Un- conventional ways to LEO

GW Johnson · 2020-11-28 14:06:13

Edit: Content of post moved here, per request from SpaceNut.

kbd512 · 2020-11-28 19:52:19

Edit: Content of post moved here, per request from SpaceNut.

kbd512 · 2020-11-28 20:06:53

SpaceNut,

Topic cleanup has been completed. If you want, I can remove the prior posts in their entirety since all content has been "copy-pasted" into the topic created for micro capsules and micro space planes.

tahanson43206 · 2020-12-02 08:21:11

The Yahoo News Feed delivered an interesting (to me at least) item this morning ...

Gary Hudson is a name familiar to those who've been following developments in "New Space" .... I was surprised to see his name associated with the venture described in the article at the link below.

The sled described is NOT magnetic (apparently). Instead the plan is to use a traditional rocket to accelerate the sled.

On the plus side (as I think about it), a rocket sled could be converted to a magnetic one if the business plan proves viable.

https://www.yahoo.com/finance/news/radi … 11024.html

Alan Boyle
Tue, December 1, 2020 9:11 PM ET
A patent drawing shows Radian Aerospace’s concept for a space plane on a sled. (Radian via USPTO)
For years, Renton, Wash.-based Radian Aerospace has been working on a rocket project while holding its cards close to the vest. Now several of the big puzzle pieces have been put together to reveal what Radian’s executives and backers have in mind: a rail-launched space plane that could carry passengers to orbit and back.
<snip>
Radian also is seeking a patent for a concept that calls for launching a winged single-stage-to-orbit craft with an initial boost from a rocket-powered sled on rails. One diagram that’s included in the application shows the plane docking with a space station, shuttle-style. At the end of each mission, the plane would make a horizontal, airplane-style landing on a runway.
<snip>
The inventors listed in the application include Livingston Holder, who was part of Air Force’s Manned Spaceflight Engineer program in the 1980s and went on to become a Boeing program manager.
After spending more than a decade at Boeing, he became vice president for space systems at Seattle-based Andrews Space in 2002, and then co-founded a Renton-based consulting firm called Holder Aerospace in 2004.
Two of the other inventors, Gary Hudson and Bevin McKinney, are veterans of Rotary Rocket, a space venture that tested a rotor-equipped prototype launch vehicle in 1999 but fizzled out a couple of years later.

(th)

SpaceNut · 2020-12-02 17:55:53

That's the em rail launch from the carriers that we talked about where the motor portion was a flat inductive design to move the sled.

tahanson43206 · 2020-12-03 18:34:29

The article at the link below describes an X-37b-like system that can deliver small satellites to orbit on short notice and land on any runway that is a mile long, which means many if not most.

I chose this topic for the post, because it is an "unconventional" business plan, and it already has paying customers.

None of the actual technologies or procedures are new.

It's the packaging that I think helps this system to stand out!

Ravn X's delivery system is designed for rapid response delivery, and is able to get small satellites to orbit in as little as 180 minutes -- with the capability of having it ready to fly and deliver another again fairly shortly after that. It uses traditional jet fuel, the same kind used on commercial airliners, and it can take off and land in "virtually any weather," according to Skylus. It also takes off and lands on any one-mile stretch of traditional aircraft runway, meaning it can theoretically use just about any active airport in the world as a launch and landing site.
One of they key defining differences of Aevum relative to other space launch startups is that what they're presenting isn't theoretical, or in development -- the Ravn X already has paying customers, including over $1 billion in U.S. government contracts. Its first mission is with the U.S. Space Force, the ASLON-45 small satellite launch mission (set for late 2021), and it also has a contract for 20 missions spanning nine years with the U.S. Air Force Space and Missile Systems Center. Deliveries of Aevum's production launch vehicles to its customers have already begun, in fact, Skylus says.

https://www.yahoo.com/finance/news/spac … 36117.html

This system comes pretty close to the system kbd512's been thinking about, in another topic (or quite possibly this one).

The current payloads planned are small satellites, but in time a suitably packaged human could be delivered to orbit using this system.

(th)

Terraformer · 2021-12-10 09:00:43

An airship mounted stratospheric light gas gun, powered by hydrogen and oxygen.

