Falcon 1 & Falcon 9

clark · 2004-10-19 13:27:19

Ahhh but Clark, the human componet of the proposed CEV is such a SMALL fraction of the vehicle weight, simply taking people out of it will only save you a few hundred kilos, not the several thousand you would need to put CEV on Falcon-V.

I think you misunderstand, I realize this. In my previous post you alluded to, I was stating that Falcon V is being designed to launch human cargo (via an alternative crew transfer vehicle). You have stated time and again how Falcon V wouldn't be able to do this, that it wouldn't work, and I am pointing out that they are actively working towards that goal.

Besides, Musk has stated before that SpaceX will build larger rockets if the demand is there...

GCNRevenger · 2004-10-19 13:31:20

I think that it is possible for the Falcon-V to launch people. It is a viable choice of launch vehicle for a small Gemini-sized manned orbital capsule, it can probobly do this... but this is not what we need it to do.

Bigger rockets? He hasn't even flown his little one yet, and the Falcon-V is already using a five-engine cluster for the first stage, he would basicly have to start from scratch.

Ad Astra · 2004-10-19 14:46:11

I really don't think that Falcon-I is a mini Falcon-V... going from a two-engine truck-launched vehicle to a 6-7 engine pad launched vehicle is a whole different entity.

No disagreements there. The benefits of using off-the-shelf technology are often overrated, as the established components have to be integrated into the complete system. Falcon V may use similar parts to Falcon I, but they will need to test extensively and make mods as they see fit. It will certainly act like an entirely different animal.

BWhite · 2004-10-19 15:08:42

I think that it is possible for the Falcon-V to launch people. It is a viable choice of launch vehicle for a small Gemini-sized manned orbital capsule, it can probobly do this... but this is not what we need it to do.
Bigger rockets? He hasn't even flown his little one yet, and the Falcon-V is already using a five-engine cluster for the first stage, he would basicly have to start from scratch.

What about sending up a big CEV without crew on a 5 segment SRB plus liquid upper stage. Then ferry 2 or 3 crew in a tiny Falcon V crew transfer vehicle. (3 crew and a big ship for less than $100 million, maybe less than $75 million. Dock the Falcon CEV to the orbiting ship and use it for Earth return at mission end - - return as little mass to Earth as possible.)

If Bigelow used 5 segment RSRM with RL-60 upper stages for on orbit assembly of a vacant space hotel, then ferrying up passengers in a Falcon V with a big upper stage might work.

SpaceNut · 2004-10-21 11:06:12

What I find interesting about this article is the developement of a Kerosene Lox engine with a pretty hefty isp level that is part of phase II competition.

XCOR Makes Progress On DARPA-Funded Pump-Fed Rocket Program

http://www.spacedaily.com/news/rocketscience-04zl.html

GCNRevenger · 2004-10-21 15:24:31

Frankly, I don't think it makes alot of sense to make a manned vehicle with room for less then six, which is what the ISS will eventually support. Three people to the Moon gives us Apollo again, but I also question how useful that would be, and to top it off, a bigger 6-seater CEV would be big enough to haul ISS racks if fitted with an MPLM rather then Soyuz/Shuttle port.

This is this absolutely pervasive ideal in all the AltSpace talk... smaller, Smaller, SMALLER. This is a BAD thing, we need larger and more powerful rockets then we have today, doing anything a Delta-II at a time is just plain stupid. Even the 5-segment SRB launcher or the baseline Delta-IV HLV is too small to launch a worthwhile Lunar sortie most likly. 40MT payloads should be the baseline point of entry, not nickle & dime 6-8-10MT loads.

SpaceNut · 2004-10-22 08:13:26

While others are argueing about how much it can lift others are say look how little it costs.

Launch Systems Rockets Priced to Move
Dot-com millionaire Elon Musk put his profits into orbit.
http://www.popsci.com/popsci/aviation/a … 17,00.html

GCNRevenger · 2004-10-22 08:27:25

Small costs yes, but small payloads too. The smaller the payloads, the more expensive it is to do anything big, which will offset the cheaper launch vehicle.

SpaceNut · 2004-10-25 14:06:50

Repost of LOX pump by xcor aerospace press release.

http://www.xcor.com/DARPA_LOX-pump_milestone.html

Ad Astra · 2005-03-09 18:42:59

Latest news from Robert Bigelow is that he's moving his Nautilus inflatable habitat from the Falcon V to the Russian SS-18 Dnepr. Looks like those delays with the Falcon I are starting to hurt Elon & Co.

GCNRevenger · 2005-03-09 18:47:56

Elon needs to get on with it... he's flashed his rocket for the Wright Brothers' day in DC, he's flashed it to the media and USAF... its time to "light this candle." Elon does not have unlimited time.

