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Which of these design options do you favor the most? I think the capsule would be the simplest and therefore most economical design.
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This poll would be more accurate if it was "semi-ballistic re-entry" versus "lifting re-entry." A lifting body has little or no wing area, but it behaves much like a winged craft.
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Good point. Everybody just assume that "winged" means "lifting body."
My people don't call themselves Sioux or Dakota. We call ourselves Ikce Wicasa, the natural humans, the free, wild, common people. I am pleased to call myself that. -Lame Deer
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New Apollo-Style Capsules Could Replace Shuttles
Wed Sep 17, 6:41 PM ET Add Science - Reuters to My Yahoo!
By Barbara Johnson
CAPE CANAVERAL, Fla. (Reuters) - NASA (news - web sites) may replace its troubled fleet of space shuttles with a new generation of Apollo-type space capsules, a top space agency official said on Wednesday.
Reuters Photo
"Certainly we have considerable amount of experience flying with capsules," Dr. John Rogacki, director of NASA's space transportation directorate, told Reuters. "One might say on the capsule side it could be that that design experience may lead to a capsule being available sooner than a winged vehicle."
Unlike shuttles that land like airplanes, capsules splash down in the ocean and must be recovered by ships.
The resurrection of space capsules, which last launched three decades ago, is gaining favor among astronauts, space agency officials and congressional staffers after the shuttle Columbia disaster that killed seven astronauts on Feb. 1.
The 13 members of the Columbia Accident Investigation Board were unanimous in urging NASA to replace the aging shuttles as soon as possible by using existing technology and materials.
NASA said on Tuesday that the next space shuttle flight, designed to test repairs that might have saved Columbia, would not make a March launch target and might not fly until midsummer.
The space agency has spent billions of dollars since the mid-1990s trying unsuccessfully to design a new winged spacecraft, begging the question of whether a winged plane could be delivered by 2008 under a now accelerated timetable.
"Boy, I really don't want to speculate on that because I don't want to inadvertently or unintentionally signal to our contractors that I think it is likely or it is not likely," Rogacki said.
15 TO 20 YEARS
Corin Segal, an aerospace scientist at the University of Florida, picked by NASA to design new systems, has estimated that development of the technology to produce a truly safe, winged reusable spacecraft could take 15 to 20 years.
Detailed requirements for what has been called an orbital space plane were issued by NASA this week to three contractor teams who will propose designs and compete for the work.
For now, NASA is careful to avoid publicly expressing any opinion on what shape the new craft should take, and to stress that there are pros and cons to winged and capsule designs.
But NASA spokesman Bob Jacobs said there was no requirement that the craft be plane-like despite its name.
"We haven't spelled out that it has to glide back to Earth and land like a plane. That's not a requirement," Jacobs said.
The capsule design gained momentum in March from a study headed by astronaut John Young, who has flown in both capsules and shuttles. Young, as well as Michael Kostelnick, head of NASA's human space flight program, cite the versatility of the capsule, which can move beyond low Earth orbit to the moon or beyond.
Rogacki said the orbital space plane requirements did not demand the vehicle be capable of deep space travel but that NASA will be looking at its ability to support missions beyond the International Space Station (news - web sites).
"There is a great potential for using the orbital space plane system as a basis for future exploration vehicles," Rogacki said.
The thermal tiles and wing panels used on the shuttle today could not withstand the heat and stress of trans-lunar re-entries.
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A capsule might be quicker and easier to ~build~, but the cost of constructing the things, even if the capsule is resuseable, is only a portion... perhaps a minority portion... of the total cost to fly them. Building Shuttle was not all that expensive compared to what we've sunk into flying it to date.
