Challenge: Manned Mars mission by 1999

[acgoldis]

Your challenge is to get a manned Mars mission by 1999 with a POD of Kennedy's Moon shot speech. The astronaut(s) have to do something similar to what they did on the Moon: get to Mars, hang around on the surface for a while doing experiments (the duration of the mission can be up to you), and return to Earth without major health issues.

Hmm: Soviets say "well, they beat us to the Moon, but we'll beat them to Mars!"

 

[kmmontandon]

The Vietnam War isn't escalated to the point of a half-million American combatants in-theater. Maybe just keeping at the few-thousand "advisers," until a realistic appraisal is given in '65 or so that says "No, pouring in troops won't save them."

That entire clusterfuck was a huge economic drag for a decade, and really hurt the morale of the American people in general, and their (and therefore Congress's) willingness to spend loads of money on ephemeral goals.

 

[marathag]

What's that? Interplanetary manned exploration?
Something like this carries a lander: they land take samples, and return quickly in 1978

 

[acgoldis]

Getting them to Mars is one thing. Doing so without the astronauts incurring medical or psychological issues due to a 6 month voyage each way (or whatever it is) is something entirely different. I'm almost certain you will need artificial gravity (so a rotating ship)

 

[aaronupright]

People have spent a year in space, the longest spaceflight is 438 days, by Valery Poliyakov.
So a Mars mission, say a 500 day mission is just about feasible. An Apollo-style mission.
Of course it probably needs multiple launches, an all up is pushing it.

 

[acgoldis]

People have spent a year in space, the longest spaceflight is 438 days, by Valery Poliyakov.
So a Mars mission, say a 500 day mission is just about feasible. An Apollo-style mission.
Of course it probably needs multiple launches, an all up is pushing it.

The vehicle is assembled in orbit?

Will technology and computers be powerful enough in the 1980's and early 1990's to do this?

It also occurred to me that the return vehicle that the astronauts use to get back to the ship after the surface excursion may have to be more complicated than the LEM as Mars does have an atmosphere.

Finally, 500 days in space may be plausible, but outside the Earth's magnetic field so charged particles and stuff can affect the astronauts more easily? It's not like Apollo when they were outside the Earth's magnetic field for only a week.

 

[marathag]

Will technology and computers be powerful enough in the 1980's and early 1990's to do this?

Look what the Apollo Guidance Computer could do. Core Memory and much in 16 bit paths using Resistor/Transistor Logic with it running at 1 Mhz.internal.
It had 4K in ROM and 74k in RAM.
So spec wise, not an whole lot different from the 1gen home computers like the TRS-80 and Apple II.

Orbital mechanics are no different at.Mars than the Moon.

 

[aaronupright]

The vehicle is assembled in orbit?

Will technology and computers be powerful enough in the 1980's and early 1990's to do this?

Yes. Mir was a modular station that was assembled in LEO in that time frame and using auto docking.

It also occurred to me that the return vehicle that the astronauts use to get back to the ship after the surface excursion may have to be more complicated than the LEM as Mars does have an atmosphere.

The Apollo LM was 16,000 kg. This will have to be as big and have a heatshield and more thrust for the ascent stage. Probably have to be sent to Mars orbit ahead of the main mission.

Finally, 500 days in space may be plausible, but outside the Earth's magnetic field so charged particles and stuff can affect the astronauts more easily? It's not like Apollo when they were outside the Earth's magnetic field for only a week.

Yes, but they won't be in a small Command module. You are looking at a big space station sized habitation module. Say something on the order of a Salyut in size. Size gives you protection and in any case you can make smaller more heavily protected crew spaces which they can retire to when getting too much radfiation,
But yes, Cosmic rays are going to be a problem.

 

[marathag]

People have spent a year in space, the longest spaceflight is 438 days, by Valery Poliyakov.
So a Mars mission, say a 500 day mission is just about feasible. An Apollo-style mission.
Of course it probably needs multiple launches, an all up is pushing it.

Or do it faster with Orion
1 g burn towards Mars and then 1 g burn for brake.
No slow transfer orbits needed.
There and back again in 125 days for 8 Astronauts and 100 tons of gear, per Dyson.

 

[CV(N)-6]

For a reentry vehicle for Earth, could you just have one waiting in orbit so the ship doesn’t need to bring it with, or is that too tough?

 

[Workable Goblin]

Will technology and computers be powerful enough in the 1980's and early 1990's to do this?

Yes. This is when Mir and the ISS were being designed and built, and both of them are (very roughly) in the same ballpark as a Mars mission in terms of mass and complexity. Actually navigating does not require extremely advanced computers.

Finally, 500 days in space may be plausible, but outside the Earth's magnetic field so charged particles and stuff can affect the astronauts more easily? It's not like Apollo when they were outside the Earth's magnetic field for only a week.

Earth's magnetic field doesn't make much of a difference; it cuts radiation exposure by only about a third relative to empty space. Everybody knew about solar flares by this point in time, so any vehicle design would have had a storm shelter to deal with solar particle events. Since those are composed of low-energy protons, they're relatively easy to shield against and so the effects on the crew would likely be minimal. Galactic cosmic rays would be a bigger issue, since they're nearly impossible to protect against without huge amounts of mass, but (to be very cold for a moment) they mostly cause a long-term increase in various health risks (cancer and heart disease), so if you were really bound and determined to go to Mars then they wouldn't be a huge issue.

