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NASA Tests New Breed of Propulsion Engine and System in Support of the Vision for Space Exploration
NASA engineers have successfully tested a new breed of reaction control engine and propulsion system. Aimed at furthering NASA's space exploration goals, the tests helped investigate the possibility of future space travel fueled by non-toxic propellants.
So where does this engine fit on the CEV and why is it needed since I am not knowledgeable of the term.....
The main goal is to try and minimize, or simply get ride of Nitrogen Textroxide and Hydrazine(and it's derivatives) out of the space program. They are both toxic, and unstable and produce toxic exhaust. The nice thing about them though is that they are storable and ignite on contact with each other.
That's a bit encouraging, and a bit disturbing. Fully reusable SCRAM jet technology would enable safe, frequent, affordable access to space; but the military found a way to turn it into a weapon. This research will enable the space shuttle that was supposed to be the successor to the current shuttle. Remember in the 1960s NASA intended the current shuttle to be fully reusable TSTO, with a lifting body orbiter and piloted fly-back booster instead of expendable ET and "recoverable" SRBs. The second generation was touted to be SCRAM jet based, and operational about 1990. So much for the vision of the late 60s / early 70s. Well, I guess military funding will make SCRAM jet & hypersonic airframe technology happen. However, I can't help but cringe at the idea of depleted uranium fléchettes dropped from a suborbital SCRAM jet bomber. That's quite a perversion of peaceful technology.
Um, Civilian airliners were a direct result of the military need for large bombers. Rockets grew from ICBMs. Ever use a cell phone? GPS? The internet?
Our military has always been at or near the bleeding edge and funds tons of high risk technology development that wouldn't otherwise get funding. I for one am terrified of the possibility of living in a world where our countries technological superiority has been whittled down to parity? Why cringe at the thought of a flechettes being dropped from a bomber when you can rejoice in the fact that those are ChiComs/Terrorists/Enemy de jours that won't be threatening freedom and security or sending Americans home in body bags?
If your just uncomfortable with the military in general just repeat this mantra, "aerospace tech dev is good no matter what"
I don't see the point. If you're going to drop bombs from suborbit, why bother with the fighter? Dropping bombs from suborbit is no different than direct throw with an ICBM. If the fighter requires an expendable rocket to get into space, you might as well stick to a missile. The only advantage of that scenario is if the bomber is fully reusable. I doubt they're anywhere near that.
The alternative is a high precision bomb deployed from suborbit. Instead of a blunt body aeroshell, use a hypersonic lifting body. But why bother with that? Wouldn't it be simpler to use a standard aeroshell with drogue chute, then air deploy a standard smart bomb?
The only reasonable application for HTV is a relatively low speed, low altitude bombing run to launch a high precision smart bomb or guided missile. I doubt the body shape in the picture could sustain slower than mach 5, and the text says mach 9, so we're still talking about hypersonic deployment; but that's a lot slower than mach 22.
Well the point of the program is to develop fully reuseable horizontal suborbital bomber to carry the CAVs. The CAV is supposed to provide thermal protection and guidance for a variety of payloads, part of the point of hypersonics is the kinetic energy kill. I know one of the payloads the CAV program office is very excited about is a cluster of depleted uranium flechetes depending on the size of the payload and the dispersion power you could completely decimate a few square miles with nothing but kinetic energy.
While I would love nothing more then to see two privately financed manned spacecraft, I am a bit affraid that T/Space and SpaceDev might end up killing each other and leaving us with none, there is only so much venture capital in the world willing to risk investment in space, and I'm afraid two comapnies competing for it might not be a good thing.
Anyone want to place bets?
SpaceDev has a reputation for actually making money and providing actual useable products to the marketplace, but they have never done anything on this scale before.
T/Space on the other hand is basically an alliance of AltSpace start ups trying to become a major player. AirLaunch LLC has a contract to develop their QuickReach 1, C-17 droped, booster for DARPA, and Scaled composites is riding high off of Space Ship one. Also apperantly White Knight II is being built large enough to not only take the suborbital space ship II up to orbit, but to carry T/Spaces designed booster and capsule to orbit
I honestly don't know who to root for.