One of the arguments i've heard against is that a capsule has no ability fly in the atmosphere; in the event of a catastrophy and you had to come back ~right now~, a crew member suffering a serious injury lets say, you would have to pay a hefty sum to operate more numerous landing sites to get care quickly. Also, since ease of maintenance factors big in the cost of operation, working on an airplane with a heat shield standing/rolling on its own landing gear with convienant equipment hatches jet fighter style would be a much less involved proposition than half-dismantling the capsule to access a deeply burried componet or to move/turn the thing around. And when your OSP plane does land right, you roll to a hanger, have a few Boeing/LM/USA engineers inspect and prepare it for the next shot almost as easily as a Leer Jet, roll it to the VAB, roll it up horizontally to the EELV, attach the bolts/umbilicals and fuel her up. Delta IV is processed horizontally, and just recently Lockheed badly damaged a satelite being readied for integration when trying to turn it over? Simple things with complex fragile craft are difficult. Speed is also an issue, in case you need to launch a 2nd OSP quickly for rescue like in a Columbia-style senario, or for the simple fact that time is big money when you are paying engineers, horizontal integration might be easier for a plane. The more airline-like it is to operate any reuseable spacecraft the better, cost wise.
Plus, recovery itself could be a somewhat more dangerous process than runway landing... what if you came down in water or forest a few miles off course at night for instance? Precious minutes tick away that you could have spent gliding at hypersonic speeds to a major airfield. The advances made in the strengthening heat shielding of a winged or lifting body craft have also made the "mini Columbia" disaster issue moot relative to capsules, and infact the OSP itself would be safely mounted on top of the EELV launcher, whereas a pure Apollo-copy capsule would have to ride under an escape tower which itself is a collision hazard and engine failure mode. Oh and speaking of heat shield, a good winged OSP heat shield wouldn't have to be replaced at all as opposed to the ablative shield on a capsule. Another improvement in modern aircraft design that mitigates the "heavy dumb wings" problem is the use of small wings made of Titanium or other "fancy" alloy and composit with control surfaces operated electricly instead of hydraulicly. These are things flying today on fighter jets; alot of things have changed since Shuttle was designed that mitigate the plane=heavy/unreliable issues. Plus, once you are out of the atmosphere the shape of your craft doesn't matter alot if you are intending to use the OSP for travel to higher orbits or near-Earth space. Even though a winged OSP would not be a good Mars decent vehicle, a capsule OSP would have to be highly modified for Mars atmosphere entry with a completly redesigned heatshield and possibly retrorockets for landing, which might as well be designing a new vehicle. Oh and speaking of which, another point where a winged craft has an edge is that it doesn't rely on parachutes at all. Another thing I thought of, wouldn't it be easier to put a docking/collision radar in the nose of an airplane than somehow trying to mount it to avoid the docking collar of a capsule were one to be included?
Although we have alot of experience with intermediate sized capsules, we also have quite a bit of experience with spaceplanes like the old X-Planes, Dyna-Soar, and the beautifuly efficenct new X-37 which Boeing may only have to scale up for their OSP entry. I think the 15-20 year timescale is a poor estimate considering that building such a craft won't be that hard. I will admit it is harder to put a airplane on top of an EELV than a capsule, but I think the payoff is worth it... Though I do long for the Saturn heyday, I think a warning over letting "capsule sentimentality" influence such a major decision is also prudent.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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I would enjoy a discussion which includes the return winged or lifting body vehicle being maintained at altitude by rocket burns, while slowing down from orbital speed in the outer atmosphere using thrusters to hold a 45-degrees angle-of-attack, until the airspeed drops below that which would cause heat damage to skin without an ablative coating, and then gradually pitching down to fly back to the launch area. Interestingly enough, Burt Rutan's approach to re-entering the atmosphere at a high angle-of-attack would appear to be a first step in this direction.
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I think that launching the OSP on a Delta IV Heavy will be overkill (it costs $170 million) and anything smaller will not lift lifting body big enough for four people in orbit. The escape system in lifting body is under the craft and cannot be jettisoned when it becomes unnecessary, you have to carry it to orbit and it?s hard to use it as orbit insertion stage because of the different requirements to the trust and duration of burn. I fail to see haw landing in a glider with aerodynamic quality of a brick is safer then landing on a parachute.
P.S. to dicktice - Wouldn?t the weight of the fuel needed for this maneuver be more then the necessary heat shield.
