In what is either a misreport or a stunning change of events since my chat with NASA's Ares V man Phil Sumrall in February it appears that the agency is reconsidering ANOTHER stage for the cargo launch vehicle
credit: NASA
credit: NASA
The American Institute of Aeronautics and Astronautics' Aerospace America magazine's August issue has an interview between Frank Sietzen jr and Sumrall inwhich its reported that an ongoing trade study is considering an expendable stage between the core and Earth departure stage. The two third-stage options that were considered can be seen on the right hand side of the portion of a presentation slide shown below
credit: NASA
According to this NASA presentation these options were considered last year. Talking to Sumrall in February he said that the three-stage Ares V was dropped as an option because you ended up with a 122m (400ft) rocket and there were also additional costs involved in developing that third stage
So what has happened in the meantime?
credit: NASA
According to this NASA presentation these options were considered last year. Talking to Sumrall in February he said that the three-stage Ares V was dropped as an option because you ended up with a 122m (400ft) rocket and there were also additional costs involved in developing that third stage
So what has happened in the meantime?
on August 18, 2008 5:21 PM | Reply
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a three stages rocket can be made, is more efficient and may work well (the SaturnV is a good example) but it adds costs and some risks on reliability (with three stages the failure risks could be 50% higher)
however, in my latest "Ares 33" concept, I suggest to design it in a different (better) way:
http://www.ghostnasa.com/posts/034ares33.html
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on August 18, 2008 6:40 PM | Reply
Is there evidence NASA is still considering a 3rd stage for the Ares V? This chart shows that it was considered in early 2007, over a year ago.
on August 18, 2008 7:34 PM | Reply
Maybe this generation of NASA folk just realized that it really is "Rocket Science" and that it is hard!
I can't help thinking that they would have been better off with a clean sheet of paper to start with. Using heritage hardware is fine but there are going to be so many changes that most of these vehicles will effectively be new. Then comes the Test and Integration phase, not to mention man-rating etc.
on August 19, 2008 11:28 AM | Reply
Read the Aerospace America article
on August 19, 2008 11:56 AM | Reply
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to be exact... the standard Ares-5 already IS a three stages rocket: 1st 2xSRBs, 2nd 6xRS-68, 3rd 1xJ-2X
the fact that two of these stanges (SRBs and core stage) are side-mounted, doen't means they actually are TWO full stages!
then, we must consider the NASA's study published here as a true FOUR stages rocket
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on August 19, 2008 12:00 PM | Reply
I know the Russians like to call strap-on boosters first-stages but I prefer the US approach. I always saw stages as being integral parts of the rocket while strap-on solids aren't. You have the option of removing strap-on solids, you can't remove a stage. And anyway third stage is easier to put into a headline than "a new stage between the core and Earth departure stages"
on August 19, 2008 12:27 PM | Reply
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"doen't means they actually areN'T TWO full stages" (sorry for my english grammar...)
in my opinion a "strap-on" is a small solid engine that only HELP to increase the rocket's payload (just see the Delta IV Medium family) while a "stage" is something of absolutely necessary to REACH the orbit
from this point of view, we can't consider the Ares-5's SRBs as "strap-ons" but as two full stages, since, without them, the Ares-5 (simply) can't have a lift-off... (despite, personally, I think it can't have a lift-off not even WITH the SRBs... according to my SRB5 and Ares-1 articles)
of course, the Ares-5 could fly without the SRBs but only resizing its LEO payload to (about) 40-45 mT
so it's no longer an "Ares-5" but another rocket (maybe, we can call it "Ares 2+")
the last point is about the calculations of the Ares-5 reliability, LOC/LOM, etc... also if we don't call it a "three stage rocket" it really HAS three stages, or, to be exact, "FOUR things that must all work ok to have a successfull launch" 1st SRB, 2nd SRB, core stage and upper stage/EDS (or "nine things" in total, if we consider that ALL engines and motors must work well) so, it's always MORE reliable of an Ares-5 with a further stage and LESS reliable of a true "two stage" rocket
that's very important to know especially if (someday) the Ares-5 family will be man-rated to accomplish a single-launch lunar mission like the Apollo's SaturnV
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on December 2, 2008 10:03 PM | Reply
I just wish someone would make a rocket that threw about 5 times what the Saturn V did, so we could get on with building awesome, giant space infrastructure while I'm still around to see it.