Crew vehicles discussion

GCNRevenger · 2005-04-08 06:13:36

And I think you are on a Bush = Bad/America = Bad rant.

The ISS is an orbital construction platform just about as much as an inland office building is for a ocean-going shipyard. You can't build anything there because the ISS wouldn't handle the extra mass, and it would tear itself apart trying to maneuver. Its also in just about the worst orbit possible for efficent access.

And a space elevator? To the ISS? You obviously know nothing about space elevators. They have to be connected to a FAR higher orbit, all the way out to GEO, and must be in an exactly equitorial orbit, connected to the ground right on the equator.

Maybe you aren't aware of it, but the US has agreements in writing with foreign governments to finish the job. Violating those agreements, reguardless about saving face, would probobly not be a good idea.

And I don't think its about saving face, since the ISS is "done enough" to put people on it, that its close enough to finished for that purpose.

srmeaney · 2005-04-08 06:47:27

That's why I said you better hope it's option A. Orbits can be changed. The Main Truss can be used as the structural support for a toroidal of Nodes and a couple hundred Habitat/ Lab Modules. A ring allows Robotic Arms to reach inward and produce a higher intensity of assembly to construct a space wheel with the toroidal (or Partial Toroidal) as a maintenance sleeve. That would give us a Space City we could construct between the Earth and the Moon. It would be a third generation Space Station. Once the ISS is finished constructing the first Torroidal it could Construct a second one. That way you get an Orbital Space Station assembly Platform and an orbital Space vehicle assembly Platform. Both with permanent 100 cosmonaut crews working around the clock and constantly supplied with monstrous amounts of resources to get their jobs done.

That means a commitment to Space that will shadow the Millitary budget.

And here we are again. way off topic.

RobertDyck · 2005-04-08 07:46:20

Last night I attended a presentation of "Canada's role in space" by the past president of the Canadian Space Agency. One point he made is that Canadian use of ISS is proportional to financial contribution, however that has shrunk. Canada delivered its contribution on time and on budget but Europe, Japan and America are all over budget. Ah huh! Well, he also pointed out that the remaining space for Canadian science experiments is still larger than Canada can use, so Canada is looking to barter. My point is that Canada has built a reputation for delivering high quality niche space components on time and on budget. Isn't it time America did the same?

GCNRevenger · 2005-04-08 08:07:37

Anywhere within half a tank of gas of a Blackhawk or a Chinook would do.
You're still thinking in terms of "cost is no object" luxury. Not a helicopter, a truck. Pick up astronauts with a minivan or Hummer. Pick up the capsule with a flat bed truck with truck crane.

Nah, you want to be able to reach the crew quickly even if they land off-course, since reentry is rough on the human body (or if its an emergency), and you want to be able to secure the spacecraft in short order so no damage is done by it sitting there.

Sending two or three military helecopters with medical and security teams is a job small enough for national guard units, and won't be a signifigant expense. Certainly no where near the expense of actually flying or developing the thing... you've got your priorities all wrong.

"Orbits can be changed. The Main Truss can be used as the structural support for a toroidal of Nodes and a couple hundred Habitat/ Lab Modules..."

Yep, which is where you were trying to drag us, off topic... your plan is insane, better to start from scratch.

dicktice · 2005-04-08 10:48:02

(a) Full marks, on your new positivism, GCNR. I agree with everything you've written re. reentry crew capsules. Are you sure your real name isn't Boris?
(b) What caused your diatribe: "And a space elevator? To the ISS? You obviously know nothing about space elevators. They have to be connected to a FAR higher orbit, all the way out to GEO, and must be in an exactly equitorial orbit, connected to the ground right on the equator." I looked and looked, but couldn't find so ill-informed a post as that. I can't believe you'd be suckered, but are you sure it wasn't an April Fool? I didn't go back that far.

GCNRevenger · 2005-04-08 12:57:01

Heh... I guess I like being a critic too much...

