Friday, April 29, 2005

Space Access Society Conference Notes Thursday, April 28th

Thursday's full day of talks at the Space Access Society's conference in Phoenix was a rocket scientist's dream. The theme of the day was alternative launch systems for space. There was a presentation on laser-array launches, tether applications, cannon assisted rocket launches, and design plans for a reusable space capsule and a reusable space plane. Most of the talks today were highly technical discussions of engineering. Being a lawyer it was hard to keep up. The audience mostly of males and engineers ate it up. What I took away from the talks is that the constraints of physics are a severe limitation. The talks that sought to change the rules of the game dealt with the development of new launch technologies, such as laser-array launches, cannon-assisted launches, and tethers. Of the three, the laser-array launches looked most promising for human payloads to me. Its use of off-the-shelf technology and the fact that it need not rely on aerospace companies for its development makes it an attractive alternative to rockets. It also need not rely on single sources for its components. It does suffer from the need for a rather large capital outlay but the marginal launch costs are very reasonable.

Tomorrow's lineup of speakers includes lawyers and government officials and the talks are about the latest legislation and regulations regarding private human space flight. I can hardly wait!

As best I can relate it here's a summary of Thursday's talks. It might read a little rough at times because what follows is essentially a transcription of my hand-written notes:

Notes for Space Access Society Thursday April 28, 2005

The first lecture was by Henry Spencer. His talk concerned sustainable spaceflight beyond LEO. After he made a gratuitous comment that his talk would not be limited to the “vision of Pope George I” he delved right in.

First he asked where are we going beyond LEO?

The first stop is the moon. Not as a stepping stone or merely a test bed but as a destination in itself because there’s a lot of lunar exploration still to do. It barely got started when Apollo ended.

What are the principles of sustainable spaceflight beyond LEO?

“Mars Can Wait.” A dash to Mars guarantees unsustainable spaceflight. Once you’ve accomplished your mission you’re done. They call it a crash program because of what happens after the program is done.

Sustainable means reusable hardware.

Why?

-Less costly if done right. By that he means low turnaround costs. In other words you shoot for a system where all you have to do with your ship is refuel it and fly it again.

-Expendable hardware increases risk of losing the program when you reach natural break points in your program.

-Reusable means testable. Very difficult to engineer a machine to be reliable the first time it is used. This is a major difficulty with expendable hardware.

Building a Heavy Lift Launch Vehicle is a terrible mistake. He lists the following major reasons.

-Cost is very high.
-Program will outgrow your HLLV sooner than you think. He said that as designed Saturn V was insufficient to send Apollo and Lander to the moon. Von Braun was worried about this and secretly designed Saturn V to be more robust than needed. Turned out to be correct decision as Apollo/Lander combination barely met Saturn V’s capabilities.
-In orbit assembly will be necessary. Since that is the case it makes sense to start designing for it now. The major advantage of orbital assembly is that you decouple your launch vehicle requirements form your mission. Even Apollo had orbital assembly but in lunar orbit.

A robust and sustainable spaceflight program will have orbital assembly and frequent launches. Thus, a base in LEO is needed. LEO base could have small tug. Launches don’t have to go all the way to base’s orbit, and payloads don’t need to have a docking mechanism. Let the tug do the docking.

Where to put the base? Here’s where he went into a lengthy discussion of rocket science. Factors needed to consider in base placement are

-Getting maximum payload out of launches.
-Your launch location on Earth.
-Getting maximum use out of base’s orbital velocity.
-High enough above atmosphere but below the Van Allen Belt

His bottom line conclusion is best place for base in LEO is where it will be best for sending a mission to the moon. For destinations beyond the Moon orbital placement is not as critical. He describes a 3 burn system for sending missions beyond the Moon that is not dependent on suitable placement of base in Earth orbit.

Some of his major points regarding the implications of Sustainability.

-Think in terms of long-term solutions.
-Don’t design vehicles to make sure they are completely self-sufficient. If design assumes assistance during emergency then design is easier.
-He said a Naval rather than aviation analogy works best beyond the moon. Think in terms of multiple ship missions, forward basing
-Think in terms of backup plans for emergencies rather than abort mode. Abort mode puts severe constraints on design. In other words, rather than designing mission where failure means the ship returns design mission where failure means the ship finishes mission as best it can. Comparison he makes was to Amundsen’s Antarctic mission. Amundsen was dropped off at Antarctic by ship and ship left leaving him and his men with two tasks until ship could return: survive and make it to South Pole, both of which he did.
-Think bigger. Build in margins for safety buffer. Don’t push performance margins. This gives mission better chance of success even with failure.
-In a related vein, live with inefficiency. Design for profitability with vehicle flying half-full.

He had some interesting things to say about the harshness of the lunar environment. If the hydrogen at the poles is water ice it’s likely to be rock hard permafrost that is combined with dust. So it would be a rock hard and abrasive rock.

He described how the estimated lifetime of an Apollo suit on the moon was one week. One of the astronauts on Apollo 17 had his helmet stuck due to dust buildup after just 3 days. Gene Cernan had outer gloves for his suit to protect the pressure suit gloves from the dust. His outer gloves were shredded by the time the mission had ended.

William Kelly of Triton Systems.

