Bob Clark
http://exoscientist.blogspot.com

just how united and organized are cis-lunar next supporters? Certainly nowhere nearly as much as Mars first supporters.

True enough, but there’s a big difference between the two pathways: Cislunar Next is affordable and technically achievable. Mars First isn’t.

Certainly. But I am wondering if there is more that could be done. Although we may not be in a position to directly change policy, perhaps there might be some effective means of indirectly affecting policy (i.e. influencing the policy makers more effectively). For example, it now seems that Romney might actually have a chance. Yet it is not obvious to me that his choice of NASA administrator will support a cis-lunar next policy. Perhaps we could do something now to increase that probability. Also, just how united and organized are cis-lunar next supporters? Certainly nowhere nearly as much as Mars first supporters.

Your assumption is that these are goals that they actually intend to pursue. I am not convinced of that.

Since we’re dealing with motivations, none of us can be certain. My guess is that Obama doesn’t want to tangle with space state senators. This is why his administration reversed direction and went along with SLS. I also guess that he doesn’t want to be known as the one who killed BEO HSF. So, he’ll just move SLS forward until the end of his second term and then hand it off to someone else. He’s not going to expend political capital on something that is small and not a priority.

I’m guessing that it will be close to impossible to get him to make the change to a strategy of a large cis-lunar next program. In such a situation, I think that the best we could do is to advance development of cis-lunar hardware with only about a half billion per year. For example, ULA and Masten’s cryogenic lunar lander could be developed for that amount if funded in an SAA manner. Just an idea.

For the earth-moon system, L1 and L2 are about 1/6 of a lunar distance from the moon. The moon is about 1/4 of earth’s diameter.

So far as scale goes, the graphic looks like an earth-moon system. If it’s supposed to be a portrayal of the sun-earth system, the proportions are way off.

A Hohmann from 0 km perilune to 300 km apolune is about an hour.

LLO speed is about 1.6 km/s. A 90 plane change from an equatorial LLO to a polar LLO would cost about 2.3 km/s. In terms of delta v, Plane change expense at EML2 is practically zero. Accessing a polar LLO from EML2 would save a big plane change expense.

I’m sure this is being looked at, but my understanding is that the Orion will not actually be stationed at the L-2 point, but will be in a “halo” orbit around the L-2 point (if they were AT L-2, communications with the Earth would not be possible). I suspect that this halo orbit will keep the spacecraft illuminated except under rare circumstances.

Your assumption is that these are goals that they actually intend to pursue. I am not convinced of that.

None of us have the power to change policy, but by stating and re-stating the logical path forward, we can eventually make ourselves heard. Spread the word.