HABITAT SYSTEMS

The focus of the Habitat Systems domain is enabling the crew to live and work safely in deep space. Activities include the BEAM inflatable habitat, deep space habitat capabilities, reliable life support systems, logistics reduction, radiation measurements, and protection. Experiments to improve spacecraft safety are also underway to better understand how fire spreads, and how to recover from fire events in microgravity.

This all sounds pretty preliminary, but at least the list of activities is good.

Galileo and Cassini flew by Earth and Venus on their way out to Jupiter. Getting the payload to Earth is the easy part with a free return trajectory you don’t need propulsion to head back towards Earth(You just need a bit of propulsion for course correction). Landing safely is the hard part. There are issues with the Orion capsule in that the heat shield isn’t built for trips beyond the moon and in that the G-forces the crew would experience could be fatal. Those issues are solved by testing and Mars 2021 does not include that testing.

“I think the only laughable idea here is assuming that you will jump from cis-lunar space to a full blown mission to Mars that includes a landing/takeoff and safe return.”

If you use Chemical Propulsion to go to Mars, you won’t have much of a choice. You will either wait in Orbit for Earth and Mars to realign or land on mars and wait for the planets to realign. This isn’t like the Apollo 8 mission. You cannot use this method to go back and forward to Mars regularly.

“ The “mull over” comment implies that we use all of the systems data collected and information provided by first hand veterans to study and prepare for the next Mars 2033 mission that will include a lander.”

The systems you would need to do this would be very different. Mars 2021 does not go into orbit and thus saves the mass of propellant (and systems) needed to get into and out of orbit. Any real system is going to need that or land. You will also need much longer life support and possibly greater radiation shielding.

If Mars 2021 were a mission that tested an system capable of repeat journeys to Mars, like Apollo 8 then it might be an worthy test mission, but here it is just an stunt and while I would love to see the stunt, I don’t think NASA should pay for it. There is very little science or engineering worth the risk.

No, it is not. This mars plan makes use of the free return trajectory. Normally free return trajectories to Mars are not possible with chemical propulsion. In 2021 and in the next cycle the delta V to go to Mars is very low and thus for these years the Mars 2021 can work, but it cannot work for other years. So this mission as set is not a full application and implementation of a human-mars journey.

Free return trajectories are the preferred method for human space flight trajectories because you can use the gravity of the planet (or moon) that you are heading towards to send you back to Earth if you have a problem. This results in a large savings in terms of propulsion. Apollo 13 used such a trajectory to get back home and all Apollo missions traveled to the moon using them for as long as possible, only leaving the trajectory to get to a trajectory that would put them where they needed to be for the landing. Apollo 13 actually left the free return and had to maneuver back on it to get home.

The trouble with the free return trajectory and Mars is that with chemical propulsion usually by the time you have gotten to Mars, Earth and Mars are too far apart for a free return to work. This mission uses the low delta V needed to get to Mars that year to enable a free return trajectory. The delta V it takes to get to and from another body isn’t fixed, but varies and some launch windows will require less delta v than others. In 2021 there is a particularly good window that allows a chemical rocket to have a free return trajectory from mars. Other years it may not be possible.

Without the free return an Chemical rocket mission must either go into orbit around Mars or land on Mars and wait for Earth and Mars to realign for the return. This makes for missions that are longer than Mars 2021 mission and require far more mass in terms of both propulsion(propellant), life support, and may require more complex systems.

The free return trajectory for mars is possible with Nuclear and Electric Propulsion, but this mission uses neither. Mars 2021 isn’t a much of a test of any system that you would use for regular mars journeys. It is a scramble to make use of a particular window of opportunity.

