Jump to content

Supersonic reusable microsat LV


 Share

Recommended Posts

https://www.space.com/40918-air-launched-rocket-ravn-aevum.html

 aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kv

Pretty straightforward concept. Carrier vehicle takes off autonomously from an ordinary runway under jet turbine power, climbs to high altitude, and releases the two-stage expendable rocket at just under Mach 3. The carrier vehicle returns to the landing site; the first stage boosts suborbital and the cryogenic third stage does the rest. I'm guessing the first stage is solid.

They make a big deal about "three-hour turnaround time" but that seems like a great deal of hokum.

I wonder what powerplant they'll be using on the carrier vehicle.

 

Link to comment
Share on other sites

1 hour ago, FleshJeb said:

Pratt & Whitney J58s, or a reasonable facsimile thereof?

I don't know of any other off-the-shelf engine that could do the job.

The problem is regression. Simpler and cheaper to pair a COTS turbofan with COTS SRBs if you want to get the exact same payload to the exact same altitude and speed. Which begs, why not put the SRBs on the payload? Which means you're flying a Pegasus, which means you can use an existing manned jet carrier plane, which takes us right back to current tech. And Pegasus can barely compete with SpaceX in price-per-launch, despite delivering 1/10th the payload to LEO.

Link to comment
Share on other sites

50 minutes ago, FleshJeb said:

Pratt & Whitney J58s, or a reasonable facsimile thereof?

An option, another is to use an fighter jet, guess you can get an old mig-31 pretty cheap and it can reach mach 2.8. 
Downside is ground clearance as in rocket diameter, you could however use an flattened rocket or an trolley launch. 

Dropping an huge payload in supersonic speed is another issue but probably solvable. 

Link to comment
Share on other sites

But why even go supersonic?

Benefit from reduced dv for rocket stage is not significant, but there is a whole list of issues that is attached to supersonic flight.

Separation, as mentioned by magnemoe (hey dude, how do you pronounce that?)

Design limitations (shape, materials, engine)

Operational limitations (flying supersonic above populated areas is frowned upon. People tend to complain)

 

Three hour turnaround? I'm sure ATC will be delighted to clear the skies for you every couple of hours.

Link to comment
Share on other sites

25 minutes ago, Shpaget said:

But why even go supersonic?

Benefit from reduced dv for rocket stage is not significant, but there is a whole list of issues that is attached to supersonic flight.

Separation, as mentioned by magnemoe (hey dude, how do you pronounce that?)

Design limitations (shape, materials, engine)

Operational limitations (flying supersonic above populated areas is frowned upon. People tend to complain)

 

Three hour turnaround? I'm sure ATC will be delighted to clear the skies for you every couple of hours.

Main benefit is probably high drop attitude and in correct trajectory, and yes the extra 2000 km/h don't hurt. 
If you launch an tiny rocket drag is an major issue, 15 km up its far less of an problem and you will not stay down there for long. 

Note that this implies using an fighter jet because you can get an old one cheap. Constructing an new supersonic plane is probably not worth it and this restrict second stage size. 

Now an mach 6 plane changes stuff at least if it can operate in space as in 60 km up. Note that now you get a lot out of the plane, you don't even need fairing if upper stage is internal and you separate in space so no supersonic separation. 
Downside is that an mach 6 plane will be very expensive to develop even if rocket powered for peak speed. 

Benefit of air launch is that you are an plane until you start the climb and you can do this in an remote area making it easy to get clear for launch. 
 

Link to comment
Share on other sites

14 minutes ago, Scotius said:

Old, used fighter jet probably would be cheap - but precisely for that reason maintenance would be a nightmare. And you could forget about 3 hour turnaround.

Any mach 3 plane is pretty high maintenance and it would be a bit simpler being demilitarized, you would not want an worn out plane but something with low block number would not be an issue. 
I would at least start with them before making something custom. 

Link to comment
Share on other sites

45 minutes ago, Wjolcz said:

Cool. The more New Space launch providers the better. One of them is going to succeed eventually lowering launch costs even more.

