“…there are some out there who seem to think that Commercial can do it all.

This is a false argument. I don’t know anyone that states commercial space will have the desire (or the resources) to do leading edge exploration.

The only time commercial will be pushing out ahead of NASA is when there is money to be made in exploiting the resources outside of Earth. But that will be so far in the future that it’s not relevant to what’s going on today.

I don’t know why, but some people think the discussion about NASA and commercial space has a binary outcome – it doesn’t. What commercial space does best is the routine, and what NASA does best is the unknown/unproven. Both are needed for the future.

“the Shuttle overhead is high, but in one case where a mission (tethered satellite) was reflown, the additional cost was less than $100 million.”

You’re talking marginal costs of course, which are on top of the $200M/month fixed costs that the program needed to run.

It’s hard to get any firm cost estimates for what Side Mount would need, but the Ares I numbers that Space Policy Online found last year provide some insight. They dug up NASA testimony where it was stated Ares I would need $781M/year for fixed costs, and $138M/flight (marginal cost).

http://spacepolicyonline.com/pages/index.php?option=com_content&view=article&id=817:how-much-would-ares-i-cost&catid=67:news&Itemid=27

Ares I was a single SRM without a 1st stage LOX/LH2 tank, whereas Side Mount is essentially the Shuttle with the orbiter replaced with a cargo pod.

While the Shuttle program was going full speed, the costs for the two SRM’s (not yet assembled into SRB’s) were $34.3M each, or $68.6M for the flight set. The ET was costing $173M/unit, which likely rolls up the unit cost (what’s shown on the DD250) plus compensation for operating and maintaining the government owned Michoud facility. That equals $241.6M/flight, but is predicated on full-up production, not start-up or low-rate.

It’s also interesting to see that NASA was estimating that the Ares I fixed costs would be about 1/3 that of the Shuttle. I would imagine that the Side Mount would require a higher fixed cost that Ares I, since there is more assembly/complexity required.

Bottom line is that compared to existing launchers, Side Mount won’t be cost effective unless you have a need for lots of mass in orbit, and I don’t see a program that Congress is ready to fund that provides that need.

“HLV can have more than one customer besides NASA: DOD and the intelligence community have a need to lift big things into orbit-LEO and GEO. Get their input on what their requirements are before settling on a final design.”

The DoD and intelligence communities already use Delta IV Heavy for their needs, and if they have a couple of near-term and far less expensive options (compared to the SLS) if they want to put something bigger into space.

For LEO, Atlas V Heavy is 30 months away from launch after getting a customer order, and it will put 28% more mass (64,820 vs 49,470 lb) into LEO than Delta IV Heavy.

For GTO, Falcon 9 Heavy, which is advertised for $95M/launch, can put almost 50% more mass up than Delta IV Heavy (28,860 vs 42,990 lb).

Neither Atlas V Heavy nor the far less expensive Falcon 9 Heavy have any customer demand. If there was customer demand for these bigger launchers, then one could make the argument that the trend for ever bigger payloads will continue. But as of now that trend does not exist, and the biggest near-term launchers are not needed.

Congress and others saying there is a need for an HLV does not mean that there is a true need, only a perceived one. Hard to pay the bills with perceived money…

“As the 80-plus history of modern rocketry shows, the ‘advances’ you champion have been made by government funded and managed space programs, under many guises, for geopolitical ends, not for financial interests.”

What are the advances I actually champion here? Re-read for comprehension my comments.

“For profit, free-enterprised efforts have never lead the way in this field and in the wealthy Western nations, it was, in fact, starved for funding and any investment for advance reactive rather than pro-active; a follow along, cashing in where it could.”

I am not even sure this makes sense. You’ll have to expand a bit on your “reasoning” here…

“It’s a fools errand to believe anything close to ‘Reaganomics’ is going to fuel the expansion of the human experience out into the cosmos.”

What the heck does Reagan have to do with any of this? Just because I support commercial exploitation of space does not mean I support Reagan’s economics. Nor does it mean that for anyone with ideas similar as mine.

Oh well…

“But ambition can get out of control, and bring things down to a more…realistic level.”

Just like Constellation did.

“They will have at least one (maybe more) “learning event” before all is said and done. And hopefully no one gets hurt or worse as a result-but that comes with this territory.”

What kind of comment is that? This is all you have to offer to fellow engineers who work damn hard to make HSF stay alive in the US? Pathetic.

“HLV can have more than one customer besides NASA: DOD and the intelligence community have a need to lift big things into orbit-LEO and GEO. Get their input on what their requirements are before settling on a final design.”

Nonsense, if they did they would have requirements out via an RFI, RFP etc.