Post central for information on CEV - iformation station for the spacecraft

Rxke · 2004-01-26 13:12:42

Personally, I think that Boeing is using terms like 'in orbit around the Moon' because it thinks L1 is too hard to explain to the general public.

aargh! I sprayed my coffee all over the place!:D

It's probably true, though...

*off to get some cleaninng stuff*

RobW · 2004-01-26 14:49:20

Hmmm - well I guess that's one way to get your keyboard clean. :laugh:

Rxke · 2004-01-26 15:19:47

Worst thing is, it happened *twice*, I read one of Clark's comments in the ice igloo thread a bit later... and it happened again! It's a conspiracy!

RobertDyck · 2004-01-26 22:24:31

Is it just me, or does the Boeing proposed equipment look lame. It does use the TransHAB, but has a large and heavy looking disk at the end of the Autonomous Cargo Vehicle, and Crew Habitat. Why is that heavy disk there, what do you get for the investment of mass? But most importantly, this looks like it will take multiple launches of the most expensive launch vehicle currently in America's inventory, and be assembled in Earth orbit just for a trip to the Moon. Apollo did it in a single throw. True, a larger number of smaller rockets give you economy of scale, but how many launches does it take just to send a simple capsule to the Moon? The vehicle itself looks like recycled 40-year-old equipment. The Crew Control Module looks like an Apollo Command Module, the Resource Module looks like the Service Module with strong influence from Soyuz, and the Crew Habitat - Lunar Surface Version looks like an Apollo Lunar Module with the cabin replaced by a TransHAB inflatable. True, using inflatable cabins and solar panels are a couple improvements over the 1960's designs, but I would expect more after 40 years.

For one thing I expected Delta IV Large to lift something the size of a space station module into LEO, not just a capsule with resource module. The Delta IV Large is supposed to have a lift capacity of 25.8 tonnes to 185km orbit. The Soyuz-FG can only lift 7.42 tonnes to 193km orbit, and it carries a 3-crew Soyuz-TMA spacecraft to ISS. The Apollo Command and Service Module had a mass of 30.325 tonnes, but it had enough room below the seats for lunar samples that instead you could fit 2 more seats. In fact, a kit was prepared to convert an Apollo Command and Service Module into an Apollo Rescue CSM that did have 5 seats. At one point during the Skylab 3 mission the Apollo CSM developed leaks in 2 thruster quads, and preparation of a CSM into a Rescue ship was started. Astronauts on Skylab were able to localize the problem and work around it, so the Rescue ship wasn't needed. So the 5-seat version of Apollo wasn't just theoretical, it was built. However that was in 1973, the modern Soyuz-TMA spacecraft is only 7.25 tonnes and can carry 3 astronauts; even if the new CEV can carry 4 astronauts, why would you need the lift capacity of a Delta IV Large just to lift a capsule and resource module to LEO?

The truly concerning feature is the complete lack of any reusability. A contractor would love for NASA to buy throw-away vehicles at hundreds of millions of dollars each. But sustainability will require a reusable craft. If George W. Bush wants to go to the Moon, won't we need a reusable craft to ferry astronauts between the Moon and Earth? Most importantly, how do we build a Moon base, lunar mines, and the ability to utilize lunar resources without the ability to send space station size modules to the Moon?

As for a lunar space station: Why? Since the Moon doesn't have an atmosphere, what do you gain in orbit that isn't gained on the surface? If you want to send lunar resources to Earth orbit, a stop in lunar orbit doesn't save any fuel; in fact circularization would cost more fuel. Remote instrument observations can be done just as well by unmanned orbiters, we need humans on the surface where they can examine the geology of rocks, build smelters or other resource extraction equipment, build radio telescopes or interferometry telescopes. A surface habitat could be partially buried for micrometeoroid and radiation shielding, and has the whole Moon to protect its underside.

The Boeing Interplanetary Crew Exploration Vehicle would take between 16-18 launches to assemble, and doesn't have a Mars lander. A mission that utilizes Mars resources would require a complete redesign.

On the positive side, it's a start. The design is a first try; needs work, but we're on the way.

RobS · 2004-01-27 00:17:35

I agree with both the other Roberts. I think the Boeing "proposal" is simply some old designs they had lying around (or maybe some hasty new oners) that they put up because the public is curious right now. I think "lunar orbit" assembly means lagrange either because they think the public won't understand or because the copy writer didn't understand. No, you can't gain anything launching straight from the moon to Mars without passing the Earth first. And there would be absolutely no point launching something from the lunar surface, as Bush implied; the delta-v to get there from low Earth orbit is more than trans-Mars injection! There are really only two places to launch a craft to Mars from:

1. Low Earth orbit

2. Lagrange, and even then you perform trans-Mars injection close to the Earth. Its only advantage is the use of lunar propellant. If you have no lunar fuel, assemble and launch from low Earth orbit.

