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Lockheed Martin unveils Space Shuttle replacement
Vegan Bob writes "Lockheed Martin released its proposal for the Crew Exploration Vehicle (CEV) in a recent Popular Mechanics article. NASA will choose this vehicle scematic or opt for the yet-released Northrop Grumman design in 2008. The CEV will replace the Space Shuttle program, and will eventually go to the moon (between 2015 and 2020)."
requires the use of failure-prone ceramic tiles for reentry protection instead of a tried-and-proven heat sheild when you're planning to use parachutes to land the thing anyhow? What's the advantage to using this thing over just a regular capsule if it's not necessarily reusable?
You seem to be forgetting that the vehicle will be on top of the stack, not bolted to the side.
This is a lifting body, it does NOT have wings like the shuttle's. Where the "wings" are on the LM CEV,LOX/Fuel Cells/and other avionics equipment is stored there.
Also, this is NOT the CEV that is going to be going to Mars. The Mars mission isn't until past 2020 and when that happens, the CEV will have been updated quite a bit.
So now, lets have a Capsule vs Lifting body debate!
If they win the contract, I hope they have their budget firmly in place before they build anything.
They are notorious for delivering under spec'ed products many millions above budget.
No. Carbon-carbon is not ceramic. And backed-up doesn't mean that it's a double layer.
Carbon-carbon is the material that forms the leading edge of the wings, which failed from impact damage on Columbia. By backed-up I presume they mean that the material will be structurally supported underneath, probably by a continuous backing layer. The leading edge of the space shuttle wings were not structurally supported underneath. The interior of the carbon-carbon pieces on the shuttle wings is hollow.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
That's because shipping cargo on the Space Shuttle was a dumb idea. Humans have very special needs (e.g. safety, atmosphere, low G tolerance, etc.) that cargo doesn't usually have. As a result, it's usually more cost effective to split manned missions and cargo missions into two seperate craft.
With that in mind, we've already got the cargo craft in the form of the Delta, Atlas, and Titan rockets. Now all we need is a human capable craft that doesn't haul 80 metric tons of (mostly) useless material into orbit.
Javascript + Nintendo DSi = DSiCade
Thats the whole point, the cargo is sent up seperately, maybe in a mission pod designed to be a cargo launcher. This way, if anything goes wrong, you jetison the CEV and leave the cargo to be destroyed. On missions that dont have heavy payloads like satillites, you arent carrying all that weight of a largely empty cargo bay up. The shuttle couldnt really be reconfigured to save weight, the CEV will be.
Mars gravity is 38% of Earth's, not an insignificant difference. Explorers visiting the place for the first time will find walking around a bit disorienting, at first, but probably a lot of fun as well.
"OH SHIT, THERE'S A HORSE IN THE HOSPITAL!"
Why on earth (or in space) would you want a manned spacecraft like this to carry a payload? If you try to build a manned craft that can carry "schoolbus sized satellites" you'll end up with something like the space shuttle, only even more expensive and even less reliable.
This is a "space compact car" to carry humans up. The shuttle is a "space SUV" that is horribly inefficient as a cargo platform or a people-mover. "Space trucks" should be (and are) unmanned.
Further, NASA was a part of the United States Air Force at the time, not a separate entity with its own (very limited ) budget.
Erm, what?!?
NASA has always been a separate, civilian agency. It grew out of the old National Advisory Committee for Aeronautics (NACA), itself a civilian organization.
The Air Force did have its own space program during the late 1950s and early 1960s (around the same time as the creation of NASA), which centered around the X-20 Dyna-Soar and the Manned Orbiting Laboratory. The USAF even built an astronaut school at Edwards Air Force Base, and Chuck Yeager was the commandant. However, that whole program lost steam in the mid 1960s and was abandoned by 1969. This led the USAF to send its best remaining astronaut pilots to NASA, and convert the school into a test pilot school.
Even so, many of the most famous astronauts from the Apollo days were not USAF pilots. Neil Armstrong was a civilian (he worked for NACA in the X-15 program), and Buzz Aldrin, Jim Lovell and Alan Shepard were US Navy pilots.