If it accelerates projectiles to 4km/s over 10km, it would subject them to 80g of acceleration. Not for fragile cargo, but water, plastic, metal etc could survive. it. Can we build solid rocket motors that would work under such accelerations, to provide the extra 4km/s to reach orbit?

If we could use hydrogen instead, and heat it externally (maybe even solar thermal?), it could send cargoes out at orbital velocity, needing only a small rocket for orbital insertion. Have them collected by a spacecraft from an unstable low orbit. The cost per kg could get very low, especially if we're using solar power (no clouds up there to cause intermittency). Almost all of the mass we need to get up there can tolerate very high accelerations, if we build furniture on orbit. Even if launching fragile things like electronics and humans cost $2000/kg, $10/kg bulk materials would make exploration really cheap compared to what it is now.

Terraformer · 2021-12-11 11:37:56

Hmm, this would also work as a means to launch bulk payloads off Mars. Oxyhydrogen should be able to reach the required velocity in one shot. It should be within the industrial capabilities of an early Mars colony to build such a structure? Far simpler than a railgun or coilgun. Still needs a circularisation rocket of course.

I wouldn't do it on Luna, but Mars has plenty of ice, and the bulk of the water will condense back out rather than being shot into space.

tahanson43206 · 2021-12-11 12:22:45

For Terraformer re #258

Your idea is certainly of interest (to me for sure)

Are you aware of the work done by D. John Hunter? There is probably more than one write-up in the forum, but here is the first I found:

http://newmars.com/forums/viewtopic.php … 76#p151976

Please ignore the response of someone in the forum. It is Not necessary to circularize an orbit if you are sending something on to Earth from Mars, if my understanding of Dr. Hunter's work is correct. If you have a friend who is good with orbital calculations (on one hand) and good with ballistics calculations (on the other), you may find that the system described by Dr. Hunter would work nicely on Mars.

The key thing you might discover if you study Hunter's work is that the gas gun depends upon the low molecular weight of Hydrogen to achieve the velocities needed. Oxygen does NOT contribute to the success of the system.

(th)

Mars_B4_Moon · 2022-04-04 09:47:58

Jeff Matthews joins Radian Aerospace as director of strategy
https://spacenews.com/mattews-joins-radian/

Radian raised $27.5 million in a seed funding round announced in January for development of a fully reusable, single-stage-to-orbit spaceplane that takes off and lands horizontally.

“The cost of transporting humans to orbit is at an inflection point that will create large-scale change in the market,” Matthews said. At the same time, Radian’s cargo capability will be one of the keys to development of a vibrant low Earth orbit economy, he added.

To date, spaceplanes have tended to launch vertically and have not shown the level of rapid reusability that Radian seeks.

“It will take a lot to get there, but we’re up for the challenge,” Matthews said.

As Radian’s strategy director, Matthews will be in charge of assessing the market and Radian’s competition. Matthews also will be tasked with building relationships with U.S. government customers and establishing strategic industry partnerships.

“Jeff is an incredibly well-respected and accomplished leader in the space sector and his work around the commercialization of LEO directly shaped the industry,” Richard Humphrey, Radian CEO and co-founder, said in a statement. “The expertise and knowledge he brings to the table is unparalleled and we are confident Jeff will add significant value to the work we are doing to transform the industry and succeed in our mission.”

Matthews led Deloitte’s work on the 2018 NASA study on commercializing low Earth orbit and on the Vandenberg Space Force Base Commercial Master Plan. He also contributed to an independent analysis of commercial high-speed transportation for NASA and to Deloitte’s updated report on commercialization of low Earth orbit.

Mars_B4_Moon · 2022-10-04 06:41:07

With Sanctions against the Soyuz after the Russian invasion of Ukraine they are looking to more ways to access space again, Branson will have his Virgin Orbit rocket packed full of satellites, which will then be flown to high altitude, dropped, and ignited before flying into space.

and Spin lunches also looked at.

