Wednesday, October 24, 2007
6:39 pm est
This news article
strikes me more as a collection of random procurement facts piled together.
The title, about Orion
orbiting Earth for six days before lunar injection, probably has more to do with launch opportunities
than any inherent design in the spacecraft (well, other than the need to rendezvous for a mission). They'll probably put
the departure stage in an orbit that allows at least one launch opportunity each day, but that comes at the trade that, if
you launch on your first opportunity, the moon isn't where you need it to be yet. The whole thing still strikes me as kind
Wednesday, October 17, 2007
Like Watching Poetry
4:44 am est
The Bad Astronomer has a tribute
on its tenth year of flight anniversary. My favorite entry (yes, the single frames of Saturn are beautiful)
is this one
showing the motion of Saturn's moon Prometheus slowly colliding with Saturn's F ring. The ripples it places in the ring
are hypnotic to me. I especially like the fact that the image blanks out for a moment, when the scene moves to the far side
of the sun and into shadow. The large version of the film is worth the bandwidth!
4:09 am est
, in my opinion, has some of the best researched and most insightful articles on space-releated issues. In order to gather
enough information to make them that way, the articles don't usually come out right as the incident is going on. Here
is an article about the computer failure on the ISS during the last shuttle mission. There are a couple points that I'd
nitpick, such as the Russians vehemently accusing the US of causing the problem (I don't deny he may have better sources than
I do, but I usually attribute such stories to overactive media types who don't understand the initial phase of troubleshooting
and focus on controversy instead of facts), and think the relationship to Mars missions is overplayed because:
- A mission
to Mars will not be constructed while it is en route. Construction wasn't a direct cause of this issue, but the condensation
control on board may trace some of its origin to the assembly of so many separate pieces.
- A Mars spacecraft is very likely
to be simpler in construction than the ISS, at least smaller and with less moving parts such as solar arrays.
- Any mission
that can't rely on Earth resupply will have to have a 'safe mode' designed into it that will provide basic life support while
problems are diagnosed and fixed.
There's also an interesting discussion going on at Slashdot
Saturday, October 13, 2007
7:42 am est
is a story based on a press release I received from MIT. It states that they've determined that Apophis (the asteroid that
has a slim chance of causing us some trouble in the 2030s) is a type LL chondrite. That's important information if we're
going to do something to change its orbit to avoid us.
When I got the press release, I looked on the MIT website to find a web version of it, but ended up searching through Google
News. I guess I could have just posted a copy of it here
7:34 am est
Posting will be more sporadic than usual, because Landsat 5 is sick
. We have a plan to get back to operations, but it's going to take some time.
Thursday, October 11, 2007
Revving up the Engines
4:07 am est
Wednesday, October 10, 2007
Hearing Postponed, Impacts not so much
3:43 am est
A Congressional hearing on the near Earth object (NEO) threat has been postponed
. A commenter to the post seems to have updated reasoning on why.
Monday, October 8, 2007
Another way to Deflect Asteroids
8:46 pm est
is an interesting story about using mirrors to heat up an asteroid's surface. The ejected material could serve as a low-thrust
thruster to alter the asteroid's orbit. The idea is intriguing, though I'm curious about the numbers.
A Competitor Shows Their Hand
8:43 pm est
I've hinted at the fact earlier, but don't think I ever stated for sure that I'd made a submission for The Planetary Society's Apophis Mission Design Competition
with my partner Jerry Horsewood of SpaceFlightSolutions
. The website says that there were 100 letters of intent to propose, which I'm guessing translates to 50 or fewer actual
One team issued a press release
on their submission, and it includes a link to a mission summary. No word whether it was their actual submission. They
chose a radically different approach than Jerry and I, going for a very low-cost mission. My approach was more for a longer-term
effort, more expensive, but allowing for multiple launch vehicles and ion propulsion for exploring other asteroids. We'll
have to see what the judges are looking for.
Sunday, October 7, 2007
Saw This Show Today
6:19 pm est
Very cool alignment
of the moon, Venus, Saturn and Regulus was visible today as I headed out for The Army Ten Miler
. They made a striking sight.
Cool Video, Missing an Important Point
4:23 pm est
Space.com has a cool-looking video
giving some great images of what a mission to an asteroid might look like. It falls into a trap early, however, by saying
that such missions are low in energy costs. That statement vastly simplifies what's actually a tough issue, which I described
. Asteroids can be low-energy targets for exploration, but only very rarely. To see for yourself, go to this web page
, and ask for a list of close approaches sorted by V-infinity. On average, an asteroid passes by with a V-infinity of less
than 1.5 km/sec every ten years or so. V-infinities must be doubled for total delta-vs.
Don't get me wrong, I think the missions are a great idea. I want all the information out there, though, before they get
overhyped and overpromised.
Friday, October 5, 2007
NEO Discussion at Bad Astronomy
5:32 am est
The original post didn't include the press release, but The Bad Astronomer
has some talk about a potentially threatening asteroid that was actually a rediscovery. Some commenters were concerned about
statements made by the B612 Foundation
, so I took a few minutes to set the record straight. It turned into basically a blog post
, including a follow-up. I guess I have to accept that I may be helping Phil with his new book.
Thursday, October 4, 2007
Late Reporting on a Strange Pronouncement
5:46 pm est
CNN is posting an AP story
today about statements that NASA Administrator Mike Griffin made about two weeks ago. Jeff Foust reported
on this on the 17th of September. Basically, Mike said that China will reach the moon before we return.
I won't say it's impossible, but given their rate of launch for crewed missions, there's a long way for China to go from their
current activities to a moon mission. They would either need to start development of a huge booster or get heavily into on-orbit
construction. Either approach is doable, and China has the economic muscle to pull it off if they choose to, I just haven't
seen any indications of it outside of some extrapolations made based on their current missions.
Methinks NASA is trying to bring back some of the old 'magic' in remembering Sputnik.
Back and Forth
4:14 am est
I'm enjoying this series
of op-ed pieces penned by Homer Hickam, the author of Rocket Boys and Rand Simberg, the author of Transterrestrial Musings
. I particularly like this quote from Rand on what NASA's role should be:
I used to have a signature on Usenet
that said, "It's not NASA's job to send a man to Mars. It's NASA's job to make it possible for the National Geographic Society
to send people to Mars."
Potential Navigation Hazard Named for Helmsman
4:09 am est
You can't see it with the naked eye, but Star Trek fans can rest easier now that another asteroid has been named after
an actor from the original series. 7307 Takei joins 4659 Roddenberry and 68410 Nichols as a heavenly body.
Wednesday, October 3, 2007
4:05 am est
It looks like the consensus on the Peru event is settling out on the idea that it was a rare carbonaceous chondrite meteorite
that struck a ground aquifer contaminated with arsenic. Now, scientists are saying
that the crater will only be there for a couple months due to water motion in the area.
Tuesday, October 2, 2007
Interesting Barrier to Cross
8:32 pm est
In the original X-Prize, it was difficult at the beginning to know which teams were some guy with a graphics program and which
teams had any chance of actually building hardware. This article
shows that the Google Lunar X-Prize
has a $1000 dollar application fee. I'll be curious to see how it impacts the number of applications. They mention some
problems with HD cameras, which I pointed out as part of my list