The launch vehicles and a stretch version of the EDS stage are definatly going to be common to both programs, the CEV will work fine for a reentry vehicle, and the LSAM lander might serve as a base for the Mars lander, but most everything else will probobly have to be new. The life support system and/or nuclear reactor for a Lunar base might also be used, if either one of those is actually developed.
The trouble with TransHAB is that it can't aerobrake, and if you are going to wrap it in a rigid biconic heat shield, you might as well skip the TransHAB part and stick with regular rigid walls. NASA's excelent DRM mission plan calls for just this. If you are already building a large rigid HAB for Earth-Mars/Mars-Earth transit, you might as well use it for the surface too and only develop one HAB.
Without aerobraking, it seems kind of unlikly that any NASA plan could suceed without radically new technology (RLV for megaloads of regular fuel or high-energy nuke engine).
I think the HAB modules will be the most expensive componets, followed closely by the landers. Basing them off the LSAM, which is almost the right size, and swapping out Hydrogen for Methane would be about right for Mars. Keep in mind that LSAM will already have to have automatic and precision landing capability.
A nuclear reactor will be quite difficult to develop; such a contraption will be completly different then a navy submarine reactor, smaller, light weight, no ocean for heat sink, high temperature coolant, different power conversion systems, etc. The USAF's old aborted SP-100 reactor would be much closer to what NASA would need, only 4-5MT and able to deliver 100kWe with no moving parts other then the external control mechanism. Being liquid metal cooled however, would be a challenge to develop. Russian space reactors are tiny compared to what NASA needs for Moon/Mars too... and the ones on their satelites keep leaking.
The one thing that could kill a Mars program is any of this L-1 business: the Moon should not be involved in any way for the mounting of a Mars mission other then as a parking orbit for vehicles launched from Earth.
You are right on the rigid HAB for transfer and the surface, but I still am kind of fond of the idea of packing and inflatable extension into the cargo/isru/accent vehicle lander. There just isn't a solution to the aerobraking issue.
The SP-100 was a truley brilliant design, and it was the product of an age before computer modeling. I know that there was significant development work on inspace nuclear reactors that used liquid metals, and in some cases, multiple liquid metals as their collants. Granted, none of these ever made it off the desktops, but the fact that there was significant dev work done should significantly accelerate the development timeline. I'll grant you it might take a while to revive the reactor program, but I don't see why a program that would essentially have no or very little technolgy development would cost over $1billion.
I'm courious as to what exactly the firs FALCON flight is supposed to test. It's essentially a Hypersonic Glide Vehicle, something that isn't exactly new. The details still lurk in the etheral mists of DOD clssification but we developed and at least had one or two flight tests of an HGV designed to be launch from B-52 that could carry one or two warheads into the Soviet Union at an altitude, speed, and trajectory that it would likley be undetected, and more importantly unintercetable by the then feared soviet ABM program....
I'll grant you it was a purley expendable a program, so prehaps this flight will serve as a materials test bed, but this seems like an example to me of what's old is new again.
ESAS says very little about the Mars architecture other than hints about NTP and it seems unlikely that NTP will happen for a long time. So how much of a Mars architecture can be put together using HLV, CLV, EDS and CEV components? Clearly a MSAM is needed, but is there enough flexibility in those components to begin Mars exploration and to evolve them into a sustainable system?
I would say cautiously yes, the two big things we need for Mars that are going to come from the first portion of the VSE is a resurrected American heavy lift capability and a (semi)expendable crew capsule. With the resurrected J-2S+ on the upper stages of both the CaLV and HLLV we will have a space startable cryogenic engine that could be used as part of the TMI stage, likely derived from an extended version of the Lunar EDS. One launch to put the upper stage in orbit, one with a payload that docks with it. No on orbit assembly just docks. Crew then goes up on the stick (when applicable) and you’re off.
I'd say on the list you would need to develop is a program wide biconic type aerobrake for landing payloads on the surface, a common landing bus( i.e. same legs and decent engines for every payload), a Mars accent vehicle with ISRU factory, common habs for on the ground and space, a nuclear reactor, and finally a pressurized rover.
The aerobrake would be a deceptively big project since it would be maybe the most mission critical item to be launched. That being said, we've been making ablative heat shields for a long time.
