Space Initive Launch Vehicle

comstar03 · 2004-09-09 21:29:53

Anti-carrot,

I didn't high speed ( velocity ) I am looking at the thrust factors of ion drives , where they are long with high velocity, we need continuous thrust like jet engines not rapid burn and they shutdown.

The runaways are build across the world in every major city in the world. What we need is a crew spacecraft that is designed on similar terms as a passenger airliner for space with crew seating, cargo for seats and other small cargo arrangements.

At the same time still use the primitive vtol systems to test individual new technology components, and still supply the ISS commitments for human spaceflight. Once the drive systems are designed and tested for HTOL flights, it will also help deliver large cargo transports for one-way missions from Ground to Earth Orbit.

ANTIcarrot. · 2004-09-10 06:20:34

I didn't high speed ( velocity ) I am looking at the thrust factors of ion drives , where they are long with high velocity, we need continuous thrust like jet engines not rapid burn and they shutdown.

Erm... Eh?

The runaways are build across the world in every major city in the world. What we need is a crew spacecraft that is designed on similar terms as a passenger airliner for space with crew seating, cargo for seats and other small cargo arrangements.

Try getting take off permission (or even fueling permission!) for your 1000ton bomb at a place like Heathrow. You won't get it. The big commercial airports will not want to risk their runways. You are therefore restricted to building your own, using abandoned airbases that all have overflight problems, or using NASA facilities.

And agreed that we ned a spacecraft that operates like a 747 - but that doesn't mean it has to look like a 747.

GCNR...

I also am not convinced that you need a powerd flight capacity, getting down within range of the runway isn't the hard part.

It isn't really, but it lets you land in bad weather and solves cross range problems. Most people accept it as a given that one of the things that screwed up the shuttle was the cross range requirement. With jet engines it could afford to reduce the gliding cross range significantly, as long as the jet engines can compensate.

as it is that you can't land with accuracy.

Paragliders land with accuracy all the time. NASA's X-38 landed roughly where they wanted it IIRC. A VTOL would probably have a powered last minute and a soft touch down on the pad.

The DH-1 concept, as previously mentioned, is a pitiful toy many times too small.

Yeah yeah yeah. Something you've said many times. I'm still waiting though for that application that can't be broken down into two ton sections. You've had enough time to think of one.

A real TSTO spaceplane able to carry Shuttle sized payloads would not be a signifigantly larger than a 747 airliner. A DC-I style rocket with a similar payload would also be on the order of >60-70m long,

So in other words, that are exactly the same size. And again you're compairing apples and oranges. A TSTO VTOL would be able to carry more into orbit without being significantly bigger than a SSTO VTOL.

The only thing on your checklist which couldn't be just as easily be applied to a VTOL TSTO design is
-Lift body design - Prototyped by Russia, X-38 ACRV, various ground tests and confirmed modeling
-NASA experience with spaceplanes of high complexity - 20+ years and counting

To which I counter:
*Capsule design - prototyped by everyone who've ever recovered something.
*NASA's experience with capsules. Getting on for 40 years now.

ANTIcarrot.

SpaceNut · 2004-09-10 06:34:31

Either or a half dozen of gubbered combinations and along with many clean slate designs for either, neither or both craft combinations but we still have none.

Why is that?

when the ones that most likely will be selected are the same ones in use today in Lockheed and Boeing. It is not in there best interest to have already done the actual work for they have no garanteed money though contracts so they will not do it.
Yes we recently gave them and others a little seed money to scratch a pen or pencil to paper or even to use the most advanced cad system to come up with the all purpose dream vehicle for the CEV or constellation project.
we have already been though numerous studies and concept cycles in the past and some are still on going. Not to mention 6 months followed by a possible 6 more. When will the cycle end?.....

Grypd · 2004-09-10 15:33:41

You are considering two stage or even single stage to Orbit tsto or stto and vertical take off, vtol.(this is for guests who may not know the terms).

But why if we are trying to build a space plane with two stages does it have to be vertical launch. If we are going to go for two stages make the lower section another plane. This way the lower stage can use already available technology to get to a decent height before igniting rockets to speed up before releasing the second stage at the required speed. This principle was shown to work look at the X15. I have ignored single stage as the mass fraction that can be sent up is of a very low magnitude with the materials we have currently present. Another advantage to using the two plane method is the lower stage may be used for other purposes so reducing operating cost.

SpaceNut · 2004-09-10 19:49:39

Same concept was used by the SpaceShipOne xprize contestant. It does make sense but for only LEO crew carrier but probably would not be of benifit for cargo. Simular principles are being also used with the scramjet technology demostrator as well just with an extra boost stage to get it to mach 6.

ANTIcarrot. · 2004-09-11 11:03:13

You are considering two stage or even single stage to Orbit tsto or stto and vertical take off, vtol.(this is for guests who may not know the terms).

Almost right.

SSTO = single stage to orbit - possible but not practical
TSTO = two stages to orbit - the compromise accepted by most design teams.
HTOL = Horizontal take off and landing - like a 747
VTOL = Vertical take off and landing - like the DC-X or a helicopter
VTOHL = Vertical take off and horizontal landing - like the shuttle.

