Mar 27 2010
If you haven’t gotten excited about Phobos recently, you should! Europe’s Mars Express will approach within a mere 3000 km of Phobos a few hundred times during the next two years.
Mars Express will measure Phobos’ mineral composition, probe its subsurface with a radar/altimeter, and study its plasma environment. Plus high resolution images will provide the first global map of the potato-shaped moon.
It’s treasured proximity to Mars and its asteroid-like, milli-g surface combine to make Phobos a unique world. In fact, for those who aspire to exploration beyond the Earth-Moon system, Phobos is the “key to the cosmos”! This is because — every two years — a launch window makes Phobos easier to reach (energy-wise) than the surface of our own Moon.
In my recent decade-forecast post (DecaState of the Wave — 10 Space Trends for the Decade 2010-2020), I suggested that Russia and China might surprise the world during the 2015 Maslow Window by jointly establishing a manned outpost on Phobos, as a safe, inexpensive, and smart first step toward their colonization of Mars.
This idea is supported by the impressive space activities and capabilities of Russia and China and would be a logical outgrowth of their planned joint robotic mission to Phobos. The Phobos-Grunt mission is to be launched in late 2011 or 2012 and would collect samples from Phobos and return them to Earth for analysis; i.e., the first-ever attempt at a sample return from the Mars system. (See: China & Russia Take the Smart Road to Mars)
Russia and China appear to be on a path similar to one sketched by those of us at the first Phobos/Deimos Mission Workshop (chaired by S. Fred Singer) during The Case For Mars III conference in 1987 (see Cordell (1989) AAS 87-277, pp. 601). Our first recommendation was:
An unmanned sample return mission to Phobos/Deimos should be studied and executed before the end of the 1990s. A sample return is essential to both our scientific understanding of Ph/D and our plans for in-situ propellant production on these moons …
Is Phobos Hydrated?
Space- and ground-based spectra suggest that the surface layer of Phobos is not hydrated. However, this regolith may not be entirely native to Phobos; e.g., UK planetary scientist John Murray suggests some of it may have originated from major impacts on Mars itself.
Thermal data by Mars Global Surveyor has shown that Phobos’ surface layer is a fine powder about 1 meter thick that sits on material believed to resemble carbonaceous chondrites. However, Mars Express has established Phobos’ density as 1.887 gm/cm3 (water is 1) which indicates a body with significant porosity, and possibly even large caverns. Thus significant water ice and hydrated silicates could be stored in Phobos’ interior.
Fraser Fanale’s (University of Hawaii) 1990 model of the interior of Phobos — which included orbital and rotational effects, thermal history, and diffusion — showed that if water ice was ever present inside Phobos, most of it should still be there. Fanale predicts that ice may be found at high latitudes from 20 to 60 meters depth, and that it should outgas — mainly at low latitudes from less than 1 km depth — at about 3 gm/sec. In 1990 the Soviet spacecraft Phobos 2 detected a comet-like interaction of Phobos with the solar wind, and estimates of observed Phobos outgassing were consistent with Fanale’s model, although the spacecraft died before they could be confirmed.
Mars Express will help greatly and Phobos-Grunt, the joint Russia-China sample return mission, will be essential before humans can make Phobos into a space service station.
How Much Would A Phobos Outpost Cost?
In the late 1980s at General Dynamics, Space Systems I led an internally-funded study of a propellant facility on Phobos. The unpublished study was presented to several NASA centers by me in 1989 (it was a good idea but suffered from horrible long-wave timing in 1989!). Our team used realistic groundrules and assumptions for technologies, vehicles, trajectories, and operations, as well as General Dynamics cost models, for several scenarios that we developed. Although the focus was on a Phobos propellant facility, our results provide insights into the challenges associated with a possible, near-term manned Phobos/Mars initiative by Russia and China. We estimated that the cost of a Phobos propellant outpost was between $ 10 and 15 B (1989 USD); that’s about $ 17 B – 25 B in 2009 USD.
Is a Manned Phobos Outpost Near 2020 Feasible for Russia and China?
According to The Space Report (2009), in 2008 Russia and China (estimated) spent $ 1.54 B and $ 1.7 B on space respectively, (all in 2009 USD); as a fraction of GDP that’s 0.067% and 0.021% respectively. These are relatively modest GDP commitments when compared to 0.2% GDP for the U.S. averaged over the entire 1960s Apollo Moon program.
Just as an illustration, let’s take $ 20 B (2009 USD) as the cost for Phobos base. It would only take about 6 years for Russia and China — using only their current space budgets — to pay for the program. Two effects make it even easier: 1) both economies are capable of significant growth (China now at 8+ %; Russia at 7% during the decade prior to 2008) so the %GDP could drop with time, and 2) a major Phobos/Mars initiative would create much excitement (i.e., ebullience) and make increased %GDP factors (characteristic of past Maslow Windows) very likely.
So a joint manned Phobos base appears to be financially feasible for Russia and China during the 2015 Maslow Window.
Without going into details here, keep in mind that Russia has a wealth of historical experience with long-term micro-g effects on humans from their own space station days and currently on ISS, and, of course, after Shuttle retirement Russia will be launching American astronauts to ISS. Rather interestingly, Russia is about to start a 520-day Earth-based simulation for human test subjects of a manned mission to Mars. And China not only has its own manned Earth-orbit space program, but also has one of the largest and fastest growing economies in the world. Plus China will complete its fourth space center which is also its first low-latitude (19 deg) launch facility, by 2015 …
… near the expected opening date of the long-awaited 2015 Maslow Window.