In between you have radiation belts you don't want to be traversing a lot, so long-term elliptical orbits are out. On the other hand, for Mars, the equivalent of the lagrange 1 "Gateway" is probably a 24.6-hour elliptical orbit; it would stay over the landing site most of the time so the mother ship could be a communications relay, would be only 0.2 km/sec shy of escape velocity, its inclination and the direction of the line of apsides can be "walked" easily so that it's pointed toward Earth at the right time, and it would have a low periapsis where you perform trans-Earth injection. But the Earth's van Allen belts rules this sort of orbit out for a terrestrial space station. Mars has no radiation belts because it has no magnetic field.

I also agree the Boeing proposal is a bit lame. It struck me as a Boeing battlestar galactica fantasy. But it may be the best we will get after the NASA safety freaks go over the plans and double the mass of everything.

-- RobS

Pendragon · 2004-01-27 08:54:33

Maybe someone could clarify for me, but I thought the L1 point was unstable. In which case you would put any spacecraft in high lunar orbit (just inside the L1 distance) where a small nudge would send it towards Earth in the method that RobW mentioned.

RobS · 2004-01-27 11:48:14

Yes, L1 is unstable, but a small ion engine is sufficient to keep a spacecraft in place. But a small delta-v won't send your ship toward Earth because L1 is orbiting Earth at about 1,000 miles per hour (0.5 km/sec). Instead, something leaving L1 will wander off into a different orbit around the Earth, or will head toward the moon, because the moon is also orbiting the Earth at about 1,000 miles per hour. I saw a website that said a spacecraft needs about 0.2 km/sec (400 mph) to reach the lunar surface (which it would then hit at 5,000 mph/2.3 km per second unless its engines fired). The moon's gravity is weak, but it is probably strong enough to send the spacecraft back toward L1 at the same speed it left, but directed toward earth rather than around the earth. Somewhere I saw that it could bring about gravity assists of 0.5 km/sec.

What I don't know is how long it would take something to fly past the moon if it leaves L1 at 0.2 km/sec, and how long it takes to go to Earth. It may be too slow to be practical for crewed vehicles, though I doubt it would take more than a week or two.

-- RobS

Ad Astra · 2004-01-27 17:45:17

I think that the Boeing concepts have been given some significant thought over the past year. It looks like the Crew Control Module and Automated Cargo Vehcile were designed to meet the ISS needs while retaining the potential to go beyond earth orbit.

The heavy disk on the end of the ACV is probably a re-entry capsule for high-priority ISS cargo. It seems wasteful to re-invent what Europe and Japan have with the ATV and HTV, but the Boeing design adds the ability to return some of that cargo to earth.

The Crew Control Module isn't just an Apollo knockoff, although it uses Apollo's shape. Remember that the Apollo capsule was 4.5 meters in diameter. The CCM will be 5 meters to match the Delta IV booster. It will also have a universal docking adaptor in the nose, while Apollo had the smaller but less versatile probe-type docking mechanism. The capsule will also be recovered (according to at least one report) with an X-38 style parawing. I'm a bit disappointed that Boeing didn't choose the "Big Gemini" shape over Apollo, but the current CCM design looks like a good start.

I think that Boeing's current designs really demonstrate the need for an HLLV. I don't care if they roll out a shuttle derivative, a resurrected Energia, or even the upgraded EELV that Zubrin was talking about. I just want some kind of mammoth rocket to launch these ships, and I want this mammoth rocket now!

RobertDyck · 2004-01-27 20:04:31

the Apollo capsule was 4.5 meters in diameter. The CCM will be 5 meters to match the Delta IV booster.

The Apollo capsule was 3.9 metres in diameter, not 4.5. Atlas V 401 can lift 12.5 tonnes to 185km orbit at 28.5?. The '401' variant uses the standard Atlas payload fairing: 4 metre diameter. Atlas V 401 is priced at $77 million per launch in 1998 dollars, while Delta IV Large is $170 million in 1999 dollars. I think 4-crew CEV should be sized for this medium size EELV rather than the most expensive one available.

