I watched part of California Near Space's balloon flight yesterday. The plot is still available, though as time goes by you'll need to set the time back farther and farther to include the flight date
of 30 Aug. The balloon was tracked to the ground (with additional data gathered after landing), but the team couldn't get
to the payload due to some rough terrain and local plant life. Stratofox, a team I've worked with in the past, were on chase support. If you're ever doing anything in near-space, balloons, rockets,
etc. Be sure you contact Stratofox.
While the article that drew me to them today wasn't about space, the Wikipedia Article, talking about their original applications in aircraft, made me think about their possibility for space applications. The
low pressure is certainly a plus, though I'd be curious to see the trade offs for the high density coolants. A quick search
didn't reveal anything obvious.
I've been wondering why someone doesn't do a "pusher" (as opposed to a "puller") launch escape system for quite some time.
Boeing talks about using it for their escape system here, though I think SpaceX got word out about theirs first.
A pusher (assumed to be liquid as well) escape system has the option of also being a third stage or allows the propellants
for use in maneuvering on orbit.
Asteroid discoveries over time, animated. What fascinates me is the narrow band that discoveries are made, radiating away from the sun. Near
the end of the video the WISE spacecraft starts making the discoveries leading and trailing Earth.
I'd seen comments throughout the space blogosphere from Trent Waddington, but I had no idea he was doing so much work on asteroid
mission planning. His analysis of a (soon to be?) published Lockheed Martin study on using Orion to travel asteroids is pretty cool. He's done more in-depth work on specific asteroid close-approaches, including an awesome Java applet that lets you see some Earth-centered orbit traces of many asteroids which are quite artistic.
I hadn't given much thought to the precision that we can date the age of the solar system, just remembering that it started
forming about 4.5 billion years ago. Turns out, some new information set the start time back by just shy of 2 million years. This is a big deal because the half life of a critical element
, iron-60, is about 2 million years. Amazing!
A Last-Minute (Well, Last-Days-to-Hours) Asteroid Warning System
Two years ago, an asteroid was spotted just about 20 hours before it plunged into the atmosphere over Africa. No damage was done due to the asteroid's
small size, but some people have come up with an idea to do a dedicated survey for asteroids like it that are on their way. Two telescopes 60 miles apart would scan the entire sky through the night,
looking for points of light that are close asteroids. Very cool. As mentioned in the article, this is something that universities
or astronomy clubs could also participate in.
SpaceX dropped its Dragon Capsule (no permalink, it's currently in the 'current updates' section) from a helicopter for a splashdown in the Pacific. It didn't
drop very far before deploying the drogues, so the speeds aren't what they'll be on return from orbit, but a good test is
better than a bad one.
While it makes sense to do so, I didn't know that the MESSENGER spacecraft is using its quiet times between Mercury encounters (and eventual Mercury orbits) to look for vuclanoids. Vuclanoids are asteroids that orbit extremely close to the sun. None have been found yet, but as a side benefit, we get
to see humbling images like this
Much has been made of parallels between Star Trek technology and everyday items that come along later. 3.5" floppy disks
(of course, I'm dating myself) bear a strong resemblance to the memory modules used on the original series, but this is a much stronger correlation.
I got earlier information from the NASA NEO Workshop webpage, but this article pointed out a talk(pdf) given by Lindley Johnson at HQ. In it, he narrows down candidate asteroids based on several criteria, including delta-v
limitations set by using an Atlas V, mission length limited to 6 months, asteroid size (>50m only need apply), and opportunities
for uncrewed precursor missions prior to the prime launch opportunity. The graphs showing the process are pretty interesting.
While I agree with Rand Simberg that the Ares V assumption is limiting, I like the general direction they're pointing. The three asteroids?
Update: Just read the presentation in-depth. Turned into an advertisement for an infrared telescope in the vicinity of Venus.
I like the idea, and it's been mentioned before as part of a NEO survey, but the search for human-landing targets is a new
angle, and it might just get some interest.
Update 2: I note that none of the asteroids mentioned here align with
mine, though I didn't apply the size criteria. I note that SG344 was on the short list (and had very short mission durations
of about 2 months with 7km/sec delta-v), but was DQ'd due to size.
I saw the headline of this article: "International Space Station could tackle asteroid exploration next" and had bad mental images of concept art showing a
VASIMR-powered ISS leaving Earth orbit to fly to an asteroid. Turns out, the concept is a little more thoughtful (pdf), using Node 3 as a central hub for exploration, and possibly even inflatable habitats.
