Space Plane to launch from Rail

tahanson43206 · 2024-09-03 17:46:09

For Space Nut ... we had two topics with the words "space" and "plane" but neither was a good fit.

The opening for this topic is a report on a design for a space plane that would (if ever built) accelerate on a rail system of some kind before climbing up to LEO under rocket power. The design is intended only for a small number of passengers or small amounts of high value cargo.

https://www.msn.com/en-us/news/technolo … 8737&ei=13

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tahanson43206 · 2024-09-03 17:48:17

This post is reserved for an index to posts that may be contributed by NewMars members over time.

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GW Johnson · 2024-09-04 08:36:17

Anytime you do horizontal launch, you have to use lift to at least pull up into a near-vertical climb. Above about Mach 1 speed, the turn radius gets enormous at any practical turning gee (as does the wing). You will enormously increase your drag loss with parasite drag of the wing, and an enormous amount of drag-due-to-lift, over that incurred during a vertical launch into a non-lifting thrusted gravity turn.

As a result, such designs will inevitably need the theoretical dV factored up enormously to cover the huge drag loss, and they will have a higher-than-anticipated inert mass to incorporate the large wing.

Anyone who can run a rocket equation calculation with a proper weight statement can verify that the required mass ratio gets ridiculous, even with hydrogen-oxygen propulsion. Such numbers go with a huge propellant mass fraction, leaving very little for payload and inert mass fractions. And that is incompatible with the higher mass fraction needed for the big wing (and its heat shield).

This sort of design approach is feasible with Isp values corresponding to nuclear thermal propulsion. But not hydrogen-oxygen chemical. And anything less than hydrogen-oxygen Isp is just totally infeasible. I have already shown that in verifiable bounding calculations.

In my opinion, this thing is more marketing hype to attract investors, than any real promise of anything that might ever fly with chemical propulsion. It would have to be nuclear to work.

GW

Edit same-day update: Go see the current posting on my "exrocketman" site, titled "Rocket Equation-Based Launch Vehicle Analyses", dated 1 September 2024. In particular, see Figure 11 and Figures 21, 22, and 23! Know also that this was all done with the spreadsheet tools made available with the "orbits+" courses. Any of you can use those tools and do this as well as I can. Both the course materials and this "exrocketman" posting show you exactly how to use those tools correctly.

Last edited by GW Johnson (2024-09-04 09:04:08)

tahanson43206 · 2024-09-04 10:58:54

For GW Johnson re #3

Thanks for taking a look at this proposal.

It appears there is a patent pending or perhaps issued.

That means of the $22,000,000 seed money invested so far, at least $5000 has been allocated to the patent.

I found this at the Radian One web site;

Raidan spaceplane operations
A Radian patent outlines its plan to use a rocket sled-launched aircraft to reach space. US Patent Office
Startup Radian Aerospace is seeking a $20 million Series A to develop a spaceplane that uses a rocket sled to boost a crew of five into orbit
The company is fronted by US Air Force astronaut Livingston Holder, with billionaire investors including Golden State Warriors' owner Bruce Karsh
Rocket engine testing is already underway in rural Washington state
Visit Business Insider's homepage for more stories.

I assume Livingston Holder knows all the points you have raised.

The launch velocity of 535 miles per hour seems slow to me, but on the other hand, if that speed is given to a large vehicle full of propellant, perhaps it would make a difference. The patent drawing seems to indicate the launch would be on an incline. There ** is ** mention of a pull up maneuver. I see this as an opportunity for an enterprising member of the NewMars forum to locate the patent and print/post part of it to help us better understand how Mister Holder plans to overcome the serious challenges GW Johnson has identified.

The concept is not all that different from the work of kbd512 right here in this forum.

Both gents make the point that modern composite materials offer opportunities not available previously.

Let's see if we can collect more details about this proposal.

Someone (or several persons) with deep pockets have decided to place a bet on this gent.

It seems to me a bit early for anyone to predict how this will turn out, although the winds in the face of this idea look serious, both literally and figuratively.

Can anyone figure out the significance of the 537 miles per hour figure?

