Wednesday, September 30, 2009

Pegasus XL

The next installment in my "just cut and paste rocket crap from Wikipedia" series is all about a fun little rocket, one of the smallest satellite launchers ever.








"In a Pegasus launch, the carrier aircraft takes off from a runway with support and checkout facilities. Such locations have included Kennedy Space Center / Cape Canaveral Air Force Station, Florida; Vandenberg Air Force Base and Dryden Flight Research Center, California; Wallops Flight Facility, Virginia; Kwajalein Range in the Pacific Ocean, and the Canary Islands in the Atlantic. Orbital offers launches from Alcantara, Brazil, but no known customers have performed any. The capabilities of Alcantara are superfluous to other sites, without being any more convenient.

Upon reaching a predetermined staging time, location, and velocity vector, the aircraft releases the Pegasus. After five seconds of free-fall, the first stage ignites and the vehicle pitches up. The 45-degree delta wing (of carbon composite construction and double-wedge airfoil) aids pitch-up and provides some lift. The tail fins provide steering for first-stage flight, as the Orion 50S motor does not have a thrust-vectoring nozzle.

Approximately 1 minute and 17 seconds later, the Orion 50S motor burns out. The vehicle is at over 200,000 feet in altitude and hypersonic speed. The first stage falls away, taking the wing and tail surfaces, and the second stage ignites. The Orion 50 burns for approximately 1 minute and 18 seconds. Attitude control is by thrust vectoring the Orion 50 motor in two dimensions, pitch and yaw; roll control is provided by the nitrogen thrusters on the third stage.
Midway through second-stage flight, the launcher has reached a near-vacuum altitude. The fairing splits and falls away, uncovering the payload and third stage. Upon burnout of the second stage's motor, the stack coasts until reaching a suitable point in its trajectory, depending on mission. Then the Orion 50 is discarded, and the third stage's Orion 38 motor ignites. It too has a thrust-vectoring nozzle, assisted by the nitrogen thrusters for roll. After approximately 64 seconds, the third stage burns out.

A fourth stage is sometimes added for a higher altitude, finer altitude accuracy, or more complex maneuvers. The HAPS (Hydrazine Auxiliary Propulsion System) is powered by three restartable, monopropellant hydrazine thrusters. As with dual launches, the HAPS cuts into the fixed volume available for payload. In at least one instance, the spacecraft was built around the HAPS.

Guidance is via a 32-bit computer and an IMU. A GPS receiver gives additional information. Due to the air launch and wing lift, the first-stage flight algorithm is custom-designed. The second- and third-stage trajectories are ballistic, though, and their guidance is derived from a Space Shuttle algorithm."

- WIKI

According to the specs, this rocket costs $11 million per launch. Given a LEO payload of 400 lbs, that is a pretty expensive $25,000 per pound!

Sunday, September 27, 2009

Saturday, September 26, 2009



"The balloon and camera were launched at 7:44 AM, the balloon burst at 10:51 AM at 107,145 ft. and the camera landed via parachute at 11:40 AM, 89 miles from the launch site after a 3 hr. & 56 min. flight. The camera recorded a total of 4 hrs. & 22 min. of Hi-Def Video before it stopped recording 53 secs after landing, when its 32GB of memory was full. The only thing better would have been if the camera had recorded for several minutes more to captured the sound of us approaching and video of us opening its container."

Nice footage from the Bear-4 mission! Next time send up an O motor rocket and get that camera into space guys!

Wednesday, September 23, 2009

Some interesting searches to this page

These are from the past few hours:

saturn 5 pictures
how high does first stage rocket send space shuttle
long high powered rocket
high power rocketry altitude record
kosdon rocket

And dozens of searches for "High power rocketry" or something like that.

Monday, September 21, 2009

A.R.C.A. rockoon project


Based on a post at The Rocketry Blog, I found out about a project (really a series of rockets based on the same fascinating, very novel design) for a many staged rockoon. This large rocket, to be launched from an even larger balloon (rock-oon), is supposed to eventually send a rover to the moon to claim the Google X-prize moon landing reward: $30 million to soft land on the moon and rove a few hundred meters (500). If you click on the post, you will see my shocked reaction to a project that is right up my alley. This project has rockoons, high mass fractions, and a unique design. New ideas are really nice to see.

