Perspective

There's been a lot of discussion in the news lately about the James Webb telescope. It's planned orbit is about 1.5 million miles from earth. I was curious how this compared to existing space objects so I rigged up a scale representation. The larger dotted circles are just for clarification of finding the much smaller centers and locations of the objects. The moon is about 250,000ish miles out from the earth and the hubble telescope, at 366 miles, would have been visually on top of earth in this view so I left it off. What do you think, does it properly convey the scale and ambition of the Webb telescope? 

Next step in space

SpaceX, a private rocket and space flight company, is designing the second most powerful rocket in history. I talked on here before how disappointed I was when Obama (and congress) cut the Ares Rocket program which was supposed to be the replacement space flight rocket after the shuttle is retired. Nothing compares to the Saturn V rocket that was responsible for the impressive Apollo program, and SpaceX's new rocket is supposed to have about half the power. Meaning we'd need two, or two stages, to get to the moon again. But it's still better than anything we've got now, especially as our soon to be defunkt shuttle program is only a low orbital space program.

 

To Obama's credit, I guess we do see that private industry is developing and doing amazing things. But of course if we wanted to use these we'd actually have to buy them. SpaceX estimates they'll cost $80-$125 million for each launch. Angry commenters on the NPR article ask what good is it to spend $125 million when we're cutting money on education and social programs every day. And I agree, it's frustrating. I don't think we should educate kids any less just to go to space. But maybe we need to put this $125 million into perspective.

 

Currently each shuttle launch costs us $1.3 billion. That's including total equipment cost, subcontractors, and support. So that $125 million mentioned above would have to be rolled into a larger number to include a lander, training, ground support, electronics payloads, etc. I've also talked about the alternate engine for the F-35 joint strike fighter in the past. The alternate engine, meaning the one that lost the initial development contract, made by GE has continued to be funded by congress at a total cost since 1997 of $2.5 billion. That's for an engine we haven't actually bought any of and probably will never be able to use or buy. That is pure development dollars for GE. Funding was cut off earlier this year and it was estimated $900 million to complete the F136 development engine. That's right, before we could even buy any.

 

The estimated total cost of the Iraq war up to 2010 has been estimated to be $704 billion. Combining that with the war in Afghanistan it's expected to cost $2.4 trillion by 2017. One week into our "no fly zone" in Libya we were up to $550 million in additional costs to the department of defense for that effort.

 

Don't get me wrong, I am pro-defense spending. But like Secretary Gates I'm for smart spending. Spending that supports our troops and develops new and uesful technologies when we need them, and holds defense companies accountable for cost and timetables. But more importantly, this is not an either or situation. We don't have to gut defense or education in order to have a viable space flight program. We may have to stop giving people tax breaks on their second homes or stop taxing capital gains (interest earned) far less than we tax labor income. We may have to raise the edge of eligibility for social security or reduce benefits to those who have assets above a certain amount. But when you put the costs in perspective, especially when you compare it to a few wars nobody really likes, I think it's worth it.

 

I hope the US develops an earnest interest in science and technology again. I hope, like the title of an excellent book, that we develop a passion for mars.

Future of Spaceflight: No single point sollution

Too often we look for a single perfect answer to our problems. In the energy crisis people are often disappointed when hybrid batteries are found to be so environmentally unfriendly or that wind power is often incredibly harmful to local bird life or that solar cell arrays often use a lot of water in areas that are pretty arid to begin with.

Researchers looking into the future of space flight looked at combining a rocket propellant with an electric sail. An electric sail has some similarities to a solar sail in that they are both low mass propulsion systems however a solar sail uses the acceleration of photons to create slight accelerations to the apparatus while an electric sail uses an array of long, thin positively charged tethers that repel solar wind protons while attracting solar wind electrons. These arrays have all been proposed as a method of space flight that would require no additional propellant as accelerating and decelerating more mass requires more wasted energy. However an electric sail would only function in space and the gains to acceleration can sometimes be minute.

The researchers used the Hohmann transfer numbers as a starting point for interplanetary travel between Earth and its neighbors. Typical planet to planet rendezvous would include a period of time where the spacecraft was accelerating to give it a necessary velocity delta to escape Earth's orbit, then a period where it would coast to reach the orbit of the planet it's attempting to reach. Minimum flight times were calculated for this basic transfer orbit as between 0.289 years to reach Mercury and 30.613 years to reach Neptune.

The authors looked an ideal thrust-on time in comparison to minimum flight time because while shortest flight would generally be ideal you would also want to reduce your thrust time in case of your propulsion system failure. So it was better to look at a ratio between the two. They looked initially at having a secondary thrust phase after an initial coasting phase but found using the total time and thrust time ratio meant it was always optimal to have only one thrust phase followed by a coasting phase.