A common landing bus would likely be the most expensive item on the list as it would likely be one of the most complicated; no one to my knowledge has ever landed a 30-40 tone payload on another world before; let alone a soft, upright landing. Hopefully with a common landing system for the surface hab, cargo pallets, MAV, ISRU plant ECT. will help at least partially bring the economies of scale to the problem.
The MAV could just a CEV capsule with tanks and engines mounted under it, and RL10 has already been run on methane so there shouldn't be much problem here.
The ISRU plant, at lest the H2+CO2 part anyways doesn't seem like it would be a problem to develop at all, CO2 cracking for oxygen though might be a trick, also some sort of permafrost water extraction system might be nice. After the landing bus itself I'd think the ISRU plant would be the second biggest development project.
Finally habs for surface and space. The transhab was at a high degree of technical readiness when it was canceled, and dev work continues at Bigelow Aerospace, so with any luck maybe by the time the Mars program happens perhaps we could actually get by buying habs from them on a true commercial basis.
(list assuming a program that at least sort of looks like the DRM)
The one thing we might be able to do to accelerate the program along is the fact that several of these systems would serve to advance the lunar program. The Transhabs could expand a permanent base on the moon, the big mars Common landing bus with less propellant could deliver big payloads to the Martian surface, and I would guess a pressurized rover would be applicable for both the moon and Mars.
The reactor for power on the ground shouldn't be too hard to develop, the Navy has significant expertise in operating small power plants safely for long durations, and the Russians have been flying reactors in space to power their radar reconnaissance sats since the 70s. I think it would be smart to develop a common reactor for both in space use and on the surface.
The other needs of the mars program, like the aerobrake are small enough for their development program to start concurrently with the lunar program to slowly build up the hardware so that by the time we stop making sandcastles out of lunar regolith we can throw them together and go. The one snag I see would be the reactor, but I think if you enlisted the help of the Navy as JIMO was going to and got the national labs with you not only could it be done easily from a technical stand point, but would likely be a political god sent to the labs who are having a major retention problem....guess it's a pretty boring job being a physicist at a weapons lab that isn't designing new weapons. We need to reopen our nuclear weapons production capability but I'll save that for another thread....
Of course and NTR would be nice as well, but, lol, we'll see hopefully enough hippies are dying out by now for people to have a more rational view of nuclear power.
Shit, maybe we aren't getting anything out of the lunar program...especially if the battlestar glactica people get their way and want to use and L2 based fire baton as the start of the program...
I agree, Griffin is taking the sane approach.
Shuttle, ISS have proven to be unfeasible, largely because of too complex, hence the spiralling costs.
I'm not saying it will be easy, but it looks like he's pruning and keeping the stuff that's promising and doable w/o having to try and shoehorn unproven or overly complex tech into the program. Too many projects got axxed that way (Venturestar for instance)
It's a good thing what's happening, given the state NASA is in. Once the shuttle is mothballed, and ISS finished enough to either 'sell' or write off, it looks like there WILL be things happening out of LEO. At last.
Well the X-33 just wasn't going to get anywhere close to the mass fraction it needed to be an SSTO. At the same time though dumping the entire program more or less because of a fabrication error that was found to be the cause of the tank failure seems very iffy to me, especially since composite tanks are going to be and important bit of hardware if we ever go down the RLV path again...The Venturestar might not have gotten to the point of being an SSTO but it would have been an excelent place to start for a TSTO.
Everyone will wear ultra tight jumpsuits that are color coded to your duty and you will talk to one another by crazy jewlery that doubles as cellphones.
Sex with aliens will be frowned upon, but still very convinent since nearly every alien a human has sex with dies in an unlikley accident shortly afterwords....
The abandoning the SSME for the J-2S might indeed be a cost saving move, but it's one for commonality of engines since as GCNR pointed out they will be used on the HLLV upper stage anyways.
I have a love hate relationship with Griffins go fast attitude, on the one hand we need to get on the moon as fast as possible so we can get on with Mars, which should have been where we started anyways. On the other hand, doing things like dropping the lCH4 requirement for the CEV is short sited. We can't start morgaging Mars to pay for the moon.
The again, I don't understand why developing the CEV for orbit is taking even as long as it is, we are litterally inventing nothing, it's just well proven, existing engineering.
