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Shuttle Set for Launch on Dec 18th, Says NASA
Tony J Case writes "Just a quick note for you guys - According to space.com, NASA's target date for the next shuttle launch is Dec. 18th, with a whole bunch of new guidelines."
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The new guidelines:
No night launches for the foreseeable future.
So they can see any stuff that falls off better.
A revamping of mission management from the ground after a shuttle crew takes off.
So when bad stuff happens, someone actually does something about it.
Jettisoning the external tank during orbital daylight.
So they can see any stuff that falls off better.
And under consideration:
Limiting shuttles to flights to the International Space Station or the Hubble Space Telescope.
So they can see any stuff that has fallen off better and so they have a place to stay when bad stuff happens.
Keeping a second shuttle on standby when a sister ship launches.
So when bad stuff happens and someone actually does something about it there's a way home.
To me it seems like most of these new guidelines are things that should have been taken care of before any accidents happened. Did you know that foam has fallen off the "bipod" of the shuttle's tank "on at least six other shuttle missions." Why was nothing done about this previosly?
Hopefully now they'll be willing to put the extra effort (read money) in that it will take to make space flights safe(r)
I have often regretted my speech, never my silence.
-Xenocrates
I really can't believe they're actually resuming Shuttle flights. I was worried that we would bury our heads in the sand for a few years like we have after similar accidents in the past.
I'd still like to see an actual, cheap, reusable space vehicle though.. The shuttle isn't so hot on that front (no pun intended).
GeekNights!
Late Night Radio for Geeks!
Continuing to fly the shuttle,l and explore space is definitely the best memorial they could ever give to the people on Columbia.
Maybe they should think of some better uses for the shuttle than literally shuttling stuff back and forth from the ISS.
It's time for something new and exciting.
Disagree all you want to, I'm just happy that the space program was not ended.
Fly on, NASA.
There is no reasonable defense against an idiot with an agenda
:wq
discovery.com is just now reporting a new problem with the shuttles; the force of the exploding bolts that detach the boosters has been found to be too close to the strength of the dome that catches them. they predict that this will ground them further.
Perhaps it's time for NASA to take a look at how the Russians handle things -- their track record for the last 25 years is much better. At least no fatalities, and guess who had to step in when the US didn't dare send up another shuttle to rescue the stranded ISS 'nauts.
Regards,
--
*Art
Without getting overly technical, that's not feasible because it's necessary to have a significant percentage of the thrust be variable and steerable. While the SRB nozzles can gimbal a bit, the thrust is totally predetermined. Also, I don't see sitting next to huge steel cylinders of ammonium perchlorate/aluminum powder as being safer than the cryogenic gasses used by the SSMEs. There was much resistance at the outset of the shuttle program to using solid fueled boosters on a manned vehicle, and those concerns are still valid. No, I'm not a rocket scientist.
Dec 18, LotR: RotK, or the shuttle.
:D
Guess which I'm more excited about.
... to see that this useless vehicle is put back into operation, wasting money that could be spent for good space science and efficient transportation.
A winged vehicle has nothing but disadvantages, except looking nice on TV when landing:
- Wings impose a huge weight penalty
- Re-entry with wings is unstable and requires active control
- Wings are vulnerable due to their large surface
The space shuttle is anything but re-usable. The boosters are not re-used, the tank is lost anyway and after landing, the shuttle is completely dis- and re-assembled.
State-of-the-art expendable launchers can haul people into space (and bring them safely back) at a fraction of the cost: use a ballistic capsule with escape rocket and a parawing for enhanced flexibility during landing.
The shuttle's only purpose is to fly to the ISS. The ISS's only purpose is to justify the existence of the shuttle. For the Hubble telescope alone, the shuttle would never have been built.
Its going to make the shuttle one incredibly expensive taxi service for the ISS.
When the shuttle launches equipped to dock with ISS, it has an ammount of its payload bay consumed with the docking adapter.
If the shuttle is used for the originally slated US module launches, this would indicate a valid use (although still very expensive in comparison to a Soyuz module launch).
Now, here's my thinking. The Shuttle was a severe compromise of an originally good system (Flight launch Horizontal TakeOff and Landing) but ended up with the return vehicle pointlessly (and expensively) attached to an SRB+LOX rocket system.
NASA is now likely to resume using the Shuttle - apart from anything this is quite political with China probably joining the elite club of nations who have launched people into space later this year. What NASA ought to be doing is saving the pennies by retiring the shuttle - not neccesarily immediately, but soon and putting out to tender a contract for a brand-new cost-effective launch system.
The new system could be based around the original Ho.T.O.L concept which was mean to be the Shuttle.
At the same time, NASA can be doing lots of new research into aerodynamic re-entry to safeguard lives in the future (FYI 2 aero-re-entry incidents to date - 1, X-15 and 1, STS).
The major sticking point is simple: The U.S. government would have to get their wallet out!
Ripping an new rectum in the fabric of spacetime.
One thing to remember is that most of our rocket technology is based around getting ICBMs off the ground, and over the horizon. In other words they are designed around high thrust to weight ratios, and fairly high G forces.
There have been a few other concepts for rockets, including variable thrust and SCRAM jets, (for the in atmosphere portion at least) that do not have the same requirements for thrust to weight, and can be less costly to operate.
Another observation is that there are several alternative launch mechanisms that do not require nearly the volume of fuel that the current mechanism does, as they launch from higher altitudes, or from launch platforms that are already moving in the direction they desire the orbiter to go.
As far as space travel being safe, it is neither safe to stay in bed, nor to get up. And that's without leaving the planet. That's part of life.
-Rusty
You never know...
Its good that America wants to keep sending people into space but I can't help wondering about the politicism of the date.