The difference between then and now, in terms of budgets is this: First, the entire nation was deathly afraid of the Red Menace and national pride was on the line (nobody wanted go to sleep by the light of a Commie moon); Second, a very charismatic US President had staked his legacy on the US getting to the moon before the end of the 1960s (this at a time when the US had only put one man in space, and briefly, at that) before being assassinated and leaving the entire nation in shock.
Congress voted big dollars to the space program because it helped fight the blasted Commies, and because Lyndon Johnson, among others, helped spread the pork to important states (California, Texas, Missouri, New York, Florida, etc.). It also helped the nation pay its final respects to JFK. By the early 1970s, however, Americans began to question the investment in the space program, regularly saying things such as, "I don't think it makes sense to spend so much money to send people to the moon when we have so many problems here on Earth that we need to deal with first, such as hunger, pollution, disease, poverty, etc."
You made some valid points in the rest of your piece, but your glaring fallacy about NASA's status kind of undermines your credibility, don'tcha think?
Thats some really expensive material.
.5% of the mass of the Earth is titanium. The high cost is due to the chemically intensive refining process. Due to incremental improvements titanium prices are relatively low and stable. Titanium has only been available in commercial quantity for about 60 years. Our ability to produce it has improved rapidly.
The element itself is rather common; over
As such, it is no longer thought of as an exotic SR-71 class material by engineers. The A380 is 9% titanium by weight; that's just under 30 short tons of titanium per aircraft.
New processes are being developed that should help drive the cost of processing ores down substantially. There also happens to be large titanium content in moon rocks.
Lurking at the bottom of the gravity well, getting old
A catapult first stage? You're right, it's not too practical. Bear in mind the final speed for orbit is (I think) 17,000 mph. A better idea is launching from an aircraft at altitude, White Knight-style. That does not get you much speed, but saves a lot of atmospheric drag on the vehicle in the early stages. Of course, the mothership for something this size (and it's booster rocket) would need to be very, very big!
If you read TFA, you have a wild imagination to see some of the things in there that you claimed were in there. But to answer your questions specifically:
Why add an orbital rendezvous requirement to all missions?
We don't use the Shuttle for all missions, and the Russians don't use Soyuz for all missions. If we don't need humans or a rendezvou, we use Delta and Atlas rockets. You build to the mission, and this is built to the mission.
Why use a shape like this which, I presume, requires the use of failure-prone ceramic tiles for reentry protection
It says no such thing. In fact, from a reentry standpoint, this craft looks like what the shuttle was *supposed* to be, but wasn't because of budget constraints. It uses a titanium frame - this allows it to run hot on reentry, which means that heat dissipation issues aren't as serious, and damage isn't as threatening. A side advantage is you'll get a far better payload ratio.
With a titanium frame, you generally only need to protect your leading edges, and they're using RCC, which is the best material out there in the present-day for such extremes (and isn't tiles). It's expensive, but it's a one-time production run, barring damage.
Titanium frames also fatigue a *lot* less. In short, you get a safer, much lower maintainence, and longer lifespan craft. The only downside is higher initial cost.
instead of a tried-and-proven heat sheild
RCC is a tried and true heat shield. If you mean "ablatives", don't delude yourself into thinking that they're cheap, either - this will be far cheaper than ablatives when amortized over a few flights. Ablatives are costly and tricky to apply properly (just like other spray-on things, such as foam insulation) - and are very difficult to use around moving parts.
when you're planning to use parachutes to land the thing anyhow?
Parachutes don't slow you from orbital velocity. You might have noticed, if you had read, that it has wings. Do you know why? It's not to meet Buck Rogers Stylistic Guidelines(tm) - wings let you skim the atmosphere longer on reentry, burning off your heat slower. Then, on this craft, a drogue chute will fire, followed by the main chute. It's the best of both worlds - the wings can be smaller and optimized for hypersonic flight only, while they still give you a gentler reentry profile.
it's not necessarily reusable?
