What’s the absolute minimum budget for a manned mission to Mars (going there, staying a few months, and coming back) - assuming a nation that was willing to play things a bit fast and loose with lives in the name of speed and cost-saving? (say, Russia or China)
$100 billion?
It really depends very strongly on how the technology develops.
SpaceX’s Starship is designed for flights to Mars. But it’s unclear as of now what it will achieve, cost-wise.
Pessimistically, it might only achieve $1000/kg to LEO. That’s about on par with Falcon Heavy, though it would allow 100+ tons to orbit at a time. Optimistically, it could achieve as low as $10/kg.
So which is it? That’s a 100x difference between the two. Launch costs are not the only factor, but extremely cheap launch could open up new mission techniques (such as sending cargo on cheaper but lower-reliability transfer vehicles). So the entire mission design depends on the launch price, which is nowhere close to being set in stone yet.
The lowest realistic costs for an opposition-class Mars mission (30-40 day surface stay) are around US$200B for a crew of 3 to 4. (The estimates of success I’ve seen range from 80% to 95%, compared to the NASA human spaceflight threshold of 99.5%, but honestly those are all just guestimates.) In reality, there are so many unknowns and technology that needs to be developed and matured I think that is a gross underestimate. A significant of portion of the costs is driven by the cost per unit mass to get to a Mars transfer orbit because you can obviously solve a lot of problems like consumables and shielding with more mass but there are also some fundamental problems that no one (including SpaceX) has really addressed, such as protecting and sustaining the crew during the ~8.5 month interplanetary transfer; successful entry, descent, and landing (EDL); power generation for a long duration stay; high bandwidth communication from Mars to Earth to support a crewed mission; assuring the crew can function and will remain in good health after the freefall interplanetary transfer and in Mars reduced gravity for an extended duration; sustaining the crew in situ without having to send enough food and consumables for the entire 2.5 year duration; and the reliable ascent from Mars after a vehicle has been sitting for a couple of years or longer (assuming the vehicle was prestaged with a dedicated descent stage) or that an ascent vehicle can be restarted after over a year of sitting idle after descent (assuming a single descent/ascent vehicle).
Stranger
Sometimes I wonder if the future of manned space flight might simply be to bypass Mars in favor of its moons and the asteroid belt. Set up a command and control station on Phobos or Deimos and just send the occasional rover down to Mars, to be controlled remotely (as needed) from orbit. Meanwhile, let’s start cracking open (metaphorically—a few well-placed holes for samples would do) some of those rocks beyond Mars’ orbit and see if any of them might pay off.
Didn’t anyone watch Aliens? Sigourney Weaver better be in my crew! Talk about tough.
(30-40 day surface stay)? Doesn’t the the crew have to wait about 90 days for the Earth and Mars to line up again so the return vehicle has the best angle and shortest duration back to earth?
For opposition-class missions, it actually gets easier the shorter the duration. See the chart here (20-60 days is all pretty close). You can go with longer missions, but the delta-V requirements go up, and they are already fairly extreme for opposition-class. Conjunction-class is much easier, and likely safer for the astronauts as well since the transit time is shorter. The astronauts spend more time on the Mars surface but supplies can be dropped in advance.
That isn’t quite right. See AIAA Space 2014 (August 04, 2014 - August 07, 2014) “Trades Between Opposition and Conjunction Class Trajectories for Early Human Missions to Mars” (which appears to be the source of the summary data in the cite that Dr. Strangelove linked to, and is pretty consistent with other studies of Mars crewed mission trajectories.)
The opposition class mission profile is actually way more difficult in terms of delta-velocity and trans-Mars injection mass requirements but it basically halves the overall mission time, although the amount of time spent in transit is greater and the opposition class trajectory requires a Venus swing-by that actually increases the risk for solar particle emission event exposure. The conjunction class is the obvious choice because if you are going to send people to Mars you might as well go big, but we really have no evidence of the long term viability of humans in a fractional gravity field nor to exposure of any of the various hazards on Mars, and there will be no potential for a mission abort or rescue should something go wrong. The conjunction class will require pre-staging supplies on Mars while the opposition class essentially assumes minimal or no staging.