And if it blows up... well... thats perhaps the end of SpaceX.

Grypd · 2005-03-10 04:55:20

I thought that Bigelow was restricted in what he was allowed to launch his inflatable habitats in by law. I was always considered his sponsorship of the new Americas prize was so he could get an American launcher capable of putting those habs up.

I wonder how he managed to get clearance for his Habs to now be deployed by another countries systems or is it the SS-18 being operated by an American company ???

Ad Astra · 2005-03-10 17:15:56

The "American company" restriction applies only to the 5-man spacecraft that will hopefully be built for the $50 mil prize. Even then, the company need only place its headquarters in the US to qualify.

Grypd · 2005-03-10 19:47:44

The "American company" restriction applies only to the 5-man spacecraft that will hopefully be built for the $50 mil prize. Even then, the company need only place its headquarters in the US to qualify.

Ah but for launching his improved inflateable Habs he fell under the law forbiding advanced technology to be launched by a non US launcher or even to be taken abroad. His support and funding of the Americas prize was a cheap means to get such a launcher and a service to his "space Hotel".

I wonder what has changed that now allows him to deploy such Habitats from Non American launchers and launched and set up in Non continental US. Maybe someone in the department of trade decided to see sense. ???

SpaceNut · 2005-03-10 19:59:20

I think this is how it is getting around the issue of technology.

http://www.kosmotras.ru/
Program for development and operation of the Dnepr Space Launch System based on the most powerful ICBM in the world - 150 SS-18 being eliminated under the START Treaty is one of the largest conversion programs.
ISC Kosmotras has been permanently present at the world launch services market. As of the end of 2002, 3 orbital launches of Dnepr LV have been carried out. The total number of satelliets deployed to date is 12. Among the launch customers were companies from UK, USA, Italy, Saudi Arabia, Malaysia and Germany.

Ad Astra · 2005-03-10 20:34:21

The definition of "advanced technology" is very vague. It's unclear if the inflata-habs fall under this restriction.

GCNRevenger · 2005-03-10 20:41:18

...especially since they are a re-hash of an old technology

flashgordon · 2005-03-18 17:05:09

in terms of getting the Falcon(if it ever flies) to make a manned mission(possibly to mars seems to be were people are getting at here), instead of launching all the pieces on one big rocket, what about that old idea of launching bits and pieces and assembling them in orbit?

GCNRevenger · 2005-03-18 23:48:13

Too inefficent to do it one Falcon-V at a time. The rocket fuel stored on orbit will also slowly boil off over time, so you can't afford to slowly build it up.

Also, if it takes too long to assemble each mission, the rate at which you can fly is going to be severely limited.

Don't forget that each and every payload you launch can't just be dropped "dumb" into orbit. Each one of them must have at least some attitude control (maneuvering jets) to keep from naturally spinning. Hence it must also have a power supply. And a navigational beacon and telemetry/control transponder would be nice. The more launches you have, the more sets of these systems you need.

Oh, and the smaller you make a fuel tank or any vessel, the more surface area it will have per-volume (cube/square law), so a smaller tank or HAB will weigh more per volume and have more problems with insulation.

SpaceNut · 2005-03-21 06:17:21

Well hopefully the Falcon will be successful on its maiden voyage. But I came across the European version known as the Vega. It would appear that they are both going after the same market to launch satelites in the less than 2000 Kg size.

Mad Grad Student · 2005-03-21 17:14:53

Assuming that the Falcon I can operate as cheaply as is claimed by Spacex it should be the death of all competition in the commercial small sattelite LEO market. The problem is that this is an extremely small market as it currently stands. If miniturization technology progresses far enough perhaps some of the current market on slightly larger LVs can be grabbed, and Spacex might be able to convince customers to forgo launching multiple payloads on larger launch vehicle and use the Falcon instead. Without government-sponsored payloads, however, it will be much more difficult for them to stay afloat.

For example, the Vega will be far more expensive to operate and probably less reliable than the Falcon I, but will automatically have 100% of the market share for ESA-sponsored light payloads. Spacex must grab the American market from Orbital Sciences and the Pegasus or else they'll never see much of a return on their investment. Or perhaps having such a low-cost launch vehicle will open up a much wider market for commercial payloads. It's a possibility, but I'm rather skeptical of it happening right now.

John Creighton · 2005-03-21 17:33:51

Oh, and the smaller you make a fuel tank or any vessel, the more surface area it will have per-volume (cube/square law), so a smaller tank or HAB will weigh more per volume and have more problems with insulation.