A Delta IV Medium would be the backup launch vehicle; it can lift 8.6 tonnes to 185km orbit, and has a 4 metre fairing, but costs $90 million in 1999 dollars. Far less bang for the buck. A Delta IV Medium+ (4,2) has 2 solid rockets added to the standard Delta IV Medium. It can lift 11.7 tonnes for $95 million.

Another way of looking at this: the Soyuz was originally designed to be the Russian lunar vehicle, equivalent to the Apollo CSM. It includes 2 weeks of life support for a 3 person crew, but the Soyuz-TM still masses 7.15 tonnes. The Soyuz-TMA with its larger seats (for taller, heavier astronauts), upgraded parachutes (for heavier astronauts) and two additional display monitors has a mass of 7.25 tonnes. Even using the 7.25 tonne figure, that works out to 2.4167 tonnes per astronaut. That's for the complete spacecraft, from launch pad to lunar orbit, and back to Earth surface. It doesn't include the launch escape tower or translunar insertion stage, but those were separate for Boeing's proposal and Apollo; Apollo used the 3rd stage of Saturn V. An equivalent for 4 astronauts would mass 9.67 tonnes. That's for an all-metal spacecraft; advanced composites such as graphite fibre should reduce it.

Ad Astra · 2004-01-27 20:41:57

I stand corrected on the base diameter of Apollo; but Boeing's renderings do show the CCM on top of their Delta IV heavy which is five meters in diameter from top to bottom. And the CEV/CCM will be more massive than Apollo or Soyuz. It's often said that Soyuz was a three-man spacecraft, but it was originally designed for the crew to not wear pressure suits in this seating arrangement. The lunar version of Soyuz only seated two. Apollo seated three in comfort or five to seven in an emergency. I expect CCM/CEV to carry seven astronauts as some sources have suggested.

RobertDyck · 2004-01-27 21:41:29

It's often said that Soyuz was a three-man spacecraft, but it was originally designed for the crew to not wear pressure suits in this seating arrangement. The lunar version of Soyuz only seated two. Apollo seated three in comfort or five to seven in an emergency. I expect CCM/CEV to carry seven astronauts as some sources have suggested.

I've never seen a 7-seat configuration of Apollo. The standard Apollo configuration accommodated 3 crew with a total body mass of 216kg, or 72kg (158.7 pounds) each; crew seats and provisions of 550kg, and miscellaneous contingency of 200kg. Apollo 17 acquired 117kg of lunar samples.

You're right the original Soyuz was designed for use without suits, but after the Soyuz 11 accident all missions used the 10kg Sokol suit. I'm surprised you haven't mentioned the difference of delta-V. The Soyuz 7K-LOK was designed as the lunar vehicle. It accommodated 2 crew for 13 days and had room for lunar samples. It had a larger service module which provided 1100m/s total delta-V and massed 9.85 tonnes. The Soyuz-TMA only provides 390m/s total delta-V and masses 7.25 tonnes, but it accommodates 3 crew for 14 days and no lunar samples. However, a big reason for the reduced mass is improved technology since 1968.

Don't mistake my statements as an attack on anything American or support of anything Russian. I'm saying I have great expectations for a new vehicle developed 40 years after Apollo, and current designs have the very bad habit of adding all sorts of unnecessary luxuries causing extreme weight creep. Don't let it increase cost to the point that congress cancels it again. Perhaps I should word it as a challenge: if Russia can build a spacecraft that masses 2.4167 tonnes per astronaut using 1990's technology, can't America do at least as well using 21st century technology?

Ad Astra · 2004-01-27 22:12:03

I don't see anything anti-American about what you're saying, Robert. I'm not really skeptical about the prospects of CEV getting off the drawing board, because this time we've set the design bar so low that success is almost guaranteed (although similar arguments could have been made for X-34 and X-38.) The challenge here is to meet reasonable cost, weight, and schedule goals, and the industry has yet to prove (in my mind, anyway) that they can do so in the 21st century.

clark · 2004-01-28 12:45:29

CEV will be called Project Constellation.

For more info:

[http://www.spaceref.com/news/viewsr.html?pid=11680]http://www.spaceref.com/news/viewsr.html?pid=11680

RobS · 2004-01-28 13:19:49

The White House statement at

[http://www.whitehouse.gov/space/renewed_spirit.html]http://www.whitehouse.gov/space/renewed_spirit.html

has this very nice bullet point summary of objectives, also. Note the CEV is supposed to start the first exploration missions by 2014, not the first human missions. The focus of the CEV is exploration, Maybe it'll go to ISS before 2014 and provide crew transportation there--it should, since the first unmanned launch is 2008--but that isn't its main purpose.

