WaveSpace - Space

Spiraling Outward

nospam@example.com (Guy McArthur) — Wed, 22 Oct 2008 12:31:41 -0400

One of the few good legacies of the W administration may be the refocusing of NASA's human spaceflight program on exploration--leaving Earth orbit and establishing ourselves beyond this planet. I say 'may' because, for a variety of reasons, it has yet to happen.

First we need to use our shuttle fleet for finishing the International Space Station, repairing and upgrading Hubble, and launching the Alpha Magnetic Spectrometer. Secondly, we need to complete a new launch architecture that can fulfill the mandates of Bush's Vision for Space Exploration (VSE). NASA's is developing the Orion spacecraft and Ares launch vehicles for this purpose, though they must wait until the shuttles retire in order to pay for them. Then, finally, we need to embark on missions that will sustain the program and catalyze further exploration.

It's that last part--the actual missions--that is tricky. The VSE puts forth the Moon as the prime destination and only after, Mars (it's mentioned as a brief afterthought). I was disappointed that Carolyn Porco in Wired's 2008 Smart List (15 people the next president should listen to), basically endorsed the VSE as-is. The person the next president should listen to on space policy is instead Robert Farquhar. In a recent issue of The Planetary Report (XXVIII.2) he detailed an alternative to the as-is VSE that has substantial advantages.

Basically, Farquhar's plan is a stepping-stone approach that builds infrastructure for expanding outward. The first destination is a spot in space beyond the Moon that is gravitationally balanced (the Sun-Earth L2, or second Langrangian, point). This point is the planned location for the next-generation space telescope, the JWST. Other telescopes are currently planned for this destination, so there is some incentive to have the capability to send astronauts there.

He envisions a "Deep Space Shuttle" that would ferry astronauts and equipment between Earth and L2, and an "Interplanetary Transfer Vehicle" that would swing by L2 and out to Near-Earth asteroids or Mars. The DSS, despite the name, has no hardware in common with our current Space Shuttles; it is a pure spacecraft, a re-usable "taxi" that doesn't need to fly through an atmosphere. It does month-long circuits; presumably, the space station could be the staging point for outbound astronauts.

The best part is that L2 can be used as a hub for destinations in the inner solar system. The cost and energy savings versus going down to the Moon and back are considerable. The ITV could use gravity-assisted flybys of the Moon for further savings on its circuits in to, or out of, L2.

This plan has a lot going for it. There are real economic incentives such as the ability to service telescopes and determining the feasibility of asteroid mining. Telescopes have also been talked about for the Moon; large, expensive projects utilizing the far side. It's also possible that one day, lunar soil could be a source of fuel; namely, tritium for fusion reactors. Needless to say, that is still in the realm of science fiction. This Near-Earth plan by contrast has smaller, simpler, more achievable goals, each of which builds upon the previous. This staging infrastructure could also be used to intercept asteroids on Earth-crossing trajectories, steering them away from potential impacts.

Another feature I like is that the plan lends itself naturally to international cooperation. The International Space Station has shown that such cooperation is not only possible, but that such large projects likely would not happen otherwise. It is extremely doubtful that we would have the political (not to mention financial) will to complete the ISS on our own. In the Farquhar plan for instance, the Europeans could build the ITV just like they recently completed the Jules Verne ATV, while we could collaborate with the Russians on the DSS.

And, ultimately, it is a more workable path to Mars. The Moon may become an Antarctic-style outpost, but Mars can provide humanity's second world. There is a fork in the road, one leads back to the Moon and the other is an outward spiral leading to a richer set of destinations including Mars.

Continue reading "Spiraling Outward"

Going Ballistic

nospam@example.com (Guy McArthur) — Fri, 02 May 2008 12:13:06 -0400

Peggy Whitson has spent more time in space than any other U.S. astronaut and commanded the latest mission (Expedition 16) onboard the International Space Station. Here she describes the wild ride of the Soyuz capsule on last month's return flight.

...over the next probably minute or so we built up to 8.2 Gs... after six months in zero gravity, that felt like a pretty long minute! ...I could feel my face being pulled back and it was pretty hard to breathe. The ground indicates that we hit once and then bounced and then rolled after that. My sensation was that we hit the ground and rolled.

I guess the old pilot's saying of 'any landing you can walk away from was a good one' probably applies here.

I think Soyuz is a very reliable spacecraft and I'm sure that the Russians will get to the bottom of the potential causes of why we were downmoding to the ballistic mode in an unexpected manner.

On To Mars

nospam@example.com (Guy McArthur) — Fri, 18 Jan 2008 21:38:51 -0500

Some leaders of the space science community are pushing for trips to Near-Earth Asteroids or Mars instead of a return to the Moon. Huzzah! Private-sector participation would be enhanced. Nothing could be better than NASA and our next president being persuaded by the merits of these ideas....

