Thursday, April 30, 2009

N - Prize



One can hardly improve upon the many posts and articles regarding the N-Prize, which has now been active for quite some time. We have discussed many of the possible plans and debated everything including the value of such a competition; one that is nearly impossible to complete. But all the same, there have been no substantial posts on this subject here at High Power. Below are some most relevant links, divided into general information and teams. This post will also be placed on a new R2K blog; N-Prize.

The official rules are:

"The challenge posed by the N-Prize is to launch a satellite weighing between 9.99 and 19.99 grams into Earth orbit, and to track it for a minimum of nine orbits. Most importantly, though, the launch budget must be within £999.99 (about $1500) - and must include the launch vehicle, all of the required non-reuseable launch equipment hardware, and propellant."

The reward is about $15,000, but really the reward is doing something very very hard.

Essential links and media reports:

N-Prize official site
Wiki entry
Google Group
Make article
New Scientist article

Participating teams:

Neblua
Epsilon
SARA
Micro Launchers
CU Spaceflight
Potent Voyager
Team Prometheus
Little Monster Rocket
Kiwi 2 Space
QI Spacecraft
Yit Space
Aerosplice
Daedalus Aerospace

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I would like to finish this brief discussion with my, purely hypothetical proposal to achieve the prize. Many of the above listed teams have great plans, some are traditional and others quite unconventional to say the least.

My plan:

The launch team would prepare a large helium balloon, probably an inexpensive homemade zero pressure balloon suitable for flight to or slightly above 100,000 feet altitude (near space.) Indeed if possible, 110,000 feet or 115,000 feet would greatly increase performance at little additional balloon costs. Attached to this balloon, large enough to carry approximately 100 lbs. to near space, will be a gondola package, launch tower, and rocket system. The electronics and documentation package will be maximally lightweight, on the order of 1 kg. The launch tower will also be as light as possible, made of carbon fiber or other composites (more on how to avoid the high cost of this item below), and will likely be on the order of 10 feet long. Most importantly, the rocket system will consist of an amateur O motor contained within a very light weight, minimum diameter dart airframe. This should be a high thrust O motor, an O 10,000 would be a suitable choice, or perhaps faster still. The reason for this is to achieve aerodynamic stability quickly in the thin air, which will be assisted by a 1 - 3 fps spin:





The rocket is to be fired at a 45 degree angle. At burnout, this rocket is expected to achieve a velocity of at least 5000 fps. This is, however, far short of what is required for orbit. After a short coast period, sufficient to allow the rocket to achieve an altitude of more than 50 miles, the second and final stage of the launch process will be ignited. However, as a result of the high cost of conventional rocket stages (rapidly pushing the price point over the limit), this 2nd (or perhaps 3rd) stage will consist of a shaped charge:


A powerful conic shaped charge will ignite. At the focus of this shaped charge, there will be a small metallic slug. This slug is to be lunched into orbit. This metal slug will consist of several layers, and will retain a basic useful form as in explosively shaped projectiles (see below.) Within the metal projectile, a burning thermite charge could eject chaff into orbit (for the sake of government assisted tracking), or some gas could be evolved from a filler material that will glow against the night sky and be visible from ground based telescopes. This may be compared to a tracer bullet, though it would have a full thickness of tracking material, sufficient to remain visible for 9 orbits:


This project minimizes to (according to my understanding) the lowest possible disposable cost, given a reasonable and realistic initial investment. The per launch cost, per the prize rules, would consist of the rocket propellant, shaped charge, balloon, and helium (or hydrogen). It is expected that the rocket proper and gondola and tower structure will be recovered. Having said that, it is hard to see how a small rocket launched at a 45 degree angle, into space or near space, could ever be recovered. This flaw may still not break the budget as a complete O motor and rocket could probably be built for a reasonably low cost, less than half of the total budget.

Finally, it should be noted that shaped charges seldom launch solid objects at hypersonic velocity, but in this project, nothing short of 15,000 fps is needed. This would likely be a record, and requires some really smart shaped charge design (if it is possible at all.) It may be that a 2nd or even 3rd stage would be needed to assure orbit. Also, care must be taken to avoid too much velocity, which could cause solar orbit. Perhaps using several stages could allow orbit without a shaped charge, but at what cost and complexity increases? I would welcome any comments about this plan.

Future posts may explore more about individual teams and their attempts.