. Exploration Activities in Low Earth Orbit
Space Shuttle

Return the Space Shuttle to flight as soon as practical, based on the recommendations of the Columbia Accident Investigation Board;

Focus use of the Space Shuttle to complete assembly of the International Space Station; and

Retire the Space Shuttle as soon as assembly of the International Space Station is completed, planned for the end of this decade;

International Space Station

Complete assembly of the International Space Station, including the U.S. components that support U.S. space exploration goals and those provided by foreign partners, planned for the end of this decade;

Focus U.S. research and use of the International Space Station on supporting space exploration goals, with emphasis on understanding how the space environment affects astronaut health and capabilities and developing countermeasures; and

Conduct International Space Station activities in a manner consistent with U.S. obligations contained in the agreements between the United States and other partners in the International Space Station.

B. Space Exploration Beyond Low Earth Orbit

The Moon

Undertake lunar exploration activities to enable sustained human and robotic exploration of Mars and more distant destinations in the solar system;

Starting no later than 2008, initiate a series of robotic missions to the Moon to prepare for and support future human exploration activities;

Conduct the first extended human expedition to the lunar surface as early as 2015, but no later than the year 2020; and

Use lunar exploration activities to further science, and to develop and test new approaches, technologies, and systems, including use of lunar and other space resources, to support sustained human space exploration to Mars and other destinations.

Mars and Other Destinations

Conduct robotic exploration of Mars to search for evidence of life, to understand the history of the solar system, and to prepare for future human exploration;

Conduct robotic exploration across the solar system for scientific purposes and to support human exploration. In particular, explore Jupiter's moons, asteroids and other bodies to search for evidence of life, to understand the history of the solar system, and to search for resources;

Conduct advanced telescope searches for Earth-like planets and habitable environments around other stars;

Develop and demonstrate power generation, propulsion, life support, and other key capabilities required to support more distant, more capable, and/or longer duration human and robotic exploration of Mars and other destinations; and

Conduct human expeditions to Mars after acquiring adequate knowledge about the planet using robotic missions and after successfully demonstrating sustained human exploration missions to the Moon.

C. Space Transportation Capabilities Supporting Exploration

Develop a new crew exploration vehicle to provide crew transportation for missions beyond low Earth orbit;

Conduct the initial test flight before the end of this decade in order to provide an operational capability to support human exploration missions no later than 2014;

Separate to the maximum practical extent crew from cargo transportation to the International Space Station and for launching exploration missions beyond low Earth orbit

Acquire cargo transportation as soon as practical and affordable to support missions to and from the International Space Station; and

Acquire crew transportation to and from the International Space Station, as required, after the Space Shuttle is retired from service.

D. International and Commercial Participation

Pursue opportunities for international participation to support U.S. space exploration goals; and

Pursue commercial opportunities for providing transportation and other services supporting the International Space Station and exploration missions beyond low Earth orbit.

Goals and Objectives

The fundamental goal of this vision is to advance U.S. scientific, security, and economic interests through a robust space exploration program. In support of this goal, the United States will:

Implement a sustained and affordable human and robotic program to explore the solar system and beyond;

Extend human presence across the solar system, starting with a human return to the Moon before the year 2020, in preparation for human exploration of Mars and other destinations;

Develop the innovative technologies, knowledge, and infrastructures both to explore and to support decisions about the destinations for human exploration; and

Promote international and commercial participation in exploration to further U.S. scientific, security, and economic interests.

[Intersting note: this last para. is accidentally repeated twice in the White House web page!]

RobertDyck · 2004-01-28 15:01:28

These are very well worded documents. This new focus for NASA should be very beneficial.

I'm not trying to say the CEV will only go to ISS. I'm saying the CEV should be able to launch on an Atlas V 401 or Delta IV Medium+ to go to ISS, and if the lunar vehicle is assembled in Earth orbit then the CEV should also be delivered to the assembly with the same launch vehicle. Keep the crew vehicle small to keep cost down, and make room for useful equipment such as lunar base modules, resource extraction equipment, etc. If mission plans start by doubling the launch mass of basic equipment, we will never deploy "the innovative technologies, knowledge, and infrastructures both to explore and to support decisions about the destinations for human exploration; and Promote international and commercial participation in exploration to further U.S. scientific, security, and economic interests." Of course I would like to emphasize scientific and economic interests, but security always seems to get in there.