If You Build It...

nospam@example.com (Guy McArthur) — Tue, 06 Feb 2007 22:12:55 -0500

...they will blog. I set up a blog site for SEDS and it is really taking off. [RSS feed]. It uses the Roller weblog system, which works pretty well for multi-user multi-blog system.

Coming Attractions

nospam@example.com (Guy McArthur) — Tue, 06 Feb 2007 21:58:57 -0500

Being as 2007 is the 50th anniversary of spaceflight (Sputnik 1), it's fitting that a number of space-themed movies are in the works.

Sputnik (IMDB entry) and In the Shadow of the Moon (IMDB) are documentaries. Then there is the highly fictional Astronaut Farmer, with Billy Bob Thornton building a rocket in his barn. I'm looking forward to all three.

On To Mars

nospam@example.com (Guy McArthur) — Thu, 15 Dec 2005 23:40:19 -0500

Follow this link to the HiRISE Operations Center to get the latest news on the project and some snapshots of my co-workers in action. We've completed the final sequence of calibration images before we arrive at Mars in March. Much of my work lately has been in fine-tuning our automated "Ground Data System" processing. Basically the idea is, whenever chunks of images come down to the Jet Propulsion Lab in California, we'll grab 'em, check 'em out and do everything to turn them into final products, ready to deliver to the public and the scientific community. And by we I really mean our software; the goal is to be entirely automated. So the past few days have tested this in a live setting. The spacecraft (Mars Reconaissance Orbiter, MRO) can transmit at up to 1.5 Mbps (about 187 kilobytes per second), roughly the speed of a cable modem, which is pretty good considering it is hundreds of millions of miles away. The folks at JPL's Deep Space Network have the difficult task of making sure all those bits are received here on Earth. There's a labyrinth of networks and servers within JPL's home near Pasadena, but eventually our images pop up on a particular file server where we can fetch them over a dedicated fiber optic line or Internet2. And hey, it has worked pretty damn well! Tuesday evening the first images started to trickle in, everything worked flawlessy, final data products started coming out the other side. I was actually excited later that night when the first problem occurred: an image file that was truncated or much smaller than expected. But we knew this could happen because of the difficulties in interplanetary communication... there is some window of time where they can have the spacecraft retransmit this "gappy" and/or truncated data, or they recover data from other DSN stations... but the new versions are not always better than the first... dealing with these new versions is one thing yet to be automated. Sometime Wednesday, the data rate was cranked up, and we are keeping up. My next task will be to design and build some kind of web-based reporting tool to keep track of these downlink operations when we do it "for real" while orbiting Mars!

Houston, We Have A Space Program!

nospam@example.com (Guy McArthur) — Mon, 26 Sep 2005 14:07:18 -0400

For as long as I can remember, humans have ventured only a few hundred miles away from Earth. Apollo-Soyuz is the earliest NASA mission I remember clearly; it was the last Apollo mission, basically a publicity stunt but a fitting end to an era where two superpowers competed for supremacy in space. I remember the strange sight of Russians welcoming our astronauts; I guess I expected them to be hostile, or maybe look like Klingons.... Ironically, while we won the race to the Moon, we abandoned it after a few years. They focused on space stations and long duration spaceflight, building up the expertise for interplanetary voyages, but never embarking on them. So for 30+ years, humans haven't gone any farther than Low Earth Orbit. I think the Hubble servicing missions have gone the farthest out, a couple of hundred miles. All the interesting stuff is hundreds of thousands to or hundreds of millions miles away. Quietly in the last year, NASA has been turning the battleship around: to retire the shuttle and build craft to take us back to the Moon and on to Mars. One of the biggest moments came last week when the hardware plan to get us there was announced. This is pretty exciting stuff, even though it may be heavily based on old concepts. It'll be able to send 275 thousand pounds out of Earth orbit, significantly more than the Apollo V could. Crew will launch on a rocket that is essentially a Shuttle SRB (Solid Rocket Booster), with a second stage on top. The second stage will be powered by a single SSME (Space Shuttle Main Engine). Cargo will launch on a rocket with two extended SRB's and five SSME's. So you're basically launching the weight of the shuttle, plus all of its cargo and then some, as pure mission-specific hardware. Plus it's all in-line with the booster, no wings hanging off on the side, in fact, no wings at all. So it takes many of the best elements of the Shuttle program (the SSME has never failed in 5 x 100+ shuttle missions, the SRB hasn't failed since the O-Ring caused Challenger disaster) and puts it together in new configurations that do one thing and do it well: move metric assloads far beyond Earth.
Continue reading "Houston, We Have A Space Program!"

Going To Mars

nospam@example.com (Guy McArthur) — Sat, 16 Jul 2005 07:26:12 -0400

Over at the amazing Encyclopedia Astronautica, a detailed look at the history of proposed Mars expeditions. My favorite is still Zubrin's Mars Direct.

Life On Venus

nospam@example.com (Guy McArthur) — Mon, 14 Oct 2002 00:00:00 -0400

Is it possible that life exists in the atmosphere of Venus?

Some scientists think so.