Long-time readers will also notice the idea of using a counterweight-spin system to generate artificial gravity is gaining
After the earlier post, I emailed the links to an email list that I frequent. A response came back that, while the commenter doesn't mind SpaceX
developing a heavy booster, he thinks NASA should be building a backup just in case it doesn't work. My response was that
it'd be much more cost effective if SpaceX, Lockheed Martin, and Boeing were each tasked to build a heavy lifter (which again,
I don't believe is necessary) similar to how the Air Force developed the EELV. Short version:
In the 1990s, the AF and NASA split the roles of developing the next generation launch vehicle. NASA took the reusable path
(we all know how that worked out Cough! X-33! Cough!) while the AF looked to make incremental improvements in the expendable
launch vehicle fleet.
The AF let 4 contracts for $30M (note the M, not a B, or the newly in-fashion T) each to Boeing, LM, McDonald Douglas, and
ATK, asking them to design their best boosters. Lockheed and "Mac Dac" were selected the winners, and Boeing promptly bought
out Mac Dac. Each were given $60M, told to build their booster family, and given a promise that the AF would purchase the
The fact sheet is missing one important part of the cost numbers. After the commercial satellite boom (which was critical
to the low cost numbers due to the expected high flight rates) went bust in the very late 90s/early 00s, the AF gave each
contractor a cash infusion ($350M sticks in my mind, but I don't know whether that number's right, or whether it was to each
contractor or split between them) to make up for the loss. The cost per flight also went up at that point, officially (and
I believe it) due to the decrease in flight rate.
The result? 34 flights (13 Delta IVs, 21 Atlas Vs, with 1 partial failure each), and 32 declared successful. While the
cost per flight is still very high ($140M-$170M according to Wikipedia), the development cost paid for the system is on the
order of $550M - $800M (Rounding up to $100M each in the initial 2 contracts, then varying by whether they split the $350M
or each got $350M). Even on the high end of that estimate, we're looking less than 1/20th the cost of the Ares I, estimated
between $28B and $40B according to Wikipedia, though I'd guess high since $9B have already been spent.
On a Transterrestrial discussion, I mentioned some earlier research I'd done on asteroid missions. Then I asked if anyone had more info. I got a link to this page which lists asteroids and the delta-v required to reach them in increasing order of the amount of delta-v required. I was
happy to see that most of my targets are pretty high on the list. The calculations are based on this paper (pdf, pg 245-256), and it appears to me as though the delta-vs are based on Earth to the most efficient apse (periapsis or apoapsis) of the
asteroid. Mission lengths are described as being on the order of six months to a year, which wasn't the analysis I was doing.
It's also possible that the delta-vs listed are only theoretical minimums, with no thought as to when Earth and the asteroid
would actually align for such a mission.
Update: Looking at my article, I didn't do too badly in finding asteroids near the top of the chart. My delta-v calculations
were off, but considering my methods I'm not surprised. Here are the asteroids I focused on and their percentile (the asteroid
rating 99.99 has the lowest delta-v requirements for a mission) in the list:
Multiple sources are reporting on SpaceX's recent presentation where they discussed the Falcon X and Falcon XX. It appears as though the media is picking up on Elon's call for the government to develop nuclear rocket upper stages while commercial entities work on the heavy lift solution.
I glanced through the slides (their Raptor LH2/LOX upper stage engine is throttleable from 50-100% and advertised with a
specific impulse of 470(!), while the space shuttle main engine is rated at 452 and the RL-10B-2 is 464), and I'm a little
overwhelmed. Maybe more later.
Dr. David Livingston of The Space Show fame is running a series of shows that he calls "The Space Show Classroom." Basically, he got tired of some of the way out
discussions and questions that come up during his normal shows. To give readers a solid grounding in the reality of space,
he got together with frequent guests to host 12 shows (so far) that cover very specific topics (the rocket equation, orbit
mechanics, business models, etc) with more planned. The shows are available in MP3 form for download so you can get caught
up if you like, posted together with lesson notes. I'm currently involved in a discussion with the guest host for classroom #3 on orbital dynamics.
Having already stepped on a landmine with the last line of my comment entry for it's not being 'backed by evidence', I advise
anyone commenting to avoid doing so casually.
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