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I think that a HL-20 style lifting body or even maybe a scaled up X-37 would be light enough to go on top of a "single barrel" Delta IV Medium or Atlas V, if the design were kept small enough and simple enough. The Delta IV Medium+ with four small SRBs can loft about 10,000kg-11,000kg to an ISS orbit without breaking a sweat which would cost $60m less and cut in half the number of liquid-fueled engines you would have to rely on... Anyway, the original HL-20, sans adapter/escape stage, would weigh around 10,000kg, and that is for a ship with room for ~TEN~ people, with landing gear. If the HL-20 were scaled down to seat 4-6, even with an adapter/escape module weighing 25% or so could still be accomodated. With living with the "Space 747" Shuttle as the only manned launcher for so long, it is difficult to convince people how small a winged OSP could be!
It is even possible, X-33 style, that the heat shield could be entirely made of metal and re-used many times with a minimum of inspection, unlike having to replace an ablative shield, a major and delicate componet of a capsule, every flight or three. Even if a plane-OSP used Space Shuttle style thermal protection, the much much smaller area coverd would be pretty easy to inspect and refurbish without the need for total replacement. Have a look at my longish post about the ease of handling and processing a horizontal ship with wheels.
The nice thing about not needing parachutes is, well, one less thing that can go wrong that would doom the crew. Another factor i'd like to mention is that a capusle decent would expose the crew to fairly high G-loads; while this isn't a big problem for a fresh crew going up, it might not be such a good idea for a deconditioned/injured crew coming back down. Even if Soyuz-TMA worked properly, the crew would still be hit with 4G's during reentry... And you have to worry about coming down where you don't want to.
The HL-20 areodynamics have been pretty throughly explored, Russia even flew one (the BOR-4 military plane), and X-15 pilots that flew the simulator had no trouble landing it. With the know-how gained from the X-37 project, 100% automatic operation shouldn't be too hard to integrate relative to a capsule system.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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From what I've read in recent issues of Aviation Week, the baseline OSP design will be either a capsule or lifting body. Wings have been all but rejected. The baseline booster is going to be a Delta or Atlas Heavy, but a single-core Atlas 552 is also under consideration.
Right now, I have lifting-body leanings. If the OSP will be used for emergency evacuations as planned, it will be beneficial to re-enter at a benign 1.5 g's instead of between 2 and 4 g's for the capsule. Reusability is also a big factor. Reusable capsule designs (like the Russian Zarya) have been quite heavy, making the weight of a reusable lifting body seem justified. I believe that the projected flight rate will be the deciding factor of whether an expendable capsule or reusable lifting body is more economical.
A lifting body should be safer than the shuttle and more resistant to the type of failure that doomed Columbia. Should something go wrong, though, the crew could ride out the fall
in a heat-resistant crew compartment and then use jet fighter-type seats to punch out before impact.
I expected the X-37 to be a contender at first, but the X-37 will not fly in space until 2006. OSP is supposed to fly unmanned by 2008. Clearly there is not enough time to make the transition. The accelerated time schedule means that OSP will be built with current, well-understood aerodynamics and materials. I believe that both HL-20 and an enhanced X-38 should be studied, as well as Apollo and Big Gemini capsules. The only area where a big technological breakthrough should be incorporated is the thermal protection system. Clearly we can do better than the current shuttle TPS.
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Wow, is OSP going to really have that much Earth-to-orbit mass that will require a Delta-IV HLV or Atlas-V HLV? Even Soyuz-TMA only weighs 7,250kg and the X-38 around 8,000kg (sans trans-stage componets). Surely NASA isn't seriously going to build OSP with a mass of 20,000kg! If a large 10-seater HL-20 weighs a shade over 10,800kg and a Soyuz even less, then that means NASA must be being forced into having compatability with the Delta-IV series. The maximum LEO payload for a Delta-IV Medium+ 5,4, the largest single-barreld version, is 11,500kg whereas the Atlas-V 552 is around 20,500kg... The low "big Delta" performance makes me wonder if Boeing wasn't intending for the HLV to be the standard vehicle in the first place, since it costs $80m more.
