Category Archives: Space

IRIDIUM 33 + COSMOS 2251 = BOOM

It was reported that an Iridium satellite and an “non-functional Russian satellite” collided yesterday. I was curious, so I did a bit of digging, and found out that NASA had reported that it was Iridium 33 and COSMOS-2251. A bit more work uncovered orbital elements for both objects, so I was able to plug in their numbers and determine the location of the collision. A bit more of scripting, and I had GMT generate the following map (click to zoom in some more):

world

According to my calculations, they passed within 100 meters of one another (but my code gives an uncertainty much greater than that.) Each satellite is travelling about 26,900 km/second hour (sorry for the typo, but the math holds). I don’t have the mass numbers for the satellite, but even if you think they are travelling at perfect right angles, each kilogram of the mass generates about 28M joules of energy. According to this page on bird strikes, a major league fastball is about 112 joules, a rifle bullet is about 5,000 joules, and a hand grenade is about 600,000 joules. This collision generated 28M joules per kilogram of mass. Ouch!

Addendum: It’s been a long time since I took basic physics. If you care, you shouldn’t trust my math, you should do it yourself and send me corrections. 🙂

Phoenix to land today…

Mars Phoenix, on the Martian SurfaceThe Phoenix probe to Mars should land today around 6:00EDT. It’s a lander designed to dig in the Martian top soil to look for sub surface ice that the Mars Observer’s data indicates is just below the surface in the northern polar regions. It will subject this soil and ice mixture to a battery of scientific tests, hopefully which will give us some clue as to the possibility of biological viability in the Martian biosphere.

NASA – Phoenix

Update: It’s down safe! Congratulations to the NASA team.

To PCSAT-1 on 5w into an omni…

Now that I have a DC power converter in my car, I am able to run some experiments. Last night I left my radio in my car and hooked up to my mag mount roof antenna, tuned to 145.825Mhz, the frequency which has been designated for use by the APRS system via satellites. NO-44, NO-61 and the ISS (at least on occasion) are supposed to be able to digipeat APRS positioning packets on this frequency. This morning, I had three different stations recorded in my APRS log. I then decided to turn on broadcasting (once every 2 minutes). Sure enough, just an hour ago I managed to get a packet injected into PCSAT-1, showing my position @ Pixar Animation Studios.

Via PCSAT-1

Google Maps APRS

This isn’t too bad, considering I’m sending only 5w into an omnidirectional antenna, and only once every two minutes, with unreliable transmission. Very neat.

MRO to be new Mars moon on Friday

Phil Plait reminds us that in about three hours, around 10:30PST, the Mars Reconnaisance Orbiter will fire a 27 minute retro burn and enter a highly elliptical orbit of Mars. Over the next several months, it will dip into the Martian atmosphere, aerobraking to reduce speed and circularize its orbit. Then, serious science and imaging can commence!

Ah, the relentless march of science.

[tags]Mars,NASA,Mars Reconnaisance Orbiter,Science[/tags]

Addendum: I copied Phil’s original message which contained an error: the time was actually 1:24 PST. As I am typing this, the burn is over half completed, all systems are nominal.

Addendum2: The spacecraft completed over sixty percent of its burn, but telemetry is currently “LOS” as the spacecraft is occulted by Mars. The burn will continue, and the spacecraft should emerge from behind the planet in about a half an hour.

Addendum3: MRO has emerged from behind the planet, and is now in Mars orbit.   Congratulations!

New Horizons in Hold

I’ve got Realplayer fired up and watching NASA TV and the impending launch of the Atlas V launch vehicle that will carry the NASA New Horizons probe. They are currently holding at T minus 4 minutes, and have rescheduled to a new launch window at 1:45EST. Apparently there are some issues with wind gusting above their launch limits, and they are taking time to consider some valve issue (mentioned in the audio of the NASA TV feed, nothing on the web page about that as far as I can see). Hopefully we’ll see a launch in about 28 minutes.

NASA – New Horizons

Addendum: Now on hold till 2:10 EST.

Addendum: Looks like they are go for launch at 2:23EST. They are about to resume the countdown.

Addendum: T-4 minutes and counting.

Addendum: Argh!  T-2:34, went to no-go as a redline monitor fault.   They now are down for a 24 hour recycle.

[tags]NASA,Pluto,New Horizons[/tags]