That is actually the way it is about space elevators, at least ones on Earth anyway. If you drop your elevator from a point that is less then 36,000km high, the the elevator cable won't kindly sit at a stationary point on the ground end. If the cable is only a few hundred kilometers long, it would wiz over the surface faster then the speed of sound. It also must, MUST be positioned directly over the equator, or the cable would move hundreds of kilometers north and south all over the place.

SpaceNut · 2005-04-08 13:12:35

Would it not move north and south with the seasons even if it is at the equator?
So what ever end is in space must also compensate for the earth motion as well?

GCNRevenger · 2005-04-08 14:54:31

No: seasons are caused by the orientation of Earth's axis not changing as the planet moves around the Sun. Since the Earth's axial tilt doesn't change angle w.r.t, only its direction of tilt, then a space elevator built from the equator would be fixed year-round, provided the anchor station/satelite is an a perfectly equitorial orbit.

srmeaney · 2005-04-09 08:28:16

Kenya sits right on the Equator. An ideal location for a space cable. Geologicaly stable, Currently low in terrorist priorities. Nice People, Could do with the Economic benefits. It would Make Africa a critical player in Space.

Ad Astra · 2005-04-09 16:43:24

Sending two or three military helecopters with medical and security teams is a job small enough for national guard units, and won't be a signifigant expense. Certainly no where near the expense of actually flying or developing the thing... you've got your priorities all wrong.

Of course, NASA would never send out the National Guard to rescue its media-darling astronauts. Bet on NASA to find some pricey, high-profile way to bring the crew back home.

GCNRevenger · 2005-04-09 16:50:15

Sending two or three military helecopters with medical and security teams is a job small enough for national guard units, and won't be a signifigant expense. Certainly no where near the expense of actually flying or developing the thing... you've got your priorities all wrong.
Of course, NASA would never send out the National Guard to rescue its media-darling astronauts. Bet on NASA to find some pricey, high-profile way to bring the crew back home.

I wouldn't bet on that for sure, Vandenberg is pretty boring as far as Shuttle landings go... maybe for the primary landing site and leave the Guard to handle the backups.

John_Frazer · 2005-04-10 03:26:19

The problem with the ESA/CNES Hermes is that it grew into a "Mini-Shuttle", a camel (beast designed by a comittee). They wanted it to do all the missions a Shuttle could, and stay on-orbit for 90 days or whatever.
A "shuttle" doesn't do that. A PLS crew launch/landing assuredly safe vehicle doesn't do all that.
It puts all its capabilities into carrying people with as close to asured safe recovery as possible. Instead of payload bay, robotic arms, EVA-prep areas, and comsumeables for 4 people for 3 months, it has landing gear and airbags/chutes. It has survival gear for arctic/land/desert/ocean abort and landing sites. It's not stripped down to bare bones so it can have any useful payload on top of all the various equipment all these other requirements has. The total weight you can put on top of a booster is dedicated to keeping people alive and healthy no matter what happens from sitting fueled at zero altitude-zero speed on the pad to hypersonic abort halfway to orbit.
It's definitely easier to do this without a payload bay and communications satellite and everything.
That weight creep is what killed Hermes. No version of the Arianne launcher could carry it, so funds had to be diverted to a new booster development program, and together, they ran out of funding. A good example of two designs chasing each other's numbers around in circles, getting ever bigger.
They went ahead with the newer versions of the Arianne V booster, but the wished for wet-dream of a super do-everything Shuttle died of obesity before it was born.

Except for small stuff that can take the place of people inside, it doesn't work to put a lot of payload capacity into a crew vehicle. Reusability adds a lot of complexity, making it manned adds more, and making it big enough for cargo drives both of them up. You don't need to give a satellite as much protection as crew, and you don't want to spend as much on cargo. You can insure a satellite, but you don't want to treat a crew the same.
I don't believe that any kind of technology development is going to change that, unless we get super-efficient and clean and reliable fusion powered rockets and everything is so well known and used that we have no doubts about a "Shuttle II" or "III" that again is designed to be a combination hotel/research vessel/industrial park/free-market cargo hauler/hypersonic exo-atmospheric interceptor & satellite inspector & Fractional Orbit bomber all at once.

