fredinno
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Posts posted by fredinno
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4 hours ago, ProtoJeb21 said:
What I despise about the Cassini mission is that instead of landing on low-gee Enceladus and just staying there, NASA wants to burn up the poor probe. I don't get why NASA doesn't want to attempt a nice, soft, radiation-free landing on Enceladus! Crashing into that moon will be terrible. But landing on Enceladus? That's incredibly important child's play.
1. Cassini probably was nowhere near the twr on its apogee engine needed to land on that moon.
2. The entire point of burning the probe up is to prevent it from contaminating that moon. Landing on it defeats the purpose.
3. It would probably be better to put it in a graveyard orbit around impetus, for example, if you really want to save the probe. There , it won't infect anything.
9 hours ago, wumpus said:I'd assume that the GS-13/15 who are making all the decisions that can be done without congressional approval all came on board with Apollo and like rockets. Anyone in NACA at 16 would be 74 today, so I expect nobody at NASA even had a mentor who remembered NACA. And of course, the Air Force is still full of generals who flew planes (and ICBM babysitting has lost all punsk it might have had after the cold war ended).
I'm not remotely surprised that NASA likes vertical takeoff (and is indifferent to landing) while the DoD (lead by the Air Force) clings to Horizontal landing (and possibly takeoff). And as far as capability matters, that doesn't really seem to be an issue with congressional funding.
Until recently, NASA'S biggest employer was the shuttle, a space plane. Also, a significant portion of nasa is still aeronautics. Granted, nasa supported lifting body/space-based until right before project constellation.
On the other hand, DC-X was a DOD program....
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53 minutes ago, benzman said:
Correct me if I am wrong, and knowing this forum somebody certainly will, but I had heard that two bodies of the same size, or nearly the same size, cannot have a stable orbit, One of the bodies has to be a lot smaller than the other for a stable orbit to persist.
Actually, no. Binary planets, though rare, do exist. However, a figure-eight orbit moon is probably unstable.
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13 hours ago, Boovie said:
I would argue that sending a separate probe to Europa would absolutely not be pointless. A lander could glean far more information from the surface and sub-surface ocean than the Clipper will gain from orbit. Congress ordered the two to be done together to save money, but what price can you put on data gleaned from other worlds and moons?
But the original proposal was to survey Europa via clipper, and near the end of the nominal mission, send the lander down to Europa. Obviously more risky, but a whole lot less expensive than another flagship probe and lander on SLS.
46 minutes ago, wumpus said:While the shuttle had plenty of abort options, my understanding was that they didn't have very good coverage and the ones they had the simulators nearly always ended with total crew death.
Probably because it is vastly easier to become an Air Force general by piloting a plane than by being a missile jockey. I wonder if the Navy was still had its turf, would we have Orion [the big boy]? Possibly with an admiral or two with a distinct bias toward capital ships?
While the shuttle obviously had to hit the runway, and the LEMs flew to their intended landing areas, is it possible to know how accurate US capsules were? I mean, as long as you come within helicopter range of a ship capable of carrying a helicopter (wiki claims HUS-1 for mercury), you can get the collar on and recover.
QuoteWhile the shuttle had plenty of abort options, my understanding was that they didn't have very good coverage and the ones they had the simulators nearly always ended with total crew death.
I'd image Vostokhod would have those sorts of abort options available- after all, the Shuttle "aborts" were built into a ship without any real abort capability.
QuoteProbably because it is vastly easier to become an Air Force general by piloting a plane than by being a missile jockey. I wonder if the Navy was still had its turf, would we have Orion [the big boy]? Possibly with an admiral or two with a distinct bias toward capital ships?
NASA had the same situation, but the Shuttle hit them hard, and spaceplanes at NASA have been on the decline since then. You'd think the USAF would come to the same conclusion after all this time?
In either case, the Nuclear Orion wouldn't have been made, since it capability was way too high in payload to be useful.
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9 hours ago, Exoscientist said:
What I mean to say is the reduction of the ISP of the rocket at sea level causes a reduction of the delta-v achieved by the rocket by a known amount. So you can add this reduction onto the delta-v you are requiring for orbit, just like you add ca. 1,000 m/s for gravity drag and add ca. 100 m/s for air drag onto the 7,800 m/s delta-v needed for just the orbital speed.
Example, when it is commonly said that you need in the range of 9 km/s delta-v to reach orbit, does this mean the rocket is traveling at 9 km/s when it reaches orbit? No, but you can use this larger value than just the orbital speed in your rocket equation calculations because you are aware of how gravity and air drag detract from your actually achieved delta-v. In the same way, you can just use the vacuum ISP in your rocket equation calculations once you add back onto the required delta-v to orbit the loss due to sea level ISP reduction.
Note this means you are using a higher required delta-v to orbit than if using an average value of the ISP. You could use some estimate of the average ISP of the flight based on the sea level and vacuum ISP and then you would use a lower value of the required delta-v to orbit. The result would be the same either way for the payload.
The calculation was for an expendable SSTO with altitude compensation to show the payload could be in the range of currently used multistage rockets in that case. To make it reusable you would lose payload but this also happens with the multistage rockets.