Is there something special about that number?

Update: I found an article that goes into a bit more detail, and it puts the launch velocity at 300 mph instead of the 500+ reported in the original article.

https://www.businessinsider.com/space-s … ne-2020-11

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GW Johnson · 2024-09-04 15:43:44

At sea level on a US 1962 or an ICAO standard day, 535 mph is almost exactly Mach 0.7. For almost any shape, that would be close to, but still below, the start of the transonic drag rise.

GW

tahanson43206 · 2024-09-04 16:14:52

I would like to offer a scenario that might explain what is intended here...

The idea that "wings" are involved may be incorrect. My interpretation of what little I can pick up from the information I have seen so far, is that the rocket engines are intended to carry the entire load of boost to orbit, without relying on "wings" at all.

The ideal launch angle would be 45 degrees, if the rail system can provide that amount of incline.

In order for this topic to advance in a non-speculative way, someone in the membership needs to take on the task of pulling the patent from the US archives, and show as much of the design as possible.

At this point, considering the background of the project lead, I am inclined to imagine this person has thought through all the basic physics. I cannot imagine this person has not carefully studied drag of the Earth atmosphere at sea level, and accounted for it.

The contents of the patent should reveal a great deal about the plan that has been funded in the amount of $22,000,000.

The folks who invest at this stage of a venture can afford to lose their investment, and at the ratio of 9 out of 10, they expect to lose the investment.

Does this mean the venture has one chance out of 10 to succeed. Maybe... I don't think anyone has any idea.

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tahanson43206 · 2024-09-04 18:16:55

I'm hoping at least ** one ** other member of NewMars has a bit of free time to investigate the Radian Aerospace rail launch concept. It turns out there is more than one patent application on file:

Search results
Results for query "(radian).as. AND (aerospace).as."Showing 1 to 5 of 5 records
Result # Document/Patent number Display Title Inventor name Publication date Pages
1 US-12065267-B2    PDF Text Earth to orbit transportation system Holder; Livingston L. et al. 2024-08-20 60
2 US-11920543-B2    PDF Text Rocket propulsion systems and associated methods Holder; Livingston L. et al. 2024-03-05 22
3 US-11649070-B2    PDF Text Earth to orbit transportation system Holder; Livingston L. et al. 2023-05-16 60
4 US-11643994-B2    PDF Text Rocket propulsion systems and associated methods Holder; Livingston L. et al. 2023-05-09 22
5 US-11059608-B2    PDF Text Earth to orbit transportation system Holder; Livingston L. et al. 2021-07-13 59

It should be possible for a NewMars member (or anyone for that matter) to pull one or more of those patents, and report on the contents.

We don't need to speculate on what the company is going to try to do. All we have to do is to invest the time to find out.

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tahanson43206 · 2024-09-04 20:30:08

Follow up on Post #7

To see the most recent patent application:

1) uspto.gov
3) Basic Search
3) Enter patent number: 12065267

On page 34 of the pdf file, there is a description of the thermal protection system: "TUFROC".

On Sheet 36 of 36 of the illustrations section, there is a drawing of the vehicle. My question for GW Johnson is:

As you examine the drawing, do you see the features that you have warned about repeatedly, having to do with the shock wave cutting off parts of the aircraft.

Since the Space Shuttle had an elevated tail that clearly survived re-entry, perhaps a high angle of attack can protect the windshields at the front of the vehicle, and the raised vertical fins at the back?

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#1 2024-09-03 17:46:09

Space Plane to launch from Rail

#2 2024-09-03 17:48:17

Re: Space Plane to launch from Rail

#3 2024-09-04 08:36:17

Re: Space Plane to launch from Rail

#4 2024-09-04 10:58:54

Re: Space Plane to launch from Rail

#5 2024-09-04 15:43:44

Re: Space Plane to launch from Rail

#6 2024-09-04 16:14:52

Re: Space Plane to launch from Rail

#7 2024-09-04 18:16:55

Re: Space Plane to launch from Rail

#8 2024-09-04 20:30:08

Re: Space Plane to launch from Rail

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