Of course it may be that by the time we get to 2040/2050 (which I believe was part of the orrigonal question) we'll be able to make carbon 10^8m nanotubes and the issue will be largely redundant!

ANTIcarrot.

Grypd · 2004-09-11 16:44:55

You are considering two stage or even single stage to Orbit tsto or stto and vertical take off, vtol.(this is for guests who may not know the terms).
Almost right.
SSTO = single stage to orbit - possible but not practical
TSTO = two stages to orbit - the compromise accepted by most design teams.
HTOL = Horizontal take off and landing - like a 747
VTOL = Vertical take off and landing - like the DC-X or a helicopter
VTOHL = Vertical take off and horizontal landing - like the shuttle.
Of course it may be that by the time we get to 2040/2050 (which I believe was part of the orrigonal question) we'll be able to make carbon 10^8m nanotubes and the issue will be largely redundant!
ANTIcarrot.

Thanks ANTIcarrot just there have been a lot of guests on and it might help them understand when we go to lingo what we are talking about.

Cargo to orbit is best sent one way the mass fractions for any space plane either two stage or single are small and a dumb booster rocket can beat them easily if all you want is to send things up and not return. Spaceplanes though are excellent passenger light satelite carriers and will return so when we have a need for a lot of people in space then the spaceplane age will come true at last. But, until that time that we have a need for a lot of people travelling to stations in LEO then rockets will be our mainstay.

SpaceNut · 2004-09-13 07:19:03

TSTO spaceplane technology checklist:
-Composit fuel tankage - Mature/Prototype by MSFC etc
-LOX-boosted turbine engines - Prototyped, F-15 engine modified and ground tested
-Large reuseable LOX/LH2 engine - Development by P&W
-Metal heat shield materials - Prototyped and flight tested on STS
-Lift body design - Prototyped by Russia, X-38 ACRV, various ground tests and confirmed modeling
-NASA experience with spaceplanes of high complexity - 20+ years and counting
-Computer modeling and design now common
-Composits, ceramics, metal alloys, engineering polymers, etc have advanced considerably since the Shuttle days

It is great to see the shopping list for the new more advanced RLV spaceplane.

But If we are going to try the Metal heat shield materials - Prototyped and flight tested on STS Why then bother to retire them once this is done. Most of the shuttles refurb cost are tile replacements.

Mark S · 2004-09-13 09:44:16

Back when the shuttle was first designed, there were plenty of innovative designs that were rejected then but still are valid now. These include:

1) The Chrysler SERV, a VTOL rocket that used lift-jets for landing. Lift-jets save on the weight needed oxidizer. The design also used a conventional heat shield rather than the unproven "plug nozzle" heat shields of the period.

2) The Lockheed LS-200 / Starclipper, a lifting body that was assisted by putting some of the propellant in two external fuel tanks that formed a v-shaped collar around the nose. The vehcile was designed by RLV proponent Max Hunter, and the only expendable component would be the simple fuel tanks.

3) Max Faget's DC-3, a TSTO space plane. The vehicle's payload was smaller than the eventual STS, which enabled its feasibility. Yet the concept dictated the development of two different vehicles, an expensive impediment to building the system. Also, Faget's stub-winge orbiter had a tendency to spin at hypersonic velocities, meaning that it would need some serious re-design.

My knock against TSTO is that it requires development of two separate vehicles in most schemes. I prefer concepts like MUSTARD and Boeing's SLI study that use two or three similar boosters with propellant cross-feed. That way you can develop one vehicle but still schieve two or three-stage orbital designs.

Ther are probably appropriate uses for all three configurations: SSTO VTOL, stage-and-a-half VTOHL, and bimese TSTO VTOHL. There is also a case to be made for a Kistler-type TSTO with parachute recovery of both stages. If there was greater privatization of the launch vehicle sector, perhaps there would be competition to design a Delta II or Pegasus replacement that would result in many different, competing vehicles being built and competing on a per-launch basis.

SpaceNut · 2004-09-13 10:33:18

Chrysler was sort of pyramid shaped, very simple design concept.
The starclipper design sort of scares me though for when the external tanks are jetisoned.
Boeing's SLI like everything else sort of cancelled or in limbo after the space exploration announcement.

comstar03 · 2004-09-15 23:00:27

We need launch vehicles for different purposes for humans and cargo, It is also two different journeys earth - space and space to earth. Human flight goes both ways earth-space-earth but cargo could go one way from earth-space or space-earth from space processed resources.

When you study the processes then you will discover two or three types of space vehicles - two different launch vehicle types from earth and two different re-entry vehicles types for space to earth.

The cargo launch vehicle might be expendable or recyclable in orbit depending on the contractor and what the customer requires ( medium cost to low cost) , similar to aircraft development.

But the human vehicles are complex and also re-entry designed thus are similar to hand-crafted satellites and very expensive but used many times.

once you determine the customer and then you can build the vehicle to suit the customer needs or provide the vehicle through you assembly plant or custom production facility. The best company to deliver this process will be Boeing Corporation.