Bob Clark
But a reusable SSTO would fall down into the negatives, or into the smallsat class. Considering how much larger the F9 is, I highly doubt it'd compete vs even an expendable methane TSTO in cost.
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12 hours ago, Robotengineer said:
Really? So we should just forget that SpaceX is building an SLS class rocket? Just because the old guard pessimists (who hide behind the moniker of 'realism') have to do it their way ('we'd be lucky if we have boots on Mars before we're dead') doesn't mean we have to. I'm not even trying to turn this thread into a SpaceX thread, I only brought it up because @Boovie was making it seem like SLS is the only option for heavy-lift, when it isn't.
With the 'realistic' outlook, we won't be landing human's on Mars before 2040 anyway, so what will SLS be used for in the 2 decades between when it becomes active and when manned Mars missions become a reality? ARM is off the table, there is the Europa mission, and a few other Cassini style missions floating around, but nothing manned, unless you are going to make up some reason to do a manned mission just to use SLS.
SpaceX is working on Raptor right now and it can be assumed they are working on BFR as well.
Technically, BFR is well above SLS payload capacity.
And there was the Gateway Station being floated around Boeing and NASA for the majority of the SLS program. Lunar missions have been canned so far to allow for Mars by 2039.
9 hours ago, RCgothic said:I know this was a bad mission, but can we stop killing Orion missions please? The launch rate is awful enough as is!
We need to fund things properly! Permanent moon base by 2025! Boots on Mars by 2035! Let's get some proper infrastructure up there!
I cannot believe how hard people are making this. In 1960 we hadn't even put a man in space. Nine years later, moon! And 50 years later we can barely fund four manned missions over a decade? Come on people! This is so frustrating.
Truth be told, there are more manifested SLS missions- the SLS originally had 2 missions- ARM and EM-1. Now, there are 3 test missions for SLS, and 1 operational mission to send Europa Clipper to Jupiter.
7 hours ago, cantab said:It's the idea that I sometimes see expressed or implied that governments can do no right and corporations can do no wrong that aggravates me.
Unless you're ULA, LockMart or Boeing. Then, you're worse than the Kraken.
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21 hours ago, Panel said:
This does not surprise me at all.
I'm glad that they are pushing for the moon again. I could not find a single thing that asteroid missions would help with reaching Mars.
Asteroid missions would test out the Deep Space HABs, long durations in deep space, and be applicable to Phobos missions.
21 hours ago, kunok said:Being so close to the elections this really means something? the next one can give money again. (Not from usa, i could be wrong)
The president and White House are the main political supporters of this mission. Once they are gone, ARM's prospects seem bleak.
21 hours ago, Spaceception said:Congress needs to get a grip, space exploration isn't for changing stuff up every year, it's for long term missions, once you fund something, keep funding it!
@Red Iron Crown That isn't too political, is it?
This is one case where cancellation was a good thing. No one liked ARM, except Obama.
21 hours ago, PB666 said:I had my misgivings about the program, namely i did not think it was going to work, it was too dreamy eyed. And from congresses point of view and distrust of government, what if they screwed up and safe asteroid hits earth. That would be the end of space exploration.
As for funding next cycle, forget that the HoR will not change.
If they screwed up, the boulder grabbed was intended to be small to burn up in the Earth's atmosphere without damage. Larger objects, like Skylab, have fallen uncontrolled, into Earth's atmosphere at lower speeds, and no one got hurt.
21 hours ago, Astrofox said:WHAAAAT?!
Someone! Kickstarter this mission!
And I totally agree with that @Spaceception
I don't like that they change stuff that would make us greater, and more memorable for something good rather than redirect funds to:
[insert thing that makes you cringe here]
After all, this'd be the first time man moved a celestial body into orbit around another.
If you call a boulder a celestial body, than sure.
20 hours ago, Emperor of the Titan Squid said:im not happy about this, as it would have a nice scientific return, but it will free up more money, which is good. what i really hope they do, is build a deep space vehicle, and fly to NEOs, instead of bringing NEOs here.
Nope, the focus has sifted to the Moon, apparently, according to the article.
20 hours ago, insert_name said:You mean like OSIRIS-REX, the sample return mission from asteroid Bennu. I know @IonStorm is working on it.
ARM would have gotten tons worth of material, vs the grams of OSRIS-REX. ARM is great in the sense we have a lot more stuff to study.
19 hours ago, tater said:You know that they abandoned moving an entire asteroid a long time ago, right? The last iteration of ARM had a robot probe taking a small rock (a couple hundred kg?) off the surface of the asteroid, then bringing THAT to the L point (think that was the plan), then they send Orion up to pick up the tiny rock. It is no more moving a celestial body into orbit than any single rock sample collected by Apollo was then put into orbit around the Moon by the LEM.
There is nothing about ARM that could not have been done by a robot, sending people was make-work for Orion, nothing more.
It was actually to a distant retrograde lunar orbit, but close enough.
