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Thursday, October 16, 2014

Mars One: Bouncing the Reality Check

Today a group of engineering students from MIT published a very well-researched feasibility study about Mars One, the Dutch plan to put a human colony on Mars by 2024, for a reality TV series.

The study is good, and solid. It basically comes down to "they don't know what they don't know" (the news.com.au headline about the study was "Humans on Mars One mission would start dying in 68 days" which sums it up pretty well). You can read all of the MIT feasibility study here, it's a pretty interesting read.

http://web.mit.edu/sydneydo/Public/Mars%20One%20Feasibility%20Analysis%20IAC14.pdf

The elephant in the ballroom here is that Mars One, to date, has raised a grand total of about $600,000 worldwide. With that, they can buy one pretty nice brand-new single engine Cessna, and maybe fuel, a bag of donuts and a thermos of coffee for the flight to wherever a Cessna 172 can get to from Amsterdam.

Tuesday, October 14, 2014

Snowballing

This Sunday the Oort Cloud comet Siding Spring (also called Comet C/2013 A1) will pass within 140,000 kilometers of Mars. This is about half the distance from the earth to the moon, and much, much closer than any known comet fly-by of earth. It will be observed by rovers on Mars and spacecraft in Mars orbit, as well as terrestrial land-based and space-baced telescopes. Currently orbiting Mars are the Mars Reconnaissance Orbiter (MRO), MAVEN, Mars Odyssey, the ESA Mars Express, and India's Mars Orbiter Mission (MOM). It is only by blind, dumb luck that this one-in-a-million flyby is happening at a time when we are actively surveying Mars for eventual human colonization. This should be a very interesting week.

Friday, October 3, 2014

Cargo to Crew

This is the ULA Delta IV Heavy that will launch the Orion spacecraft on its uncrewed maiden voyage this December.

This raises the issue of the difference between rockets for cargo flights into low earth orbit versus crewed flights to the same destinations, and specifically why we can't just use the same rockets for what is nearly the same job. It turns out that modifying an existing cargo rocket for crewed flight is a fairly involved exercise.

The reason is safety, mostly. Rockets have an unhappy propensity for exploding, so any crewed vehicle must be able to safely escape an explosion. Part of the solution is a Launch Escape System, which is simply a small rocket on top of the spacecraft to pull it away from the main engines and fuel tanks in the event of a catastrophic failure. Here is an example, with an Apollo space capsule.

Cargo rockets take the shortest, fastest and simplest (hence closest to vertical) route to orbit that their engines allow, with little consideration for the massive changes in g-forces that the cargo is subjected to. Humans need a slower and gentler ascent. Also, cargo rockets maximize the distance they coast upward unpowered between stages, and by launching essentially vertically the exhaust remains below them. Neither of these are problematical so long as the launch proceeds normally. However, if the LES needed to deploy at certain parts of the launch trajectory (such as at the top of one stage's coasting before the stage above it ignited, or the first few seconds of a launch when the huge exhaust fireball is below the rocket), the LES would be unable to safely extract the spacecraft. These time intervals in which the LES cannot launch the crew safely away from an exploding rocket are called "black zones." Every crewed rocket has some, but the goal is to minimize both the amount and duration of these. One method for accomplishing this, for example, is to launch the rocket in a lower parabola so that for most of its flight to orbit, the spacecraft does not have its own exhaust gasses below it.

The currently used Delta IV, Atlas V and SpaceX Falcon rockets are all presently being modified for commercial crewed flights. Each of these rockets will be discussed here in greater detail, as this series progresses.

Monday, September 29, 2014

Orion Promo #7

Just two months to go before the maiden flight of the Orion spacecraft, on 4 December 2014. Yes, I'm shamelessly reposting NASA propaganda videos here. Because, you know, rockets!

Churchill Downs

Ok, so, if we're going to have a "Space Race," we need to define the racetrack.

There are two really important things to understand about the immediate future (next couple of decades, say) of human spaceflight. One, space flight is really difficult. Two, the main reason space flight is really difficult is that the places we want to go are really far away.

There are only a few destinations worth realistic consideration between now and 2040, and hence part of what I would consider the current Space Race; Near Earth Orbit, the moon and lunar orbit (and the earth/moon Langrangian orbits), near-earth asteroids and comets, and Mars and its moons. That's it, that's as far as humans will possibly get in the next quarter century, if we're very ambitious and very lucky. The one possible addition to this is that if the Dawn spacecraft proves that Ceres is a helluva lot more interesting than currently assumed, it could be prioritized into the mix, but I consider that highly unlikely. The moons of Jupiter and Saturn, tantalizing though they are, are going to have to wait for later generations. Hopefully we will land robot probes there much sooner.

