The weight figure is not yet well established. Actually, we have a big advantage because of the removal of one J-2X engine, that saves about 2.4 tons, but with all the additional equipments, the overall weight is not expected to be lower than the regular Quasar 452 upper stage.
Could the BLEO propulsion module be used for other purposes? Say, you wanted to send a probe somewhere, like the outer solar system, but you had to do it really fast for some reason. Could you attach the probe to the top of one of those stages and would it work?
You want to launch your probe, then the propulsion module, dock it at the probe (but the docking ring is sized for Starlab!) and then perform the escape burn? This can give some advantage, but is a complicate and expensive plan for an unmanned mission...
If you want to launch very small payloads, the dry weight of your final stage is the ruler: you will be surprised to find that, for a tiny New Horizons-class probe, you can obtain a similar escape velocity with a Jarvis rather than with the colossal Quasar 452. In fact, until a payload of 5,000 kg, Jarvis M has a slight advantage on delta V for BLEO missions. Obviously, for heavier payloads, the things changes radically... Quasar is developed for really heavy payloads, not counting that in a real world could be really too expensive for launching a New Horizons 2 space probe. You want launch it
really fast? Put a solid kick-stage on top of a Jarvis E. You can obtain more and with less complication ;-)
---------- Post added at 01:34 PM ---------- Previous post was at 08:18 AM ----------
The red and blue markings on the Canadarm are glowing at night; can be useful for understand the orientation of the arm.
This is what I meant (my poor english don't allow me to explain better):
Wrong:
Wrong:
Right:
Useful when you want to fold the arm after use.