Anyway, therefore the OSP must weigh alot more in either capsule or lift body form or else Nasa must be really really wanting to avoid a capsule for some reason. Perhaps the amount of trouble it would be to maintain worldwide global backup recovery sites for a capsule is adding up quickly?
Another possible reason that NASA wants the lifting body version... that when Shuttle is retired after the next few launches to finish ISS, Russian Progress-B and ESA ATV cargo ships will probobly not be able to carry enough cargo to sustain a 4-6 person crew + science. ISS uses a rediculus amount of water, which is quite heavy, and what of experiments? Perhaps NASA intends to fly a strip-down OSP full of cargo very often? The reason why a capsule would not be prefferd for a cargo role is quite obvious: Apollo has about 6 m^3 of pressurized volume as opposed to HL-20's 16.5 m^3. Such a scheme would save NASA from having to build their own ATV, buy them from Europe, and would be resuseable. Several tons to the ISS is not unrealistic.
As far as heat tiles are concerned, HL-20 has much less heating than Shuttle and could use -metal- heat tiles, made from Titanium, Nickel, and foamed Aluminum which are about a foot square and attach with bolts. As far as the leading edges and nose cone though, there aren't any alternatives light enough to Shuttle RCC that I know of. RCC would not be so much a danger since debries from launch will all be below it.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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dgagauzov: Re. Your P.S. My nose-up, rocket powered reentry vehicle would take on fuel in LEO, just before the de-orbit burn, with its height-maintaining thrust augmented gradually by aerodynamic lift, until orbital speed has been redduced enough due to aerodynamic braking to start lowering the angle of attack from the stall atitude. I shouldn't think weight of fuel will have any bearing. In fact, excess fuel should be allowed for subsonic cruising flight to a proper (glider) landing strip.
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dgagauzov: Re. Your P.S. My nose-up, rocket powered reentry vehicle would take on fuel in LEO, just before the de-orbit burn, with its height-maintaining thrust augmented gradually by aerodynamic lift, until orbital speed has been redduced enough due to aerodynamic braking to start lowering the angle of attack from the stall atitude. I shouldn't think weight of fuel will have any bearing. In fact, excess fuel should be allowed for subsonic cruising flight to a proper (glider) landing strip.
All this is good and well but you?ll have to launch this fuel to LEO anyway so there is no difference whether you carry it with you or refuel in orbit unless you use something different to launch the fuel.
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then use jet fighter-type seats to punch out before impact.
A high speed punch out is nothing to take lightly, ejections at speeds higher then 400 mph are incredibly dangerous. An ejection pod like used in the B-70. It has even been crashed tested :-) . Both occupants survived a high G impact with the ground after a F-104 was pulled into it's vortex.
Also, If the OSP is supposed to be a four passenger Taxi to ISS and various other LEO areas, I would vote for X-15 or Dyna-soar style craft. In the mean time use seperate craft for cargo delivery. Use specific Craft would save money and allowed for continued evolution of craft. Just like the Wright Brothers didn't envision One Aircraft that will do everything, we shouldn't try to have one Spacecraft that does it all poorly, instead of something well.
Just my two cents.
Also, if it comes down to Super-Gemini or Super Apollo, a Capsule is better then nothing!
We are only limited by our Will and our Imagination.
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I agree, hyper- or supersonic ejection should simply not be planned for unless OSP launch weight without escape pods is far far lower than it seems like it will be. Also, considering the small size and relativly low weight of the craft, it would be easier to simply harden the vehicle itself and equip it with emergency landing systems than it would to figure out how to build the thing around a half dozen ejection seats.
