Today. Here’s Who Were The First Men On The Moon?, How Many People Have Walked On The Moon?, What Is The Distance To The Moon?, and You Could Fit All The Planets Between The Earth And The Moon.
For more information, be sure to check out NASA’s page on The Earth’s Moon and Solar System Exploration Research Virtual Institute
Original publication date April 10, 2008