For the detailed information, please ignore my post and consult the PDF document directly: 20 page PDF on Haas

This video is an overview of the flight plan. I won't lie, I don't really get what the lunar landing may be, or what kind of delta V it would take to soft land directly on the moon. I suppose it depends on the flight time to get there:




Next, these are two overview images of the rocket:





Here is some information about the rocket as designed:

HAAS technical data
Type: Air launched orbital rocket
Stages: 3 (H1+H2+H3)
Rocket vehicle length (with ELE payload): ~18 m
Rocket vehicle diameter: ~4 m
Rocket vehicle gross weight: 23 300 kg
LEO mass: 400 kg

Stage H1
Type: Rocket powered, pressure feed
Used for: Rocket acceleration
Gross weight: 14 800 kg
Burn time: 100 s
Fuel: Hydrogen peroxide 85% + bitumen based fuel
Thrust: 47 600 kgf

Stage H2
Type: Rocket powered, pressure feed
Used for: Rocket acceleration
Gross weight: 7 350 kg
Burn time: 110 s
Fuel: Hydrogen peroxide 85% + bitumen based fuel
Thrust: 24 800 kgf

Stage H3
Type: Rocket powered, pressure feed
Used for: LEO injection
Gross weight: 2 100 kg
Burn time: 168 s
Fuel: Hydrogen peroxide 85% + bitumen based fuel
Thrust: 5 850 kgf



And the balloon:
CARRIER BALLOON technical data
Type: "0" pressure Solar Montgolfier balloon
Used for: rocket launcher lifting to altitude
Balloon diameter: 160 m
Gross weight: 7 000 kg
Volume: 2 000 000 m3 (*Really big!*)
Max. flight altitude: 18 000 m

Here are some additional images of the rocket that I find most impressive. Obviously this is not a flight ready rocket, but even as a model, any real rocketry fan can't help see the potential of thin, lightweight spherical tanks, high altitude bell nozzles, and thinking outside of the box (or cylinder.)







Conclusion and commentary:

Obviously my love of rockoon projects has been made clear. ( Farside 1 Farside 2 ) I particularly enjoy the fact that these rocket stages are very simple, cheap, and reliable.

There are, however, some major concerns. The low ISP of H2O2 is well known. Can a hydrogen peroxide rocket even make orbit? Can it overcome the low ISP? How about cold soaking in space? How about heat in space? Does it need to be vented? What amount of insulation is called for on the upper stages? These are just a few questions that I have.

Having said this, they claim an ISP of 245 sec. for the first stage. If realistic, this is a pretty darn good number. I intially thought that they planned to use the H2O2 as a monopropellant, with a catalyst. This excited me, but also raised the very real question of low ISP. I think the ISP of hydrogen peroxide as a mono prop is, at best, similar to solids. And perhaps often quite lower. However the density of hydrogen peroxide is better than I had expected, at around 1.4 pure. This is really good, far better than hydrogen and even a touch better than liquid oxygen!

By way of advice, I would propose that at least the lowest stage use solid rocket fuel. Perhaps they should even consider, and I know this goes against everything they want because ARCA states that they desire an environmentally sound propellant (and solids are actually among the worst polluters in the rocket world), but perhaps they should consider making all of the stages burn solid fuels. When you go for high mass fraction, you may want to go all out. However, this could change the chamber and tank requirements because of increased insulation and nozzle ablatives. Solids are pretty darn cheap, and very simple. The most advanced solid rocket motors look quite a bit like the stages of this rocket. That is a good sign for these guys - they are taking advantage of the sphere for maximum performance. If only they could get a thin layer of aerogel in there to allow for cryogenics without heavy insulation... but that would greatly increase the costs of the project, and the complexity.

In any event, this is one project to keep your eye on.

Source:
ARCA Space ( Aeronautics and Cosmonautics Romanian Association)

Sunday, September 20, 2009

Thursday, September 10, 2009

Ares I Solid Rocket Motor Test



"NASA tested the new first-stage solid rocket motor for the Ares I rocket. The static firing of the five-segment solid motor, designated development motor -1 was conducted at the ATK test facility in Promontory, Utah."

Once again, I am very happy with the use of large solid motors in NASA rockets. Overall, they are less expensive and often reusable.

Also check out this NASA sim. of what the upcoming test launch may look like: