Carolyn Porco, unlike many of her colleagues in the planetary science community, seems to like Ares V (or at least, she's attempting to make lemonade out of it). Like Jeff Foust, I think that she's being unrealistic (read the comments as well).

While an increase in flight rate for additional missions will bring down per-flight costs somewhat, it will still be a very expensive vehicle to operate, and will cost several hundred million per flight. Where will the planetary science community come up with that kind of money, let alone the money that will be required to develop and build the kinds of megaprobes she has in mind?

No, we won't be able to carry out such grand ambitions until we get the launch costs down. Ares is not on the path to that goal.

Rand

There are complex reasons why the planetary community would like the Ares 5.

First astronomers like large apertures. The problems with the James Webb telescope indicate to most in the community that the 6.5 meter aperture of that scope is the largest that can be stuffed in an existing launch vehicle. The scientific community desperately wants the Terrestrial planet finder. It needs an aperture of at least 10-12 meters. Therefore the fairing of the A-5 is tailor made for their desires. With JWST costing over $5 billion dollars and TPF coming in at considerably more what do they care about launch costs?

Now the counter argument (which I support along with Dr. Roger Angel at the University of Arizona) is that ISS makes an ideal place for building an aperture of N size. However, the planetary science community is deeply ambivalent to humans in space and would probably opt for ground building and testing and A-5 launch simply because most of them do not understand the value of orbital assembly for large apertures.

I have sat in on several meetings of the community and that is my current sense of the issue.

The ISS would be a hostile environment for hosting a large space telescope. If you're talking about directly connecting the telescope to the ISS, you have to deal with vibrations from the human occupants and associated machinery. You'll also have to deal with the risks of contaimination from ISS, Soyuz, Progress, and Shuttle thruster spew. If the idea is to have the telescope fly in some kind of loose formation with the ISS (so it could be serviced) but not directly connected, you can reduce these issues somewhat. However, to stay in formation, the telescope will need a propulsion system (the HST doesn't have one) to match the ISS as it boosts its altitude from time to time.

This is the "build it and we will find a use for it" theory...

Build the space shuttle, the manifest will materialize that will make it cheap to operate...build ISS and WOW everyone will want to do something (not quite sure what but something) on it....now its Build Heavy lift..and then Zounds! (sorry I like that word)

ONe would think that we would have tried this enough in just space policy to where someone would say "lets try something different"...but no.

What was that Star Trek NG episode where they kept repeating the same time loop just with different variations? ONly Data somehow pulled them out of it.

How many loops do we have to do of 1) promising super project, 2) promising it wont affect anything else at NASA, 3) well 2 isnt operative anymore but dont worry it will be great when we get 1 built...and then 4) Ok 1 doesnt work so hot, lets move on back to 1 again this time with a different project?

In the end, unless policy radically changes...we will have spent oh 30 years (1980-2010) flying the shuttle so it can build the station and then saying good bye to the station...for what?

Lets try something different...Wingo (gasp!) has got some idears...but we are at stage 4 of the space station...Its Dead Jim.

Robert

Larry,
I don't think Dennis meant to hook it to the ISS, just to assemble it there, then move it somewhere else.

Larry

Who said anything about it being permantely there? Good lord, how about considering that people who propose BUILDING a telescope there know better than to keep it there.

I would not propose formation flying either for the reasons that you state. The big aperture can be moved from ISS altitude to just about any orbit you want.

Hey Oler

How's that job with Howard Dean working out? Oh and by the way a Southwest pilot friend of mine has some very funny comments about how you conduct your training.

How about focusing on something that you know, rather than on things that you know nothing, let see like space.

glad you have pilot friends Dennis.

LOL

Robert

> The scientific community desperately wants the Terrestrial planet finder. It
> needs an aperture of at least 10-12 meters. Therefore the fairing of the
> A-5 is tailor made for their desires.

Dennis, the case for in-space assembly is even stronger than you state.

The TPF design is an optical interferometer that uses 3.5 meter mirrors, which would fit easily within the small (4-meter) Delta IV or Atlas V fairings. Even the Ariane V couldn't launch a 10-12 meter mirror, since its fairing is only 5.4 meters in diameter.

Ed

RLV's, and or smaller launch vehicles, and orbital assembly are natural complementary technologies. I have been working with a company in New Mexico that is making silicon foam mirrors 1 meter in diameter that only weigh about 5 kilos. Stack several of them up along with the mounting hardware and splat: you have TPF on steroids.

Posted by Dennis Ray Wingo at February 21, 2007 04:37 PM

wave hands..more miracles.

Yeah.

Robert

You know a lot about miracles don't ya.

Oh yea I forgot, your space company failed and you have spent the last 20 years whining about everyone else.

Dennis...

Failure is good for the soul, if the lessons are learned and applied correctly.

And I do believe in miracles...

take care.

Robert