Separate vehicles for different requirements. Why carry ocean abort survival gear beyond LEO? The point about free-return aborts is good, but I don't think it makes sense to design every CEV as if we expect it to come in at better than escape speed. Is our ISS crew carrier going to be designed so that it can be easily and cheaply be built instead as an interplanetary speed re-entry vehicle? Are the requirements so similar that one vehicle frame design can do it all? Isn't it chaper to build different capsules instead of an F-35 Joint Strike Fighter?
What, modular construction so that extra comsumeables can be added for interplanetary flight? A lifeboat doesn't need to be continuously habitable for days and days, in space, drawing power and cycling air refrigerating fuels. Better not.

The Shuttle is the first and only crewed launch vehicle that didn't have crew escape. I recall reading testimony from Michael Coates saying that he remembers sitting strapped into a Shuttle (in '84, I think) while a hydrogen fire burned below them. They all knew that if it went out of control, hey'd never be able to get away in time, so there they sat. With every other launcher, they can jet up and away in seconds (because it's not a 100 ton behomoth that needs a perfectly controlled runway landing or it's destroyed).

The HL-20 was designed so that normally, it could land at any commercial airport, plus parachutes and floatation bags for a water splashdown from a pad abort. I'd personally like to see even more payload given to a supply of fuel and a jet engine like the MiG-105 or Pioneer Rocketplane for cruise, go around, and self-ferry. If the landing gear don't work, get down near landing/stalling speed, pull the handle and plop it down on the airbags.
Again, you've got to be really careful of trying to design it to do too many things, but even if it only carries 4 people, extra capacity to get them down safely fits the beast's only design criteria.

GCNRevenger · 2005-04-10 08:13:14

Except for small stuff that can take the place of people inside, it doesn't work to put a lot of payload capacity into a crew vehicle. Reusability adds a lot of complexity, making it manned adds more, and making it big enough for cargo drives both of them up. You don't need to give a satellite as much protection as crew, and you don't want to spend as much on cargo. You can insure a satellite, but you don't want to treat a crew the same.
I don't believe that any kind of technology development is going to change that, unless we get super-efficient and clean and reliable fusion powered rockets and everything is so well known and used that we have no doubts about a "Shuttle II" or "III" that again is designed to be a combination hotel/research vessel/industrial park/free-market cargo hauler/hypersonic exo-atmospheric interceptor & satellite inspector & Fractional Orbit bomber all at once.
Separate vehicles for different requirements. Why carry ocean abort survival gear beyond LEO? The point about free-return aborts is good, but I don't think it makes sense to design every CEV as if we expect it to come in at better than escape speed. Is our ISS crew carrier going to be designed so that it can be easily and cheaply be built instead as an interplanetary speed re-entry vehicle? Are the requirements so similar that one vehicle frame design can do it all? Isn't it chaper to build different capsules instead of an F-35 Joint Strike Fighter?
What, modular construction so that extra comsumeables can be added for interplanetary flight? A lifeboat doesn't need to be continuously habitable for days and days, in space, drawing power and cycling air refrigerating fuels. Better not.

I half-way agree about not mixing crew and heavy cargo, though I think there is a half-way solution... with our current technology, a single-stage reuseable space vehicle (or for that matter, any vehicle) isn't very practical because of small payloads. Plus, there aren't any engines that work well through the entire flight regieme, from ground all the way to orbit.

So, if the need for Shuttle-II comes before we have a next-generation superengine, then build the thing in two stages. This way, you do have enough efficency to launch 20MT class payloads without getting too big, and you can use different engines where they are most efficent.