(Warning big PDF file – 25MB)
http://www.nasa.gov/sites/default/files/files/508_2015_Budget_Estimates.pdf

Unless you’re thinking aerobraking or something, a free return route to Mars is just well-understood basic physics. Nothing mysterious or chancy about the astrodynamics. That there are active life support systems on board is totally irrelevant to the trajectory. For goodness sake. If you’re really that worried about testing a free return trajectory with an active life support system on board, why in the world do you want to test it with humans? That’s just nuts. Just send out an ECLSS system with instrumented crash test dummies instead.

So you agree that if you want to test survival systems in cars, you shouldn’t use humans? Good stuff. But if you want to test survival systems in long duration spaceflight, you do? Sorry, but that just makes zero sense.

Now, you still want cis-lunar missions to test flight systems for Mars 2021, but you haven’t said where the money is going to come to buy into the very lean schedule. This is the stuff of wet dreams. “Simply” adding $10-20B over the next six years? Isn’t that the budget increment that Constellation wasn’t able to achieve? It didn’t end up being that simple to Constellation. Unlike Mars 2021, Constellation wasn’t a stunt. The goals of that mission were vastly more substantial than briefly putting people in the general vicinity of a destination. So the sell to get that funding increment for Mars 2021 is going to be a LOT harder than it was for Constellation.

My entire purpose of posting this response was to point out how quick many are to fawn over an idea that, in the long term interest of putting functional humans on Mars, just isn’t sensible, except as a stunt.

BTW, the words “scientific value” don’t apply to “flight systems”. Technical value, or engineering value maybe. But not scientific value. You’re misusing that phrase. NASA certainly doesn’t refer to flight systems as being of scientific nature. So stop hiding behind science.

The state of human spaceflight is hardly “atrophied” in LEO systems, except in that new destinations aren’t being achieved. New knowledge and understanding is being achieved that will engender further human work in space. Of course we can fling humans to new destinations and NOT gain that new knowledge and understanding, but that seems like a less desirable plan. NASA is not all about going places, though many people think that’s all it is. NASA is about using and understanding space.

Yes, it might be a shame not to study the concept further and put an estimate on it. How much of the remaining six years to you want to devote to that effort? So after a year of analysis and cost estimation, we then have only five years to actually do it? Holy moley.