Saturday, April 25, 2009

Largest hobby rocket to date



Rocket was about 1600 LBS (a record) flying on one central P motor and 8 N motors. Recovery was good (unlike the last record.)

More coverage at The Rocket Dungeon

Thursday, April 23, 2009

In the event Apollo 11 is lost



"On July 20, 1969, Neil Armstrong and Edwin "Buzz" Aldrin became the first men to walk on the moon. The following speech, revealed in 1999, was prepared by Nixon's then speechwriter, William Safire, to be used in the event of a disaster that would maroon the astronauts on the moon:

Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace.
These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery. But they also know that there is hope for mankind in their sacrifice.

These two men are laying down their lives in mankind's most noble goal: the search for truth and understanding.

They will be mourned by their families and friends; they will be mourned by their nation; they will be mourned by the people of the world; they will be mourned by a Mother Earth that dared send two of her sons into the unknown.

In their exploration, they stirred the people of the world to feel as one; in their sacrifice, they bind more tightly the brotherhood of man.

In ancient days, men looked at stars and saw their heroes in the constellations. In modern times, we do much the same, but our heroes are epic men of flesh and blood.

Others will follow, and surely find their way home. Man's search will not be denied. But these men were the first, and they will remain the foremost in our hearts.

For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind."

Moon Disaster Speech

Tuesday, April 21, 2009

Some insane images from Saturn











The flagship scale space missions always produce great results. Cassini may be the most incredible planetary mission to date.

"NASA's Cassini spacecraft is now a nearly a year into its extended mission, called Cassini Equinox (after its initial 4-year mission ended in June, 2008). The spacecraft continues to operate in good health, returning amazing images of Saturn, its ring system and moons, and providing new information and science on a regular basis. The mission's name, "Equinox" comes from the upcoming Saturnian equinox in August, 2009, when its equator (and rings) will point directly toward the Sun. The Equinox mission runs through September of 2010, with the possibility of further extensions beyond that. Collected here are 24 more intriguing images from our ringed neighbor."

Cassini Big Picture 3
Cassini Big Picture 2
Cassini Big Picture 1

Saturday, April 18, 2009

Earth gravity data




Gravity Data

"CHAMP (860 days) and GRACE (200 days) satellite gravity data have been combined with 0.5 x 0.5 deg surface data (gravimetry and altimetry) to generate the high resolution global gravity field model EIGEN-CG01C."



More details on these two spacecraft:


CHAMP






GRACE

Wednesday, April 15, 2009

Reaction Research Society Boosted Dart


Despite being among the most impressive amateur launches ever, I have yet to post about this project. The reason for posting at this time (many years later) is because I was recently given the flight data for this launch.

The best article about this boosted dart flight is not online, but rather in the November 1997 edition of "High Power Rocketry." HPR was by far the best rocketry magazine ever made. It is really more of a journal. In any event, the same magazine that got me started with the OuR rocket, had great coverage and analysis of this flight as well. That great coverage is exactly what is now missing from so many other projects. Perhaps it is tempting to just move on after a project, particularly if the flight fails, but that is doing a great disservice to the community. So in other words, please put as much effort into the debrief as you can for the sake of others.

This was an R motor with a stainless steel boosted dart on top. The dart carried a camera and transmitted images from near space, including a shot of the Blackrock lake bed looking about as big as a thumbnail. Both the booster and dart were recovered, the apogee was around 55 miles, give or take. Here are some of the interesting data that were sent to me by RRS member Bill Claybaugh:

To help catch everyone up on this flight profile; essentially the booster burn was about 4 seconds long, at which point the dart was released. Boosted darts are thin, dense, and designed to coast really well. It makes sense for a short burn booster in this case, so the dart spends most of its time alone coasting with limited drag. After the dart flew on, the booster was actually unstable because without the dart, and above mach 3, the CP and CG were overlapping. This caused the booster to corkscrew (yet somehow survive the stresses involved) and lose velocity really quickly. The booster, an R motor, only hit about 3 miles! The dart flew on, took footage, and nearly hit space. Incredible performance. This chart shows clearly how the dart maintained velocity well. At the end of the radar documentation, the dart is at about 25,000 feet and still cooking above mach 3.

Here are some fun numbers (keeping in mind I do not know the errors involved, but the listed stats are interesting to me and judged at least initially to be realistic.)