Anyway, build a common lower stage carrier plane that can reach suborbital performance aproximatly, but have two different but similar models of the upper stage: one that is unmanned for hauling heavy cargo, and the other that sets up to 12 (inc. flight crew) and has the airlock. Possibly have a small cargo bay on the crew model if volume permits... Anyway, with a good 20-30MT to play with, the crew vehicle could be built very sturdy and with plenty of supplies, perhaps even with an jettisonable crew cabin.

As far as capsules, this is a case though where one vehicle can do both jobs reasonably well that making seperate vehicles would be a waste of money. Launching 2-4 crew capsules a year to the ISS would be pretty easy, and it wouldn't cost much more versus developing an expensive new mostly-reuseable mini-shuttle.

Whats wrong with the F-35 JSF?

And lifeboat/crew vehicle DOES need support for a few days if it is coming/going from the ISS, because you have to sync orbits with the station (which takes about two days) or wait until the stations' highly inclined orbit passes near your desired landing site (which can takes a few days too).

DanielCook · 2005-04-12 13:34:16

Kenya sits right on the Equator. An ideal location for a space cable. Geologicaly stable, Currently low in terrorist priorities. Nice People, Could do with the Economic benefits. It would Make Africa a critical player in Space.

The last time I checked, Kenya was the location of four of the most recent terrorist attacks in Africa.

Geologically stable? Um ... ever heard of the (Great) African Rift Valley? It is a vault line, like San Andreas. Or for that matter, do you know that Mount Kenya is actually a volcano? As is, for that matter Kilimanjaro, in nabour Tanzania.

Check your facts, heh?

John_Frazer · 2005-04-12 17:31:43

the "Space Elevator" Digression
(and we should start another thread about other, more advanced methods of reaching space, since this one was hoped to be a clearing space for info on the CEV)

It depends on what you mean by "space elevator".
GCNR like everyone else who hears the term, thinks of the farthest out variant, the one that until buckytubes became laboratory curiosities, was only a mathematical exercise in absurdity.

What GCNR described, attached to the ground at the equator, extending up to a counterweight or equal length/mass past GEO, may be called the beanstalk, for obvious reasons.
Unless you're a tremendously enthusiastic fan of buckytubes, and think we could start assembling millions of tons of them right now, then the beanstalk is out -except as a mathematical exercise and "what if?" curiosity.

Another option is the hypersonic skyhook, and if the ISS were suitable as anything but a money pit, it would work, even in the 58degree orbit.
This one could possibly be built with kevlar, and some polyethylene fibers would work too.
Extend a cable down from a massive structure like a station or collection of spent tanks and rocket stages in LEO, so it drags through the rarified upper atmosphere at several km/sec.
There, hang something that looks and functions like a warship's helo arresting/landing deck.
A sub-orbital craft, like a DC-X derivative or the SpaceshipOne meets and is snagged by it during the plane's brief hyperbolic tip-over at the top of its trajectory, and is winched in. Passengers and freight are taken up the cable, while the ground hopper is simply dropped over the side within landing range of a runway.

That one works well with a minimal spaceplane crew vehicle. Launch requirements are vastly lowered, re-entry heating is minimal, and rocket equpiied plane could practically take off from an airport, boost up, and when done at the spaceport pad in the stratosphere, drop off for a powered landing at the same or any other airport.
The key is many airports, many services flying the planes, and several skyhook stations in various orbits.

The next sort is the rotovator. A tether from a ballast mass station in LEO extends a cable long enough to reach down to about 150km, and the ends spin. The rotation of the cable end is subtracted from its airspeed, so it's moving slower at the bottom, and faster at the top. A payload attached to it at the bottom needs only a little rocket power to gfet up to it, and if released at the top, carries far beyond LEO with the excess velocity it's been given.
For small payloads and small velocity increments, fiberglass might work, but better kevlar or plastic.

