Idea: Project Fire Rain

[Lunar_Lander]

Hi everybody!

Just had an amazing flight with Xathcha's HARP add on, and maybe it is an idea for an expansion of the addon (or maybe even for real-life research?).

All I did was pointing the cannon at 90° pitch, set the power to 100% and then BOOM! As soon as the flames disappeared, I fired the first stage, and then successively the second and third. Finally, I used the Satellite's RCS to stop the rotation, fired it's engine until near depletion, and turned it then around to face the Earth. Then I waited. Finally I maxed out at 6,340 km ALT. Then I came back, reached an amazing VS of -7.8 km/s just before entry interface, had a re-entry about 3 seconds long (yes, the flames were only there for a blink of an eye ). Finally I impacted in the North Western Gulf Of Mexico at 20 m/s VS.

And now my idea: This could be used as an excellent and cheap possibility for a research flight: First you fire the satellite into space with the gun. Then you fire the Martlet 4 until depletion. During this ascent phase you can already make measurements.
Then you give the sat a final kick with it's on board engine. After that you have about 1,500 seconds before the apogee and probably the same during descent. That gives 3,000 seconds = 50 Minutes of measuring time.

When you hit the atmosphere on the way down, you have a little re-entry capsule inside of the satellite which survives the impact on the atmosphere and the re-entry. The remainder of the Satellite is completely destroyed of course. And if you can harden the electronics in the capsule for the gun launch, it will also stand the re-entry forces.

At about 7 km ALT the capsule ejects a parachute and then comes down like every other space capsule before. During the parachute descent other measurements can be taken. Dye marker and radio beacon then help the recovery forces to find the capsule.

Now, what do you think about that? I believe that this could work, because it works in Orbiter (not like the Million Miles satellite). And my favorite question: What instruments could be carried in the satellite/capsule system?

It would be great if you could express your opinions here .

Cheers ,
Lunar_Lander

 

[pete.dakota]

Sounds like a half-way decent idea, sure. I'm not aware, however, of any material or technology that would allow that kind of super-hot, super-quick re-entry. To an extent, at those speeds, it would be like shooting the heat shield into a brick wall.

The best chance may be having the satellite beam it's data real-time down to the ground, or any time before entry- with the notion of the payload being destroyed during entry.

If you consider the cost of design, research and construction- combined with perhaps not so realistic practicality; it may not work out any cheaper than an orbital mission.

It's a nice idea, though. And certainly lots of fun in Orbiter.

 

[Urwumpe]

The deceleration will always be tough for such a orbit, but, a inflatable heat-shield could increase the surface of the payload so much, that the heating will be tolerable.

Most stuff which does not like heavy accelerations - for example all stuff which needs to be deployed, will not be available for experiments. On spinning satellites, you could let centrifugal forces deploy wire antennas. Radiation detectors might also survive the launch.

 

[jarmonik]

And now my idea: This could be used as an excellent and cheap possibility for a research flight: First you fire the satellite into space with the gun. Then you fire the Martlet 4 until depletion. During this ascent phase you can already make measurements.

What kind of scientific instrument could possibly survive from this ? Sledge and anvil ?

 

[joeybigO]

The deceleration will always be tough for such a orbit, but, a inflatable heat-shield could increase the surface of the payload so much, that the heating will be tolerable.

Or perhaps a heat shield extending the length vertically to be extended horizontally to deflect as much heat as possible, I've not done the calculations in awhile, however most of the heat could be placed away if the center of gravity is pulled away from the capsule, meaning making it oblong would place the heat outwards.

 

[Woo482]

thanks for telling me how to do that now I can kill my Ummu's By re-entering them at -7.8 km/s

 

[Lunar_Lander]

@woo: Well, I suspect, that they'll survive the ascent anyway .

@jarmonik: Back in the 60ies, Bull's technicians made great efforts to protect the electronics at launch by putting them into a mix of sand and epoxy. They even once had a Langmuir probe onboard a Martlet 2!

And one last thought before I go to bed now: Maybe you would want to fire the gun at 85° Elevation, not 90°. Because then you will not have the problem, that the first stage falls down and hits the cannon (or something in it's vicinity). What do you think?

Good night,
Lunar_Lander

 

[tblaxland]

And one last thought before I go to bed now: Maybe you would want to fire the gun at 85° Elevation, not 90°. Because then you will not have the problem, that the first stage falls down and hits the cannon (or something in it's vicinity). What do you think?

The Earth rotates 15° per hour, so hitting yourself shouldn't be a problem. You might want to think about your neighbours though

 

[Lunar_Lander]

Well, if you have a launch site at the sea or in the desert, this problem wold be a lot easier to solve (just thought of the Barbados site, but missed out, that it is quite easy to hit the coast for Nothern Brazil from there, when the Earth rotates away under the bullet).

Anyway, I now started to write a little text about it, scientific paper style. Just as a premature question: Do you all know how to use Rapidshare ?

 

[Lunar_Lander]

I had another idea concerning the Project: The Martlet 3A was to be the first stage of the Martlet 4 vehicle. Now, the complete Martlet 4 would have weighed one ton, and would have delivered a 50 pound satellite into LEO.

50 pounds is quite small a value for the proposed research capsule. So the idea could be to launch the sat with a Martlet 3A. With that we don't have to carry the second and third stage, and make the capsule heavier. Of course we wouldn't get the great altitude reached by the Martlet 4.

Could you give me the formulas for calculating the new allowable payload mass when we use Martlet 3A instead of 4?

 

[penlu]

Is 7.8 km/s as fast as 28,000 mph? Because we've done that. I'm too lazy to do calculations!