GCNRevenger · 2004-09-16 08:19:09

If we are going to do an RLV, we better do it right this time... and that means, spending more in development dollars with launch costs and reliability costs being paramount. Not development costs, if it costs more to build, then it costs more to build, but if the design is going to see hundreds or even thousands of flights then the development costs are simply not going to be as huge a factor compared to the money saved.

For example, stacking up multiple identical stages to save a buck today means you can't optimize each stage for its different flight regieme, which will cost you efficency down the road and increase launch costs (especially limiting flight rates). If the superior and more robust design costs $1Bn extra and has 100 flights a year (two launches a week) for a decade and you save a measly $1M a flight, then you get a better vehicle for the same money. Additional flights, and the rest is gravy... The vehicle must also be really, truely, completly reuseable tanks and all. The STS Shuttle tanks cost in the region of $50-60M apiece, and tacking that on to a medium launcher's launch costs is simply not an option.

That said, I doubt that NASA is going to build more than one RLV vehicle any time soon, but they could do one and a half vehicles perhaps... common lower stage, with one payload-centric upper stage and a human-centric one outfitted with an escape pod. Plenty of mass to kill since people don't weigh much, and would make the thing much much more safe.

I still favor a winged vehicle, because of its inherint advantage of lift, ease of return/processing, and safer dynamics. (lower TPS temp, unpowerd glide)... Parafoils don't have as good an attitude control capability nor the meter-accurate landing of an airplane, not to mention a bumpy landing without accurate engine control. I don't much care for Cryslers' lift-jet VTOL schemea, as it would require lugging along jet engines which would have a hard time keeping cool, like the Harrier's engines.

I should also like to note that an expendable rocket does have a fairly high minimum complexity to achieve reasonable realiability, and that any RLV concept must be highly reliable (on the order of >99.9% vehicle reliability) to mitigate the replacement costs when one inevitibly fails.

comstar03 · 2004-09-16 23:08:34

I am talking about GCNRevenger, we might have the idea wrong that is one ship fits all, it was better thinking two types of ships will work - Human and Cargo, then design multiple designs for each, expendable and recyclable for cargo and reusable for humanflight.

In all S/F Programs you don't see one space vehicle type they have many types for different functions. Secondly we design these like naval ships base design and interior upgrades only until major systems change like drive systems.

Then production can recoup costs that relate to tooling and casting components, designing and building assembly lines.

Mark S · 2004-09-16 23:21:06

Why not a modular vehicle that can be configured for crew or cargo but not both at the same time?

Boeing's Space Launch Inititive vehicle had two identical flyback boosters, mounted in parallel, with either a small, X-37-ish spaceplane or a cargo pod on top of the stack. In a similar design from Northrop-Grumman, the lifting-body spaceplane sat axially atop one of the boosters (ensuring for easy emergency escape.)

The lesson we can take from Delta IV and Atlas V is that vehicles should be designed from the start as modular systems that can adapt to different missions.

GCNRevenger · 2004-09-17 08:45:05

Why not make a dual-mode spacecraft? Because you cannot optimize the vehicle to do either role well, I would think that Shuttle would have proven that by now. The design philosophy of the entire vehicle is different for people and payload, making one ship to do both is fundimentally not a great idea. How much more payload could be afforded if the STS didn't have to lug that passenger cabin to orbit just to run cargo? About 50% more at least, maybe double... A drop-in "passenger pod" in the cargo bay would also be a terrible compromise and still increase vehicle complexity, as separation in event of "incident" would be harder to pull off, but you are still basicly putting people in a vehicle designed to maximize mass, not safety or gentle-ness of flight. People and cargo have such vastly different requirements and focuses, that it would be a terrible idea to design a single upper stage to do both.

There are some things that could be built common between two vehicles, have them share aerodynamic mold lines, main engines, aerodynamic and attitude controls, TPS & landing gear, perhaps fuel tanks, docking hardware... but the entire section where you would put payload or people ought to be tailored specificly for that role from the structure and dynamics up.

Grypd · 2004-09-17 16:03:14

If we are sending Cargo to space then why do we need all the extra components that a manned vehicle needs. For a start a manned vehicle needs to be able to return to Earth where as it does not make financial sense for this to happen for a cargo vehicle. A manned vehicle needs to have life support and heat shields, it will also likely reguire to have space for pilots as who trusts a completely automated vessel and the seats, instrument panels that they need. So when it comes down to it using what will likely be possible the best way is to have one shot cargo rockets which would be a form of heavy lift and reusable space planes which carry people and very light loads.

SpaceNut · 2017-05-24 17:17:51

bump just 3 pages to fix in this one....

SpaceNut · 2018-07-17 19:29:19

Fixing an old topic that has the conversion of forums artifacts

SpaceNut · 2018-12-25 08:50:02

Bump topic needs repair

Just now finished and see that I flagged the topic along time ago....

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#51 2004-09-09 21:29:53

Re: Space Initive Launch Vehicle

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