Slashdot Mirror
Separate Cargo and Personnel Missions for NASA?
l8f57 writes "Hal Gerham (from the NASA CAIB report) is calling for cargo and people to be separated into different missions. He also goes on about how a re-usable spacecraft may not be the most cost efficient vehicle."
I believe this is about minimizing cost and lead times, not risk reduction.
I think the idea is that each type of ship would have different requirements, so you could design each to meet the requirements of its cargo, be it human or stuff.
Ie; a cargo shuttle full of tiny screws to be sorted in space doesnt need fancy atmospheric systems and oxygen recirculators and a seven million dollar toilet, etc.
The Russians did this, all through Mir. They had the Soyuz (sp?) rockets for people, and another kind to send supplies up. Or something like that.
I don't need no instructions to know how to rock!!!!
Cargo is already sent up separately from crews... it's just that people have never really tried to meet back up with it...
An article written about the idea, this year:
Space Elevators Maybe Closer To Reality Than Imagined
Much more info here:
The Space Elevator Reference
CB
free ipod and free gmail!
Who needs a lousy space station? It's TV science, with no practical value that couldn't be achieved much cheaper and with no loss of life.
ScienceSeeker.org
Why continue to run the shuttle? Why not just use the money for fast development of new vehicles? Cheaper to buy Soyuz/Progress rockets from the Russians for now..
:-)
Now isnt that ironic - The US would end up having to buy what is essentially much the same rocket that Uri Gagarin used in 1961..
"You lied to me! There is a Swansea!"
I think this idea is post shuttle, not separate human/cargo shuttle flights. You design a small, safe dedicated people carrier. 4 seats, about the size of a small business jet. Payload - 4 human beings, kept very safe. Allow each human half a ton, including space suit, enough oxygen and water for a couple of days in orbit in case things go wrong. No food - you wont starve in two days - and minimal toilet facilities. Payload two tons. Keep one on standby for rescue duty; can launch unmanned, so can bring back 4 astronauts in a hurry. Don't compromise the design for military reasons, as the shuttle was; the cold war is over and anyway it will only carry people, so secret gismos.
Send the cargo up on disposables - Atlas, Delta, Ariane. We know how to build them, and their 99% reliability is acceptable for cargo whereas it would be totally unacceptable for freight.
The people carrier may be re-usable; it will be relatively light and will carry a lot of expsnsive safety equipment. But let the engineers decide, not the politicians. If disposable is cheaper, for the desired level of safety, go disposable. Probably not all disposable - it might have something like the Saturn's launch escape tower.
Once you have a component, rather than monlithic, system, you can start on other interesting developments like a dedicated Earth Orbit to Lunar Orbit ferry - and so on. You make rational decisions instead of being blinkered by a huge white elephant. The ISS, while (currently) needing the shuttle, also makes it obsolete: it provides a rendezvous point for people and cargo.
Consciousness is an illusion caused by an excess of self consciousness.
Actually no. The Challenger accident was not a statistical failure of the shuttle so it should not be included. Engineers knew the boosters were being operated outside of their specifications. Once someone decides to launch outside of operating parameters all bets are off. So your past performance for at least one failure shouldn't count because you were operating outside of specs.
Excessive forking causes un-wanted children.
You can't move all combustible and people at the same time. You need to prior upload all combustible, and merge people+ship+combustible on the fly.
Other option is to generate your own combustible on the fly:
go to mars with 50% combustible, generate 50% at mars.. and return.
My english is crap
-Woof woof woof!
One might suspect the odds are 1 in 65, but they'd be wrong. If I flip a coin twice and get heads both times, I might suspect the odds of getting heads are 1 in 1.
All you're saying that the ratio of failures to successes is 1:65, this has nothing to do with oddsmaking, though it could be a parameter.
Go to Vegas and have a chat with some real oddsmakers. The fact that some sports team is 12 and 5 for the season doesnt mean they have 12:5 odds for the superbowl.
I don't need no instructions to know how to rock!!!!
Getting into outer space isn't that hard. The problem lies in designing ships and rockets that can get into outer space and _come back_. If we just leave out that last part, the design process becomes much easier and the costs much lower. All this concern over coming back down is just so much balderdash. I bet if you polled all the astronauts and would-be astronauts, the great majority would prefer to just stay out there. Just strap a big can on top of the rocket with some acceleration couches and you're all set.
