Official Armadillo Q&A thread

Hey, welcome! Very cool to have someone from Russia on the forum!

I think that what Ben was saying is that if you use a GLONASS receiver for determining your location, then you need a GLONASS signal. I bet the Russian government has the ability to turn off that signal, just like the US government can turn off GPS. So, if you use GLONASS, then you depend on the Russian government allowing you to do so.

According to Wikipedia, GLONASS fell into disrepair in the late 1990's, but has since been brought back to its full capabilities, and is currently only slightly less accurate than GPS (and slightly more closer to the poles). Apparently you can also use GPS and GLONASS simultaneously, which makes it easier to get a lock.

With GLONASS being more recent and less widely used, I can imagine that the receiver electronics are not yet as far developed in terms of power usage, size, weight and so on. On the other hand, you do have GLONASS smart phones and handheld GPS+GLONASS receivers, so it can't be too far off. Whether those parts are suitable for use in a rocket I can't say though.

Hi! Thank you. I am a game developer and my icon is John Carmack. Thats how I am here. And I'd love to see Armadillo venture into space.

Most of the things you said right.

By the way recent IPhone 4s supports GLONASS .

Sure, you won't use GLONASS in military equipment but for the so called and getting more popular 'precise positioning' and in the city environments it might be worth looking at.

Is there proof that the 4S uses GLONASS? There have been a few posts that claim it because it comes up in one dialog, but I haven't seen a hardware teardown that points out a GLONASS receiver.

GLONASS isn't as precise as GPS and the electronics haven't gone through as many revisions, I'm not making that up. Feel free to try to prove otherwise. It's also quite straightforward and off the shelf to get differential GPS, which is accurate to 1cm; is that true of GLONASS?

I'd love to have a clean-sheet rocket that had differential GPS with GPS attitude, 3dof accelerometers, 3dof FOG gyros, GLONASS, Galileo, 3dof magnetic, &c, but for a real world rocket you have to make trades for cost and ease of integration.

Well differential GPS may be a really good solution if you have access to it in your area (which as far as I know isn't as widely available in Europe as it is in (some areas?) of the USA.

The thing about GLONASS: the Russians decided to use a static code to encrypt the military signal, which has been cracked ages ago. If you dig around a little I bet you can find the information, if i remember correctly you can even buy "hacked" receivers. With the military signal you get centimeter precision without a differential signal to correct the error. As far as I know, GLONASS has already been used for various geological surveys and similar things, even before the satellite constellation was fully operational because for such an application it doesn't matter if you have to wait for a few hours/days before enough satellites are overhead

(I got this information from an university lecture about satellite navigation i took a few years ago, so I'm not sure if all this is still up to date).

I seriously doubt that claim of centimeter resolution without a differential signal. There's too much interference from the atmosphere and surroundings to get that level of accuracy without some kind of correction, a static receiver and a long measurement time.

I think you can also do differential GPS without a network, if you have two receivers. You put one of them at a fixed, known location, move the other one around with whatever you want to measure the position of, and then compute the distance between the two and add it to the fixed location. That cancels out atmospheric disturbances.

For a rocket, you need the exact position relative to the launch pad and/or landing zone, so you could just set up your GPS base station there and compute differences.

According to wikipedia my information regarding the military code is not entirely accurate: they didn't encrypt the "code" (aka the SatNav signal) at all, they just didn't tell the public how it is structured. But now they are employing some techniques (like transmitting in random bursts instead of continuous) to make it harder to use for those who are not authorized to do so (who knows, once the old hardware is phased out (sats and receivers) they could even change that code completely).


@ Ben: Thank you very much for the update! (finally found the time to actually read it)

Me too, thanks! And well done! There seems to be quite some significant progress: no transport damage, engine and related stuff working fine, GNC accurate in the subsonic regime, and performance-wise they seem to be on track as well. And a 100kft+ GPS lock! And while the recovery system wasn't flawless and the rocket was damaged, it's repairable.

The things that didn't go quite right are all new things that they're still pushing the envelope on and have no or very little prior experience with. Roll control during the supersonic transition, and a ballute for slowing down the return. I imagine the parachute should have worked fine if it had opened at a lower speed. With a bit more development, which they should be able to do quickly enough given the demonstrated rapid turnaround, I can see this thing working all right.

And then to build a few more, and staging, and...well, one thing at a time.

One question: you were surprised by the cost of Stig, which was much more than a mod. Did you manage to reduce the costs with Stiga? How satisfied are you with that aspect?

nice to see space : )

now push it to the limit (soundtrack from scarface)

since the atmosphere is a costly thing, maybe build a really crude straight profile wing with a spine and tail plane to lift it up to 10-15km and near 1000km/h. some small used jet engines if possible. think of it as an RC plane. very crude but effective. ugly is allowed.

and then 2 or 3 stages of high Isp engines.

get it up there and scratch the paint of ISS : )
bring a pizza and knock on the door

I am planning on writing an article in the Journal of the British Interplanetary Society (JBIS). I would like to somewhat modify the Spudis-Lavoie paper (1) proposing a particular approach to lunar return but using a commercial (e.g. COTS and X-Prize) approach.

What I would like to know is what a reasonable amount for a NASA-funded Lunar Lander X-Prize or a Lunar Lander COTS program. The goal of that program would result in a successful lunar landing of cargo lander but (like the Dragon capsule) would be developed with man rating in mind.

Can Carmack or another qualified individual at Armadillo suggest that amount?

Historically, the Eagle lunar lander is said to have cost about the same amount to develop as the Saturn V itself. Applying this ratio to SpaceX's development of the Falcon 9 as well as their estimate of the cost to develop their capsule puts both at about $400 million. So, I am inclined to use this number in our paper but that would be a full 200X what it cost Armadillo to develop its winning X-Prize lander.

Reference
1) http://www.spudislunarresources.com/Pap ... r_Base.pdf

Twitter / @jeff_foust:
Just got a press release from the NM Spaceport Authority that Armadillo Aerospace did another STIG-A test flight today at Spaceport America.

Twitter / @jeff_foust:
Take was successful according to the release and rocket reached 137,000 ft. However, its recovery system "did not function properly".

here is the press release:
http://www.parabolicarc.com/2012/01/29/ ... t-america/

The latest images look amazing!

"The next incremental step for Armadillo Aerospace will be a 100-km (~62 miles) plus “space shot” with the successor vehicle STIG-B, which is provisionally scheduled to launch in early spring from Spaceport America."





Amazing

Congrats

50 miles apparently - next attempt will be >62m i.e, space!

100km should be pretty cool but after that they should really stop doing incrementals and start doing the math for a LEO shot of minimum commercial payload size 1-10kg.
Elon Musk didn't take steps he went straight for full scale.

go for gold. it's the most cost effective

Dan please stuff it up, well you know where.


For years we have seen you post your garbage about what others should be doing because you claim to know best what should be done in others' projects.


But what have we seen of anything you have claimed to start doing?

ANSWER: NOTHING AT ALL.

Where is your supercar? NOWHERE TO BE FOUND!
Where is your space telescope? NOWHERE TO BE FOUND!
Where is any of the projects you claimed would be so great? NOWHERE TO BE FOUND!


You can't even complete the simplest tasks you claimed to have started, yet you are ready to tell other people who are spending their own money, time and resources to risk it on your stupid ideas (yes they are stupid ideas because you have not supplied a valid reason to date as to why to do any of them) that will likely fail, and if they don't fail accomplish nothing worthwhile to the original long term goals of said projects.

Dan! Stop posting until you can show you can complete a project yourself from start to finish.