This is just not true. I worked on three of those servicing missions as an engineer. They were required to keep HST running and to enhance it's capability. Adding COSTAR to fix the mirror fuckup was one tiny piece of the servicing missions.
There were 6 Hubble missions all of them where manned.
I suggest that the savings of using unmanned missions, not making a serviceable telescope, and saving 1 full trip would have paid for construction of 4 additional telescopes with minor design updates for instruments and or fix bugs but no changes to major systems. With the added advantage of not risking astronaut lives on a publicity stunt.
How would you have gotten even one HST sized telescope into orbit without a manned mission? Do you know what life span of a Hubble would have been if it were not serviceable? Your approach would have cost more, not less. More manned fights, more time consuming, expensive design and construction. Believe it or not, they thought about this stuff.
The James Webb Space Telescope is ~5x larger than HST, and it will be launched on an Ariane 5 rocket, with a lifespan goal of 10 years and no opportunity for repair or replenishment. You should ask them how they can deploy such a large telescope without a crew. Or ask the NRO how they launch a KH-11 spy satellites, which is the same size as Hubble, and launched on a Delta IV Heavy rocket.
Hubble was built assuming shuttle launches would be cheap. It wasn't.
Fair point on launching big stuff - I suppose that a Hubble derivative could have been designed to work with one of the bigger rockets. But a hoped for lifespan of 10 years is not even close to what you get out of Hubble servicing missions. The ability to improve and repair a working telescope is not without value. Things go wrong all the time with these instruments. No serviceability = higher risk.
You can indeed adapt your designs for unmanned launches and get a good life span out of them, but there are significant tradeoffs to doing so that impact the mission.
Further, there is value in manned missions just because. How are we to gain experience operating in space without sending people there?
There's a question of cost though. Each repair job costs about $1 billion and has a ~1% chance of killing the crew. (When Hubble was designed, it was thought that the Shuttle would be cheaper and safer than it was.)
If we could build an launch a Hubble for $1 billion, then it's obviously cheaper to send up a new one than repair it each time. If it lasts for 10 years, then if the unit cost to launch were under $3 billion then it would still be cheaper to launch a new one than fix one in-place.
So how much did Hubble cost? Wikipedia says $2.5 billion to construct. http://www.nasa.gov/pdf/499224main_JWST-ICRP_Report-FINAL.pd... says "Again, to put this in context, HST, which was a much less complex mission [than Webb], had a total cost-to-launch of approximately $5 billion in current dollars. Hubble’s LCC was approximately double this because of servicing costs over 20 years." (Those are 2010 dollars.)
Hubble also had huge cost overruns. The KH-11 has an estimated unit cost, including launch, of US$2.26 to 3.16 billion in 2015 dollars, says http://en.wikipedia.org/wiki/KH-11_Kennan#Cost . We've built several of those, which I assume helps reduce the per-unit costs.
If we could get the Hubble-like unit cost, including launch, down to $2.5 million, and with a 10 year life time, then we could launch 4 for what we've spent on Hubble, and lower risk through redundancy. "No serviceability" = "cheaper design" = "can launch more" = "lower risk". Again, this is based on the experience since the 1970s that manned missions are expensive and risky.
Regarding just because - your original question was "How would you have gotten even one HST sized telescope into orbit without a manned mission?" That's all I'm addressing.
Yeah - I take it back - I spoke too quickly. You can certainly launch large satellites with rockets. I was too focused on Hubble specifically.
That said, I remain deeply skeptical of the idea of being able to do so cost effectively or in a way that allowed for iteration and development of the systems. That's a lot of eggs in one basket to make 4 duplicates - they'd all fail in the same ways (which Hubble did early and often) and they'd be space junk in a heartbeat. You'd also want different cameras, which would have different requirements, etc. Once the contractors got a hold of that, they'd wind up 4 separate projects costing a fortune, and you'd be right back where you started, except without the budget. Keep in mind how long it took to build the HST. A servicing mission turned around in about 3 years.
It wouldn't be duplicates. A better plan would reuse the same chassis, and have a staggered production. There have, after all, been 16 KH-11 satellites over 30+ years; they surely didn't all use the same technology.
Part of the reason for the expense of HST comes from the delay after Challenger. Hitching it to the success of the Shuttle helped make it more expensive.
