Antares was my choice for SLS's name!
We can scratch that one off the list I guess.
Orbiter
I like it, tho one thing bothers me about this design: why choose a solid upperstage? Performance-wise that doesn't seem like a very smart move to me, as solids usually have a pretty low isp, no?
There have been improvements. Castor 30 provides 301 to 303 sec ISP, closing the gap a bit on, say, gas generator hydrocarbon liquid alternatives. A solid upper stage could prove more reliable than a liquid upper stage that uses cryogenics, though that is not guaranteed. In addition, a solid upper stage requires less work (umbilicals, propellant loading) on the pad, etc.
Of course a real issue was lack of liquid upper stage alternatives in the U.S.
- Ed Kyle
Well, it may be slightly lower performance but in an upper stage it matters a lot. Plus a solid upper stage is inflexible wrt to restart and has lower insertion accuracy all things compared. I understant that you are focusing on the upsides it may have, but it's still a bad idea.
In the past did they not talking about some sort of HAPS derivative to address the accuracy issue.
I like it, tho one thing bothers me about this design: why choose a solid upperstage? Performance-wise that doesn't seem like a very smart move to me, as solids usually have a pretty low isp, no?
There have been improvements. Castor 30 provides 301 to 303 sec ISP, closing the gap a bit on, say, gas generator hydrocarbon liquid alternatives. A solid upper stage could prove more reliable than a liquid upper stage that uses cryogenics, though that is not guaranteed. In addition, a solid upper stage requires less work (umbilicals, propellant loading) on the pad, etc.
Of course a real issue was lack of liquid upper stage alternatives in the U.S.
- Ed Kyle
Well, it may be slightly lower performance but in an upper stage it matters a lot. Plus a solid upper stage is inflexible wrt to restart and has lower insertion accuracy all things compared. I understant that you are focusing on the upsides it may have, but it's still a bad idea.
Which is what HAPS and the Star 48 optional third stages are for.
It was just an available constellation name.
Star, not constellation!
http://en.wikipedia.org/wiki/AntaresAntares is the beating red heart of Scorpius. Interestingly, it's one of the brightest stars close the ecliptic, apropos for planetary missions.
It was just an available constellation name.
Star, not constellation!
http://en.wikipedia.org/wiki/Antares
Antares is the beating red heart of Scorpius. Interestingly, it's one of the brightest stars close the ecliptic, apropos for planetary missions.
... which is why I expect a press release any day now renaming the Cygnus spacecraft to the Scorpio!
To be really pedantic, the name of the constellation is Scorpius; Scorpio is the associated astrological sign.
