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Originally Posted by tbzep
The Delta II family is the most reliable launch system in US history when considering it has over 150 launches. I hate to see it retired. As much as I admire the Saturn family launch record and the immensity of the Apollo project, I don't think the Saturns could match the nearly 99% success rate the Delta II has. With 153 launches, it has one partial failure (lower orbit than intended) and one true failure, both in the mid 90's. I blame the Clintons.  |
Indeed--even if it was "just" because the Delta launch team was troubled and distracted by their "reality TV soap opera." :-) (They’re going to try to launch the Delta II early Saturday morning at the same time as this morning [1:47 AM PST; 0947 GMT], with Sunday as a back-up date.) Speaking of the Delta II's retirement:
I think Boeing and NASA should re-think it, for more than one reason. Launch vehicles got bigger because satellites--which were called upon to do more and more over the years--grew larger and heavier, but today that trend is reversing in many cases, as miniaturized components enable very small and lightweight satellites to do more and more. Now:
Not only can the Delta II--which can fly with just six or three solid boosters if they're all that's needed--orbit lighter payloads (*and* using just its lower two stages, if the solid third stage isn't needed for particular payload mass/orbit combinations, making it able to orbit a wide variety of different payload masses and sizes [using its "straight 8' fairing" or either of its "bulbous" fairings]), but it can also orbit single, dual, triple, or multiple spacecraft. Even the upcoming mission consists of several CubeSats in addition to the weather satellite primary payload, and--as with the recent Minotaur-C launch--the Delta II could carry a large number of all-small satellites, optionally with one of the maneuvering space tug satellite carriers to inject them into different orbits. With these capabilities, it seems unwise to retire this most reliable launch vehicle. Also:
The Delta II's components may also be useful for creating a "Delta II-Lite" version that could orbit still smaller payloads, more cheaply. It could use--depending on the mission requirements--either just the "stretched-Thor" first stage (with no boosters) and the pressure-fed, restart-able hypergolic second stage (it would be essentially a "Super Thor-Able Star"), *or* the liquid propellant second stage could be replaced by a spin-stabilized (or TVC--Thrust Vector Controlled) STAR spherical solid motor, whose size and type would be chosen based on the mission requirements, and:
From the mid-1960s through the mid-1970s, two of the simplest and cheapest SLVs were the two-stage Thor-Burner 1 (Thor-Altair) and the Thor-Burner 2 (there was also, for reaching higher orbits, a three-stage Thor-Burner 2A). These utilized an un-boosted Thor IRBM (or later, a long-tank Thor), topped by a spin-stabilized Altair-type FW-4 motor (Thor-Burner 1), or a STAR-37B with TVC (Thor-Burner 2), while the Thor-Burner 2A used either a second STAR-37B or a smaller STAR-13A solid motor as the third stage (all of these vehicles can be seen here:
http://www.b14643.de/Spacerockets_2...ption/Frame.htm and
http://www.google.com/search?source...1.0.CKJWkQ_Tz_4 ). A "Delta II-Lite" could utilize any of the numerous available STAR motors as second (and third) stages. Such "big first stage" liquid + solid propellant SLVs (South Korea's Naro-1 [see:
http://www.google.com/search?ei=g3Q.....0.geOev6an36M ] is of this type) are simple and inexpensive.