You are right though that it plays to the sunken cost fallacy. Hubble happened because the initial budget was low. Then it ballooned. Congress would likely not have budgeted $10 billion if they knew that was going to be the final cost of Hubble. It's even less likely they would have funded four space telescopes for that price.
As to lifetime, we don't need a 30 year lifespan. If you average 6 years * 5 satellites you get 30 years and I suspect we could easily average 8-10 years.
As to thinking about this stuff. Clearly, but Hubble was specifically designed to make the Shuttle seem more relevant. Just about all of the major decisions where made for political not technical reasons.
Every decision at NASA is political - it's a government entity (look up Triana - that's another one I worked on. It's laughably ridiculous). But you're grossly oversimplifying. There isn't a prayer in heaven that would keep Hubble alive for 10 years on its own. Hubble made sense as a shuttle payload for a lot of reasons. I'm sure someone could have cooked up alternatives, but the one we got obviously did some good.
As government programs I think both Hubble and the Space shuttle where significantly better than average. Realistically redundancy is the first thing that gets cut at budget time etc etc.
Still, what makes you think building a Hubble equivalent that would last 8-10 years is outside the realm of the reasonable when Hubble is expected to last 7 or 8 years after the last servicing mission.
What you're saying isn't crazy. I guess I don't have a lot of faith in their estimates. NICMOS was supposed to last something like 4 years if I remember correctly. It died in about two. A whole slew of gyros failed, degrading performance, and jacking up schedules so we could replace them. COSTAR is a pretty obvious failure that wasn't fully recovered from (COSTAR took up one of four slots that were meant for instruments). Lots of stuff goes wrong. But maybe they could have designed a Hubble-class telescope that would last ten years back then. I don't know for sure. My gut says the first one would have been a piece of crap with a bad mirror and shitty gyros. That's a lot of work to throw away.
Either way, would launching three (or six or whatever) of those on rockets really have been cheaper than the Hubble in terms of science/dollar? I have some serious doubts. Throw in the politics and overhead of three major missions, and you're talking big numbers.
And that ignores the intrinsic value of manned missions for their own sake - you must do them to get good at them. There are people who say that we should never do a manned mission, and that all the data we want to collect can be had by unmanned satellites and whatnot. While it may be very close to true, that's a very short-sighted point of view in my opinion.
I get what you're saying, and I agree it's possible. But I think the position you're taking is too strong, in that you seemed to have accepted that it must be true. I think that what you're saying is reasonable, possible, and could be the case. But I don't think you have enough information to claim so strongly that it is certainly true.
That’s probably the most reasonable statement I have ever seen on the internet.
I try to judge past decisions in context not just based on what worked. At the time we did not know that each of those servicing missions would work or even if the initial launch would work. Though, clearly one path worked and the Servicing missions where incredibly valuable experience. But, they could have also cost a shuttle and several astronauts lives. Granted, the odds of multiple telescopes being sent up in a fairly short time period is tiny so it's only reasonable on a technical level.
In the end I think the Hubble program is completely justifiable, but that justification needs to be about more than just a quest for pretty false color pictures or worse an example of the sunk cost fallacy.
You bring up an interesting point regarding astronaut safety. It's interesting to me because I have the polar opposite opinion. This will sound cold, but astronauts are basically expendable. We can expect a small percentage of them to die. Much like in the military, the mission takes priority over safety, which comes second.
Given that we have no shortage of astronauts willing to accept that, and that we do put a ton of effort into their safety, I have no qualms whatsoever pushing the limits of what is possible. I've met a lot of astronauts - I don't recall meeting a single one who didn't fully understand how dangerous the work is. It's not for everyone. Personally, I think they're nuts to take that risk for what amounts to floating around in a stinky can for a few days, punctuated by brief stints of mechanic duty.
This always struck me as a major disconnect between the brass at NASA and the engineers. The higher up the chain you went, the more concerned with safety, politics, and perception they were, and the less concerned with what I would say the true goals of the space program are - the actual exploration of space.
Hubble was specifically designed to make the Shuttle seem more relevant.
It flows both ways. Hubble was designed to take advantage of the planned capabilities of the shuttle, but also, the Hubble was an important use case in setting shuttle requirements. And as I pointed out elsewhere in this thread, the shuttle dropped the ball on many of these, both functionally and in terms of delivery dates.