From what I have been gathering, OSP will almost certainly come in one of three forms, with dedicated CRV and CTV varients and possibly with a cargo varient:
-HL-20 lifting body:
http://www.astronautix.com/craft/hl20.htm
-"Big Gemini":
http://www.astronautix.com/craft/bigemini.htm
-"Averikan" version of Russia's Zarya:
http://www.astronautix.com/craft/zarya.htm
None of these vehicles at launch weight with all equipment and 1,000kg payload will be able to ride on the Delta IV Medium class rockets (~16,000kg, too much for 12,000kg Delta), but then all these are designed to seat ten or haul >3 tons of bulky cargo, so if their weight were reduced by 25% along with the crew to 6 then its possible. I am also wondering if OSP or a dedicated cargo varient could be used as an American ATV and launched on a non-man-rated Heavy booster to help replace Shuttle's cargo ferry role. Various big issues include...:
-Due to ISS's "diagonal" orbit, it will be expensive to operate the multiple recovery sites for a capsule to meet the CRV emergency return role, but HL-20 could glide 2000mi or so. Recovery of a capsule on the ground is also a less percise undertaking, and the very limited crossrange of a parafoil would probobly not be signifigant. Note how this situation is much different than the near-equitorial orbit of Gemini/Apollo.
-A capsule will unavoidably subject the crew to higher G-loading on landing, around 3.5-5G probobly, as opposed to HL-20's 1.5G. Impact for a capsule is also an issue, where using air bags or simple retro-rockets to soften landing would help, the Zarya's "near hover" rockets are heavy, produce massive vibration, and use non-storable liquid fuel.
-A capsule system cannot easily recover its OMS engines, as they have to ride behind the heat shield practicly while they can on HL-20, but the cost of replacing versus reuseing this system is unclear.
-Unless the Pentagon can perfect its Kerosene/Peroxide recycler engine, the CTV version of OSP will probobly have to use conventional N2O4/Hydrazine engines, since these are almost off-the-shelf, and cryogenic propellants like Methan/LOX are not storable. The CRV version of OSP would probobly best rely on a X-38 derived solid rocket OMS engine to maximize on-orbit life span in my opinion.
-The heat shielding on HL-20 or a capsule could probobly be re-used a similar number of times, but the HL-20 experiences much less heating, which could permit the use of a METAL heat shield for the majority of the craft if there is signifigant launch weight margin, other than some RCC on the nose and wing edges. Tile technology has also improved considerably (Boeing X-37) however and they are much stronger now, so this combined with low chance of damage on launch should perclude any "Mini Columbia" calamity.
-HL-20 would probobly be too big to ride in a payload faring of either the Delta or Atlas rockets, even if it were several feet narrower, nor would you want HL-20 to ride in one due to how much harder it would be to escape from a running booster. This is also a reuseability/mass concern, where the launch escape system on either HL-20 or a capsule is heavy, and would have to be thrown away on each flight.
-Although a capsule has very good areodynamics, it could probobly not survive re-entry unless it were at least roughly aligned with its re-entry vector, percluding a no-computer return (Apollo 13 had the Lunar Module to align it first), and would be very hard to recover from a bad allignment when the air starts to get thicker. HL-20 would be the opposit, that re-entry is a much more delicate operation, but with its control surfaces would make correction possible though difficult. With the proven Shuttle system (provided its heat shield works...)
-Both HL-20 style or capsules would definatly have the equipment to perform an emergency water landing, like parachutes and air bags for floatation, but the HL-20 would be able to glide much further, perhaps all the way across the Atlantic, whereas a capsule may have to ditch in the middle of it if there were a booster failure.
Thoughts? Other ideas?
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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I don't remember where I saw it but NASA is reasearching a new heavy lift rocket motor.. R-84 or something. looking for 1 Millions LBs thrust. possbile full scale test by 2007. Ummh. A basic 4 person capsule would work in the interim. If it could have a minimal developement cost, I say go for that, then in the mean time develop the space plane. spend a bit mroe money over a bit more time to develop something that is a bit better. like the U-2/SR-71. The U-2 was a cheap easy Interim and the SR-71 was the final product. (who would suspect in 1967 the U2 would be extensivly updated and redesigned, with a 40% increase in size and fly for another 37 years!)
We are only limited by our Will and our Imagination.
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A lifting body need not glide back to base if the launch is aborted. It could simply ditch in the sea, suspended by its landing parafoil. You'd probably lose the vehicle, but such is the price of rescuing the crew and saving weight on heavy wings and turbines.