In fact couldn't you just scale up the Apollo CM to 5.5M diameter and switch to modern alloys, prehaps with a larger OML angle.
The big Delta-IV is about powerful enough, but I don't think that NASA would consider it for CEV unless in a dire situation.
The biggest reason for that would be safety right? As we all know the solid rocket boosters are by far the safest rockets ever built.
I don't think there is any chance of NASA going with the Delta IV heavy for the Crew launcher, there are too many failure modes in the triple barrel configuration and I think the stick has more potential for being lower cost, the RSRB has been in production for many years and has been reliably produced at cost, unless boeing was willing to sell CBCs on a true comercial basis for less then an RSRB.
http://www.msnbc.msn.com/id/10805240/?GT1=7538
Directed energy could revolutionize warfare, expert says.
Sounds a lot like Reagan's Star Wars. I've never been overly impressed with energy weapons. Anything deflected by a shiny surface just doesn't seem practical to me.
In my opinion nukes will remain the number one weapon of choice until something better is available.
I personally don't see any immediate replace of nukes with these high energy weapons right now. I see them as being niche weapons for certain application, but not for a general use weapon. But, over time these weapons will probably replace nukes as the weapon of choice, but that will probably take fifty years or longer and depending on how much research we do too on these weapons system. Even if the technology were developed tomorrow with massive break through of new technologies, it would still take years to totally utilize this technologies. Beside building the weapon, we would also have to build the support infrastructure and fund other technological projects and new development to support such a weapon system. We would have to do everything from develop targeting system, to a defense for the weapon to maintenance, etc. Even a nuclear weapon we had to develop rocket and other delivery system protecting them in silo, etc. and the same will be true of these high energy weapons too.
Larry,
Actually nukes will likely be replaced by nukes in the next 10-15 years. Well nukes without any radiogenic fallout or fissile materials. Pure fusion weapons are the next big step in warfare, able to be used in applications ranging from high end tactical, think a MOAB that only weighs 500lbs and is the size of a dorm room refrigerator to the big strategic turn Mecca into glass variety.
The two promising technologies to initiate a fusion reaction without the need for a fission primary are isomer (hafnium specifically) explosives, and nitro-silicon based hyper explosives with pulsed destructive magnetic containment. Both of these methods hold a lot of promise, although an isomer primary would require large new infrastructure investments at the national lab for its industrial scale extraction and production.
The other advantage of pure fusion bombs is that under current arms control law they are not considered 'new nuclear weapons' since they do not contain fissile material. We can produce these things by the tens of thousands and the only thing that would happen is the blue helmets would condemn us for not being subservient disarmed members of the global village.
Eventually though space based weapons will take an increasingly important role, they would offer instantanious 'close air support' that's always on station and real time tactical recon beter then any drone could provide...that is once the Air Force has a cheap and reliable launch on demand system in the 20 tonne class. That's either a few years off or already in existance out in the badlands of Montana or the Nevada desert. Who knows?
Oh I agree, that using five SSMEs may be ruinously expensive (we're talking $200-250M versus $60M for four standard RS-68s if they can't make a "discount" model), but the financial cost isn't the only consideration here (obviously), since if the SSME shop was closed down then the Stennis Space Center would cease to exsist, and so the political cost might be too high. The lower Isp of the RS-68 would reduce maximum payload by a little too.
NASA came to the conclusion that modifying the SSME for multiple firings was probobly harder then just building one for air-start/high-altitude use and reviving the old J-2, so the HLLV will likly have two or three on the EDS stage. The SSME really is a monsterously complex beast.
Edit: About the only way that SSME makes sense is if you could reuse those five engines, but an engine pod contraption is going to be a whole lot of trouble. I really can't see why NASA is going for it instead of a quartet of RS-68 other then politics. "But its reuseable!" has been a deception since the beginning.
How much aerospace evil has been justified by 'reuseablity'? The Shuttle, X-30, X-33, SLI....I have my doubts that I'll see as you put it a 'no kidding' reusable launcher before I have grandkids. (I'm 20)
The good ol' SSME is a real (expensive too) beast, and NASA is rightly concerned that they can't build them. The J-2 was a good enough engine in its day, and is slated for use on the big CaLV EDS stage since it can be restarted while SSME (nor RS-68) can't be restarted. Making the SSME fire repeatedly would require too much of a change. Its quite possible that reviving J-2 for TheStick might be easier then modifying SSME, and NASA is going to do it anyway... You are right, that reliability is a concern, but NASA absolutely has to get the Moon program, not just the CEV, started as soon as possible to avoid cancelation by the next administration. It might be worth a slightly reduced reliability.