---- El diablo esta en mis pantalones! Mire, mire!
Agreed, using the same vehicle for crew and cargo clearly compromises safety and capability for both.
I'm a bit perturbed, though, by the idea that we should go back to launching crew in single-use vehicles a-la 1960. Sure, it would probably be safer than the shuttle, but (and I'm getting tired of hearing it) safety should not be NASA's primary goal. If you want safety, stay home already. Safety as an open-ended goal cannot be satisfied; it is both a money sink and a rhetorical ace-up-the-sleeve. Witness the current "safety from terrorism" efforts.
Part of NASA's reason for being is to advance the state of the art for the public benefit; redeploying fourty year old technology won't do that. The purpose of the Mercury and Gemini projects were to make mistakes and learn from them, to eventually culminate in Apollo. The shuttle is the Mercury of reusable ships. Twenty-five years between technology generations is far too long. Let's learn from our mistakes and (with the cargo-carrying requirement dropped as a mistake) build the next generation shuttle already.
Reusable crew vehicles are ultimately preferred, as they have greater inherent capacity for safety than single-use craft. Which flight of an airliner would you rather be on - its 1000th, or its very first?
Launch the cargo on big dumb boosters but develop an elegant, safe way to get people to and from LEO .
If I remeber correctly, the delta-t argument goes something like this: you have observed an event/situation but have no idea how typical/un-typical your observation could be. But using logic and probability you can say there is a 50% chance that the period during which you saw these events will continue for between 1/3 and 3 times the period of the original observation.
There is a 50% chance that between one and six (yeah, bear with me) additinal shuttles will be destroyed in in the next 5 - 45 years. Unless things at NASA change eg they run out of shuttles.
I've got an even better reason for sending up seperate cargo missions: you can leave the containers up in orbit.
See, you have just spent a lot of cash to boost tons of container material up into space. Why would you then waste the money spent to get it up there when you could instead re-use the containers themselves? If the containers were designed in such a way that when they were emptied they could be hooked together, pressurized, and turned into modules for space stations then you would have a great recipe for an easy and less expensive space program. You could even do this with some of the top fuel tanks used to boost the containers into orbit.
The personnel missions can now be much smaller and more efficient because they don't need to boost up a large amount of container material. You just boost up a personnel module and then have it splashdown at the end of the mission. Design that part well and it can be reused also.
With this sort of setup virtually everything is reusable except for the lowermost booster sections and the fuel. Yes you can probably make the lower boosters reusable but that has been shown to not be worth the effort.
Sapere aude!
This is silly. Even a return of 10 lottery winnings out of 200 doesn't mean your odds are 1 in 20. It just means you were lucky. The odds are based on the total number of tickets sold. This is a very bad analogy. As for the shuttle, the design is fairly safe. It is the implementation and follow-up that sucks. Even a perfectly safe car can't be saved if there is an idiot behind the wheel. The Challenger disaster was not a design "flaw". It was launched outside of it's specs. A stupid "human" error. The Columbia on the other hand shows a serious flaw. These foam pieces have apparently come off in several flights. NASA simply decided that if it wasn't a problem before, it wouldn't be again. Once again, we have poor judgement as the primary cause of the accident. No design, no matter how perfect can be made to prevent human error...unless the humans are removed from the decision making process. One thing you can do though is simplify the design. This allows fewer opportunities for stupid human errors. I think this is what they are suggesting. Seperating the crew from the cargo allows for two much simpler designs to be flown. Plus, the majority of the focus can be spent on the crew vehicle without worrying about the cargo. I wholeheartedly disagree with the assumption that NASA cares more about cargos than people. The fact is, they have lost several cargos over the past few years on Atlas and Titan rockets. It's no big deal. Some satellite builders actually build 2 at a time just in case they lose one. The price of the "2fer" is what is quoted as the price of the satellite, although they actually built two. Usually, you never hear of them talk about the 2nd one because it simply isn't newsworthy" On the otherhand, when people die, people at NASA lose jobs, careers, and lots of people look down on them. There are huge investigations, congressional inquiries, and flights stop. This is not beneficial to the organization, so it is always in their best interest to protect the lives of the crews. To think otherwise is just plain ignorant.