Their initial starting point was an object in circular orbit around the earth to which they then simulated times it might take that object to reach planets in the solar system using either a typical rocket propulsion system or the hybrid rocket and electric sail option. In the first option the rocket propellant and inertia allow it to reach the escape velocity. But in the case of the electric sail, the sail's acceleration can contribute during the thrust time towards achieving the delta velocity which of course reduces the amount of propellant the spacecraft would have to carry. I summed up their results in a slightly more clear graph.

Perhaps not surprisingly flights to Mercury and Venus were worse with the hybrid system. Though, an electric sail only system would save considerable fuel and mass and could be considered to Mercury and Venus. The major time savings were seen the farther out into the solar system. The hybrid system doesn't solve long term space flight concerns but it does add another weapon to our arsenal that perhaps future spaceflights will employ multiple methods of propulsion.

Quarta, A., Mengali, G., & Janhunen, P. (2011). Optimal interplanetary rendezvous combining electric sail and high thrust propulsion system Acta Astronautica, 68 (5-6), 603-621 DOI: 10.1016/j.actaastro.2010.01.024

All systems go

Congratulations to the crew of STS-133 Space Shuttle Discovery for making it safely into orbit. Also a hearty thanks to the crews at NASA's Kennedy Space Center, Marshall Space Flight Center, and the Johnson Space Center in Houston. An extremely historic day being the final launch of a space shuttle.

On the shoulders of heroes

Twenty-five years after and the airwaves and blogrolls are a mix of personal memories, trying to define what it meant to us, and what it means now for us and how we can best honor and pay homage to seven people. A lot of the commentary talks about Christa McAuliffe the first teacher in space. I wanted to highlight the story of Ronald McNair, Ph.D., and MIT graduated physicist. He was only the second African American in space. His brother Carl spoke about him briefly on StoryCorps and it's worth listening to. He talked about his brother's curiosity and risk taking. His intelligence and the barriers he overcame.

Weekend at the movies

I saw The King's Speech over the weekend and it was very good. Well, very good if you like an extraordinary cast of excellent British actors, enjoy your history, and are somewhat of an anglophile or take an interest in the British royals. I recommend it if you think you might fit into one of these categories. It was rated R, apparently for language I'd have to guess, but if you're okay with language and have a teen or adolescent who enjoys these sorts of things I think you'd have no problems taking them to it.

 

Then I watched An Education on Netflix which is somehow rated PG-13. It was all right, not as good as a lot of other movies but not bad either. I enjoy a lot of the British actors who were in it and there wasn't a whole lot of sexual scenes or anything but given the adult themes of the movie I had to wonder how something like that gets a PG-13 but something else with too many uses of the f-word gets an R.

 

At the theatres watching The King's Speech a preview came on and I got rather excited. It appeared it was going to be this year's Apollo 13, but instead about the moon landing. The quality looked good, there were all the engineers watching at NASA, and some dramatic shots of the astronauts. Turns out it was some cheap bullshit to introduce Transformers 3. Fuck you Michael Bay.

Cheeeeeeese

The first private company to both launch a spacecraft into orbit and then successfully recover it just completed that. And if we wondered whether the company was secretly run by Wallace and Gromit now we might have a clue. The payload for this flight was a wheel of cheese, homage to the Monty Python Cheese Shop sketch.

 

SpaceX launched its Falcon 9 rocket, which is the launch vehicle for a NASA contract they won Commercial Orbital Transportation Services (COTS, not to be confused with COTS commercial off the shelf) to provide a medium or heavy lift craft to bring stuff to the International Space Station. The Falcon 9 is a two stage vehicle using liquid oxygen and kerosene along with nine rocket engines for the first stage and a single, vacuum capable rocket engine for the second stage. The first stage provides a whopping 5 meganewtons of thrust and it's capable of carrying from 4,600 kg up to 8,500 kg depending on the type of orbit desired with plans for a larger 15-29 kN rocket. That is a lot of cheese.

DARPA Thursdays: Coming in 100 years, to a galaxy near you

From the same people who brought you the internet and bombing the moon, there is an exciting new effort to build a long distance interstellar travel program. Exciting if you can wait 100 years. DARPA and NASA's Ames Research Center are pairing up to look into the foundation and business model necessary to accomplish some serious space travel in another century.

 

Their goal is a noble one; inspire a multigenerational effort to do now what is necessary to accomplish this huge task in 100 years. Because something this big will take many generations and extensive planning. It will take government funding, private business models, and scientists and engineers inching us closer to the technology needed while an inspired public encourages the efforts that will get us into space again. It hearkens back of course to the space race: the Apollo program and JFK's still chilling words (at least to me). The words that let us look beyond elections and taxes and deficits and think about where we really want to go. Turn our eyes to the stars and think about what could be of America's scientists and engineers.

We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.

Still gives me goosebumps when I hear the audio. So maybe DARPA and NASA's effort seems a little too far reaching, a little impossible and unsustainable, maybe even naive. But if we could go to the moon in a year when my TI-83 would be the size of a room, maybe this too is possible. Or in the words of the poet Robert Browning,

Ah, but a man's reach should exceed his grasp,or what's a heaven for?

