It’s a fair question, considering that we put a man on the moon forty-four years ago and fifty years ago General Dynamics promised us we’d be on Mars by now (see this post).
It’s not an easy question, given the challenges involved, but the doctor thinks he has the answer. But first, consider the following:
1) Putting a man on the moon cost 400 Billion in 1969 terms. (Source: The Cost of the Moon Race) That was roughly 9% of the US GDP in 1969. However, the effort really started in 1959 with Project Mercury, which had the goal of a manned earth orbit. In other words, the US put a man on the moon in 10 years using only 1% of GDP. NASA’s annual budget today is about 18 Billion, which is about 0.1% of GDP, or roughly 1/10th of what they were getting when the race to the moon was on. (With respect to the Federal Budget, in 1966 they had 4.41%. This year, they have less than 0.5%.)
2) Current robotic missions to Mars take about 8 months. Improvements in technology could probably shave a few months off of that. However, given that the orbits of Earth and Mars around the sun allow for opportunity’s to embark and return roughly every 26 months, even if the trip were shortened, it would just mean more time on Mars as one would want to minimize trip distances to ensure enough fuel. So that means over two years in space. Given that a Russian cosmonaut spent 1.2 years in the International Space Station, it’s obvious that humans could train, and endure, a mission of that length.
3) Damage from asteroids is a big concern, as they have an average orbital speed of 25 kilometers per second and we know of asteroids with orbital velocities of over 30 kilometres per second, or almost three times the estimated speed of the rocket. Large ones will be detected long before they reach the ship and enable it to make course corrections. Smaller ones could pose a problem.
However, we have the technologies to produce titanium-based metal alloys up to four times as strong as steel, exceeding 2 GPa, carbon fibres that approach 6 GPa, and lonsdaleite, an allotrope of carbon with a hexagonal lattice that is commonly called a hexagonal diamond, but which is 58% harder than diamond and able to resist pressures of 152 GPa (GigaPascals), which is a pressure that is roughly equal to 1.5 Million times atmospheric pressure. Given that standard atmospheric pressure is roughly 14.7 psi (Pounds per Square Inch), lonsdaleite can withstand an impact of up to 22 Million psi! That means we can make mighty strong spacecraft.
In other words, it’s not a question of money, trip duration, or the ability to create a space ship that can safely withstand the dangers of intra-solar system travel. So why aren’t we dealing with extra-planetary supply management on a daily basis?
Come back next Sunday for Part II and the answer.