The bigger problem with any Mars mission plan is always who is paying for it and why. Neither the Soviet Union nor the United States was really particularly excited about a Mars mission, which would have been very costly to develop and launch. You need to find either some huge motivation for them to go through with it anyway (and it needs to be huge, as in "we found an alien city on Mars" kind of huge) or collapse launch and hardware prices so it's not such a huge program. It's hard to see either of those being the case with any post-Sputnik PoD, or even most pre-Sputnik PoDs. Even if (extremely unrealistically) the Shuttle was totally, 100% successful in its goals, for instance, the sluggishness of the political process meant that it almost certainly wasn't going to get a Mars program started until the 1990s at best, which is too late to meet the 1999 goal.

Realistically, to get a Mars mission launched by 1999 you probably need a pre-1900 PoD to speed up the development of rocketry so that the "rocket age" starts 20 or 30 years earlier and you have more time to get costs down. This probably needs to be combined with nudging space programs into pursuing what were, with hindsight, the "right" paths to take in various areas (for example, focusing on reusing the boosters and not the orbiter, in the Shuttle program) so that they advance more rapidly than OTL (which is a huge feat, when you think about it). Otherwise, it's most likely going to be one of those things that keeps getting talked about and not actually done, just like OTL.

 

[e of pi]

For a reentry vehicle for Earth, could you just have one waiting in orbit so the ship doesn’t need to bring it with, or is that too tough?

Having one waiting is easy. Braking into Earth orbit to meet it is hard. Slowing from Earth escape (11 km/s) to Earth orbit (~8 km/s) takes enough delta-v that a hydrogen engine with ISp of 450s needs about the same mass of propellant as vehicle dry mass. Thus, slowing a pretty minimal 4-person crew cabin massing 6 metric tons (like an Apollo Command Module without the TPS or the Dragon of today) would take about 6 metric tons of propellant, while giving it its own heat shield takes a much smaller mass--the Apollo heat shield was about 1.4 metric tons.

 

[aaronupright]

A bare bones Mars mission would need.

1. A lander.
2. A taxi to take the astronauts to and from Earth orbit and back home.
3. A large habitation module with supplies and living space. Something like a Salyut 7 in size.
4.A large rocket and tank to get them out of Earth on a Trans Mars trajectory.
5 A smaller rocket and tank for the Mars orbit insertion burn
6 Another rocket and tank for the Earth return burn.

An Apollo-style Saturn V all up would be basically impossible even today. You will need a super Saturn V (basically a Saturn core stage with two S1-C boosters stapped on, thats insanely complicated).

The other realistic option would be assembly in Earth orbit and then departure.
That's feasible with contemporary technology (and lets face it, space tech hasn't really progressed much in the intervening era, Elon Musk's propaganda machine notwithstanding).

Both the Soviets and Americans have assets which can undertake assembly. The Proton and Energia for the Russkies and Titan III and the Shuttle for the US.

For 1, the lander you need to send it to Mars first. The challenges are i) its heavier than any probe ever launched which left the Earth-Moon system (I think Cassini was 5000 kg), and the Apollo LM was 15000kg. The Martian lander will be at least that weight, plus any heatshield and nose cone and ii) it will have to survive significant time in space, which is doable, Soyuz's survived nearly a year in this timeframe.

Say one launch to place it in orbit and another one to rendezvous it with a rocket that sends it to Mars.
3-6 all need to be assembled in LEO. So you end up with something like Earth Departure Stage-connected with-Mars Insertion stage-Connected with Return Stage-connected with habitation module. which connects with the Soyuz/Apollo-style capsule, which the Cosmo/astronauts are launched in and what they land in at mission end.

So a mission profile after assembly goes something like this.

Step 1: Launch in Soyuz/Apollo
Step 2: Rendevous and docking with the Salyut stack in LEO.
Step 3: Earth departure burn.
Step 4: 5-6 months coast
Step 5: Mars orbit insertion.
Step 6: Soyuz/Apollo undocks from the Salyut stack and transfers to the Martian lander, docks and powers it up. In the 1980's there was a mission which transferred crews from Mir to Salyut 7 and back again, so its doable.
Step 7: The actual landing.
Step 8: Launch to low Mars orbit and rendezvous and dock with the Soyuz/Apollo
Step 9: Transfer to and dock the Soyuz/Apollo with the Salyut stack.
Step 10: Earth return burn
Step 11: several months coast
Step 12: at Some point just before Earth arrival transfer to Soyuz/Apollo, undock and make an adjustment burn before reentery.
Step 13: splashdown, after a re-entry at interplanetary speeds.

Its technically possible. Expensive. And risky as fuck. Especially since after Step 3 they are on their own. I guess the Russians could do it. The Americans, no way, not once the Mercury-Gemini and Apollo era guys had left and the safety-first mindset was paramount. OTH, John Young was still around and OTL Pete Conrad, who worked as VP for a major defence contractor was considered for a Shuttle mission as a payload specialist in the 80's, which he refused.