All of this assumes chemical propulsion. With nuclear fission electric or solar electric transit times go down and opportunity windows increase significantly, but then that means developing those technologies that are really nascent at this time. Nuclear thermal rocket propulsion (which I used to be an advocate for) looks increasingly like a technological dead end because of the prohibitive mass requirements and the enormous amount of waste heat that has to be shed, and any effective nuclear thermal propulsion system will have to operate on the edge of stability. And those exposure times beyond LEO will subject astronauts to radiation levels beyond lifetime allowable limits in addition to other physiological hazards of high energy cosmic radiation, microgravity, and other potential hazards.
Being able to send more mass into Earth orbit for lower costs addresses one particular limitation in mission planning but it is far from a panacea. The main hurdles, and in particular the EDL problem remains a technical challenge that cannot be solved just by adding more mass.
Stranger
I’m not sure what thing I said you disagree with–as best I can tell it’s consistent with what you said. There is of course room to quibble about the trade between time spent in deep space vs. time spent on the Martian surface. While we don’t know a lot about either, I don’t think it’s a great stretch to say that the surface is going to be better for human health. The radiation environment is significantly better, especially considering that the crew would have time during a conjunction mission to build shelters. And while we don’t know for sure how good 38% gravity is compared to 100%, it is undoubtedly better than 0%.
The pre-staging is an advantage–if it goes wrong, you just try again until it goes right. And for bulk cargo like food and water, you can get away with less sophisticated EDL methods.
While EDL on Earth is undoubtedly easier than on Mars, the basic principles are nevertheless the same for a powered lander like Starship. Its “skydiver” style reentry and “backflip” to a tail-first landing will be approximately the same. So SpaceX will at least have some degree of practice beforehand.
Probably not worth answering these but:
What obvious reasons, precisely?
Women do as well or better in astronaut testing and training.
And human societies risk, and for that matter kill, women all the time. Go read a news site. Or a history book.
There are approximately 7.8 billion people in the world. We have absolutely no shortage of wombs.
Everywhere I’ve worked has been mostly male… Groups of males work really well together. Groups of women, ehh… not so much. And throw a young woman in with a group of guys and the dynamics totally change. I’m sorry, but they do. Yes, we realize this and work to rise above, but the bottom line is there are effects in mixed-sex working groups.
What line of work are you in?
But much of that level of automation and AI is being developed anyway because it has countless important uses both on earth and in space exploration. I and others I know have been direct beneficiaries of advanced robotics in medicine, for example. It would be far more productive to accelerate our efforts in that direction than to expend perhaps nearly a trillion dollars to send fragile meat-based intelligence to Mars, even if your sole objective was space exploration and disregarded the enormous benefits of such technology to life on earth.
As for knowing “very little” about Mars, that’s true only in comparison to what we know about our own planet and its history. Advanced robotic missions will continue to give us more and more information. And we know literally almost nothing about potentially far more interesting places like Europa compared to what we know about Mars. I’d much rather see a much smaller sum spent on orbital and lander missions to Europa and other moons of Jupiter and Saturn – much of it using reusable multipurpose technology – than to spend a fortune sending humans to Mars to collect a sack of rocks and drill a core sample.
Gay porn production.
Years ago I came to the sad conclusion that even Mars is too far away. Even under the best scenario, we are generations, centuries, away from having the money, organization and technology of getting off this rock.
Now let’s move onto what we can do. What we can do is a most-excellent telescope on the Far Side of the Moon.
Much of the work of the world, all through history and probably much of prehistory, has been done by groups of women working together.
Then one or both of the above would seem to be out of place in this thread.
William S. Preston Esquire and Theodore Logan wildly agree.
Tripler
They told me at the Circle-K.