After calculating... 9,000,000 mph!? nowai.

How fast did you go up?

 

[Lunar_Lander]

Hi there .

Yesterday I made a flight with 85° gun elevation, 110° heading. I reached 3,167 km ALT and landed South of Cuba (the gun really needs to be relocated to Barbados ). So I only managed to get half the altitude as with 90° elevation, but I don't know whether this is the only contributing factor to maximum altitude.

@penlu: On yesterday's flight, I set the gun power to 50% and the muzzle velocity to 600 m/s. Surface MFD gave a VS of +4000 m/s. During boosting, I reached about +5800m/s. Descent, this time, maxed out at about -6640 m/s.

A little calculation :

[B][SIZE=4]7[/SIZE][SIZE=-2] [/SIZE][SIZE=4]800 m/s* 3,6 = 28[/SIZE][SIZE=-2] [/SIZE][SIZE=4]080 kph[/SIZE][/B]
[B][SIZE=4]1 Kph= 0.621371192 Mph[/SIZE][/B]
[B][SIZE=4]28,[/SIZE][SIZE=4]080 * 0.621371192 = 17,[/SIZE][SIZE=4]448.1031 mph[/SIZE][/B]

And a question: We cannot have deployable instruments, but could we have a rotationg camera/telescope? Because I was amazed how far I was able to look during the ascent (with the Surface Markers in Planetarium Mode).

Cheers :beach:,
Lunar_Lander

 

[Lunar_Lander]

Today I made a firing with 70° elevation and wrote a five-page firing protocol about it. I'll scan it and put it up here for you for analysis !

Was quite a lot of fun!

 

[Urwumpe]

And a question: We cannot have deployable instruments, but could we have a rotationg camera/telescope?

Would be hard, but not impossible, the optics would be a weak spot. I know artillery grenades which have IR or laser senors, but these produce only very blurry images.

 

[Xantcha]

Just managed to read this (my attention is a bit blurry this days)
Sounds like a very interesting project. Sadly I'm hardly an expert in anything, especially in science experimentation equipment.

Recently there was addon package that included Lunar-A probe (haven't tried it yet) which reminded me of my duties at IOSA (if it is still active). But it also made me think about this - acceleration stress for planetary surface pentrators and gun launched probe are comparable, so may be information on penetrators can be usefull for this projects. I undertsand that measurements will be made under very different conditions but at least something basic can be still valid

 

[Lunar_Lander]

Hi Xantcha: Thanks for your kind words ! Without your work, I would never gotten the idea of this Project here.

The Penetrator idea really sounds suitable. Weren't there also penetrators on Mars 96?

Here is the promised firing report. I hope the scands are readable, because I set my scanner to 75 dpi for small filesize, set IM to 640x480 and finally my awful handwriting !

http://img152.imageshack.us/img152/9615/docu0063vf8.jpg
http://img261.imageshack.us/img261/2484/docu0064lr0.jpg
http://img169.imageshack.us/img169/8496/docu0065di0.jpg
http://img169.imageshack.us/img169/6370/docu0066te7.jpg
http://img292.imageshack.us/img292/1346/docu0067la9.jpg
http://img374.imageshack.us/img374/4122/docu0068nz0.jpg

Cheers,
Lunar_Lander

 

[Xantcha]

May be handwritten scans are not perfect form for mission flow records
Still was nice to read - even had an idea to check if they are detailed enough to make a succesfull repetitive test based on described conditions. Just was not in enough dedicted mood. So may be later

Also - I wan't to make clear one thing about cannon (sorry if I haven't described it precisely in manual). - there is no point in setting muzzle velocity seting and gun power simulatenously.

Default mode for calculating muzzle velocity is using table data (for masses between 200 and 1250 kg values are somewhat correct for other values thery are just wildly interpolated). Then this value is multiplied by "gun power" coefficient.
But if muzzle vel is set directly then it's the same value no matter what payload mass is. A "gun power" coefficient is never applied in that case.

 

[Lunar_Lander]

Ok thanks for the info! I thought you've to set up both values. I first entered the 50% power and after that the 600 m/s muzzle velocity. Did the 600 m/s then override the 50%?

A friend of mine who is an engineer told me about some LCD cameras about 3 mm in size which are quite rugged and should survive the launch. The main problem wlod be the optics and drives.

 

[James.Denholm]

And a question: We cannot have deployable instruments, but could we have a rotationg camera/telescope? Because I was amazed how far I was able to look during the ascent (with the Surface Markers in Planetarium Mode).

A friend of mine who is an engineer told me about some LCD cameras about 3 mm in size which are quite rugged and should survive the launch. The main problem wlod be the optics and drives.

Interesting thought: If you can get all your photos done before the perhapis, you could transmit the photos via radio to a satellite or something which then transfers to your base back at Earth (I'm guessing that you need a bigger radio to get through the atmosphere), hence eliminating the need for re-entry! And as for drives, solid state flash memory. Military grade construction. Would that survive, do you think? How many g's does the thing go through during launch?

EDIT: Second thought: Could this be used by countries to spy on each other?

 

[Lunar_Lander]

Interesting thought: If you can get all your photos done before the perhapis, you could transmit the photos via radio to a satellite or something which then transfers to your base back at Earth (I'm guessing that you need a bigger radio to get through the atmosphere), hence eliminating the need for re-entry! And as for drives, solid state flash memory. Military grade construction. Would that survive, do you think? How many g's does the thing go through during launch?

The forces sustained are 12,000 to 50,000 G, the flash memory should survive that. But what I really meant by drives were the mechanical parts of the optical system, like shafts, motors, gears and such things.