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Nasa is developing a "modern F-1" mega LOX/RP1 engine, but they haven't done much beyond technical study phase. Building a brand new launcher, thats man-rated, in two-three years before the OSP CTV deadline is probobly impractical. Nasa has already all but decided to use the current EELV launch vehicles with man-rated modifications. I expect they will make a formal decision about specific Delta 4/Atlas 5 varients early next year.
http://www1.msfc.nasa.gov/NEWSROOM/news … 3-119.html
As far as a late-stage malfunction on launch, a winged OSP can't return to The Cape because it can't turn the booster around to push it back. What it could do is go accross the Atlantic and come down on a Shuttle emergency strip. This sounds alot better to me than trying to find a capsule over one or two thousand miles of ocean... as far as early-stage launch malfunction, both types of craft would have to come down in water. The HL-20's wings are also not all that big, and if you do have to abort late-stage, then you don't need jet engines because you are moving so fast already, up in the higher mach numbers. Shuttle doesn't need turbines to achieve its 3000mi re-entry crossrange.
Although in a 4-seater OSP would suffice for the basic "US Core Complete" ISS, there ought to be contingency to expand that crew to 6. Further, since the CRV and CTV vehicles will have to come online at almost the same time, and since the cost of building OSP will be fairly high, I really don't think that Nasa has neither time nor money to develop two radicly different craft. Whatever the CRV is, the CTV will be almost identical, so it will be capsules or wings... not both.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Oh, and for VERY early stage, like a pad abort or in the first minute or two, then a HL-20 could probobly do a RTLS for runway landing.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Orbital Sciences estimated that the HL-20 could get back to KSC after about within the first two minutes of launch. If it aborts between 120 sec and 420 sec into launch, an ocean splashdown is necessary. Still, these options are better than he shuttle emergency option in the same scenario (put your head between your legs, kiss your butt goodbye.)
As far as OSP engines, they will probably be similar to the Shuttle RCS and OMS. Not a lot of thrust is needed, and off-the-shelf is good. The RS-84 kerosene engine is a positive technological feat, but it has no bearing on the currently-envisoned OSP system. Although the Saturn's F1 will be marginally more powerful than RS-84, the new engine is smaller, reusable, and dispenses with the asbestos insulation of the F1. Perhaps the new engine will be used in a flyback first stage or in an all-new heavy lifter.
OSP's four seats should not be a problem. The plan is to carry three on the Soyuz and four on OSP, so there should be seats for everybody. Still, I'd like to see OSP have the ability to carry six to eight in an emergency (i.e., the Shuttle is fatally damaged and its crew has taken refuge at ISS.)
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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dgagauzov: Re. Your P.S. My nose-up, rocket powered reentry vehicle would take on fuel in LEO, just before the de-orbit burn, with its height-maintaining thrust augmented gradually by aerodynamic lift, until orbital speed has been redduced enough due to aerodynamic braking to start lowering the angle of attack from the stall atitude. I shouldn't think weight of fuel will have any bearing. In fact, excess fuel should be allowed for subsonic cruising flight to a proper (glider) landing strip.
All this is good and well but you?ll have to launch this fuel to LEO anyway so there is no difference whether you carry it with you or refuel in orbit unless you use something different to launch the fuel.
That's right, the fuel would be surplus, left over from eg. supply launches and stored in orbit, instead of being discarded.
But, wouldn't you rather discuss further main engine powered altitude maintenance / thruster angle of attack controlled, reentry scenario?
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I really think that limiting OSP to four seats is a terrible idea... if (hopefully when) we increase the ISS crew to six, then we could do away with the six-month-only rollercoaster reentry Soyuz capsules entirely.
Another case for the "big OSP" is that it could possibly become an "American ATV" to ship light cargos unmanned, or if you put the thing on a non-man-rated Delta or Atlas HLV, lift several tons to orbit.