This is off topic but….I think you frequently overstate this problem. The cube square law is true for a sphere but for a cylinder it would be the square linear law. At any rate this just speaks for the surface area and not the dead weight. As far as supporting a given amount of pressure the cube square law is irrelevant because the walls in the tank with twice the diameter or twice the radius would have to be twice as thick. As far as insulation goes foam is pretty light and perhaps tanks should have a layer of foam sandwidged between two layers of metal. Additionally if the tanks are packed tightly together the gaps between the tanks could add to there insulation.

dicktice · 2005-03-21 19:24:54

Water in orbit--lots of it, accumulated as payload ice in white painted powered core units, booster launched and ultimately strapped together in orbit. A good anchor for tethered momentum transfer missions to higher orbits, including cislunar one, as well as a storeable source of H2 and O2 for solar electrolycised fuel on demand.

GCNRevenger · 2005-03-22 21:36:32

I think you frequently overstate this problem.

No it isn't, because fuel tanks won't be under really high pressure, at least with turbopump engines.

RobertDyck · 2005-03-23 03:16:45

Good point. One reason to use cryogenic propellants is to lower the pressure. According to NASA, the Shuttle http://www.spaceflight.nasa.gov/shuttle … n.html]LH2 tank operates between 32 and 34 psia, and the http://www.spaceflight.nasa.gov/shuttle … n.html]LOX tank between 20 and 22 psig. psia = pounds per square foot absolute, psig = pounds per square foot gage (relative to outside). Cylinder volume and surface area is linearly proportional to length, but volume is proportional to the square of radius while surface area is linearly proportional. If you keep length to radius a fixed ratio then surface area is proportional to the square of "size" while volume is proportional to the cube, so the cube square law still holds.

Liquid oxygen boils at -182.96°C at one atmosphere pressure, while liquid hydrogen boils at -252.8°C. Cryogenic propellants are stored at their boiling temperature because they can be kept cool simply by letting some gas boil off, and because it minimizes heat required for phase transition to gas. Transition to gas causes expansion, which is what causes thrust. The differing temperatures of LOX and LH2 require insulation between tanks. Kerosene fuel for commercial jets has additives to prevent freezing; Jet A freezes at -40°C while http://www.petrovalue.ca/Products_JetA.htm]Jet A-1 freezes at -47°C. Military fuel NATO F-34 known by the U.S. military as JP-8 also freezes at -47°C. http://www.astronautix.com/props/loxosene.htm]RP-1 (rocket propellant 1) doesn't freeze until -73°C (really good fuel line anti-freeze), but kerosene/LOX rockets still need insulation between tanks.

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#51 2004-10-19 13:27:19

Re: Falcon 1 & Falcon 9

#52 2004-10-19 13:31:20

Re: Falcon 1 & Falcon 9

#53 2004-10-19 14:46:11

Re: Falcon 1 & Falcon 9

#54 2004-10-19 15:08:42

Re: Falcon 1 & Falcon 9

#55 2004-10-21 11:06:12

Re: Falcon 1 & Falcon 9

#56 2004-10-21 15:24:31

Re: Falcon 1 & Falcon 9

#57 2004-10-22 08:13:26

Re: Falcon 1 & Falcon 9

#58 2004-10-22 08:27:25

Re: Falcon 1 & Falcon 9

#59 2004-10-25 14:06:50

Re: Falcon 1 & Falcon 9

#60 2005-03-09 18:42:59

Re: Falcon 1 & Falcon 9

#61 2005-03-09 18:47:56

Re: Falcon 1 & Falcon 9

#62 2005-03-10 04:55:20

Re: Falcon 1 & Falcon 9

#63 2005-03-10 17:15:56

Re: Falcon 1 & Falcon 9

#64 2005-03-10 19:47:44

Re: Falcon 1 & Falcon 9

#65 2005-03-10 19:59:20

Re: Falcon 1 & Falcon 9

#66 2005-03-10 20:34:21

Re: Falcon 1 & Falcon 9

#67 2005-03-10 20:41:18

Re: Falcon 1 & Falcon 9

#68 2005-03-18 17:05:09

Re: Falcon 1 & Falcon 9

#69 2005-03-18 23:48:13

Re: Falcon 1 & Falcon 9

#70 2005-03-21 06:17:21

Re: Falcon 1 & Falcon 9

#71 2005-03-21 17:14:53

Re: Falcon 1 & Falcon 9

#72 2005-03-21 17:33:51

Re: Falcon 1 & Falcon 9

#73 2005-03-21 19:24:54

Re: Falcon 1 & Falcon 9

#74 2005-03-22 21:36:32

Re: Falcon 1 & Falcon 9

#75 2005-03-23 03:16:45

Re: Falcon 1 & Falcon 9

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