Re: NASA's grand plan to revive human exploration...

[gaetanomarano]

"...nobody wants to repair their old satellites..."<br /><br />it is true for old and obsolete satellites that remains unused in orbit due to launch of advanced comm or TV satellites<br /><br />with expensive commercial, military or scientific satellite (like Hubble) repairing may be a big saving, but can't be made

 

[tap_sa]

<font color="yellow">"the extra fuel (or extra rocket) may need half-SDLV payload (or less, with only another "stick" launch with extra fuel tank instead of CEV-SM) "</font><br /><br />Huh? Breaking into LEO from moon means about 3500m/s deltav. IIRC the CEV main engine has 360s Isp. Put that into rocket equation and find out that you need a mass ratio near <i>three</i> to make that happen. IOW CEV returning from moon needs twice it's own empty mass of propellant.<br /><br />Now, work that backwards through all the phases of moon mission and find out what above does to required TLI mass. The additional propellant doesn't magically appear into CEV tanks out of thin vacuum when needed, you have to first send it towards moon along with everything else, break it into moon orbit and finally send it back towards earth.

 

[gaetanomarano]

<br /><br />Hubble was repaired... for other satellites the problem is unreal because it is simply impossible to do<br /><br />

 

[gaetanomarano]

remember that 90% of earth-to-moon "mass" will remain on the moon or will be lost<br /><br />only the crew ferry-module will come back (that may be twice a CEV and only 10% of the entire lunar-system weight)<br /><br />your evaluation is very pessimistic<br /><br />

 

[nacnud]

Exactly, the SM couldn't slow into LEO from the moon without aero-braking. To use rockets to break into LEO from the moon would take a prohibitive amount of propellant.<br /><br />

 

[radarredux]

> <i><font color="yellow">I believe the technology for a better spaceplane is not here yet. I agree it will be eventually.</font>/i><br /><br />I am very comfortable leaving the next-generation of "space plane" (whatever it might look like) to private enterprise.</i>

 

[gaetanomarano]

"...not just fuel..."<br /><br />the "generic" term "fuel" I've used (and I will use again) indicate (of course) the "combination" of (oxidizer and fuel) propellent that NASA will use for each module of lunar mission (a choice to-day we don't know), so, when I say "refueling" this means "refuel of both",<br />ok?<br /><br />

 

[gaetanomarano]

<br /><br />"...a better spaceplane is not here yet..."<br /><br />the Shuttle technology (that exists and works) is 30 years old, so, to-day, there are MUCH BETTER technologies for EACH single part of Shuttle (some applied to Shuttle) that can be ALREADY used for a better spaceplane

 

[aftercolumbia]

"capsule has ZERO maneuverability on reentry"<br /><br />Apollo hypersonic L/D was somewhere in the range of 0.8:1. Until the drogue opened, Apollo CM was controlled like an airplane at high AoA...it didn't come in flat...neither did Viking.<br /><br />Let me quote Apollo 13's Kevin Bacon (Jack Swigert):<br /><br />"We got a corridor light, we're coming in too shallow...I'm going manual...5 gees...we're coming in too steep...I'm going to stay in this _roll_ and see if I can pulls out out of it...8 gees...9"<br /><br />Hanks (Lovell): "We're at 12 gees, we're burning up...how ya feeling Freddo?"<br /><br />Notice where I highlighted _roll_. I've flown entries in Orbiter (www.orbitersim.com) and I've done exactly this. The only way his statement makes sense is if he was upside down.<br /><br />If capsules had no control on entry, then what point would there be to "going manual"?<br /><br />To compare, the hypersonic L/D of Faget-type straight wing Shuttle Orbiter was 0.56:1...real Shuttle? 1.9:1...typical aircraft: 9:1 or more.

 

[aftercolumbia]

" Imagine how less cluttered your kitchen would be if you could put, and use, half of the items in it on the ceiling! "<br /><br />I've had nightmares about my bedroom losing gravity...I know me...I'd simply be surrounded by junk in three dimensions instead of two.<br /><br />It is true though that microgravity does make small spaces seem bigger.

