New Mars Forums

Thanks for that. Let us know how it works out.

  Bob Clark

Remember the Early Lunar Access (ELA) proposal uses all lightweight hydrolox propulsion for the in-space stages. This makes it much lighter than the Apollo approach, which used dense hypergolic propellants in space. Total mass required to LEO was ca. 50 metric tons for ELA compared to the 130 mT of Apollo.
The capsule for ELA was also only half-size of the Apollo command module. And at 3 mT dry mass it was only 1 mT heavier than the dry mass of the Apollo lunar module anyway, without needing the extra 6 mT of the command module.

  Bob Clark

December 25, 2014
NASA seed funds SR 72 hypersonic drones as other countries race for hypersonic missiles.

http://nextbigfuture.com/2014/12/nasa-s … rones.html

I like that it is using both turbojets and ramjets. But my preferred system would have the turbo/ram jets integrated into one by having a single combustion chamber as with the SR-71's engine.
You could then potentially produce a SSTO by having a rocket engine also use the same combustion chamber.

     Bob Clark

The 25% reduction in "flight mass" might be for Mars landing requirements. I don't think it's relating to Earth landing since an Apollo ablative heat shield was only 15% additional mass so if you reduced the "flight mass" by 25% you would be reducing the actual capsule mass.

This is similar to the "parashield" concept investigated by Prof. David Akin at the Univ. of Maryland's aerospace dept.:

Phoenix: A Low-Cost Commercial Approach to the Crew Exploration Vehicle.

http://nia-cms.nianet.org/RASCAL/2010-W … SC-AL-2006.

From the report:

From the specifications listed it looks like the parashield would weigh about 12% of the dry capsule mass, i.e., without propellant.

  Bob Clark

With the recent reports of liquid water being possible on Mars as brines, I like the Noctis Labyrinthus region because of the frequent low lying fogs:

  Bob Clark

It is likely to get high power density as a rocket you would want to liquefy the fuel and oxidizer anyway, so you might want to find the temperature and pressure to liquify all of CO2, CO, O2, and N2.  Then use a centrifuge to separate them.
For an air-breather you don't normally need to liquidfy the air but still it might be doable on the fly.
Also, for rocket or air-breather you want the fuel and oxidizer delivered at high pressure so maybe the cenrifuge and turbopumps or compressors can be done by the same device.

  Bob Clark

According to the wiki page they are headed to Proxima Centauri so they must have some sort of fission drive. Project NERVA developed a rocket engine using nuclear fission in the 60's so it's not so far out of what was technically feasible.

  Bob Clark

The Martian atmosphere contains a small percentage of oxygen:

Atmosphere of Mars.
Chemical species    Mole fraction[1]
Carbon dioxide    96.0%
Argon            1.9%
Nitrogen    1.9%
Oxygen    0.145%
Carbon monoxide       0.0557%
http://en.wikipedia.org/wiki/Atmosphere_of_Mars

While this is a low percentage, it's a much higher percentage than that of CO2 in the Earth's atmosphere on which all plant life on Earth is dependent, and therefore on which all animal life is also dependent.

Because of the presence of free O2 in Mars atmosphere, conceivably you could have unlimited spacesuit time on Mars with the oxygen drawn from the surrounding atmosphere. However, the amount of O2 on Mars is so small you would need a fan to draw in more atmosphere. How much air flow would there have to be to get the required amount of breathable oxygen for a person?

  Bob Clark

Weird Crystal Can Absorb All The Oxygen In A Room -- And Then Release It Later.
Popular Science
This could potentially make fuel cells, space travel, and scuba diving a lot more efficient.
http://www.popsci.com/article/science/w … e-it-later

Could this be used for air breathing propulsion?

   Bob Clark

With the higher cited thrust of the Raptor engine, SpaceX's proposed super
heavy lift launcher could lift 100+ metric tons to orbit as a SSTO.
As a two-stage vehicle it could manage 200 mT. And using three cores, it
could do over 500 mT.

A SpaceX Heavy Lift Methane Rocket, Page 2.
http://exoscientist.blogspot.com/2014/0 … -page.html

  Bob Clark

The National Research Council just released a report on how to get to Mars. It considered that NASA’s plan of getting to Mars via the asteroid return mission as a stepping-stone might work. However, actually the NRC considers it a bad idea, with plans going to the Moon first being preferred:

NASA could not deliver humans to Mars, says new strategy report.
Published time: June 05, 2014 02:39
Landing humans on Mars is unattainable for NASA if the space agency’s current strategy and level of funding are not modified in the near future, according to a new congressionally-mandated report.
…
Of the three pathways to Mars that NRC suggested, two were associated with a return to the moon. A lunar landing and habitat would hone technologies that could later be employed on a Mars mission, the report said.
The Obama administration has publicly expressed distaste for continued, expensive moon landings. In outlining US space policy in 2010, President Barack Obama said, “I just have to say pretty bluntly here: We’ve been there before.”
The third option outlined by the report includes the Asteroid Redirect Mission, a plan still in the study phase but currently endorsed by the Obama administration.
Such a mission would send robotic spacecraft to essentially grab and re-orbit an asteroid passing near Earth, allowing astronauts to take samples of the rock.
That mission, though, is not preferred by authors of the report. Safety issues and development of “dead end” technologies render the asteroid mission inferior if NASA wants to reach Mars, it said.
The asteroid option “cannot provide the flight frequency required to maintain competence and safety,” the report posits.
http://rt.com/usa/163736-mars-nasa-funding-strategy/

In point of fact the current NASA idea of dismissing any return to the Moon is making it that much harder for us to understand how to get to Mars. The only reason for the perception we can’t return to Moon is the idea developing a manned lunar lander would be too expensive. But you need a lander anyway to land on Mars, and by developing a lunar lander you can also use that as a Mars lander. And if you break your mindset out of the box that the lunar lander has to look like the $10 billion Altair lunar lander, you grasp the lander can actually be developed at over a hundred times cheaper than that. Both the Masten XEUS lander and the NASA Morpheus lander can be made into manned landers at only a few 10's of millions of dollars in development cost.

So this self-imposed limitation on their own thinking is making it that we can’t get to Mars either.

  Bob Clark