QUOTE (djellison @ May 6 2014, 10:24 PM)
Both heatshield and parachute's have already been thru initial testing... The first of three atmospheric tests comes later this year.
Well and good. My understanding is that Mars missions are booked through the end of this decade. So if it's going on a spacecraft, it's not happening before the 2022 launch window at the very earliest. No?
QUOTE
Dawn increases upon the Delta V of DS1 by nearly an order of magnitude. 1.3km/sec -> 10km/sec. That's revolutionary.
Yes, it is -- but we're discussing design, and Dawn's design is conservative.
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The only reason Sunjammer may not fly is budgetary - not conservative engineering or 'enthusiasm'.
Budget cutting isn't some automatic process; there are presumably reasons Sunjammer got cut instead of something else. My point is, while IKAROS provided an impressive proof-of-concept, at the moment nobody is building on it. I don't know of a deep-space mission using solar sail propulsion that's scheduled to launch in the next five years; do you?
QUOTE
I would urge you to do a little research of your own - and ponder Mike's question
Let's compare the current decade, 2011-2020, to another. Picking the 1960s or 1970s would seem a bit unfair, since those were periods of explosive development and experimentation. So let's choose something more recent: 1991-2000. We'll include only missions that launched during the decade, so that leaves out Galileo, Magellan and Ulysses at one end, and Mars Odyssey at the other. From memory and brief googling, here's a partial list of significant missions.
Clementine
Yohkoh
A bunch of early 1990s stuff on MIR that's now mostly forgotten, but was pretty amazing at the time (advanced solar panels, the Rapana truss structure, the Spektr module, etc.)
Mars Pathfinder (and Sojourner; strictly speaking a rover isn't a spacecraft but if we're including EDL architecture, that was definitely something new)
Mars Global Surveyor
NEAR-Shoemaker
Lunar Prospector
Cassini / Huygens
Construction of the ISS involving a whole host of new technologies
Stardust
SOHO
Mars Observer, Mars Climate Orbiter, Mars Polar Lander, Nozomi (not sure we count failed missions, but anyway there they were)
Deep Space 1
Deep Space 2 (ion engine!)
and, right at the end of the decade, the ISS going live as the first astronauts took up residence in November 2000.
I've left out a lot of stuff, obviously. No orbital space observatories, for instance. The 1990s were a crazy time for those, a Cambrian explosion. But I think that gets a little gnarly in definitional terms, so let's leave it be.
Now, this is a list of /missions/ rather than of /design innovations/, and I'll be the first to concede that those are two different things. However, looking at the list, we can see that a lot of these missions involved fairly major advances in design. Cassini, for instance, had to drop a lander on Titan and was the first deep space probe deliberately designed with an eye towards a ~20 year mission. Cassini was originally supposed to be another Mariner mission, but got upgraded and redesigned (albeit at the cost of cannibalizing its sister mission CRAF). So while Cassini certainly uses heritage technology -- its RTG is a standard design that had already flown on Galileo and Ulysses, and its CPU is a 1750A from the early 1980s -- whole chunks of it ended up being rebuilt from scratch. Mars Global Surveyor was deliberately done on the cheap with a lot of heritage tech including lots of stuff recycled from the lost Mars Observer. Nevertheless, it included several design innovations, including the biggest solid state recorder in deep space up until then, a new attitude control system, the first nickel-hydrogen batteries to travel beyond Earth orbit and an upgraded communications system that could downlink at a blistering 85 kbps. And so forth.
So, does 1991-2000 overall look more innovative in terms of spacecraft design than 2011-2020? Less? About the same? It's a sincere question. I'm an interested layman, but many of you are experts. What do you think?
Doug M.