I would prefer a heavy lift launch vehicle. The sort of utilization of the Moon alluded to, an effective mission to Mars, or equipment for asteroid mining, will all require cost effective transportation of heavy equipment to space.

Michael Bloxham · 2004-01-28 20:11:44

Why is it that we won't land on the moon before 2015, when the craft that will get us there will be ready by 2008???? Will it take us 7+ years to figure out how to fly the damned thing? I'm telling ya, I won't be surprised if this whole thing turns to custard... Use your noggin, NASA. :;):

clark · 2004-01-29 10:08:47

2008 the CEV is decreed to be ready for flight testing. By the sounds of it, they will be developing multiple versions of the CEV- so you have a basic model that will get us to LEO and back. Then we must have a flight ready, man-rated, version of the CEV completed in 2008 capable of taking us to the moon by 2014.

We still have the Shuttle, which can still carry people, till 2010. That means in a worst case scenerio, if the CEV is not ready by 2008, we still have the Shuttle for two more years. Now, just becuase we say it has to be done by a certain date does not mean that we can't do it sooner. It's a timeline, and they padded it. What better way to make your actions look even better?

My guess is that they man rate the thing by 2010 for LEO trips. Then man rate it with a lunar flyby by 2012. Which sets the stage for hitting the lunar landing by 2015.

Michael Bloxham · 2004-01-29 23:11:04

Your right, Clark. My mental image was optimistically a one-piece SDV-thrown vehicle. I forget the modularity of the (okay, proposed) CEV.

RobS · 2004-01-30 00:53:55

If you look at the Boeing design, it gives a rough idea of what they could do. There's a capsule, but it would have life support for a short time only; maybe two days. That's what you flight test a mere four year from now. There might be a living module; not needed for ISS, but needed for the moon flight. The living module has a more robust life support system, too. That is ready in 2012 or 2014. A version of the living module can also serve as a cargo vehicle; it wold be needed after 2010. The translunar injection stage and the lander might be ready in 2014, or maybe 2019 (since the plan sets the latest date for the return to the moon at 2020).

-- RobS

GCNRevenger · 2004-01-31 11:50:50

I hearty "Amen" to RobW about the reliability of complex manned systems... About if we ought to ditch the SDV concept or not, I think that is largely a question of cost. MarsDirect obviously will need a launcher of that size, but the Moon since it is so close doesn't have to have it if Lunar water is available. As far as an orbital assembly mission to Mars, that depends... will the cost of developing and flying a worthwhile SDV given the vast army of ex-Shuttle engineers who would be retained outweigh the cost of designing a Mars ship out of 20-ton payloads? A TransHab, a CEV for the return trip, a NERVA nuclear rocket, etc can all comfortably fit on a Delta-IV HLV/Atlas-V HLV/Ariane-V/Angara-5/7. However I have my doubts that economies of scale would kick in for large and expensive booster rockets without a very high flight rate or very long contract.

GCNRevenger · 2004-01-31 11:51:38

whooops wrong window

jabe · 2004-02-04 14:55:56

[=http://www.projectconstellation.us/news/]CEV info web site...

be interesting to see what appears on it.. non NASA site BTW

RobS · 2004-02-04 16:49:57

It doesn't seem to have anything new. The illustrations on top are taken from the Boeing photo release site we all heard about a week ago. Putting the interplanetary CEV in front of Mars is symbolically nice, but of course to get there the CEV would have emptied and jettisonned the fuel tanks that the picture shows!

-- RobS

Bill White · 2004-02-05 10:09:04

Can anyone detail the process needed to "man rate" the Delta IV or Atlas V?

Doesn't the Bush plan call for Delta IV to be "man-rated" by 2014? Why do we need ten years to man-rate Delta IV with six years (2008 - 2014) devoted to flying uncrewed CEV?

clark · 2004-02-05 11:18:22

As far as I can tell, man-rating a launch vehicle involves proving the darn thing won't just blow up. Probably includes maximum failure rates, abort options, stress-loads...

I wouldn't place much stock behind some of the dates though, since we have been launching the EELV for a bit of time now already, so we are fairly confident with it's abilities. It's probably a matter of proving that the CEV will have acceptable safety margins when coupled with an EELV... so that means we have to wait for the CEV first, before we can man-rate the entire process.

The time frame also gives NASA some extra time to work out any CEV related bugs post-development. And remember, the 2014 is for a man-rated lunar version. It has to be able to take people to the Moon by 2014.

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