The trouble with the RS-68 is that a regenerative nozzle would probobly not be any lighter (carbon versus metal), and the engine itself operates at a much lower pressure then SSME does. So, its not likly that the RS-68 can be modified to have similar Isp to the SSME. It also isn't anywhere near man-rated like the J-2 is.
The five-segment SRB is not just like the four segment, because ATK calls for using a different fuel mixture, probobly to slow down the burn rate to keep thrust from getting out of hand. NASA needs the CEV sooner rather then later, which is why they picked the regular four-segment engine. I agree that the five-segment engine is a better deal, but it would take time that Griffin doesn't think he has.
I didn't know that NASA was planning on using the J-2S on the Earth Departure Stage, that actually makes alot of sense to use as many of the same engines as possible.
I still am worried about the RS-25s cost for the Cargo launcher though, is that what they are still planning on?
With NASAs problems developing an airstartable and simplified RS-24 there has been talk (I don't know if there is official word yet or not) on developing the stick with a five segment SRB instead of the existing four and using a dual J-2S upper stage.
The five segment SRB doesn't worry me; it has been studied in internal ATK studies for several years and is simply a new assembly of existing components that are in production, simple, and at least in aerospace terms, cheap.
What worries me is the choice of the J-2S, an engine that while developed, has not ever been in production, not to mention was designed in the late sixties and early 70s. I don't know if a modern J-2S rolling off the Rocketdyne assembly lines would have improved performance or not but, as is the twin J-2s lack 6% the thrust of the single RS-25 and is likely what prompted the downsizing of the CEV to a 5M diameter.
As far as safety is concerned I know that expander cycle engines are significantly safer then turbopump fed ones as there are far less catastrophic failure modes, but that being said I think that the one benefit of the J-2S over the SSME is likely counteracted by having two engines, twice the parts that can fail, and if you have one failure you have to deal with off axis thrust to such a degree I'm not sure if gimballing on those engines could handle it.
So that got me wondering, are there any engines existing or near existence that might foot the bill for the upper stage of the crew launcher?
The RLX was an engine that was at a significant development level when it was canceled when SLI went under. It had problems for its SLI application because of being a split expander engine, which isn't great for ground launch. Essentially though, it's modernized and enlarged RL10 with provisions for reusability from what I understand. If developed as an expendable engine it would be even more similar to the RL10 and simpler. The RLX has the potential to significantly out perform the modernized J-2S. How much more time consuming/expensive would it be to revive the RLX vs. the J-2S?
For that matter the existing RS-68 is an engine that has high thrust then the SSME and is currently in production. As is the RS-68 is unsuitable for this use since it has a significantly lower ISP then the SSME and is heavy. I suspect that a lot of that weight is associated with it's current ablative nozzle, which if replaced with a regenerativly cooled one (I think) would allow for a high ISP as well as weight savings. What else could be done to tweak the RS-68?
I'm just spitballing, it seems like there aren't really any options that don't involve some engine development, but my question is, is reviving an Apollo era engine really our best bet here?
Also how does this affect the Cargo launcher? Are the problems associated with air start or with streamlining the engine for a cheaper unit cost for expendable use?
There are different types of aerobraking, but only one of them lets you get away with a modest structure and light-weight heat shield, which is the shallow decent called for in NASA's DRM plan. Going in nose-first is going to require a very heavy shield and put alot of stress on the vehicle. Are the other options? Sure, but none worth the trouble.
Folding up the hab is impractical, so why do you care that its technically possible or not? Is it practical, or isn't it? Stiffend walls will make for lighter walls or at least better over all meteor armor. TransHAB's current design calls for a thick layer of foam to decelerate meteor fragments, and this isn't going to be easy to bend after its deployed. The difference in temperature of the outer skin will also complicate things if the polymers are thick or temperature sensitive enough that their ability to flex will be different. I'm sure there are other reasons that I haven't thought of too.
