#1
|
|||
|
|||
update FD 1
STS-122 - LAUNCH ENGINEERING REPLAYS http://www.space-multimedia.nl.eu.or...300&Ite mid=2 STS-122 - FLIGHT DAY 1 HIGHLIGHTS http://www.space-multimedia.nl.eu.or...299&Ite mid=2 STS-122 - EXTERNAL TANK HANDHELD Video http://www.space-multimedia.nl.eu.or...298&Ite mid=2 STS-122 - POST LAUNCH NEWS CONFERENCE http://www.space-multimedia.nl.eu.or...294&Ite mid=2 STS-122 - LAUNCH REPLAYS http://www.space-multimedia.nl.eu.or...292&Ite mid=2 STS-122 - ASCENT FLIGHT CONTROL TEAM VIDEO REPLAY http://www.space-multimedia.nl.eu.or...301&Ite mid=2 Expedition 16 In-Flight Interviews - February 8 http://www.space-multimedia.nl.eu.or...302&Ite mid=1 |
#2
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
John wrote:
STS-122 External Tank Venting Liquid Propellent post Separation STS-122 - EXTERNAL TANK HANDHELD Video http://www.space-multimedia.nl.eu.or...298&Ite mid=2 ....really interesting video. In-plane liftoff, increased residual propellent. I wouldn't doubt that the front moving past the cape may have giving the Shuttle a tailwind and an additional increase in residual propellent. Looks like there was plenty of gaseous and liquid propellent pouring out of the tank in the video, really quite spectacular with the sun setting on-orbit, large chunks of ice floating in formation. One of the chucks looks like a fast spinning set of dumbbells. A large blob on each end. Watch the venting, gaseous venting with a very wide plumb, liquid venting a stream of liquid like a hose. Burps of gas. What a shame, all that could have been recovered and used to get to the Space Station or used at the Space Station. Another ET thrown away like trash. Are both the Hydrogen and Oxygen pressure relief valves in the intertank? -- Craig Fink Courtesy E-Mail Welcome @ |
#3
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
Jochem Huhmann wrote:
Craig Fink writes: Looks like there was plenty of gaseous and liquid propellent pouring out of the tank in the video, really quite spectacular with the sun setting on-orbit, large chunks of ice floating in formation. One of the chucks looks like a fast spinning set of dumbbells. A large blob on each end. Watch the venting, gaseous venting with a very wide plumb, liquid venting a stream of liquid like a hose. Burps of gas. It might look more impressive than it actually is, with the sun shining on the plume against a dark background. LH2 streaming into a vacuum is bound to produce a large plume... The venting is done intentionally, so the tank starts to tumble (to make sure it breaks up and burns on reentry). It looks impressive and is impressive. It probably is also quite dangerous to be that close to a stream of liquid hydrogen in space. The Orbiter is hot from ascent, nose, wing leading edge and aerodynamic heating. The plasma show around the Orbiter is also quite impressive at ET sep. Can you imagine what would happen if a Hot Orbiter meets an extremely cold stream of Liquid Hydrogen. The astronauts were lucky the stream of liquid wasn't pointed at them. There are two types of plumbs in the video, gaseous and liquid. The liquid looks like a stream coming out of a hose. It's staying liquid, possibly turning to a solid. An Orbiter getting dusted by Hydrogen snow? Sounds dangerous to me. What surprises me are the large chunks of ice. How did they manage to cling to the tank with all the vibrations and aerodynamical loads of the launch? Having such large, hard and heavy pieces of ice hanging somewhere during launch seems to be more than just a bit dangerous. The large chunks of ice come off the Orbiter, the video of it coming off, bouncing off the tank and possibly the bottom of the Orbiter were discussed in the "At ET Sep" thread. I would agree that it may be a bit dangerous as not every mode that the ice might come off might not have been fully explored. Although it is very close to the tail end of the Orbiter, any possible damage is limited to the aft ET attach point to the body flap. What a shame, all that could have been recovered and used to get to the Space Station or used at the Space Station. Another ET thrown away like trash. Well, you *will* have a propellant margin and you'd better make sure it's a positive margin. And lots of people have moaned about throwing ETs away, but in the end there are not many useful things to do with them. Not without adding lots of mass which eats 1:1 into the actual payload of the mission, anyway. And doing some major redesign. Won't happen. Well it's free to the Space Station if the excess propellent is used or sold when it gets there. One man's trash, is another man's treasure. Just the shear mass of the ET is worth a Billion dollars if you can find something to do with it. At the space station, there are plenty of things to do with it. From simply using it as a warehouse for all the clutter onboard the Space Station, to simply cutting it up into one long strand of wire to experiment with on-orbit manufacturing. 50,000lbs of Aluminum Lithium. A billion dollar opportunity wasted. I'd still like a free ET, at the space station would be nice so I can start right away renting out storage space, to pay for the incidentals required to make it useful. -- Craig Fink Courtesy E-Mail Welcome @ |
#5
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