Unless it's a new dot-com bubble. Space market is very specific and limited.

Link to comment
Share on other sites

1 hour ago, kerbiloid said:

A hypersonic global aeroballistic missile?

Mach 2.85 is not even hypersonic. You need a ramjet or rocket to get to hypersonic speeds, and you need a scramjet to stay there. Presumably this would be powered by a bypass turboramjet.

Link to comment
Share on other sites

6 hours ago, Scotius said:

Old, used fighter jet probably would be cheap - but precisely for that reason maintenance would be a nightmare. And you could forget about 3 hour turnaround.

An old used fighter jet would limit you to an entirely solid rocket (or at least non-cryogenic, but do you really think you can bring DSMH to your friendly neighborhood airport?).  Expect even LOH to require considerable "topping off" while getting to altitude.  At that point, you pretty much have a Pegasus that needs ~600m/s less delta-v to get into orbit.

At worst, this is pure vaporware.  At best, the R&D team has a real vision, that has been "sexied up" by the marketing team to the point of inability to uncover the basic idea.  Note that trying to add this capability to a blackbird (which was presumably designed in from day 1) destroyed the plane and killed the launch operator (the pilot survived), but presumably could be tried with some of the MiG aircraft.  If you were really serious about such a craft, I'd assume that you would at least claim to be in talks with Stratolaunch (even if they keep hanging up on you), as they seem nearly complete with the more expensive side of the 400/9000 m/s split.

If I were designing this, I'd assume the "plane" was rocket powered and landed shuttle style (launching might be arbitrary, and allow for a TWR<1 with lift from the landing wings).  Aerospike design (assuming you have to make a specific rocket engine for the "plane") mostly in hopes that I could get this to be air-augmented [linear aerospikes should be easier] as opposed to hopes of aerospike efficiency through the atmosphere.  Separation would be outside the atmosphere followed by X-15/shuttle style re-entry (although spaceship 1 might be a better inspiration).  Or you could "double down" on the airplane side and forget the aerospike (unless you really can make it air-augmented) and build a rocketplane launching from Stratolaunch and again separate outside the atmosphere (at >"mach" 6).  The whole point of the rocket propelled aircraft frame would be to avoid a hoverslam and allow a pilot (preferably on the ground controlling the thing like a drone) to land it like a plane.  I suspect that taking the wings to even "mach' 6 would be too much, but people/[investors?] like plane launches.

Link to comment
Share on other sites

I was thinking "oh, an actual whole rocket ?", then sees another new airplane design, then gone flat.

 

Seriously, unless someone else pay for that airplane cost it's never profitable.

Can we start strapping them to passenger airplanes ?

Link to comment
Share on other sites

40 minutes ago, Nibb31 said:

You mean "continue"

No, this time I mean "start".

 

You can fly transatlantic and get a free firework display mid-air.

They get themself a free launchpad and some extra cash.

Edited by YNM
Link to comment
Share on other sites

1 hour ago, YNM said:

No, this time I mean "start".

 

You can fly transatlantic and get a free firework display mid-air.

They get themself a free launchpad and some extra cash.

Brings me to the question, do they actually put crew on the Pegasus Launch plane, or is it unmanned.

Not passengers, obviously :sticktongue:

Link to comment
Share on other sites

1 hour ago, NSEP said:

Brings me to the question, do they actually put crew on the Pegasus Launch plane, or is it unmanned.

Think there are crew on it. At least pilot, copilot, flight engineer and payload engineer (?), given that's what the aircraft requires plus someone to look for the payload mechanism.

 

EDIT : But my proposal is to launch them from a passenger-carrying flight.

Edited by YNM
Link to comment
Share on other sites

3 hours ago, YNM said:

Think there are crew on it. At least pilot, copilot, flight engineer and payload engineer (?), given that's what the aircraft requires plus someone to look for the payload mechanism.

 

EDIT : But my proposal is to launch them from a passenger-carrying flight.