What cave are you living in that you didn't learn that the CEV was to be a reusable vehicle? The *launch vehicle* isn't expendible - it will probably be a modified Atlas or Delta, which are very good launch systems. Sure, I'd love to see a fully reusable booster that doesn't cost a fortune (which, by all means, should be possible), but one thing at a time.
Overall, this is a great looking craft, and it will benefit greatly from all of the research that went on from the Shuttle program (and there was a *lot* - cost-reduction and safety-enhancing research was a good portion of the Shuttle's budget). My only real question is that its hypersonic drag profile looks a bit odd. Namely, there's no visible pinch as the wings widen (drag at hypersonic velocities is largely proportional to the maximum cross sectional area, so you typically pinch the fuselage as the wings eat up more cross section). I guess I'd also like to know why they chose ethanol biprop propulsion over, say, kerosene or LOX/propane. Still, great basic design principles on this craft.
It's a Cyrillic alphabet. It's like all those keys you never push on a calculator.
Erm, the foam on the shuttle is to keep ice from forming on the ET. (if you watch many cryogenic rockets during liftoff, you can see large chunks of ice falling off the rocket, and those that aren't white (like Soyuz) have a visible layer of ice on them) It has nothing to do with the heat shield, aside from falling off and hitting it (ice would be more dangerous though, i'd imagine). Of course, the CEV will be sitting on top of the launcher, well out of the way of any falling ice or foam.
What concerns me in that picture is what looks like exposed superinsulation material with no aluminum shell covering it around the propulsion stage. Seems rather susceptible to ice damage. Now that insulation is probably covering a tank that is strong but if you lose the insulation your fuel could boil off rather quickly. And if you can afford to have less fuel, you wouldn't be carrying it in the first place. And what about all the wires and plumbing on the outside of the tank that are not as strong as the tank itself.
Also, from what I can see from other pictures, it looks like the crew module is lacking an airlock. It would appear you have to use the entire back half of the crew module as an airlock. Or, in airline terms, the cockpit would remain pressurized while the passenger compartment would be depressurized. There does appear to be a full airlock between the two halves of the crew module. Also, it looks like the rear hatch is used to couple with the mission module which means that you can't even use back half of the crew module as an airlock when you have a mission module - the mission module itself needs to be used as an airlock if you wan't to go EVA. Or else you need to depressurize the cockpit when you want to step outside to fix something. Personallly, I would like to be able to step outside to fix something without wasting that much oxegen or having everyone have to change compartments or put their helmets on everytime I came back in for a different size wrench :-)
Heres a really good run down of the kliper.
Looks like the nose cone section of the shuttle without any wings or tail
liqbase
Once you have some lift, you have some crossrange that comes with that. It's coupled together.
You can get lift in capsules. The hypersonic lift to drag ratio of an Apollo capsule was about 0.25, just from flying the reentry tilted a bit. Wings get you better L/D ratios (up to better than 1.0).
Crossrange is also used to land away from the ground track of the orbit. Which is necessary given how narrow the ground track is on usual orbits.
You can get crossrange by changing your orbital plane a bit a quarter orbit before reentry, using rockets. That's not the usual way, but if you work out the numbers, it takes about as much weight as wings do to get you extreme crossrange.
Fuel is cheaper than wings...
In summary: Crossrange good, wings not necessary.
They could easily have ones for the crew, but obviously that'd be of little benefit to passengers. They are not left out because there wouldn't be potential use for them, but since the amount of people to save is too big for those approaches to be practical. So while safety has improved, airplanes are much safer than rockets/shuttle, it's much more practical and useful to have personal escape mechanisms for spacecrafts.
Here's a sample:
Enjoy.
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Here's an interesting factoid: The Space Shuttle Enterprise was slated to be called "Constitution". Which would have made the Space Shuttles "Constitution-class". Just like the USS Enterprise NCC-1701!
It was actually going to be named after Richard Nixon, which is ironic because most of the shuttle's drawbacks are his fault. NASA wanted something completely different, Nixon made it cost less in the short term and a ton more in the long term, and wouldn't fund it at all unless it could be used for military applications as well. And all the while, he comes off as a big space guy.