19 hours ago, benjee10 said:As it stands, ARM really isn't much use as an extinction prevention mission, particularly not the manned portion which, as previously noted, seems like a needlessly complex way of returning an asteroid sample. A purely unmanned redirection mission with the manned portion being reassigned towards a return to the Moon seems a much more sensible proposition to me.
But they canned both....
16 hours ago, Spaceception said:I've never really agreed with this mission, I wish they just shot straight for Mars, but they've funded it, they have some hardware, just let them do the mission, and stop wasting money!
The problem with that is that bearing a minimalist strategy like Mars Direct (NASA is not interested in doing such a mission), doing a Mars mission would take more than 8 years of no missions, thus, it is at serious risk of cancellation. That's why "direct to Mars" never really takes off, and a good reason why NASA can't go to Mars any time soon- the "interm" asteroid or Moon missions become the "end goal" as the "Mars Dream" goes further away into the distance...
16 hours ago, Boovie said:One of NASA's upcoming projects is a mission to Europa. With current technology the travel time to Europa would be about 7 years. With the SLS it would be cut to about 3-4 years depending on the launch window. SLS would not the the end game, as you'd have to keep improving, but it would allow us to more easily and quickly explore the entire solar system and beyond. We need the SLS.
As of now, it's about smart spending, but I do want to throw this out there: if NASA's budget today was equivalent to what it was in the days of the Apollo missions, it would be approx. $100 billion. Instead of nitpicking what we fund and don't, let's throw NASA (more or less) that level of funding so that we can expand and explore the solar system and beyond.
But building an entire rocket just for a few robotic missions is not worth it. Sending probes to the outer solar system on SLS is less the end goal, and more "let's use what we have!".
Good luck on that budget part.
16 hours ago, Bill Phil said:I think they should have at least made a program to try and capture a small roid. The extra stuff isn't necessary.
But if we put a station at EML-1, we could take the roid there. And send some equipment for prospecting?
Only problem is that neither NASA nor Congress has proposed prospecting. I'd imagine it's because extracting water out of hydrated rock, and bulilding a space smelter is well above NASA's capabilities right now.
I would send a mission to the Lunar Poles to mine water first. At least that would fit inside a discovery budget.
14 hours ago, Robotengineer said:FH wouldn't work for some of the proposed missions for SLS, but the BFR almost certainly would work (though talking seriously about SpaceX projects with little detail is taboo around here).
You know why it's taboo? Because we know sh"t about it. You might as well be arguing about the planned OrbitalATK EELV being cheaper than ULA's Vuclan. At least we have information of its basic layout.
And BFR, in any case, is too big. SLS Block 1B send 100T to LEO. BFR sends 100T to MARS TRANSFER. It's OP for any lunar missions, and arguably even early mars missions.
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3 hours ago, Exoscientist said:
To estimate via the rocket equation the payload to LEO, you can just use the vacuum value of the Isp (rather than taking an average) since you can regard the loss of performance at sea level as just another loss such as gravity and air drag and add that onto the delta-v required to orbit. Then a value for the required delta-v to orbit is in the range of 30,000 ft/sec about 9,100 km/s:
http://yarchive.net/space/rocket/fuels/hydrogen_deltav.html
The rocket equation for the rocket's delta-v is: ΔV = Isp * g0 * ln(Minitial/Mfinal) .
We need specs on the F9 first stage. In this lecture Elon Musk provides a key parameter, the propellant fraction, of the F9 v1.1 version:
About 30 minutes in, he gave the propellant fraction of the Falcon 9 v1.1 first stage as around 96%, or perhaps 95.5%.The propellant load of the F9 v1.1 has been estimated as 385 metric tons. Then using the 95.5% propellant fraction number this would correspond to a gross mass of the first stage of 385/.955 = 403 metric tons. The dry mass is then .045*403 = 18 metric tons. Then this could loft 2 metric tons to orbit as a SSTO:
ΔV = 311*9.81ln((403 + 2)/(18 + 2)) = 9,177 m/s.
Now suppose we could get the first stage engines to have the same vacuum Isp of Merlin Vacuum at 342 s by altitude compensation. Then, by this estimation method, we could get 9 metric tons to orbit:
ΔV = 342*9.81ln((403 + 9)/(18 + 9)) = 9,143 m/s
However, both of these are approximations. To get a better estimate you need to take into account how the Isp changes with altitude. Anyone know how to do this in Kerbal?
Bob Clark
No, using the vac. ISP gets way more Delta-V out of a rocket because the rocket equation is exponential, and most of the fuel is used in the atmosphere (ie why air-launch is useful). Also, you didn't add up landing equipment mass, heat shielding, reserve landing fuel, payload fairing mass (though that is ejected, it must be added for a good estimation)...
Add that up first, even just landing fuel.
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6 hours ago, Matuchkin said:
Vostok just had landings that were approximate. I was talking about Voskhod, which missed its designated landing area by hundreds of kilometers on its second flight.
Soyuz, on the other hand, had parachutes that didn't work at all, cursing astronauts, and retrorockets that fired after landing, disintegrating the whole capsule.
But Soyuz also had missions that missed their landing zones by hundreds of km, which is also a good reason why cosmonauts carried guns in the Soyuz.