Any near-term cycler vehicle is going to be powerd by chemical or simple nuclear engines, which makes aerobraking very desireable to hold down fuel mass. Combine this with the small crews (like, 6-8 each) involved and smaller vehicle required, the total structure mass of regular Aluminum vehicle isn't going to be a whole lot greater then a TransHAB. To top it off, chances are we are going to Mars with a direct landing vehicle first before we think about a cycler, so we will have a proven design already suited to aerobraking.
Put all these things together, and I think it makes more sense to use a derivitive of the direct landing vehicle as an early cycler to minimize development headache instead of switching to TransHAB to try and eeke out a tonne or two of mass at huge expense. If we have rockets powerful enough to send a direct landing vehicle to Mars, then they are powerful enough to send a rigid cycler too, and you won't save money if a TransHAB vehicle still requires the same class of launch vehicle.
Also, if the cycler is a copy of the direct landing vehicle, then we know its heat shield is going to be sturdy, since it has to withstand Mars deorbiting as well as aerocapture. I think this is important, since heat shield reliability will be a major factor in how many times it can be reused, but more importantly if it can handle Earth aerocapture too.
My plan is for NASA to go ahead with a DRM-III style mission with vehicles sized to fit on the VSE CaLV without an EDS stage, and then mate them to either a 80MT nuclear stage or a 120MT chemical stage for TMI. A cargo ship design in the 80 or 120MT class would be built for one-launch cargo missions too. After a base is established and a source of water is secured, NASA would then send a DC-X style reuseable lander to Mars and be powerd only by local fuels. With this vehicle, subsequent HAB vehicles would stay in Mars orbit rather then landing, crews would be exchanged, and then the HAB would return to Earth with chemical engines.
We will already have a cycler big enough to seat eight, why bother with TransHAB?
I really don't like the idea of a folding heat shield still. It can't be that easy if NASA is so parinoid about the little seals around Shuttle wheel wells. What if the seals fail before the shield heats up and expands? Or how do you cope with uneven heating? And most importantly, how will the thing fit? Its just easier to stay with a proven design with a rugged shield and spend the development money on propulsion instead.
I agree with you on most points, and I understand the concern over the folding heat shields, it would arguably be one of the most mission critical items on that you would launch, the problem I see is that if you are going with a disk type aerobrake, how would you go about launching it? It would certainly be a bigger diameter then the 8.4m-10m CaLV shroud diameter. Or are they base lining biconic type heat sheilds in the DRM? I seem to remember graphics as such but I've had a hard time tracking down the actual DRM document? Know where I can find its .pdf?
As far as cargo goes though, if and when we implement cycling or reusable crew transfer spacecraft, what will be the most economical means to send cargo. Any expanding base is going to have a healthy need for replacement parts, exploration vehicles, and eventually construction equipment and automated factories. Will the best way to go still be two CaLV launches for the cargo and upper stage (be in chemical, NTR, or NEP) on a low energy transfer orbit?
Actually speaking of cyclers there is a really interesting NASA presentation over on nasaspaceflight.com over the work they’ve done on permanent transfer spacecraft with artificial gravity, I was impressed by the fire baton concept, assembled in only three 120 tonne class CaLV launches and one assembly crew. I mean, it would be a bad idea to base your initial program around anything with on orbit assembly, but this seems doable, especially after several years of manned Mars missions.
I know it has been mentioned several times that a lighter RS-68 with a regenerative engine bell, especially since there seems to be problems streamlining the RS-25 (aka SSME) for expendable use and airstart.
I know that during the days of SLI Rocketdyne was working on an enhanced version of the RS-68 for resuability dubbed the RS-83. From what I gathered it had a regenerative nozel, and turbopumps that were designed for reuse as well as acess ports?
Does anyone know how far they got on this engine development? Would it be able to be revived for VSE if nasa comes to it's senses and stops pursuing the J2-S?
Due to the speed involved with aerobraking, you actually want to come in fairly shallow and not straight on nose first. Doing so greatly reduces the heating on the vehicle, and makes a light-weight heat shield practical instead of something really thick and heavy. Those 1-2G loads are with a shallow decent too I bet. In this case, a TransHAB might not be practical, with the force of entry being on a corner which would complicate the structural loads and heat shield design. You couldn't just have a big flat disk shield on the front.