Satellite-flinging SpinLaunch puts NASA payload through the wringer
https://newatlas.com/space/satellite-sp … st-flight/

Wellcamp ‘spaceport’: Branson’s rockets to launch from Qld in landmark deal
https://www.themercury.com.au/news/quee … c322b36623

Mars_B4_Moon · 2022-10-25 17:22:44

Some in news media say it could be a Chinese version of the X-37

China’s spaceplane raises orbit and national funding

https://spacenews.com/chinas-spaceplane … l-funding/

Mars_B4_Moon · 2023-03-24 04:07:46

Liftoff of Terran 1! Methalox is here to stay

https://twitter.com/nextspaceflight/sta … 7105843202

manufactured with 3D printing processes

Avio secures Italian government funding for methane engine and small launch vehicle prototype

https://spacenews.com/avio-secures-ital … prototype/

Avio is one of only two European companies actively working on methane-oxygen engines, alongside ArianeGroup and its Prometheus engine. While Prometheus is still in its design phase, the M10 engine has completed 24 ground tests with 1,300 seconds of run time, he said.

Last edited by Mars_B4_Moon (2023-03-24 04:12:07)

tahanson43206 · 2023-04-25 18:18:50

This alternative concept for a space elevator originated in another topic which is rocket related.

If this post inspires other members to comment or to develop the idea, please include momentum management in the presentation.

All objects rising from the Earth surface with the goal of entering orbit (LEO or otherwise) must impart horizontal velocity so the object has the same orbital velocity as the destination. Calliban's treatment of the concept covers much of the technology, but it omits that detail.

Calliban wrote:

One way we could use Starship as an SSTO, would be to build an orbital chandelier platform. This works rather like a space elevator on a smaller scale. We launch a counterweight satellite loaded with ballast to an orbital altitude of say, 2000km above Earth. We extend cables down to a suspended platform with an orbital altitude of ~200km. The platform, cables and counterweight, will orbit at the orbital velocity corresponding to the altitude of the centre of mass of the whole structure, which will be much closer to the counterweight than the platform. Given that the counterweight is in a higher orbit, this means that the suspended platform will be orbiting at a velocity substantially lower than local orbital velocity. This will place the cables under tension, but not so much tension as to require the use of flawless diamond filaments as cable material.
A Starship would be launched from Earth surface to land on the platform. It's dV will be a function of the change in gravitational potential energy between 0m and 200,000m, plus the kinetic energy needed to achieve orbital velocity at 2000km. Since orbital velocity at 2000km is substantially lower than orbital velocity needed for a 200km circular orbit, the total dV required to reach and land on the platform, would be lower than that needed to achieve a 200km circular orbit. Once on the platform, passengers and cargo would disembark and would be lifted up the cable to the counterweight satellite. The Starship would return to Earth from the platform. This would involve entering the atmosphere at less than typical orbital velocity, which should reduce the design requirements of the heat shield.
At the counterweight satellite, passengers would board a ferry vehicle, which would transfer them to an Earth-Moon cycler. Cargo would be lifted to higher orbits using low thrust propulsion.
The reduced dV needed to reach the platform, reduces the mass ratio required to achieve a practical SSTO. If dV is reduced sufficiently to allow Starship upper stage to be used as an SSTO, then we eliminate the requirement for a booster and all of the infrastructure needed to recover and service that booster. If a launch assist could be used to boost Starship takeoff velocity to ~Mach 1, then gravity losses are reduced substantially, increasing the effective payload capacity.

(th)

Calliban · 2023-06-21 09:15:15

We have discussed rocket sled and various option for launch assist launch before.
https://en.m.wikipedia.org/wiki/Rocket_sled_launch

The space shuttle expended 1/3 of its total propellant mass accelerating to just 1000mph (450m/s). Much of this propellant cost is due to gravity losses. If a launch assist technique can be developed to provide a vehicle with an initial 500m/s boost, then that vehicle could feasibly be engineered to reach orbit on a single stage with a far more achievable dry mass fraction. A reusable SSTO is what is needed to achieve dramatic reductions in launch costs. But it is impractical to build one that accelerates from zero to orbital speed from Earth surface.

One idea would be to drill a cylindrical hole into the ground and insert a steel sleeve with a rail gun acceledator built into it. If we assume a maximum tolerable acceleration of 10g, for a brief acceleration of a man rated vehicle, then to achieve a muzzle velocity of 500m/s, the tube must be 1274m long. Not all of this needs to be underground.

Humans have created mines that are 4km and gas wells are as much as 40,000' (12km) deep. So drilling a launch tube 1km into the Earth would appear to be well within human capability.