3 hours ago, Boovie said:Actually the funding approved for the Europa Clipper mission includes a requirement that NASA add a lander to the mission.
I do absolutely want a lander sent to Europa, but as an attachment to the Clipper mission is not the way to do it. We need Clipper to go first so that we can figure out where to safely put a lander rather than hoping that we can just get one down.
NASA is seriously considering adding the lander seperate to the Clipper mission for that reason. More expensive, but hopefully NASA might be able to get JAXA, ISRO, or Rocosmos involved to build the Orbiter (funding a SLS mission for a small lander would be pointless) (ESA probably still has a bitter taste in their mouths from JIMO and ExoMars).
However, another option (probably cheaper) is to send ESA's JUICE spacecraft (which is ahead of Clipper in development) first on a SLS in exchange for lander development. JUICE is intended to do 2 Europa flybys. Then, Clipper is sent out on SLS, finishes JIMO's Europa mapping, then sends out the lander probe.
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38 minutes ago, SuperFastJellyfish said:
That's ridiculous. Every thread that talks about anything launch vehicle related ends up being a SpaceX knobslob. It's gotten to the point where every time there is a SpaceX launch I find myself cheering for it to explode just to watch the fanboys say, 'Elon wanted this rocket to blow up. I can't believe you guys are calling this a failure.'
Yeah, I agree. People talking about BFR at this point are seriously putting the cart before the horse (like Congress :P)
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40 minutes ago, Streetwind said:
Erm, guys? Before you celebrate/grieve/comment etc, you might want to realize that no such thing has happened.
One of the two chambers of Congress axed the mission in the first draft of its version of the bill. However, before that bill can become law, it must first:
1.) actually be finalized by the House
2.) be reconciled with the Senate version of the same bill. The Senate did not axe the mission, so there will be a disagreement, and it could go either way.
3.) be signed off by the president. You know, the very same president who ordered the mission in the first place, and has veto rights if he doesn't like the bill.So yeah, stating that "ARM is dead" based on the above (one and a half weeks old) article is about the same as going to a racing event, watching the first lap, and then running off to tell everyone that the driver currently in the lead has already won.
And in regards to "nothing of value was lost" - What about the first and only practical test of a extinction level event prevention concept that humanity has ever attempted or currently plans to attempt...?
The only part that would be useful to test asteroid redirection was the gravity tractor, and that's basic physics (Objects with mass attract each other). Not to mention, there is going to be a ESA-NASA asteroid Impact mission to test out that sort of redirection.
Also, nobody in Congress supports this mission (it has little support in the science community too). If the president vetos an entire budget bill (keep in mind, these budget bills are not just for NASA, but for a collection of agencies, all crammed together in a single bill) just for a single mission, it will survive- but the next president won't be so picky- ARM was Obama's baby.
I think it's fair to say very little was lost, and that it probably won't survive, even if it survives this round.
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5 hours ago, Kryten said:
Most of them, at least outside of SSTO concepts. Dynasoar, PRIME, ASSET, X-15B, et.c. X-37 is sort of the exception, having originally been a NASA programme, but it's now USAF as well.
Voskhod didn't even have ejection seats, that's how it was able to fit so much more into the basic Vostok hull.
I wonder why the DOD likes spaceplanes so much?
4 hours ago, Matuchkin said:Voskhod just had a stronger parachute that Vostok, and a tendency to land in the wilderness, surrounded by wolves.
Didn't Soyuz and Vostok also face the same problem of landing in the middle of nowhere?
2 hours ago, Kryten said:It also had retrorockets in the parachute lines to cushion the landing; another thing that would inevitably have led to disaster with enough flights.
why did it have it on the parachutes of all places?
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But seriously though, if it was to be the precursor to asteroid mining tech testing, instead of pure pork, it might have actually survived.
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5 hours ago, Kryten said:
Voskhod cancellation was almost certainly a good thing, no matter what the remaining missions were intended to do. The thing almost completely lacked abort options, it was only a matter of time before it killed someone.
You could argue that is the case with every spacecraft. But it was a similar thing with Gemini and Blue Gemini, ejection seats generally suck im terms of actually saving people.
But vostokod was a dead end.
2 hours ago, Matuchkin said:NASA cancelling dyna soar.
Dyna-Soar was pointless.
1 hour ago, autumnalequinox said:Hopefully soon some of those high delta-v iCubeSats will allow small groups to launch interplanetary exploration missions on their own in the future. I would love to be able to start a "club" with a $1000 buy-in where a few dozen people can run their own little mission control with their own tiny probe. Distributed exploration, hopefully un-tethered from political nonsense.
Or you know, just piggybacks on actual planetary probes.
And that cubesat constellation would provide little data, and thus less science.
1 hour ago, autumnalequinox said:I'm not exactly sure myself. I can't find the old article I read months ago about iCubeSats. I think so far they are just working on the thruster system (which had some impressive delta-v using carbon dioxide I think). I believe they are intended to be used in small "fleets" so I suppose one could be a dedicated relay to the Deep Space Network. I know the upcoming InSight Mars mission is using cubesats as relays but obviously they aren't communicating directly to Earth.