 

[aftercolumbia]

The Bigelow prize is simply impossible:<br /><br />Rule #6 "No more than twenty percent (20%) of the Spacecraft may be composed of expendable hardware (the term "Spacecraft" encompasses the launch vehicle in its entirety..."<br /><br />This requires a lot of technology development...the reason being is that it would have to be two stage, as recovering the middle stage of a three stage vehicle would not be practical. Theoretically, you could have a three stage vehicle with an expendable middle stage, but the middle stage would need to be disproportinately small (i.e. less than its fair share of the total delta-v budget for mass optimization) for it to work, allocating a larger amount of mission delta-v to the reusable first and third stages. This is probably possible, but not with Rule #10:<br /><br />Rule #10: "The Spacecraft must complete [blah blah] January 10, 2010"<br /><br />That is in 4 and one half years!!!!!!!!!!!!!<br /><br />That is less than 6 years after the contest was announced...<br /><br />To do a craft that would meet all of these requirements, optimistically, would require 9 years and $4 billion (I am being very optimistic with these numbers on an impractical three stage ballistic with an anemic expendable middle stage to relieve the dry mass fraction requirement of the upper stage...I think more realistically, 12 years and $30 billion for a practical Ashford-type 2 stage reusable.)

 

[barrykirk]

What portions of the space plane do you think can be re-used?<br /><br />1) Engines?<br /><br />2) Re-entry vehicle?<br /><br />3) TPS?<br /><br />4) Fuel Tank?<br /><br />The space shuttle re-uses items 1, 2, and 3.<br /><br />What parts are you envisioning as re-usable?<br /><br />I believe the capsule guys are planning on reusing items 2 and 3. I've asked the question is it possible to modify a capsule to re-use item 1.<br /><br />I've heard rumors that the upper stage of a Falcon 9 is completely re-usable. So what does that make it?

 

[nyarlathotep]

>>"I've heard rumors that the upper stage of a Falcon 9 is completely re-usable. So what does that make it?"<br /><br />At this stage, a paper rocket.

 

[barrykirk]

Scheduled first launch Q2 2007. Well that's further along than any paper rocket I've ever seen.

 

[gaetanomarano]

"...do you think can be re-used..."<br /><br /><br />as many parts as possible, of course, will depends of technology used<br /><br />the plane must be an "Smart" (the europen micro-car) while Shuttle is a truck<br /><br />so, all parts will cost a fraction of Shuttle: little TPS, little (multiple) engines, etc.<br /><br />in that spaceplane, change a damaged engine will not cost like change an SSME<br /><br />about fuel tanks, reusability depends of design, it's a NASA choice<br /><br />the main effort must be around TPS, using newer, better and reusable materials it will increase safety and reduce service time<br /><br />since the spaceplane must be very little, an Apollo-like TPS may be better than Shuttle-like<br /><br />-----------------<br /><br />however, I think that NASA will not change its "cone" plan<br /><br />after reading a recent news about CEV... I feel that NASA has NOT designed it but ONLY adopted a project (probably ready from years) proposed by Northrop Grumman/Boeing<br /><br />then, the "final decision" is already taken: "cone"!<br /><br />it's clear that, if NASA spends new funds for CEV, will never have time and money to make a spaceplane (no matter if it is better than CEV or not), and, since private don't have the same experience and funds, a plane will delay of minimum 5 years and will be made from China or China+Russia or China+Russia+ESA or Russia+ESA (not based on Kliper that reseble a train not a shuttle) or (may be) from Russia+China+India (I've read that 30% of NASA engineers come from India...)<br /><br />so, in the next ten years, talking about spaceplanes will be only an "intellectual game"<br /><br />but (I'm sure) the 2020 NASA Chief will say to press: "ooops... we have made another ($104 billion) mistake!"...<br /><br /><br />

 

[tap_sa]

You'll see pigs developing spaceplanes (and flying them ) before Russia wasting their scarce space-rubles on them. As you said Kliper isn't one, it's much smarter design, the crew compartment being modular. It's like a cell phone with switch-on covers. They have made mock-up 'covers' with tiny wings but it maybe more for attracting investors than real customers.<br /><br />I believe China belongs to the same club, the Shenzou design is simple and efficient, a better version of Soyuz.<br /><br />ESA, well, they <i>might</i> be stupid enough to waste a few billion euros on a dead-end study ... again. Germans may have learned the lesson but perhaps the French would like to burn some money on Saenger III

 

[gaetanomarano]