Power might be a problem. Accelerating to 500m/s at 10g, would take 5.1 seconds. A 100te vehicle moving at 500m/s, would carry some 12.5GJ of energy. That equates to an average power of 2.45GW. That is the electric power output of 2 large nuclear power reactors. But our launch tube will take time to reload, so we don't need that power 100% of the time. More likely, no more than 1% of time. So we need a powerplant that can produce power output of about 30MWe and some means of storing and rapudly releasing that energy as electric current. Flywheels, hydraulic accumulators, capacitor banks, steam drums, raised weights, all have potential to do this.

Last edited by Calliban (2023-06-21 09:34:27)

tahanson43206 · 2023-06-21 09:41:22

For Calliban re #265

Your idea (as I understand it) is to use a modified form of a ballistic launcher for a first stage impulse.

The connection I made was scale ...

Many have worked on ballistic launch of projectiles of small mass.

Every imaginable method has been enlisted for this purpose, and you have personally documented many ideas in this forum.

What I find new and quite interesting is the idea of scale....

In another topic, RGClark has been writing about use of solid rocket motors to give a powerful impulse to a rocket.

Your idea here (as I understand it) is to use a kilometer (or so) long acceleration tube into service, to push a massive rocket stage at 10 G, to achieve 500 m/s at departure from the tube.

The use of a rail gun seems unlikely to me. This is not a criticism of your idea, because physics may allow such a concept to work. My observation is that the heaviest mass that humans have accelerated (so far) using magnetic force is a fighter jet, and the distance is modest compared to your proposal.

On the ** other ** hand, gas expansion based propulsion is well studied, and there are examples of it's use at a large scale. The work of Dr. John Hunter is documented in this forum, as well as in numerous other resources. He was thinking of launching payloads to orbit using gas expansion. I am intrigued by the question of what he would do with your idea, if he were aware of it.

I'm hoping the creative minds in this forum will find your new topic inspiring, and am looking forward to posts that may appear in days or weeks to come.

(th)

Calliban · 2023-06-21 10:01:02

A steam cannon is technically easiest. At the bottom of the tube, we have a cage like structure full of crushed rocks. We heat those rocks to high temperature (400°C?) using electricity or by burning natural gas. At launch, we use a hydraulic ram to force distilled water into the cage, creating HP steam.

The R.M.S speed of water molecules is amply large enough to continue accelerating a projectile at 500m/s, at any temperature above boiling point.
https://www.omnicalculator.com/physics/rms-speed

The steam should realistically be superheated though, in order to prevent enthalpy being wasted in expelling saturated water. Energy efficiency of a gun (chemical to kinetic energy) is about 30%. So we would need to burn natural gas at a rate of about 100MW, to launch a 100te vehicle every 500 seconds.

Assuming a 20% payload fraction for our 100te rocket, the launcher could deliver up to 1.26 million tonnes of payload into orbit each year.

Last edited by Calliban (2023-06-21 10:07:21)

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#251 2020-11-28 14:06:13

Re: Un- conventional ways to LEO

#252 2020-11-28 19:52:19

Re: Un- conventional ways to LEO

#253 2020-11-28 20:06:53

Re: Un- conventional ways to LEO

#254 2020-12-02 08:21:11

Re: Un- conventional ways to LEO

#255 2020-12-02 17:55:53

Re: Un- conventional ways to LEO

#256 2020-12-03 18:34:29

Re: Un- conventional ways to LEO

#257 2021-12-10 09:00:43

Re: Un- conventional ways to LEO

#258 2021-12-11 11:37:56

Re: Un- conventional ways to LEO

#259 2021-12-11 12:22:45

Re: Un- conventional ways to LEO

#260 2022-04-04 09:47:58

Re: Un- conventional ways to LEO

#261 2022-10-04 06:41:07

Re: Un- conventional ways to LEO

#262 2022-10-25 17:22:44

Re: Un- conventional ways to LEO

#263 2023-03-24 04:07:46

Re: Un- conventional ways to LEO

#264 2023-04-25 18:18:50

Re: Un- conventional ways to LEO

#265 2023-06-21 09:15:15

Re: Un- conventional ways to LEO

#266 2023-06-21 09:41:22

Re: Un- conventional ways to LEO

#267 2023-06-21 10:01:02

Re: Un- conventional ways to LEO

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