So stick Young and Conrad in it.

 

[Hammerbolt]

You need a ship with a rotating section, for gravity. Yes, people have spent a year in orbit... and then they have to be carried out of the capsule on landing. So, if you want someone to actually land and work on Mars, you need to keep them fit, and that means gravity. No, just bikes and such is not enough, that's what those "year in space" astronauts do. You also need radiation shielding; the crew will be operationg outside of the Earth's magnetosphere for 1-2 years.

 

[aaronupright]

Mars Gravity is half that of Earths.

 

[HB of CJ]

Until we figure out some way to deal with radiation and zero gee health issues we are pretty much dead in the water ... or outer space. The technology will come .... it will just take some time, money and effort.

 

[Hammerbolt]

Mars Gravity is half that of Earths.

It's still more than strong enough. If you land there, apart from the efects of the landing itself, you still have to walk around, carry gear and perform physical tasks. Even a basic suit, like the preassure suit used by the shuttle crew, weighs close to 40 kilos. Add 10 kgs of tools. Add 80-100 kilos of astronaut= 120-140 kgs. Half gravity=70kg. Try lugging around 70kgs for hours, while being out of shape. And this doesn't include the health issues associated with long term 0 g.

Until we figure out some way to deal with radiation and zero gee health issues we are pretty much dead in the water ... or outer space. The technology will come .... it will just take some time, money and effort.

Yep. Which is why I've always felt the whole "rush rush to Mars now!" is a very bad idea, that does nothing but rob other programs of resources and money.

 

[Cryhavoc101]

The Mars Direct plan of the 90s always looked like the best and importantly affordable way

It cut out all of the NASA 'unions' wanting their part to play (main resistance was those parts of NASA working on the Space Station and advanced propulsion who both would not play a part in the plan) and went only for the necessary components required to get their, stay for a while and get back.

What I liked about the plan was the way in which it could become sustainable with rolling missions over 10 years or so leaving a viable 'base' of modules on Mars for future missions to use.

 

[NOMISYRRUC]

As the POD is 1961 and if the major change is @kmmontandon's suggestion that the USA doesn't become as deeply involved in Vietnam two things might happen. First there's a good chance that the Apollo Applications Programme won't be cut back. Second there's half-a-chance that the American taxpayer will be prepared to fund this:

Space Task Group Report, 1969

However, the manned flight to Mars planned for 1981 and the Mars base to be set up by 1990 are the parts of the Report that were the least likely to be approved, that is due to the cost and even more importantly the risk.

NASA has outlined plans that would include a manned Mars mission in 1981 with the development decision on a Mars Excursion Module in FY 1974, if the Nation were to accept this commitment. Such a program would result in maximum stimulation of our technology and creation of new capability. There are many precursor activities that will be required before a manned Mars mission is attempted, such as detailed study of biomedical aspects, both physiological and psychological, of flights lasting 500-600 days, unmanned reconnaissance of the planets, creation of highly reliable life support systems, power supplies, and propulsion capability adequate for the rigours of such a voyage and reliable enough to support man. Decision to proceed with a 1981 mission would require early attention to these precursor activities.

OTOH the POD's for a manned mission to Mars by 1999 which gives NASA nearly twice as much time to complete the "precursor activities" and the money required to pay for it can be spent over nearly twice as much time too.

 

[Workable Goblin]

Mars Gravity is half that of Earths.

No, it isn't. It's more like 2/5ths (to be more exactly, 38%).

It's still more than strong enough. If you land there, apart from the efects of the landing itself, you still have to walk around, carry gear and perform physical tasks. Even a basic suit, like the preassure suit used by the shuttle crew, weighs close to 40 kilos. Add 10 kgs of tools. Add 80-100 kilos of astronaut= 120-140 kgs. Half gravity=70kg. Try lugging around 70kgs for hours, while being out of shape. And this doesn't include the health issues associated with long term 0 g.

However, any Mars mission will involve stays of 30-600 days at Mars (for transfer window reasons). Taking a few days to get acclimated to the gravity again is not the end of the world.

Frankly, any plausible Mars mission is going to involve some acceptance of the astronauts suffering long-term health effects, however much radiation shielding and spin gravity you provide. Providing enough to completely negate any negative effects at all would be impractical and balloon the already enormous costs involved practically to infinity. The question is where you draw the line, and it's entirely plausible for an agency to decide that long-term effects aren't a big issue, they need to get to Mars...provided that they can overcome the hurdle of paying for it, anyway.

As the POD is 1961 and if the major change is @kmmontandon's suggestion that the USA doesn't become as deeply involved in Vietnam two things might happen. First there's a good chance that the Apollo Applications Programme won't be cut back. Second there's half-a-chance that the American taxpayer will be prepared to fund this:

No, not really. Congress would have wanted to cut back on Apollo in any case (and certainly was not going to pay for Mars missions). If it wasn't the Vietnam War, it would have been the Great Society or the like. And AAP was cut more to punish NASA for the Apollo 1 fire, since they couldn't cut the actual Apollo funding.