I'm going to talk a bit about linear, point-to-point distances, as a vacuum-packed crow might fly. Spacecraft don't fly in straight lines, a fact I'll be discussing in greater detail at a later point, but the distance ratios for comparison are relatively the same regardless.

Low Earth Orbit, meaning the altitude of the International Space Station, is about 425 km above the earth. That's about the driving distance from Seattle to Spokane, or Chicago to St Louis. To date, only NASA, Roscosmos and China's single Shenzhou 5 mission have successfully put humans here. Only NASA has ever put humans any higher than this.

The moon (and environs) are about 400,000 km away, some 940 times the distance to the ISS. Which is why nobody has been back there in almost 43 years.

At the very closest point in its orbit, Mars is about 100,000,000 km away from earth. That's 250 times the distance to the moon, or about 235,000 times the distance to the ISS. Which, again, is the farthest distance humans have traveled since 1972.

I had intended to create a drawing which accurately depicted these scales, and figured out that I couldn't. The disparity of scale is simply too great. And maybe that illustrates the point as well as any drawing could.

Friday, September 26, 2014

From Russia, With Love

So, there's really no better place to begin a series about the current race for human spaceflight, exploration and colonization than to discuss the realities of human spaceflight right now. As of this morning, our total presence off of planet earth right now is five men and one woman on board the International Space Station. I'll talk lots about the ISS in a later post, but I wanted to start with the rocket which got the crew to the ISS today, the venerable Soyuz.

Soyuz is like the Volkswagen Beetle of the world's space programs; small, simple, reliable, and basically unchanged since 1967. 121 crewed launches as of today; I think that's more than all of the rest of the world's crewed space launches combined. Soyuz exemplifies the Russian model of "low-tech solutions to high-tech problems," the spacecraft has always had the look and feel of something that could have been built as a weekend project in someone's garage. I kind of love this spacecraft.

Space Race 2020, Introduction

This is the first new post of a new series I'm calling "Space Race 2020," although I will very likely go back and reflag some earlier posts with it. This is what really inspired me to start blogging regularly again, after a bit of a hiatus. We are entering a very exciting time in space exploration, and I really enjoy geeking about it online. Why 2020? Partly because it is the nominal end-of-mission date for the International Space Station (although I won't be terribly surprised if it continues flying crewed missions for another decade beyond that), partly because it is a target launch date for a number of upcoming programs, but mostly because it sounded better than "The New Space Race," and I'm lazy and won't have to change it for another six years or so.

In the series I intend to talk about both the challenges ahead and the hardware being developed to meet those challenges, and focus on both big players like NASA and much smaller independent players as well. I'm specifically going to look at the immediate future of this decade and the next, meaning realistically probably no further afield than Mars. Well, maybe Ceres or Europa, if someone gets really ambitious.

So, quick disclaimers. I do not presently work in any part of the aerospace industry, and I do not own shares in any part of the aerospace industry, nor am I in any way affiliated with any particular part of the aerospace industry. I do live in Seattle, which is the home of Boeing, and also Blue Origin. I previously served aboard submarines which carried and launched both Poseidon C3 and Trident C4 missiles, and spent a fair amount of time at Port Canaveral for ballistic missile testing and telemetry (and incidentally got to see a number of space shuttle and satellite launches in the process), but my specialty was navigation, not weapons. The last time I was directly or even indirectly involved with the design, development or deployment of any rocket that did not have the word "Estes" on it somewhere, Ronald Reagan was president. I am a US citizen and a veteran of the US Navy, so naturally I have some bias toward American space programs, but my main thrust is to see successful human spaceflight under all and any flag. Russia, China, Japan, India, the European Union and other governmental agencies, and also the various commercial and otherwise independent space ventures, all are contributing to our exploration and eventual colonization of the solar system, and will be covered here in various detail. Also, my age informs my biases. I was barely old enough to watch (and be enthralled by) the Apollo moon landings, and it is my great hope to be able to watch the first humans land on Mars as well. Also, selfishly, I would very much like for the cost of commercial spaceflight to become affordable to the point of experiencing it personally, while I am still young enough to do so. Nothing too extravagant; if I can get over the Kármán line before I'm 75 or so, I'll call that a win.

The race is on.