Yes, stipulated that for everyone o these passage upwards must be paid for. Orbital energy must be balanced out somehow. For some, electrodynamic tethers are a good, elegant option for getting free maneuvering power from the Earth's mass and magnetosphere.
For others, low thrust/high isp rockets would work well. Note that the rocket equation energy curve favors accelerating a large mass by small amounts for a long time, rather than a small mass with a high impulse for a short time.
Generally having a larger ballast mass at the center point helps.
Yes, having the rope break would be bad. No, orbit isn't like the asteroid fields in bad cheesy S.F. I like the idea of lowering an orbital debris collector from a higher orbit, to clean up the trash we've left up there.
Less launches at the top of self-disintegrating rockets based on World War 2 long range artillery would also be a big help.
Hence the space elevator. Astronauts themselves don't like the phrase "blast-off". It's time we started doing something about finding a civilized way into space.

Several links
Tethers Unlimited
www.tethers.com]www.tethers.com

Bootstrapping Space Communities with Micro-Rovers and High-tensile Bootlaces
http://www.ari.net/moon/forum/mp/mp-4/b … strap.html

Space Elevator group at Yahoo (see their links/bibliography)
http://groups.yahoo.com/group/space-ele … -elevator/

Fledi · 2005-04-12 17:57:58

There is a way to lower chances of the tether tearing to about zero by taking many parallel tethers instead of one big. The guys at Tethers Unlimited even patented some kind of circular web they call a "Hoytether".
It is maybe even possible to start out with a single 20 tonne launch to orbit and deploying the tether that can then support 200kg payloads.
Docking is a difficult part since you have a window of about 30 sec to a minute plus the need to exactly time the launch when the tether passes.
Maybe a sea launch would be the best way to achieve this.
For the docking it schould be possible to get a mile above and some hundred meters sideways to the lowest tip of the tether. Then shoot a kilometer long cable from your spacecraft
orthogonal to the main tether, so it passes through its path as it rotates past its lowest point.
So you will have a tolerance of about a mile in every direction to your target spot.
I know it all sounds acrobatic, but still it could work.

GCNRevenger · 2005-04-12 21:10:43

Are you out of your mind? The Skyhook kooks are insane, somehow just barely latching on to the speeding tether in the breif seconds the supersonic vehicle would have to slip within those razor-thin centimeter tollerances, moving well above the speed of sound, in the middle of the sky... The rendevous alone would be almost as hard as the ballistic missile shield being built.

Even if the technical hurdles can be overcome, its still a stupid idea, because it is the worst of both worlds. It still requires a complex aircraft to work, it still requires reentry, and isn't suitable for scaling up.

See, there is an engineering principle... whenever you add an additional constraint with low tollerances or high performance needed, the difficulty increased geometricly. Supersonic maneuverability, meter-level accuracy to hit a fast moving object, rendevousing with it at almost exactly the same speed and vector without fatal collision... or aerodynamic disruption, the docking mechanism torque load not ripping anything to shreds, and so on. Without getting too heavy too.

You might as well build a fully orbital spaceplane instead, which could fly any time and not have to wait for a tether to pass by. If you are building a supersonic aircraft big enough for cargo, just build it a little bigger and add an upper stage with rockets. And you can build as many of them as you need right here on the ground.

The other big reason the Skyhook people are loons is that it will NEVER be easy enough for REAL routine lift like a true space elevator... just hook up a lifter and up you go. No supersonic airplanes, no risky split-second centimeter accuracy rendevous, no practical limit to cable size.

The Skyhook idea is simply retarded, its the absolute worst of both worlds and then some.

The cable required for an Earthly space elevator probobly doesn't have to be made of "magical grade" contiguous single-walled nanotubes, you can probobly get away with short nanotubes that are specially treated (functionalized, perhaps crosslinked) in a composit matrix. It wouldn't weigh a billion tonnes, but could probobly be lifted in a single HLLV shot.