Mars ain't the kind of place to raise your kids

Neither is the US apparently if you want to live in a nation where science and technology is a priority. Private industry, and what could be argued as congressional pork, are soldiering on however. For once, for the benefit of our society. ATK and NASA tested what was formerly the Ares rocket program in Utah on Tuesday.

It's a pretty impressive sight. You know that thrill you get when you are very high up and look over the edge? That's the same thrill my heart feels when I see this rocket. Be still my heart. The Space Shuttle is outdated and won't last us much longer. We still need to get people and things into orbit. The current Obama plan is to trash the Space Shuttle and trash this rocket as well. I guess we'll just use the Russian Soyuz rocket because why the hell bother with space.

Well I'll tell you why the hell bother. Stop by the NASA site, or anywhere really, and you'll find a list of all the things not possible if we hadn't developed them for space travel: scratch resistant lenses, solar power, fire resistant material, breast cancer detection and biopsy enabling chip, human tissue stimulation. More than just the material your bed's made out of, but the technology that powers your laptop, your smartphone, your GPS, and maybe your grandfather's pacemaker. The people who went into science and engineering and developed these consumer devices (as well as industrial applications) may have done so because as little kids they felt inspired by the Apollo program. If there's something we as a nation can be patriotic about I sure think it's this.

Of course, some liberals are angry they voted for Obama and now he's shutting this program down. Some conservatives are upset we're spending money on the stimulus rather than space travel. Some liberals would rather see the budget spent at home and some conservatives think NASA is just more wasteful government excess. NASA's budget is roughly 18 billion or less. That's less than a tenth of a percent of the budget. Americans spend more than three times that on soda every year.

The NY Times had this article on the probably-cancelled rocket program. It gives people another chance to criticize the costs. ATK thinks they can build two rockets a year for $300 million. That's nothing. Every F-35 we buy (or don't buy, because Lockheed is so far behind schedule) costs us $140 million. I like both programs and I think it's important the government continues to fund science and technology; both for defense and science and exploration. Trusting private companies to develop this stuff on their own is like trusting the banking industry to regulate itself. Ain't gonna happen.

So for once I put my hopes into congress to protect space flight and the rockets needed to get us there. We should be staring up at the stars every chance we get: kids and adults alike dreaming of space travel and endless possibilities.

DARPA Thursdays: The Recycled Edition

DARPA continuing to look for methods of cleaning up space debris. A machine with a giant net capable of flinging things down into the South Pacific or further down into a degenerating orbit where the objects will break up are just some of the options being discussed. Of course space debris is a problem for a lot of our satellites currently in orbit, but it came up again at the 2010 Space Elevator Conference.

 

Along those same lines, NASA is looking for a tether 50% stronger than commercially available technologies. Three teams demonstrated at the 2010 elevator conference all employing different configurations of carbon nanotubes. Nobody passed the bar this year but I look forward to seeing the continued outcome of developing along these lines.

Great Risk, Great Responsibility

Almost twelve years ago NASA launched the Deep Space 1 Probe. The first interplanetary device to demonstrate successful ion propulsion in space. Ion engines were by no means new. In fact, they are the given explanation for how the Star Trek shuttlecraft are powered in the original series. The idea is to use electric power to accelerate ions, something only possible in an engine in the vacuum of space. What results is a much higher specific impulse, a measure used to define the efficiency of chemical propelled rockets. The more impulse per mass of propellant used, the more efficient the propulsion.

 

The ion propulsion system is what specifically gave DS1 its efficiency, allowing it to travel at the same speed for about half the mass of conventional space propulsion. However, its launch was not without problems. On board it carried a multitude of different payload devices, most of which had never been tested in space. The engine also failed soon after it first started though they were able to restart it successfully and the engine continued thrust for almost two years.

 

As someone who has dealt with aircraft payload devices as well as engine hiccups its hard to imagine what this is like. Of course you do as much software simulation and ground testing as possible, but if the conditions at high altitude are different enough from those at ground, I'm sure there's magnitudes of difference between ground and lab testing versus space. Then how do you troubleshoot? There are some serious advantages to being able to take pieces of your hardware and inspect them or replace them. The advantages of being able to look everything over visually, then pull things apart. Your satellite likely doesn't even have an arm or anything you could use on itself. At least a deep sea robot device you could potentially get it to surface in order to work on it, but your satellite or space probe is never coming back.

 

Seems like the pure basics of exploration. Before humans went out in ships or on trade missions early tribes moved and explored mostly when they needed to migrate. When food or resources were scarce they journied on, not knowing what lay ahead only to find new places to survive, how they theorize Easter Island was originally settled. Technology gives us the advantage of not risking human life in many of these endeavors, but the payoff is still enormous.

 

Since DS1 numerous other devices have employed ion propulsion in space. It will be interesting to see how far this technology will take us; physically, and to what limits of our dreams.

 

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