They can use a low gain antenna due to the very low amount of produced data. Plus, there should already be a relay orbiter available, in the form of a dedicated planetary probe at the planet.
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6 hours ago, tater said:
NASA can't do what it wants. It does what Congress wants.
It's come up before, but I have no idea why Europe doesn't spend more when they mostly don't even pay their fair share of NATO. The funny thing is that there is a lot of overlap with contractors, so space spending tends to keep defense industries more robust (and space programs are more technical jobs programs than anything else).
I know that, but NASA does propose to congress, and influence its future, but NASA hasn't even done that. I think it's safe to say they aren't too interested...
Yeah, I have no idea with the EU too. Also, China's budget should be roughly equal to NASA (along with ESA), since they all have roughly the same size of GDP.
6 hours ago, Darguel said:What about public funding? For example, some astronomers are kickstarting this project to study the KIC 8462852 star.
They have a goal of 100,000$, it's not a lot of money but space agencies are not backing it up. Do you guys think they will reach their goal?
They seem to be doing well, and probably don't need the extra money to be funded. Also, it's probably already being studied by obsevatories.
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4 minutes ago, tater said:
I'm fine with a prize, heck, I might be fine with that as a mechanism for all manned flight, frankly---"We have 20 Billion in escrow for the first company to provide us with an installation we can then rent for X million per month on the Moon. We guarantee to rent at least 6 months a year for 5 years." The taxpayer than does't spend a penny until the first astronaut can arrive at the base (transportation included from the provider). There would be certain minimal standards set for safety, obviously.
An even easier and cheaper challenge would be to have a Lunar ISRU experiment challenge, or to a ARM 'asteroid'. The requirements would be a lot cheaper, and it might be accessible to smaller aerospace companies (but not private groups), and be about the cost of a Flagship if NASA did it. It should be robotic (along with the rest of the system) to reduce costs. In the finalist competition (leaving 2 final spacecraft, one backup of the other) there would be unfunded help provided by NASA. One system would be upscaled 200% for (oxidizer) production.
The same thing would be done for Space tugs, and the LV system to carry the propellant to Earth. Each would have prizes, and a small contract at the end to keep those systems operating in the weaker early years of operation.
NASA would buy out a scaled down version to do more difficult precious metal ISRU. It would likely not be economical to actually mine the stuff to send back to Earth though (for one, you'd need launch and operate a small shuttle system, like X-37B.
The thing is though, NASA could do this if it wanted, but it doesn't.
Just now, Emperor of the Titan Squid said:NTR
Ah, then that probably wouldn't happen ever in any case ever due to radiation.
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2 hours ago, fredinno said:On 5/28/2016 at 9:20 AM, CptRichardson said:
I hate that they're still funding the SLS when they should be performing the 'shower them with money' gif all over SpaceX.
If they actually showered money on SpaceX tomorrow:
1. Congress would defund them.
2. LockMart and Boeing would sue NASA for not informing them of the cancellation beforehand.
3. SpaceX would likely pocket most of the money.
4. SpaceX would get an uncompetitive advantage, and make the US launch industry more monopolistic, since now they have more than enough money to "convince" the govn't to stop giving ULA launches (and defund potential competitors funded on the RD-180 replacement program), and to absorb enough losses to easily undercut its global competitors.
5. It would be worse off for everyone. There's a reason you never dump money at one place at one time.
On 5/28/2016 at 10:08 AM, KerikBalm said:Well, from the limited information I have... it seems that SpaceX would handily win an open competition against other launch capability providers.
* a Europa/Enceledus lander rather than this BS of manned lunar flights again
* A robotic mars mission to the "Martian Geysers" which may conceivably provide a habitable zone
* A robotic mars mission to a martian cave to look at the conditions away from the surface (radiation shielding makes it more likely that biological signatures may remain.. though perchlorates could still be a major problem
*A mission to Hellas Planitia... it gets above the tripple point of water there.
* A mission to one of the major river channels on Mars, it would be so awesome to find fossil biofilms, but so far, nothing has turned up.... viking 1 and viking 2 couldn't go roving, and landed where the ocean used to be fairly deep, and wouldn't have been shallow until the seas were disappearing and becoming a lot less hospitable (possibly freezing long before that and sublimating away)
Gale crater, where curiosity is... its unclear how long it had water
* Nuclear-Electric propulsion (ie nuclear powered Ion drives, rather than the wimpy solar powered ones)
If you mean planetary probes, SpaceX generally would lose- its launch pads on the Cape are filled (and soon also at Vandenberg, due to Iridium, and DOD launches).
I agree with the rest, except that manned Lunar flights are BS. Why? We have a huge list of destinations on Luna to go to, even without an outpost, particularly the poles, Tycho Crater, Trosvoky Crater, and the far side, in general.
And do we know the location of a stable martian cave? It would still require some pretty darned fast rover, or insanely precise landing to actually get inside the cave in 1 year.
I thought we already sent/will send a lander/rover to a river delta on Mars? Any fossil biofilms are going to require a dedicated lander to detach due to almost certainly being just bacteria.