"...pigs developing spaceplanes (and flying them..."<br /><br />no... little companies don't have experience and funds, big companies make studies and research but build only the things governmental contracts they win<br /><br />probably some of them will develop a working model, but will hesitate years to launch manned<br /><br />space give great prestige and money in case of success, but great damage and descreet when missions fails<br /><br />private will remain under the (safe) sub-orbital margin and never go in orbit with a spaceplane without a giant logo of a "space agency" well visible on its (lifthing) body!<br /><br />no (little or big) commercial company will take a so big responsibility without an space agency's CLEAR support!<br /><br /><font color="yellow">that because, if a national space agency lose a crew all flights stops for a few years then restarts, while, if a private (also a big company) will lose only ONE spaceplane's "test pilot", may risks to lose its credibility and go bankruptcy, so, that company (and other companies!) NEVER try again to launch an orbital manned craft, expecially if the "private astronaut" don't die at lift-off or on reentry but remains in orbit and die after many days of (live TV) agony!!!<br /><br />it's a so TERRIFYING scenario for a private company, that they NEVER try it if (before) NASA or Russia or China don't make it (many times) successfully!!!</font><br /><br /><br /><br />"...Russia wasting their scarce space-rubles... ...China belongs to the same club..."<br /><br />I agree on Russia (its new capitalism don't grows so fast and efficient like in China) but absoultely NOT about China<br /><br />the technological (and space) growthof China will be EXPONENTIAL and will ACCELERATE in next years!<br /><br />China already have giant funds (that grows at 10% per year!) and increase the number of new engineers of 400,000 per year!!!<br /><br />China use Shenzhou capsules ONLY because NOW they don't have better vehicles, but the world

 

[gaetanomarano]

"...english dictionary..."<br /><br />I have it!<br /><br />but... when I write, I give precedence to the concepts that flow from mind, instead of details... <br /><br />it is not important which kind of "fuel" or "battery" NASA will decide to use...<br /><br />I well know (from thirteen...) how propellent, fuel-cells, capsule, etc. works, and my first job was in electronics<br /><br />please don't emphasize useless details, but give me answers to the concepts I explain and the questions I post!<br /><br />example: read the Tap_Sa post about "pigs", and my answer... waiting for Tap_Sa reply... do you know why NASA is unable to make the same job that many "pigs" can easily do??? (a low cost "pig-plane"...)<br /><br />or... can you give me a (realistic) list of USEFUL things to do on the moon (in a week) that worths the cost and the risks of an "Apollo-remake"??? ...excluding all the experiments that can be made in earth orbit or, on the moon, but with low cost remote-controlled vehicles...<br /><br />answers, please... not angry comments!<br /><br />I wait...<br /><br />

 

[tap_sa]

I was referring to the proverbial flying pigs, you do know the meaning of that expression, don't you?

 

[gaetanomarano]

"...flying pigs..."<br /><br />now I understand<br /><br />the mistake was due to the fact that I think it (the spaceplane) is so (relatively) easy to make, that, also PSC Inc. (PigsSpaceCompany Inc.), can build...<br /><br /><br />of course, "spaceplane" is a complex job for single companies, but an Airbus-like international consortium (with Chinese cash flow) can do it<br /><br /><br />

 

[tap_sa]

I'm all for Chinese money flowing into European pockets <img src="/images/icons/laugh.gif" /> (as long as it doesn't hurt Shenzou program, they have a good thing going on)

 

[gaetanomarano]

<br /><br />ask U.S. Treasure Secretary... he will say to you "who" own a good part of U.S. public debt stocks...

 

[gaetanomarano]

NASA plan was:<br /><br />2012: first "simplified" orbital CEV capsule for ISS and CEV-SM launcher... 7 years...<br /><br />2015: first "complete" version of CEV for lunar missions and bigger SDLV... 10 years...<br /><br />2018: first lunar mission... 13 years...<br /><br />but...<br /><br />Oct. 20, 2005: "CEV SELECTION DELAYED"... (to summer 2006) www.nasawatch.com/archives/2005/10/cev_selection_d.html<br /><br />that news can be read in two different ways... (but may be both...)<br /><br />a) "first doubts" about "capsule", CEV and lunar architecture... can "real" CEV be a "capsule"... or spaceplane?<br /><br />b) "first delay" (of many) in the CEV development timeline... so, 2012 will be 2013... 2015 will be 2016... etc.<br /><br />all "plans" may have (and will have) delays (expecially complex plans...)<br /><br />---------------<br /><br />NASA studies TWO alternative plans for the future... www.spaceref.com/news/viewnews.html?id=1072<br /><br />Plan A: not 19, but only 8 new shuttle's missions (7 to ISS, for logistic purpose only, and 1 to Hubble) before Shuttle end in 2010 (but, some say may be only ONE mission, to repair Hubble, now used to locate lunar landing's sites) and stop building the ISS<br /><br />Plan B: the Shuttles continue to fly and Shuttle program will be merged with CEV-SDLV development, so, while waiting (from 7 to 10 years, or more) for rockets and capsule "economic efficiency" (and reliability), NASA don't remain without an heavy launcher for 10+ years<br /><br />avoid the 10+ years launchers shortage, is one of the reasons I've suggested to convert the old Shuttles to fly (also) CREWLESS and use for 10+ years WITHOUT risks for crews... (and without 6,000 employees fired)<br /><br />simplified and revised CREWLESS Shuttle page at http://www.gaetanomarano.it/spaceShuttle/spacesh</safety_wrapper