Wednesday, June 30, 2004
Lord of the Rings
All going to plan, the SOI burn just finished (Saturn Time) - locking Cassini forever to Saturn. Cassini would then turn to Earth to bellow a minute-long triumphal arrival message through the tenuous D-ring. The remote sensing instruments, slumbering for the last, tense, week should be awakening, and then the great bulk of the spacecraft will begin to pirouette and summersault like an Olympic diver, before plunging back through the same ring gap it entered through.
The rings now frame the sun, as seen from Cassini, a grand gossamer bridge across the sky.
UPDATE: STUCK IT, as the Olympic judges say.
The rings now frame the sun, as seen from Cassini, a grand gossamer bridge across the sky.
UPDATE: STUCK IT, as the Olympic judges say.
Through the Rings!
..or not. We have to wait nearly two hours to find out if Cassini survived. The craft is now spinning around on its axis, pointing its engines in the direction of travel. SOI begins in ten minutes, Saturn time.
Much breath holding at JPL, one presumes.
Much breath holding at JPL, one presumes.
The Death Star Approaches..
Coming under the pseudo-Star Wars artifact Mimas, with its massive crater Hershel. Cassini will shortly underfly the G-ring before automatically pointing away from Earth and barging through the ring plane.
UPDATE: Under the G-Ring now - Cassini has turned toward the rings, using the dish of the HGA as a shield. This will be the deepest into the ring system that any spacecraft has gone.
UPDATE: Under the G-Ring now - Cassini has turned toward the rings, using the dish of the HGA as a shield. This will be the deepest into the ring system that any spacecraft has gone.
Tuesday, June 29, 2004
Inside Titan..
The plunge continues. Cassini is accelerating toward the inner Saturn system, which seems to lack the witches brew of organic molecules that darken (and in the case of Titan, may drench) the outer moons. It seems to be mostly water ice hereon in, though VIMS, UVIS and the main cameras of ISS will need to confirm this.
Live coverage of Saturn Orbital Insertion begins on NASA TV tomorrow at 8:30 pm CST - first pictures arrive at daybreak. This 96-minute braking maneuver may be the longest "live" chemical rocket burn in the history of space exploration - although Jupiter is far more massive, Galileo was able to use Io as a gravitational parachute to dump much of its excesse velocity, and only had to use its main engine for 49 minutes. Cassini will have something Galileo lacked - a spare rocket engine. The tale of Galileo's problematic engine can be found here.
Galileo's Unified Propulsion Module (built by EADS (then MBB) on behalf of the West German space agency) had a critical problem with the thrusters. In 1987, after Galileo was shipped back to JPL after the Challenger loss, a German comsat called TVSat 1 developed a stuck solar panel. To free the panel, the operators tried to shake it loose through prolonged firing of the thrusters. To their shock and horror, the thrusters blew up. Galileo had the same thrusters.
JPL's concern was that a prolonged burn (like the 49 minutes of JOI) would have lead to a bad day.
The fix was to limit all firings to short, minute-long pulses - including JOI - so Galileo burped its way into Jupiter space...
Live coverage of Saturn Orbital Insertion begins on NASA TV tomorrow at 8:30 pm CST - first pictures arrive at daybreak. This 96-minute braking maneuver may be the longest "live" chemical rocket burn in the history of space exploration - although Jupiter is far more massive, Galileo was able to use Io as a gravitational parachute to dump much of its excesse velocity, and only had to use its main engine for 49 minutes. Cassini will have something Galileo lacked - a spare rocket engine. The tale of Galileo's problematic engine can be found here.
Galileo's Unified Propulsion Module (built by EADS (then MBB) on behalf of the West German space agency) had a critical problem with the thrusters. In 1987, after Galileo was shipped back to JPL after the Challenger loss, a German comsat called TVSat 1 developed a stuck solar panel. To free the panel, the operators tried to shake it loose through prolonged firing of the thrusters. To their shock and horror, the thrusters blew up. Galileo had the same thrusters.