Also, good luck getting people to accept nuclear+ space
On 5/28/2016 at 10:19 AM, tater said:Real international cooperation would require countries other than the US actually spending meaningful amounts of money, which they don't.
I wonder why NASA's budget is so much higher?
On 5/28/2016 at 1:37 PM, ValleyTwo said:I would like to see NASA working on the Rotary Rocket idea for delivering cargo and people into LEO.
Rotary Rocket didn't work as well as anticipated. I doubt it would be revived soon.
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18 minutes ago, PB666 said:
Uh not just Bezos, Musk original intention was to build a mars capable vessel, when the Russians gave him an inferiorty complex he decided to build a rocket company, I don't think exploration is off the plate, and it looks like they are experimenting with motors and reland schemes. As I said science is not strictly a knowledge enterprise, is a question creating enterprise, but in answerig questions it creates new knowledge based enterprises. The upstarts will carve new markets out of the science they create.
If i remember the topic correctly why aren't we tryning to figure out better ways to exploit space than what we are doing. OK thats a question, one aspect is the attempting, the other aspect is the problem solving. You can either go out into space and bring back tons of asteroid fragments kept in vacuum and test experimental proceedures, or build an space worthy fabrication laboratory (i.e. a factory) go into space and starts seeing what can be done. This basically means taking some tools and making other tools in-situ.
For all the other caga in this thread this is the only point of meaning, all the other devices people think we should do or places we should go, no le hace. unless you are sampling with an eye on return of significant quantities of raw starting materials, there is no meaning for men in space outside of LEO. The reason is quite clear, unless you've done the material science any trips humans are otherwise hogtied. Im willing to entertaine manned missions within reason anywhere, don't really care if the men come back, the important thing are the samples. And if they decide to send robots instead or Jeff Bezos and Elon Musk, doesn't really matter. (ok maybe kepp Elon here, he has better future IQ that the overwhelming majority of businessmen).
I think they should create a prize, the first person to return rocks (100 kilos) each from Mars, Phobos, Diemos, A asteroid belt deived asteroid, a kuiper belt derived comet (frozen colloid) gets 50 billion dollars. Another 50 billion if the can return 100 kilos of surface from mercury along with Ice and gas samples from the poles.
The problem is that Space Programs are concerned more about science than applications, so it's difficult to actually get them to do things like that.
I would start on making bulk sample return probes (ie ARM)
NASA is honestly selling ARM wrong. If they concentrated on its robotic mission (moving the SLS missions to the Gateway station), and on the asteroid mining aspect, it would be a LOT easier for Congress to support it. Alas, so far, politics prevent it, and ARM is constantly on the brink of political cancellation.
A prize structure is not going to work- even the much simpler goal of landing a probe on the moon and roving it 500m has been shown to be incredibly difficult to actually get the competitors to complete.
9 minutes ago, Sanic said:Stop sending every freaking spacecraft fo Mars and go to Uranus
Even if the next flagship probe is to be Mars Sample Return, the next discovery probes for Mars would likely be a life-finder, or a Geyser Hopper, and Mars 2020 has ISRU experiments and a min-heli?
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12 minutes ago, tater said:
@fredinno, sorta. It comes down to there actually being a need to be filled, though. Servicing a remote military base is a sort of economy, but it would always remain tethered to the needs of that one customer. Unless there is a "real" market, I'm not seeing it. Perhaps rare earths might be a thing at some point (mined from stuff dragged to Lagrange points), but either that;s a real market, or it isn't.
The idea is that things like space tourism would be a lot easier with the huge amount of investment into tech and infrastructure.
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On 5/30/2016 at 9:39 PM, Exoscientist said:
A SSTO formed from the first stage of a TSTO will carry less payload than the full TSTO. But it will be cheaper and most launches don't need the full TSTO launch capacity anyway.
Key then is knowing how high that payload can be using altitude compensation for the SSTO. People dismiss the possibility because they don't realize how high the payload can be with alt. comp. Even though the calculation is no more difficult using the rocket equation than is the standard case without alt. comp., they don't do the calculation because they assume the answer is just about the same as the standard case.
In fact the answer is not even in the same ballpark. In fact the answer is in the range of currently in use rockets that have billion dollar contracts.
Bob Clark
ok, let's assume a tsto carries 28T to leo. pretty reasonable for the biggest satellites.
A altitude compensated ssto might carry around 5T, generously, which is too small for most satellites.
The performance gain from tsto is so great that the extra complexity of a staged vehicle is taken. It would also be more well-understood and less complex than air-augmenting a 1st stage.
On 5/29/2016 at 10:52 AM, Emperor of the Titan Squid said:what about conformal fuel tanks? what makes them so impossibel? is it forming the materials into complex shapes?
not impossible, just difficult enough that no one bothers since they don't need to use it.
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On 5/29/2016 at 10:47 AM, Emperor of the Titan Squid said:
Developing usful exploration technologies that are more useful than the ones they are developing now.
What do you mean? They are developing ISRU, ION, inflatable heat shields...
