Russia's Dark Horse Plan to Get to Mars (nice try)

Discover: published online May 21, 2009

excerpts:

• The same proximity to Mars that will one day doom Phobos makes it an extremely attractive staging post for human explorers. One side of Phobos always faces Mars, and on that “hemisphere” the planet dominates the sky. This makes Phobos a good place for monitoring most of the Martian surface. Moreover, any manned outpost on Phobos would be well shielded from space radiation—protected on one side by Mars and on the other by the satellite’s own bulk.
• The total delta-v required for a mission to land on Phobos and come back is startlingly low—only about 80 percent that of a round trip to the surface of Earth’s moon.
•  “Does Phobos contain any water, and if so, in what amount, form, and location? Answers to these questions will help determine how we will travel to Mars.”

Comment:

Logically, it would make sense to occupy Phobos for awhile before moving on to Mars.  If water could be found, that would come in quite handy for fuel and life support.

Delta V budgets for various destinations

Unfortunately, the unmanned Phobos-Grunt spacecraft became stranded in orbit in November.  Since that has failed, what might be tried next?  Anything?

From the chart above, it would seem that a mission from L4-L5 to Phobos would possibly be less delta v than from Earth to LEO.  Launching from EML-2 could be even less.  While looking at Quicklaunch's home page, I thought up a Lagrangian space port constructed from the moon by using multiple launches from a Quicklaunch gun on the lunar surface.

It is probably getting ahead of oneself to propose such a project, but it is interesting to speculate about.  Let's say that at the fat end of each of these was an inflatable habitat which could link with its two neighbors.

The long end would telescope out far enough to enable it to be spun up for 1g artificial gravity.  That would take about 224 meters from the center.

The masses shown here according to this illustration, as launched from Earth, are 1000 lbs each.  To launch from the moon would require much less power ( 14 times assuming that its equivalent), which would mean a much smaller gun.  So the gun would be smaller and the masses would be equivalent.  The question is how much of a habitat can you make with each 1000 lb payload?  Probably not much come to think of it.  But there would be plenty of modules.  I would guess over a 100 launches to complete the circle.

There are two circular modules shown below.  Let's say make one for supplies and the other for habitat.

QuickLaunch webpage

You would need to get to the moon first, of course.  You will need to mine the moon for water and build your space gun.  You will also need to make each of the inflatable modules--- somehow.   Then stuff it all in a gun and launch it to a Lagrange point.  Assemble at the Lagrange point.  Start sending people to man the station and begin preparing a launch vehicle to go to Phobos.

The trip back would go to the Lagrangian station instead of Earth.  That presumably would save a bit of delta v.  Not to mention not having to land and take off again from the Earth itself.  With one g of artificial gravity, a crew could rehabilitate and then go off on additional missions before coming home to stay.