The trouble about fueling decent engines in orbit is that requires a fairly delicate docking operation just so you can come back in one piece, and is not my image of a good idea.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Another case for the "big OSP" is that it could possibly become an "American ATV" to ship light cargos unmanned, or if you put the thing on a non-man-rated Delta or Atlas HLV, lift several tons to orbit.
Why pay for life support systems and other unessential gear un a craft meant for cargo? Just taking the unneeded equipment out would costs millions..(worked around government contracts)
OSP is for 4 people. I have doubts about ISS right now.. I think everyone does. Getting OSP built is not 'definite' Getting 6 people there in the next 10 years may be a bit oerly optimistic.
Most important thing about the rs-84 engine?
It's re-useable! RE-usable Heavy lift. opposed to EELV style
We are only limited by our Will and our Imagination.
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I am beginning to agree with you that a six-man crew on ISS is a little far-fetched, but it isn't rediculus I don't think when they start adding the other lab modules. Making room for two more people should not be a huge issue with the HL-20 or Big Gemini style craft. And if they don't go with a six man setup, thats extra room they can pack cargo into.
As Nasa is painfully aware, the days for Shuttle are allmost over. After launching the last modules of ISS, every launch is another too many. The ESA ATV and Progress-B cargo ferries will not be enough to sustain ISS with 4-6 and do anything useful probobly, so I fear that Nasa will keep on flying Shuttle anyway once or twice a year with a reduced crew. As this would be very desireable to avoid, and ISS would need some kind of CRV with a larger crew anyway, even spending millions for a cargo OSP could permit the penultimate goal of sending Shuttle to the Smithsonian. The biggest issues for ISS at the moment are basic life support consumeables like water and science payloads to have stuff to do. Water is pretty dense, so it will be more of a mass than a volume issue, but ISS will need at least some science cargo, more than Progress-B can haul, so volume could be an concern.
I am wondering, just curious, from a purely logistical POV, is it possible for a crew of three to stay up with only Progress-B and ATV launches?... As far as getting to Mars is concerned though, building a new manned craft would permit crew transfers to a Shuttle-C/Ares/Magnum launched Mars Transfer Vehicle, which will be without a doubt long after Shuttle is gone.
A reuseable launcher would be nice, but unless it leads to rocket able to haul up payload in the 100 ton region, then its too small to get us anywhere but LEO. Building a Mars ship out of 5-meter/20-ton sections on the reuseable stepchild of the EELVs is madness. That being said, OSP has to be finished on a rather short timeframe (no more than 5 years, preferably 3 years, until the CRV is on-station) so building a new rocket is out of the question. Delta-IV or Atlas-V is it.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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This letter from the ranking Republican and the ranking Democrat on a key OSP committee is required reading, IMHO.
Thoughts?
That being said, OSP has to be finished on a rather short timeframe (no more than 5 years, preferably 3 years, until the CRV is on-station) so building a new rocket is out of the question. Delta-IV or Atlas-V is it.
If ranking Representatives of both parties together sign a letter saying "go slow" then I submit that 3 to 5 years is extremely optimistic.
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Yes so I read... I have mixed feelings about such a move by Congress, which arrre...:
-Congress does not like not being consulted about things that get alot of press.
-Nasa HAS to start preparing to part with Shuttle right now, stay out of O'Keffe's way...
-Congress has a legitmate concern that OSP's costs cannot be controlled, as Nasa has so clearly demonstrated that it has trouble with.
-Congress has a legimate concern that Nasa doesn't know what to do at the moment about their manned strategy. Imparticularly since the ISS and Shuttle are joined at the hip, and Nasa's plans to part them are sketchy at best beyond putting people on OSP.
The RS-84 is a nice engine, though I am not convinced that the current incarnation of Nasa is able to economicly operate any large reuseable craft... A modified Delta-IV Medium or maybe the smaller Atlas-V with two or three single-RS84 flyback boosters would be a nice stepping stone though.
I also am -way p***ed- with Nasa/USAF for building the new 5-segment megabooster SRBs, adding engine-out ability of the SSMEs or an extra 25 tons of payload... and now have no plans to use them on Shuttle!!!
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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