- The booster accelerated at around 35 gs, cutting out at around 4 seconds into the flight.
- On burnout, the booster saw very wild g swings including what looks like decelerations of 60, 70, and even at a few moments 100 or more gs. This is how it drops down from supersonic to zero in just a few seconds. Granted these were abnormal conditions, but even under normal flight this boxy R motor would probably have seen 20 or 30 gs deceleration anyway.
- The rocket was supersonic only about 1 second into the flight, just about 500 feet off the ground!
- By contrast, the dart was slowed down by only about 8 gs in the lower atmosphere (tending towards 1 g as drag was reduced).
- The dart staged near burnout, around 2 miles altitude. This is interesting because that means it coasted for around (or nearly) 50 miles after this!

Thanks again to Bill Claybaugh for these interesting data. I am (as are my 100 loyal daily readers) ready for similar data from the CSXT, if they would like to send them. We accept images, videos, and raw data.

*Update 2/6/2010 - Two new videos showing on-board footage from the dart (to near space) and the ground view of the launch. The latter is of particularly low quality. In any event, one can see the booster spiral out of control as soon as the dart flies away. As said above, the change in center of gravity caused this problem, but only at high mach numbers. This remains one of the most important flights of its kind, and if there were just a K or L motor in that dart, this probably would have beaten the CSXT to space.



Thursday, April 9, 2009

Old image from the archives



This image is from about 10 years ago, but shockingly it is a the very same (and only) Graduator that I fly today. But here it had a green nose cone (still have the cone, it is interchangeable with the red one). In any event, the story behind this photo starts with the vendor recommended motors:

D12-3/150
E15-4/350
E30-4/400
F20-7/800
F21-6/700
F23-7/800
F25-9/1000
F50-9/1000
G40-10/1800
G80-13/2300

Well most of these make sense. This one rocket has flown on a good portion of this range of motors also! From memory, it has gone up on the H238, G80, G25, F50, F24, F22, E30, E16, and once, just once, on a D12-3. And that is the reason for the image above. Maybe built today, with my better and much lighter methods, a Graduator could indeed fly on a D12. But not this kit. It was simply too heavy. Ribsy was a bit nervous to say the least.

Sunday, April 5, 2009

METRA Launch - 4/5/09

Today I attended a METRA launch. Visibility was good, but wind was a steady 10 - 15 mph. Despite the wind, which did eventually die down by 2:00, several dozen flights were launched. Most METRA launches feature a few very large flights, and this one was no exception. Two most notable flights were: a large (I think N) rocket to 15,000 feet, and an M skidmark that was so loud, its sound echoed off of hills and trees for miles around for a good 8 seconds.

I was only able to make 4 flights due to some very long delays on one rocket. First off was the Art Applewhite spool rocket, flying on an F39T. Obviously this is a solid amount of power for such a small rocket, and it had a pretty intense flight with the usual spinning at burnout. Recovery was good, on the range just off a drainage ditch. The very next rocket was also an Art Applewhite; an orange 24mm Cinco. The propulsion was an F12J, and the flight was very nice indeed. The rocket fell back also close down range, however it landed directly into a drainage ditch into water. The motor case was salvaged, but the rocket dissolved. Construction was paper and white glue, obviously this could not survive submersion.

The next rocket attempted was the now battle scarred Loc Graduator on an F24W-4, one of the $1 motors from Narcon. Due to some unknown problem at the pad (probably alligator clip problems), this rocket failed to ignite several times in a row, consuming an hour of flying time! Eventually it was able to fly after being moved to the low power pads. This motor gave a nice, slow flight for the heavy Graduator, but ejection was too early. Recovery was nominal on the range, no damage despite early ejection.



Finally, I chose to fly one of the 18mm cluster kits that I had created out of the educators pack of kits. For the test flight, two A8-3 motors were used. This offered a safe test of the airframe and would have ideally allowed for recovery even if only one motor was ignited. As the pictures above show, only one did burn. The rocket flew fairly true despite this, but did not get much altitude at all. The wind was a factor, and on a still day recovery and flight on one motor alone would have been ok. In this instance, ejection was just a bit too late and the rocket (with the extra unburnt mass from one A motor no less) fell and broke off a fin. The rocket can be repaired.

Sadly, because of the long Graduator delays, the 5th and final flight of the day was not made. This was to be a new attempt at flying the Viper IV with 4 D12s. This will have to wait.