De-inflating the HAB isn't going to work very well I think. You could gain alot of structural strength by filling the walls with perminantly hardening foam. Also, I doubt you could get it to fold up so nicely as when it was packed on Earth too. It might be possible to use a fabric heat shield to make TransHAB aerobraking practical, but that would take some work.
In any event, why? We aren't going to colonize Mars with chemical or simple nuclear engines, they really aren't practical. And, if we have some advanced propulsion system, we can easily afford short transit times, which will mean speeds higher then are possible for aerobraking.
Would a biconic type aerobrake surrounding a TransHab derived modual simplify aerobraking with an inflatable vs a disk type aerobrake? I seem to remember some NASA renders from one of the DRMs a few years back featuring such a set up.
I was wondering if maybe there is a best of both worlds approach to the inflatables, prehaps some sort of collapsable hard shell that would be in overlapping pannels while the hab was collapsed for launch which would then lock into place with each other once the hab was inflated. This would prehaps add the rigidity needed for aerobraking as well as lending strength if you wanted to burry the hab for radiation protection.
Actually that got me thinking, if you had equipment on the surface to produce concrete, which I think would be pretty straight forward to develop once you had a reactor and suitable water source on the surface, you could take dozens of light plastic membranes, inflate them on the surface and then spray concrete onto them to create a series of monolithic domes. That would be a really easy way to produce a large permanent base out of materials that would be easy to extract and light weight to import from Earth.
I guess the next step might be an automated smelter to produce magnesium alloy rebar, lol, although that strikes me as being a much heavier system to launch and more complicated to develop. But then again with the recent development of microwave smelting of steel, it could be made significantly lighter weight.
As far as I know the european involvement in the Klipper is offically nothing since the last vote of the ESA funding board to not provide a dime for the Klipper.
Whats going on with The Mars Undergound... website hasn't changed in awhile
figured this would be the place to go, since I haven't stopped by in about a year, looking at some of my last posts...
That's a good question, I did some looking around the other day and I couldn't find anything about a release date, although for some reason the sound track is avalible....go figure.
If anyone knows anything about this I'd like to know looks like an intersting movie, but as much as I respect Dr. Zubrin I don't particularly like the fact that this movie looks like it paints him as the patron saint of Mars.
hey mods, could we prehaps get ISAs account blocked or something?
Launch mass wise repairing sats won't make sense until the replacement parts are produced in space, in which case why not just build a new sat.
I serioulsy hope with every fiber of my being that we can avoid internationalizing Mars, let alone letting the blue helmets govern things.
The first words said on Mars shouldn't be 'we came in peace for all mankind' they should be 'I claim this planet in the name of the United States' (or European Union, or god help us the PRC, although if that's the case I hope we have the good sense to hit there ship with an ASAT with a high yeild warhead before it leaves LEO...a red mars is a frightning though....just kidding, mostly, and pun definetly intended)
"The cycler essentially is in orbit around the sun and makes regular flybys of Earth and Mars"
Re useable life support systems make the cycler economical for people.
For heavy supplies and equipment, the cycler is not needed.Like ocean liners and battleships, the cycler will become a symbol of national pride.
Very good article. Aldrin's vision will prevail because of large scale efficiency.
But it's not really, efficent, at least not initally, it doesn't work to get large mass payloads to the surface. If you have an established base with all the infrastructurr your going to want up and going, sure a cycler would be a great way to cut down the travel cost of getting personel to Mars, but prior to that the only thing it brings to the surface is a small crew lander, not enough for the 18 months you'll be on the surface. Also I don't understand putting off the first manned landing with the short stays on phobos as listed in the article...not to mention that it puts the first human mission to Mars lasting over 10 days into almost 2040.
The only way we are going to get to Mars (knock on wood) before 2035 is if we go without needing lunar infrastructer in place. Let us also not forget the fact that the in space transfer of cryogenic propellant is a capablility that has yet to be developed...it needs to be at some point, as dose lunar and martian propellant production with orbital propellant depots. But first things first lets get a basic manufactoring capability and out post on Mars before we start worrying about L3 refueling and cyclers.
Is there any politically expedient way that we can just get the elephant of the ISS off our collective backs?