Most of the fuel is burned getting the thing up to cruising altitude, so you would be out roughly the cargo space/weight of your rocket.  You would also need to transport your payload engineering team (hopefully you can get it down to one) all the way to your destination.  While 747s are ideal for this type of thing (the extra hard point), they are being retired and I'm not sure what would also work (the LM-1011 is even more rare).

According to https://www.quora.com/How-much-would-it-cost-to-rent-a-Boeing-747-for-a-round-trip-to-Asia

a round trip charter flight of a 747 from Chicago to Seoul would be $.7 million dollars.  This doesn't seem to be a significant portion of the cost of a rocket launch, but every $.7M counts.  This also means that it wouldn't be unfeasible to launch plenty of rockets while convincing airlines that you could safely launch from their planes and customers that you wouldn't strand their cargos at the destination after an aborted launch.

Between the rare Pegasus flights (which uses similar enough tooling to other Orbital final stages that it is still in production, otherwise I doubt they would bother), and the complete lack of any rocket built for Stratolaunch, I think this is a dead end.

Link to comment
Share on other sites

Spoiler

They should try a SpaceX-like way:
Use the rocket as the plane's fuselage, with two attached nacelles aside (each one with a wing, a turbojet, a fin, and an elevon)
The plane takes off as a plane. Gets to the launch altitude and velocity.
Nacelles decouple, return to the airport, and land. Fuselage ignites the rocket engine and ascends.

 

Link to comment
Share on other sites

53 minutes ago, wumpus said:

$.7 million dollars

Going off on a tangent, is this style of writing numbers something prevalent in US? The . is barely visible in this scenario and $0.7 would be much less prone to be read the wrong way. I've seen it multiple times being the style used by (I presume USA born and educated individuals) and it keeps boggling my mind. I honestly can't think of an occasion I've seen it over here in Europe, or written by Europeans.

What gives?

Link to comment
Share on other sites

1 hour ago, wumpus said:

While 747s are ideal for this type of thing (the extra hard point), they are being retired and I'm not sure what would also work

747-8 ?

Or just 787 or 777X. Limited seats is fine - you get to see fireworks (but hopefully you're not a part of it).

Or A350 if an Airbus is worth the shot.

Edited by YNM
Link to comment
Share on other sites

2 hours ago, Shpaget said:

Going off on a tangent, is this style of writing numbers something prevalent in US? The . is barely visible in this scenario and $0.7 would be much less prone to be read the wrong way. I've seen it multiple times being the style used by (I presume USA born and educated individuals) and it keeps boggling my mind. I honestly can't think of an occasion I've seen it over here in Europe, or written by Europeans.

What gives?

Hmm, good point, I didn’t even see the decimal on my mobile until I read your post. It may be laziness, or it may be typing stream-of-thought, thinking “point seven”

Mind you, I usually took the lazy approach to. Perhaps it’s a matter of getting the “zero point“ drilled into your head  

So yeah, I was thinking 7 million was pretty expensive 

 

Edited by StrandedonEarth
Link to comment
Share on other sites

  • 2 years later...

Bumpity bump, this is still dumb, but now with a bit more info and some shiny hardware.

https://spacenews.com/aevum-unveils-autonomous-aircraft-that-launches-rockets/

https://arstechnica.com/science/2020/12/meet-ravn-x-a-fully-autonomous-air-launched-rocket-for-small-satellites/

"55,000-pound unpiloted aircraft is 80 feet long with a 60-foot wingspan."

"It releases a two-stage rocket that can launch 100 kilograms to 500 kilograms of payload to low orbits."

"Because we don’t have to worry about human pilot, we ignite half a second to 1 second on separation." which is, according to them, a gamechanger and will make existing plane air launched systems obsolete "because after the rocket is released from the aircraft, it takes several seconds for the plane's pilots to pull away to a safe distance, and by the time the rocket ignites its engines, it is accelerating back toward Earth."

"The business plan is based on conducting about eight to 10 launches a year at prices ranging from $5 million to $7 million a launch". That sounds a bit optimistic, considering Pegasus is ~$40M.

They claim to have a billion dollars worth of contracts which is impressive, including military contracts, which is impressive considering they don't have a flight article.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...