After all, rumoured to be around December this year, China is preparing to strap a hero of the communist state (a Taikonaut) to the front of an over-engineered Long-March rocket and send him for a couple of laps.
I hope that NASA isn't being asked or pressured to rush things.
In Communist China the rocket launches you!......oh wait......
Ripping an new rectum in the fabric of spacetime.
People, myself included, have faulted NASA for past mismanagement of safety concerns. But my real concern is that they spend billions upon billions of dollars and employ thousands of the brightest engineers and scientists, and still make some of the stupidest mistakes which cost lives and money, but most importantly time.
They have monopolized space exploration in the US far too long and provided a poor model for the rest of the world to follow, which has stifled innovation. They should be handing out research and exploration grants like the NSF does and performing reviews of the results to determine future funding. Not running a single space program for a single space station. All our eggs in one basket, as it goes.
Arguments about the airworthiness of the space shuttle to me are pointless. It is a big machine with lots of parts and carries some risk of failure. It has been show to be able to fly successfully a high percentage of the time. Nothing they do to it will fundamentally change that situation. But by being the only game in town there can be no comparison of risk and no judgements made based on that comparison.
NASA asks us, either fly or do not fly. This is not a free choice, to those of us that wish to see humans fly it means that we must choose the space shuttle regardless of risk or incompetence or anything.
NASA will undoubtedly want more money to increase the safety of the space shuttle flights, but to what end? Any machine can be better maintained or operated, if we collectively choose a single means, and spend our collective resources and will on that means we could be on a fools errand. Like driving a car into the ocean. Sure we can keep tuning our procedures and plugging the leaks, but it ain't gonna get us to the other side. So that basic questions of design or operation are essentially meaningless when one only tries or has a single means. Like voting for the only candidate, the choice presented to us is meaningless. To go or not to go. To live or to die. Of course we must go, as we must live.
Or do we? Maybe, when such a stark choice is put before us we must refuse to make it. Refuse the question. Should the shuttle fly or not? Ignore the question, it is inconsequencial to that which many of us care about. Space exploration is the purpose and the question, not the shuttle.
Exploration of space is dangerous and will not survive safety concerns of collective action. Liken it to any human endeavor of significant unknown and danger and you will find it must be done by individuals. Individuals that have clarity of vision and certainty of purpose. It must be done by people, not by institutions or incorporations. People who know the risks, people that see the dangers, people that take the leap because they see the oppurtunity. People that learn and reason.
If we are to keep NASA at all, then it must only be to find those people and give them a little bit of money or help. Like Queen Isabella giving Christopher Columbus enough money to get the supplies and men he needed. Not too much money though, because we know that to succeed in Space one will have to travel lightly, and the tendency of people with too much money is to buy things. We know that to succeed in space one needs to be quick, but the tendency of people with too much money is to spend time spending money.
I expect the shuttle to fly again, because there are a lot of people who depend on it for their livelyhood. I expect that the shuttle will fly again because looking at the world a certain way, it makes sense to continue to do what we have been doing for the last two decades. I expect the shuttle to fly again because it is a link in a chain that could mean the end of the space station. Because it would mean the end to an entire generation's way of thinking.
So there it is, the heads of NASA would like us to choose between their shuttle and nothing. Between the aspirations of mankind and bondage to this rock. It is a false choice.
Oh yeah, that's about the brightest idea I've ever heard. SRBs should have NEVER been rated for manned spaceflight...once they're running, they're running, and that's it. No throttling. No kill-switch. You wait until the propellant is gone.
As for the SSMEs not having much to do with getting the orbiter into space I say this: uhhhhh, what?
Here's a great site that explains the physics of the SRBs. Before this page gets Slashdotted to hell and back, I'll recap what it says: each SRB produces 3.3 million pounds of thrust, and each one weighs 1.3 million pounds (191,000 pounds dry-weight, plus 1.1 million pounds of propellant). That means the combined pair can lift about 4 million pounds. The shuttle itself weighs 171,000 pounds (empty, with engines), and the external tank weighs 66,000 pounds. So with a little rounding off, you can add 3.75 million pounds to the stack before you have an equal balance between thrust and weight (which will get you nowhere near orbit). The aforementioned external tank carries 1.3 million pounds of liquid oxygen and 227,000 pounds of liquid hydrogen. More neat rounding brings us to 1.6 million pounds of fuel, 2.15 million pounds remaining. Let's assume the shuttle is carrying its max payload -- 63,500 pounds. Leaves us with 2.08 million pounds.
So:
Booster Stack Weight + Fuel: 4.52 million pounds.
Thrust of SRBs (combined): 6.6 million pounds.
Resulting Thrust-to-Weight Ratio: 1.4.
By comparison, a F-15 has a thrust-to-weight ratio of 1.19, giving the shuttle a 15% advantage, when using SRBs alone.
That's right. I haven't forgotten about the SSMEs. When run at 104%, they provide an extra 488,000 pounds of thrust each. That's an extra 1.46 million pounds of thrust. Thus, our 4.52 million pound stack now has a 8.06 million pounds of thrust, resulting in a thrust-to-weight ratio of 1.78, or a 66% advantage over the F-15. Note that these figures are assuming that the SSMEs are run at 104% from ignition (which they're not), but also bear in mind that as the shuttle burns fuel, which it does as a prodigious rate, the overall weight of the stack is reduced while the thrust remains constant, so as the vehicle climbs, it's thrust-to-weight ratio improves, and continues to do so after the SRBs are cut loose.
Now, IANARS (RS = Rocket Scientist), but it seems to me that if we want to scale up the SRBs so that they alone can carry the shuttle into orbit, the weight of the propellant is going to exceed the maximum thrust of the SRBs before you can get enough propellant for the entire burn into orbit.
What I'm trying to say is this: leave the rocket science to the rocket scientists.
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