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On 5/29/2016 at 2:32 PM, peadar1987 said:
The economy is an incredibly complex system, and it's oversimplistic and facile to say that governments can only mess it up. While the magnitude of the multiplier effect is up for debate, it is far from settled what the actual effects of government stimulus are, which alone should be enough to show that an emphatic blanket statement like that doesn't hold. Most qualified economists agree that under current economic conditions, the Keynesian multiplier is more often than not greater than 1, meaning each dollar spent by the government grows the economy by more than one dollar (usually between about 0.9 and 2, depending on the particulars of the situation)
But I think we can all agree the less government intervention into an economy, the better it is off generally (there are exceptions)- ie classical capitalist economics.
On 5/28/2016 at 9:20 AM, CptRichardson said:I hate that they're still funding the SLS when they should be performing the 'shower them with money' gif all over SpaceX.
On 5/28/2016 at 10:08 AM, KerikBalm said:Well, from the limited information I have... it seems that SpaceX would handily win an open competition against other launch capability providers.
* a Europa/Enceledus lander rather than this BS of manned lunar flights again
* A robotic mars mission to the "Martian Geysers" which may conceivably provide a habitable zone
* A robotic mars mission to a martian cave to look at the conditions away from the surface (radiation shielding makes it more likely that biological signatures may remain.. though perchlorates could still be a major problem
*A mission to Hellas Planitia... it gets above the tripple point of water there.
* A mission to one of the major river channels on Mars, it would be so awesome to find fossil biofilms, but so far, nothing has turned up.... viking 1 and viking 2 couldn't go roving, and landed where the ocean used to be fairly deep, and wouldn't have been shallow until the seas were disappearing and becoming a lot less hospitable (possibly freezing long before that and sublimating away)
Gale crater, where curiosity is... its unclear how long it had water
* Nuclear-Electric propulsion (ie nuclear powered Ion drives, rather than the wimpy solar powered ones)
On 5/28/2016 at 10:19 AM, tater said:Real international cooperation would require countries other than the US actually spending meaningful amounts of money, which they don't.
On 5/28/2016 at 1:37 PM, ValleyTwo said:I would like to see NASA working on the Rotary Rocket idea for delivering cargo and people into LEO.
On 5/28/2016 at 2:15 PM, Streetwind said:I wouldn't call it "hate" or something similarly melodramatic, but I am disappointed that nobody has genuinely tried studying artificial gravity through centrifugal force. You know, with actual hardware in space and stuff.
There was a Mars Society cubesat mission to test it out. No idea what happened to it tho.
https://en.wikipedia.org/wiki/Tempo3
But, you'd wonder why a BIOS-M or similar spacecraft was never made to spin with its 2nd stage in LEO- or a DragonLab. Is it THAT low-priority?
Maybe an Orion mission (like EM-2) can do artif. gravity experiments on the way to the Moon by tethering to the EUS?
On 5/29/2016 at 8:57 AM, tater said:It was political to suggest that space agencies could create an economy where none exists. There is either a market for something, or there isn't. A false economy of servicing an agency isn't a real economy.
It can kickstart a economy via investment, however.
On 5/29/2016 at 8:59 AM, radonek said:There was a Voskhod mission prepared for that, but it got canceled in favor of N1-L3 and 7K-OK (later Soyuz) projects.
What mission was that?
On 5/29/2016 at 10:47 AM, Emperor of the Titan Squid said:Developing usful exploration technologies that are more useful than the ones they are developing now.
What do you mean? They are developing ISRU, ION, inflatable heat shields...
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21 hours ago, PB666 said:
The evolution of neutron star involves the radially loss with the lower mass remnant retaining most of the angular momentum, in the form of its spin. Because the neutron star is made up different phases some experience tidal forces from the adjacent star, this creates a ver strong magnetic field. According to that article, the field causes erosion of the gas in the adjacent star.
http://phys.org/news/2016-05-tides-binary-star-neutron-stars.html
I couldn't find the article i was looking for,mthe above talks about why neutron stars merge.
http://www.nature.com/nphys/journal/v11/n12/full/nphys3574.html
http://www.nao.ac.jp/en/news/science/2014/20141014-neutronstar.html
I still don't get it. How does the erosion of a binary star's gas make a neutron star?
1 hour ago, PB666 said:I think the answer is, if I am reading the press stuff correctly, that they already have produced detectable.
The bigger problem right now is they need many more detectors than hey have to make these things detectable unless they are close.
Or just build them in space.
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3 hours ago, RCgothic said:
I that case the payload is essentially negligible. Plucking numbers essentially out of the air:
Spacecraft:
Let's say guidance and telemetry can be handled by a smartphone. ~100g.
There's a minimum volume of monopropellants that would be effective for control. Call it a half-litre plus tankage, maybe 400g.
So minimum 0.5kg for the spacecraft.
2nd stage:
Payload is 0.5kg, plus engine, plus tank. Assume it does most of the work, 6.8km/s orbital insertion. Atmosphere negligible.
Smallest H2/LOX engine I could find is India's CE-20, but it weighs 590kg and has 45kN thrust. ISPvac of 443. A bit overpowered... Stage would weigh about 4.6mt with 3.6mt of fuel and 370kg of tanks at a 10:1 tankage ratio (cryogenic).