We are not far from being able to make such a material right now. CNT fibers have been produced that are far stronger then spider silk, and can nearly reach the required strength. Then it is just a matter of figuring out how to mass-produce them.

John_Frazer · 2005-04-13 01:35:45

Space Elevator digression

Let's take this elsewhere: there's a previous thread over at
http://www.newmars.com/forums/viewtopic … 7]>Science and Technology
>>Space Elevators, Ho!

SpaceNut · 2019-04-06 17:41:48

topic to fix artifact in

This was when we were switching from shuttle in which cargo and crew did not go all so well and it was decided to talk aout it being on seperate rocket designs.

SpaceNut · 2020-07-21 20:14:26

bump fixing topic

Mars_B4_Moon · 2022-05-15 03:49:34

NASA safety advisors voice concerns over Boeing’s Starliner, SpaceX’s Starship – Spaceflight Now

https://spaceflightnow.com/2022/05/13/n … -starship/

Mars_B4_Moon · 2023-05-27 11:31:30

Lunar Terrain Vehicle

NASA seeks industry proposals for next-gen lunar rover to traverse Moon
https://www.devdiscourse.com/article/sc … verse-moon
NASA said it is seeking industry proposals for a next-generation Lunar Terrain Vehicle (LTV)

The Lunar Terrain Vehicle (LTV) is an unpressurized rover being developed by NASA that astronauts can drive on the Moon while wearing their spacesuits. The development of the LTV is a part of NASA's Artemis Program which involves returning astronauts to the Moon, specifically the lunar south pole, by 2025. The Lunar Terrain Vehicle will be the first lunar rover developed by NASA since the Lunar Roving Vehicle or LRV used during the Apollo program.

Boeing Apollo era LRV had a mass of 462 pounds (210 kg) it could carry a maximum payload of 970 pounds (440 kg), including two astronauts, equipment, and cargo such as lunar samples, and was designed for a top speed of 6 miles per hour (9.7 km/h), although it achieved a top speed of 11.2 miles per hour (18.0 km/h). The Space Exploration Vehicle (SEV) was a modular vehicle concept developed by NASA a pressurized cabin that can be mated either with a wheeled chassis to form a rover for planetary surface exploration on the Moon and other worlds, on Mars a manned Rover or Car could visit a Mars habitat is a hypothetical place peharps a Biodome where humans could live on Mars.

Scientist-astronaut Harrison Schmitt of Apollo 17 said, "The Lunar Rover proved to be the reliable, safe and flexible lunar exploration vehicle we expected it to be. Without it, the major scientific discoveries of Apollo 15, 16, and 17 would not have been possible; and our current understanding of lunar evolution would not have been possible."
http://nssdc.gsfc.nasa.gov/planetary/lu … o_lrv.html

Lunar Electric Rover Concept
https://web.archive.org/web/20091029063 … et_web.pdf

Last edited by Mars_B4_Moon (2023-05-27 11:39:15)

Mars_B4_Moon · 2023-08-30 07:56:32

Bremen-based POLARIS Spaceplanes has announced that it completed the first test flights of its MIRA-Light vehicle on 22 August 2023.

https://twitter.com/AndrewParsonson/sta … 4695717004

Mars_B4_Moon · 2024-06-05 13:11:46

The Boeing Starliner designed to be compatible with a wide range of launch vehicles, including the Atlas V, Delta IV, Falcon 9, and Vulcan Centaur

Not the Gateway CEV mission but "Starliner" will have soon reached to the International Space Station with a crew, it can possibly be modified for beyond LEO.

Crewed Boeing Starliner finally launches from Florida: 'Let's put some fire in this rocket'
https://www.usatoday.com/story/news/nat … 557551007/

There is also a future mission scheduled to launch no earlier than early 2025, transporting members of a future ISS Expedition.

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#76 2005-04-08 06:13:36

Re: Crew vehicles discussion

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