Just another indicator that designers will always try to maximize spacecraft capability for a given volume/weight vs monolith construction
It's good to have these forward-looking ideas, but you don't have to be a systems engineer to look at that thing and cringe at all the stuff that has to go right. Imagine that just one of those mirrors does not fit properly. Or imagine that the arm jams. The result is that the entire telescope could be ruined.
My other concern is what sort of mechanism would you need to keep a good enough wavefront? Isn't alignment the biggest difficulty of segmented mirrors? That mechanism doesn't seems like it includes any sort of active optics (for calibration purposes, obviously).
...What is the difference between such a telescope configured for astronomical observations vs. one configured to look down from GEO for Earth observation? I imagine there are a lot of differences.
It does tells a lot that it was a proposal from an engineering company, not a group of scientists. I even wonder if they had optics engineers. But I digress.
I wonder if DoD have interest in larger satellites, but are restricted to EELV upmass? As such SLS would be attractive with the 70mt opening capacity, but is there such a thing as a DoD satellite that large?
Quote from: Martin FL on 02/07/2012 04:53 pmI wonder if DoD have interest in larger satellites, but are restricted to EELV upmass? As such SLS would be attractive with the 70mt opening capacity, but is there such a thing as a DoD satellite that large?Nope and nope.There are all sorts of upgrades to Delta IV Heavy (or Atlas V) if they need more upmass*.
I wonder if DoD have interest in larger satellites, but are restricted to EELV upmass?
Quote from: Robotbeat on 02/07/2012 05:02 pmQuote from: Martin FL on 02/07/2012 04:53 pmI wonder if DoD have interest in larger satellites, but are restricted to EELV upmass? As such SLS would be attractive with the 70mt opening capacity, but is there such a thing as a DoD satellite that large?Nope and nope.There are all sorts of upgrades to Delta IV Heavy (or Atlas V) if they need more upmass*.That's a very definitive statement to make, are you in a position to do that? Also I missed the upgrades, when are they coming on line?
I believe the plan was to phase out the RS-68 and replace it with the RS-68A, which would allow ULA to use a more-common Common Booster Cores instead of ones that are optimized for the mission at hand (i.e. it would allow them to manufacture all of the medium cores with solid attach points).
I believe (and I could be wrong) that somebody involved in the RS-68A told me, perhaps 3-4 years ago, that the impetus for developing that engine was an upcoming launch. They needed it for a specific launch, not just an overall upgrade in capability.
what a RAND launch study of 2006 implies, it was a significant factor in motivating development of the RS-68A.
I've heard a couple of launch vehicle industrial base presentations in the last few months, but forgotten most of what I've heard. I do know that USAF is primarily interested in a better upper stage engine. They think they have maxed out performance there and they need to get something better than the RL-10. I believe that the drive for that is to regain margin, not because they are building even bigger payloads.
Quote from: Martin FL on 02/07/2012 05:14 pmQuote from: Robotbeat on 02/07/2012 05:02 pmQuote from: Martin FL on 02/07/2012 04:53 pmI wonder if DoD have interest in larger satellites, but are restricted to EELV upmass? As such SLS would be attractive with the 70mt opening capacity, but is there such a thing as a DoD satellite that large?Nope and nope.There are all sorts of upgrades to Delta IV Heavy (or Atlas V) if they need more upmass*.That's a very definitive statement to make, are you in a position to do that? Also I missed the upgrades, when are they coming on line?Well, the most basic "upgrade" is to move from the Atlas V to the Delta IV Heavy. At the moment, there is no indication of higher DoD demand for Delta IV Heavys. The procurement rate is steady.
What about commercial uses? Could Bigelow, for example, buy a flight at per flight costs?