Triton is working on an orbital space plane. His talk focused on business. He said the three major concerns of venture capitalists are

1. Management team
2. Market
3. Product of service propietary advantage.

He described the things that venture capitalists look for to kill a plan.

Management team.

Does team know what P & L means? (Profit and loss)
Does team think they have no competition
Do they think they don’t have to explain anything. Enron-like arrogance.
Do they have no idea why their idea hasn’t been done before?
Is team’s main focus on owning 51 percent?

Market

Customer can’t be described.
Company will own 100 percent of market worth 20 billion per year.
Path to success is littered with dead bodies.
Market has no competitors but is worth 20 billion dollars per year.

Triton’s business model contemplates using airfield operations, suborbital tourism, microsatellites, replacing Soyuz or Progress.

Short term, they are focused on sounding rockets and microsatellites as an underserved market. Not looking for space tourism market due to cost.

He likes Soyuz as a model for orbital vehicle.

George Herbert
Venturer Aerospace
Manned Spaceflight to Earth Orbit and Beyond.


Gave a lengthy slide-show presentation pitching his company’s plan to build a reusable space capsule, mate it to an expendable launch vehicle that they would purchase rather than build, and compete for Robert Bigelow’s America’s Space Prize and build on that success to develop company as major space company.

He views the near term opportunities as being:

America’s Space Prize
2-12 orbital tourists per year
up to 12 ISS crew per year
An ISS crew return vehicle

Capsule is designed to seat 5 passengers and 1 crew. Estimates cost is 30-35 million per flight at price for customers of 6 to 7 million each. Could be operational within 36 months of funding. His plan pins hopes on winning the 50 million dollar America’s Space Prize.

He outlined a multi-step plan to develop his capsule and launch it. He said his contacts with FAA so far have revealed that manned capsule falls in a regulatory gap where there is no license for manned capsules.

He targets Falcon V from Space-X as his launcher. So designing capsule to be 4 to 4.5 tons. Weight opens options for other launchers also.

Another design consideration is transportability on Earth. Needs to fit in a C-130, 747/767A, or be truck and train compatability.

He’s developed two concept designs. One is a blunt Apollo type cone and the other is a more elongated cone. Target weight is 4500 kgs, but must stay less than 5500 kgs.

Design is to be landed on ground, on prepared landing field in desert.

Lt. Cole Doupe of DARPA spoke about Falcon and Ares program. Small launch vehicle and hypersonic craft. Air Force’s major issue is responsiveness. They very much want something that can be turned around quickly and launched simply and quickly by small crew.

Jordin Kare spoke about laser launches. His presentation seemed most developed and backed up of the lot. Perhaps because it is based on what exists now. Bottom line I took away from this talk is that laser-array launch system is doable now with current technology and would be a vast improvement over rockets. Startup time is 10 years though and capital cost seemed prohibitive at 1 to 2 billion dollars. But resulting system would be very robust.

He detailed a proposal for using laser diode arrays to launch vehicles. The laser array system involves using a large number of smaller lasers rather than a single very large laser. His system would involve using the new generation of high powered lasers to build an array of 1,000 to 2,000 lasers covering an area the size of a golf course to launch an expendable cheap vehicle into LEO. He predicted such a system could launch 3,000 tons of payload into orbit each year, with 5 launches per hour, and could also launch on 15 minutes notice. Launch vehicle would need a 600 to 800 km flight path for launch. Vehicle is designed not to have to launch straight up but rather than flies over the array on its way up.

He claimed that marginal cost for each launch would be $200 to $300 per pound of payload.

Advantages of the system are that it uses off the shelf technology, vehicles can be simple, and don’t need an aerospace company to be involved.

Gerry Nordley of Tethers Unlimited spoke about the various uses for tethers. As did Henry Cate and Vincent Cate.

One interesting talk was by Bradley Parker of Heron Aerospace on the idea of cannon assisted rocket launches to orbit. He said that an 8 inch bore portable cannon could launch a payload of 1 to 25 pounds into orbit. The cannon serves as the first stage of the launch cycle. The advantage of the system is its portability and low cost. He said that as far back as World War I the German Army had used a cannon to bombard Paris that was capable of launching a payload into orbit. But they never thought to do it. A cannon-assited system would not be capable of launching humans as the g forces on launch can range from 5,000 on up to 30,000. To make it human capable would require a cannon with a 5 kilometer long barrel that is about 20 feet in diameter. But materials could be launched as well as microsatellites and supplies from a smaller cannon.


Those are the highlights of Thursday's talks. Friday's speakers include the majority counsel from the House Science Committee, an administrator from the FAA AST, and a panel discussion on space entrepeneurship and the FAA. The afternoon talks include presentations by Space Adventures, XCOR, Pioneer Rocketplane, among others. I'll try to post my notes and impressions of those talks at the end of the night again.

-tdr

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Comments:
This is really fascinating stuff! As a non-scientist, I thank you for not only going, but also taking what were obviously dense (in the good sense of the term) presentations and encapsulating them into summaries that are understandable and relatable. Makes me really wish I could be there too ... and also shows just how much potential exists in terms of genuine space exploration, if only the powers-that-be could appropriately focus their energies and resources.

Thanks again, Dave. Ad Astra!!
 
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