wrote:
On Feb 12, 7:46 am, Craig Fink wrote: wrote: On Feb 12, 5:50 am, Craig Fink wrote: Are both the Hydrogen and Oxygen pressure relief valves in the intertank? John wrote: H2 in the intertank and O2 in the nose Are there any good places to tap into the LOX tan in the intertank, to recover the Oxygen. There is the main feed line, but are there any others? From the video, all the Hydrogen would be really simple to recover, salvage and use with something on the end of the pressure relief valve. But to use it properly, oxygen might be required. It would take more energy to put the ET in a stable orbit than could be recovered I don't believe that is the case, a stable orbit at the Space Station would be the best place to take it. That way the exchange in ownership could be made at a safe place. Including the excess residual, there is still a little bit of ascent performance by going to a zero gamma at MECO. Something that can only be done if the ET disposal constraint no longer applies. The tradeoff between LOX/LH2 propellent (Orbiter mass + ET mass) is one to one with OMS propellent (Orbiter mass only). Circularizing and finishing the Rendezvous, would be reasonable close to zero cost in terms of payload. It would probably really depend on dispersions, that are probably well within the OMS loading. On a good day, a profit might be made to the space station, arriving at the station with excess OMS propellent over having dropped the ET. Remember, it takes some OMS propellent budget just to get the Orbiter there. Privatizing the Space Shuttle would be great, I'd buy one. It's pretty easy to double the Shuttle payload to Orbit, with very little additional cost. I'd even consider taking paying passengers. Ron Paul in 08! -- Craig Fink Courtesy E-Mail Welcome @ |
#6
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
Jan Vorbrüggen wrote:
Can you imagine what would happen if a Hot Orbiter meets an extremely cold stream of Liquid Hydrogen. Nothing - there isn't enough oxygen around to do any damage by burning with the hydrogen. You are totally correct about hydrogen as fuel in space, no oxygen, no burning, density of the vapor really low, not a problem. But, that isn't what would concern me about this. It's the temperature and mass. As the liquid Hydrogen is being expelled into the vacuum, it's surface is flashing to a vapor, cooling the liquid. The temperature of liquid hydrogen in a vacuum is quite low, small blobs might even cool down to a solid hydrogen or snow. I don't know. The concern is that the density of liquid hydrogen or hydrogen snow is much higher than an expand vapor. A hot Orbiter taking a shower in a liquid hydrogen rain, or hydrogen snow blizzard could cause huge thermal stresses in some of the more delicate and brittle parts of the Orbiter. In particular, the RCC panels are coated with a thin coating of SiC, which protects the carbon panels during entry from burning in the Oxygen plasma. If the density of such a liquid hydrogen shower is high enough and long enough, the thermal stress between the thin coating and the underlying carbon graphite panel may be large enough to separate the SiC coating from the carbon-carbon. Or, separate the surface coating of the thermal tiles. Both are very brittle components. The windows are quite thick, more uniform mass, so would be less of a problem. An entry without the SiC coating on the RCC panels would be disastrous. I was really sad to see that ET spinning all alone, spewing out all the great propellent that could have taken it to the Space Station. A steady stream of liquid lasting 20 seconds or so. :-( -- Craig Fink Courtesy E-Mail Welcome @ |
#7
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
Mike Combs wrote:
"Craig Fink" wrote in message ... Privatizing the Space Shuttle would be great, I'd buy one. It's pretty easy to double the Shuttle payload to Orbit, with very little additional cost. I'd even consider taking paying passengers. After the resumption of Shuttle flights after the Challenger disaster, Gerard O'Neill (of space habitat fame) asked the question what was the Shuttle good for. He decided that the way to determine this was to ask the question, "What does the Shuttle do better than any other space system?" It seemed the answer was to get a large number of people into space and then get them back. He had noted that even before the Shuttle flew, a number of designs for passenger-carrying modules to fit into the cargo bay were starting to "come out from under the ink blotters". One design he promoted would seat 50 passengers on two decks. Fifty passenger, i can imagine that's true. Probably not the best use for an alpha vehicle, but 25 with escape system in the payload bay might not be bad. To me the Shuttle is a fine alpha concept. One that NASA is abandoning for the near futures (20-50 years), in favor of rebuilding an Apollo type program. But, it's a great concept and has more capabilities that are being lost than just carrying 50+ passengers. To me, it's more enjoyable to talk about it as if it was your own vehicle, that NASA would actually privatize the manned space program, at least the Launch/Landing portion. Something the Russians have done to some extent. From a prospective of, if they actually were sold on E-Bay, what would I do with my purchase to make it profitable. The other unique capability besides 50+ passengers, is the ability to bring the same size payloads back. Another is a standardized cargo mass/volume concept, it would be a reasonable standard. Kind of like how containerized shipping has revolutionized international trade. NASA isn't going to build a beta Shuttle, privatization of NASA manned space flight and the Shuttle would be a great step in the right direction. In the private world, the Shuttle isn't really even near optimal for travel between Earth and a Space Station/Motel/City. But it would be a reasonable first step alpha, to follow on with a beta Shuttle in the Private world. There are a lot of things that could be done to the alpha shuttle to make it more profitable in the Private world. Things that would never get done in the Public Funding world of NASA. The first being to treat the External Tank as payload instead of trash. Essentially doubling the payload of each flight. This change costs almost nothing for such a huge gain. Adding a small gas/liquid separator and gaseous H2 O2 low pressure engine to the intertank, and the residuals and unusable become usable, the ET is at the space station with a full payload bay. The smaller the engine the better, but it has to still be capable of completing the Rendezvous in a reasonable time frame. In a follow-on beta shuttle, replacing the RCS/OMS with gaseous H2/O2 engines would be great. Essentially turning all residual/unusable ascent fuel/oxidizer into something useful. Dreaming of how to modify a alpha Shuttle, leads to the next step, a better beta Shuttle optimized to go to a Space Station/Hotel/City. Treating the External Tank as payload helps build a Space Station, Hotel, City, Manufacturing, Industry. A few million lbs of Aluminum in Orbit would be quite valuable. Once the ET is thought of as payload, then other modification to it become more obvious. Things that don't cost much in terms of payload, but increase it's usefulness. Obviously, this might include a larger access door in the bottom of the ET. Maybe, even the whole docking adapter. And now NASA wants to abandon the Space Station, in favor of a Moon Base/Station. I hope Congress is smart enough to figure out that it's the right time to privatize LEO, the Shuttle and the Space Station. Giving the Shuttle an extention in the hands of NASA would just be a waste of money. NASA should sweeten the milk for manned space flight investment, encouraging Private Enterprise, instead of souring it. Maybe the Space Station will show up on E-Bay along with the Orbiters. And, I still want my Free ET, preferably at the Station. NASA has never embraced the spirit of Reagan's offer. Ron Paul in 08! :-) -- Craig Fink Courtesy E-Mail Welcome @ |
#8
|
|||
|
|||
STS-122 External Tank Venting Liquid Propellent ( update FD 1...
wrote:
It wasn't liquid. it was just gas. Wishful thinking. This might help you understand what your seeing. Turn off the water to your house and drain some of the water out of the pipes. Turn it back on and let it pressurize. Pick a faucet that wasn't used to drain the pipes, one that still has water in the line next to the faucet. Turn on the water and watch. You'll notice a normal stream of water, pay attention to what happens when the 60 psi air hits the faucet. http://www.space-multimedia.nl.eu.or...298&Ite mid=2 3:55 to 4:15 is the best section to watch This is essentially what is going on with the venting of the tank. Gaseous hydrogen or mixed gas/liquid is small spurts as the pressure relief valve opens and closes and the liquid hydrogen begins to move towards the exit. Then, a nice steady stream of liquid comes out, a burst of gas, then more liquid. Long skinny stream of liquid. Notice the cool shockwave pattern (if you can call it that), as the flow transitions from liquid to gas. It's the "" shaped pattern moving to the right as the much higher velocity gas impacts the slower steam of liquid, just like your faucet and all the spray when it spurts air. The faucet is a good analogy, another might be a hose with a hand valve on the end. Shoot a stream of water, the cut it off. Watch as the tail end of the water as it flys away. This can also be seen in the video, a nice stream of liquid hydrogen flying away as the pressure relief valve shuts. The tail end of the liquid gives a really good idea as to the velocity of the stream of liquid. Of course the gas is much faster. BTW, they had a nominal MECO the level of the Hydrogen never got below the ECO sensors in the tank, there was plenty of fuel left in the tank. As, you can clearly see the liquid vented out of the tank. Looks like the liquid might travel quite a distance before evaporating. Good thing the Orbiter wasn't in this stream of liquid hydrogen. Luckier than Monty's Dog, I'd say. -- Craig Fink Courtesy E-Mail Welcome @ |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
UPDATE: Cosmos 1 Solar Sail Update - Spacecraft Signal May Have Been Detected | OM | History | 76 | July 4th 05 05:30 PM |
UPDATE: Cosmos 1 Solar Sail Update - Spacecraft Signal May Have Been Detected | OM | Policy | 53 | July 4th 05 05:30 PM |
Saturn, last update 20040205 (last update) | Sandro N | Amateur Astronomy | 10 | February 10th 04 11:08 PM |