An Airbus Aestus based second stage (N2O4/MMH, 111kg, 30kN, 325 ISPvac) would weigh about 1.6mt, with 1.4mt of fuel and 70kg tanks (20:1 non-cryogenic). TWR a bit ridiculous at 2 to 17, but I assume our postage stamp doesn't care much about that.
So let's go with the Aestus. Burn time is 144s, which sounds not ridiculous. The first stage needs to boost this to 100km and 1km/s.
Diameter (engine) is 1.31m. Nitrogen Tetroxide is mixed at a 1:9 ratio with hydrazine. The average density is 0.93g/cm3 and required volume 1.46m3. That would fit in a slightly elongated spherical tank (~15 cm cylindrical section) with internal bulkhead, which would be hilariously stubby, but then we already know this is massively over-engined. Engine is 2.2m long, stage approx 1.3m dia and 4m long including spacecraft as a cone.
1st Stage:
Payload is second stage (1.55mt) to 100km altitude and 1000m/s at that point. Needs to fight atmosphere. Gravity approximated as 9.8 all the way to orbit. If atmosphere is negligible above 10km, then you'd need to be travelling 1660m/s as you passed 10km assuming a coast from there to orbit.
Climb to 10km is a bit of a guess. You need at least 442m/s, plus extra to fight gravity, plus extra to fight air resistance. Assuming 2G acceleration, let's call gravity losses 220m/s and probably the same again for air losses.
Earth's rotation at the equator gets us 465m/s.
That's 2.1km/s. Let's call it 2.5km/s for margin.
The smallest 1st stage engine I can find is our friend Space X's Merlin 1D FT. RP/LOX, 756kN, 470kg, ISPsl 282, can deep throttle. It needs approx 3.2t of fuel to get the job done. 160kg tankage. TWR a truly ridiculous 4.5 to 14 even at 40% throttle. Burn time 30s.
The Merlin 1D is actually smaller diameter than the Aestus, so we keep our diameter at 1.3m. Density of RP/LOX is approx 1g/cm3. 3.2m3 required. That's a hemi-ended cylinder approx 2.8m long for tanks. Engine is 2.9m. First stage approx 5.7m tall.
1st stage mass: 5.4t.
Total craft mass: 6.9t.
Total craft size: 1.3m diameter by 10m tall.
These are just my crude back of the envelope scopings dependent on what's available engine-wise according to Wikipedia. I'm sure someone else could come up with something better.
Try using an advanced SRB motor- say, a GEM motor, since those can be built a lot smaller, plus maybe a 3-stage config, and air-launch from the equator, to maximize payload capacity.
But the net weight probably isn't going below 4T...
Another way is by just launching the rocket from a balloon. NASA did it with the Mars Inflatable Heat Shield tests, and it only took a single STAR37.
Using that method, we might only need a STAR20 or smaller to make a SSTO to space. 3-stage is even better.
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16 hours ago, autumnalequinox said:
Thissssssss. If only. I always inevitably create my own STS system in KSP. Heck I'm doing it now.
Yes, it's not as "exciting" to standardize everything and build what amounts to an Interstate Highway System in space. But damn, we were just sooo close.
That and Project Orion. I always wish instead of all the exo-atmospheric nuclear testing we had just launched a pair of Orion ships. It would have produced the same fallout and they could still be up there today (or helped expand our knowledge to crazy levels).
But I am a firm believer that private spaceflight will soon step up (as it already is) and bring the force of the market to get us into space in a way governments cannot. Once we make it profitable to be up there and can create a real economy in space (as in, extract resources to be used out of our gravity well) we will finally be in the future. There was no way politicians would ever be able to pull this off. We (as in regular people, aka the market) are what's needed.
We weren't close to building IPP/STS when it was proposed. We're arguably closer now than ever-
F9/ rocket reuse : Aka space shuttle 2.0.
6 man space station(ISS): Large space stations were the core focus of the STS (minus reuasble space travel)
And aspects that we are closer to implementing than ever:
SLS/Orion: Lunar Missions
SLS: Saturn V
ION Drives/VASMIR space tugs: NTR space tugs
IVF/ACES: H2 reusable space tugs
ViviSat: Space repair
That exo-atmospheric nuclear testing would have been very useful for project Orion- otherwise we'd be launching a rocket without a clue on how nukes act in space/upper atmosphere. Also, the exo-atmospheric nuclear testing would have been a LOT less concentrated, so the net environmental effects are lower.
Also, the problem with Private Companies is that Space isn't economical because all the "markets" are either too small or a red herring. And we can't attract more investment into risky space projects and get people to go to space unless we reduce prices even more (the current 20% has been shown to have little effect on space demand).
ie, chicken and the egg problem.
A Space Agency funded at Apollo levels could kickstart it by investing into tech, building space infrastructure, and increasing demand, but can't offer a permanent space economy.
What do you hate that space agencies are not doing, which is possible?
in Science & Spaceflight
Posted
But XS-1 isn't a huge part of the DOD's budget, or any of the other lifting body/spaceplane programs either?
Yey. I don't really care. :/