1) Yes, we can agree the purpose of 2021 is not to produce direct science of Mars. That said, ti certainly could. I don’t see any reason why we couldn’t attach instruments on board for study, as well as the possibility to release a small payload (cubesats?). I don’t think that is the purpose of the mission, but we could always have secondary missions. Particularly to help solve budgetary problems. Combining some of the planetary science budget to help fund this mission by attaching certain instruments may be a possibility (not necessarily NASA either, but more on this below).
2)Trajectory testing: Ummm to my knowledge we have never sent a spacecraft to Mars and Venus orbits and had it rocket back a payload to safely land on Earth. That is a new and exclusive trajectory never before accomplished with active life-systems supporting humans and their vital instruments necessary for their survival. I realize we are making our astronauts guinea pigs here, but that is exactly what the human spaceflight program is. Everything we can do with humans can be done with robotics (perhaps not as timely or efficiently in some cases), but the science of human spaceflight is about studying the effect of space on humans in these new environments and situations they encounter. “These folks think the auto industry should put humans inside test cars instead of crash dummies.” I don’t think that is the logic at all (at least not anything I have read from folks here). Even the car companies will tell you that eventually you have to do human trials after dummies have been fully used/tested(not crashing humans into the wall… but using them to test all systems and put miles on the vehicle in different driving situations.) “The first step is laughable”? I think the only laughable idea here is assuming that you will jump from cis-lunar space to a full blown mission to Mars that includes a landing/takeoff and safe return.
3)”So we’re rushing to achieve a ‘full application and implementation of a human-Mars journey’ in 2021? What happened to all of the tests we needed to do? I thought Mars 2021 was, in your book, all about doing those tests.” I see cis-lunar as a testing ground for the flyby mission, which is a testing ground for followup Mars missions that will include landing on the red planet. The “mull over” comment implies that we use all of the systems data collected and information provided by first hand veterans to study and prepare for the next Mars 2033 mission that will include a lander. Those tests would likely be brought back to the drawing board of cis-lunar space excursions, to simulate as best as possible the lessons learned from the Mars flyby, in preparation for an even longer duration trip to the red planet in 2033. Likely there will be other Mars missions between the 2021 and 2033 missions, that won’t include humans but rather will test the landing equipment and functionality of take-off and docking in Mars orbit, in preparation for the 2033 mission.
4)”To summarize, the main problem with Mars 2021 is 2021.” I think this statement summarizes your last few paragraphs so I will try and respond to all of them in this single point. I agree the timeline is by far the largest hurdle the mission faces, and certainly isn’t an easy one. It would require us expediting SLS and Orion as well as other necessary technologies. Spending more on SLS and Orion is the hardest part in my opinion. I think there is enough support behind those projects and the jobs associated with them that Congress would gladly seize this opportunity to make a useful mission out of them, even at the cost of adding billions more funding into their progress. The biggest challenge for 2021 is making sure a) the service module is ready b) we have a habitat facility that provides more function and room than the Orion capsule (personally I think the habitat is the biggest issue). The natural fit is using a Bigelow attachment, but that requires a tremendous push in their development and construction phases for such a habitat ($$$). To my knowledge we haven’t seen a price tag for that habitat/module that is necessary for a safe and somewhat comfortable trip to Mars and back. It’s possible that Congress will be willing to dump money into purchasing this unit from Bigelow (or another??) if they are already willing to bump up funding for SLS and Orion. Another option is to secure additional funding from other sources such as private enterprise and other allied space nations (I say “allied” because who knows what our relationship with Russia or China will be over the next few years). ESA is already providing a service module, who is to say we can’t bring on other partners to support other aspects of the mission and its funding? If we are intent on doing this mission, and we see bipartisan support for it in Congress, I imagine several of our space partners would be thrilled at the opportunity of having their names attached to the first ever human flight to another planet. I realize there are a lot of factors here, none of which are easy to accomplish. The timeline is short, but it’s doable. We already have a lot of progress and development of systems we will need for the mission… we just need to speed them up. At the moment Congress is content with developing these at at snail’s pace, because we haven’t defined a mission for their application. Once we do have a real goal in sight, there is no doubt in my mind we can ramp up these efforts and have them ready for a 2021 flyby mission to Mars. My whole point in this conversation as that I believe the mission is doable, and we certainly should be inquiring as to the overall cost such a mission would be. Everything we are discussing is speculation until we get more information. Will we be able to expedite this mission by simply adding $10-$20 billion more spread out over a six year period? Could Bigelow (or another viable company) produce the habitat in that space of time, and at what price? Would another nation be interested in participating/funding aspects in the flyby mission? The inquiry has merit and should be seriously looked at and studied. My entire purpose of posting on this was to point out how quick everyone is to shoot the idea down without further analysis. Not only for the scientific value of proving flight systems and human related factors, but also the political value of putting a serious mission on the timeline for SLS and Orion that could gain bipartisan support and allow human spaceflight to get out of it’s atrophied state of LEO missions. ARM won’t likely get the political support needed to ever get off the ground, and no other serious options have been presented to make use of SLS and Orion within the next decade. After further analysis we may find this mission is too difficult to achieve in our timeline, but I don’t believe we have gathered enough data and fleshed out the details enough to make that conclusion. It would be a shame not to at least study the concept further and put an estimate on it.

1) additional modules/systems on ISS
2) a version of Nautilus X that is only LEO
3) a version of Nautilis X that goes for a short spin out of LEO

Aerobraking return anyone?

We need spaceships. Not throw away Apollo on steroids stuff.

So people are going to watch the launch …. forget about it .. for 6 months… then they flyby Mars and then what? Stay tuned for the six month ride home? Or change the channel back to duck dynasty?