JPL's concern was that a prolonged burn (like the 49 minutes of JOI) would have lead to a bad day.
The fix was to limit all firings to short, minute-long pulses - including JOI - so Galileo burped its way into Jupiter space...
Cassini Closes In...
Cassini just crossed the orbit of Hyperion - Titan will be next...
Saturday, June 26, 2004
Surprise!
John Ralston Saul, one of my favourite angry humanist philosophers, turns out to be Canada's First Lady. This is slightly topical as his wife, Canada' governor-general, will get to choose the winner of Monday's Canadian election.
In some ways the coming result resembles New Zealand's 1996 election, which forced a fragile center-left coalition and the right to battle for the affections of a 'plague-on-both-your-houses' nationalist party from somewhere off the political spectrum. Winston Peters, of course, chose to return to his Tory roots, prompting the messy detonation of New Zealand First two years later; it is not clear that the Bloc Québécois is quite so mercurial in nature, or riven by the same sort of weird chemistry as NZF, where Maori nationalists were conjoined with red-neck farmers and cops (ironically, it was the Maori MP's who would prop up the National Government after the Coalition crumbled - Winston's party of angry agriculturists was preserved when he survived Election Night in Fortress Tauranga).
In some ways the coming result resembles New Zealand's 1996 election, which forced a fragile center-left coalition and the right to battle for the affections of a 'plague-on-both-your-houses' nationalist party from somewhere off the political spectrum. Winston Peters, of course, chose to return to his Tory roots, prompting the messy detonation of New Zealand First two years later; it is not clear that the Bloc Québécois is quite so mercurial in nature, or riven by the same sort of weird chemistry as NZF, where Maori nationalists were conjoined with red-neck farmers and cops (ironically, it was the Maori MP's who would prop up the National Government after the Coalition crumbled - Winston's party of angry agriculturists was preserved when he survived Election Night in Fortress Tauranga).
Sunday, June 13, 2004
Bugger!
Cairns out scoring only 1 run. Englishman Thorpe gets a century despite Cairns' 4 wickets in the last innings. Massive humilating defeat for New Zealand with a day to spare.
Oh well.
Cairns out scoring only 1 run. Englishman Thorpe gets a century despite Cairns' 4 wickets in the last innings. Massive humilating defeat for New Zealand with a day to spare.
Oh well.
Saturday, June 12, 2004
Return to an planetary archipelago...
In 1997, a Canterbury geology student named Kylie Eckersley decided to have a 'space' themed 21st-birthday celebration. My contribution (immediately prior to a scandalous game of chandeliers and subsequent, alleged and unremembered, debauchery) was to gather up signatures and send them to the Planetary Society. They made interesting reading, as people gave excellent advice to Aliens as to how to have a good time and who they should go kidnap. I wish I made a copy. The scrawls were scanned and copied onto a DVD, which was then bolted onto the side of the good ship Cassini, bound for Saturn.
Seven years later, Cassini has arrived at the outer isles of the grand archipelago of the outer solar system. Yesterday it passed the battered retrograde moon Phoebe (pictured), as the spacecraft catches up with the ringed planet in its orbit. At the end of the month Cassini will cross in front of Saturn, pierce the outer rings directly in front of the planet, and begin a 90-minute engine burn high over the bulk of the rings that will bend its path and thread it back through the ring system on Saturn's night side. Years of orbiting and observations will follow.
This particular ring gap is thought to be clear (Pioneer 11 in 1979 and Voyager 2 in 1981 survived the crossing, although Pioneer nearly discovered a new moon the hard way, and Voyager's camera platform chose that moment of high drama to seize up.) To be safe, Cassini will batter its way through the hopefully empty gap with its communications dish pointing troubles way, protecting sensitive instruments, fuel tanks, and the all-important DVD bearing drunken insults to the cosmos.
Seven years later, Cassini has arrived at the outer isles of the grand archipelago of the outer solar system. Yesterday it passed the battered retrograde moon Phoebe (pictured), as the spacecraft catches up with the ringed planet in its orbit. At the end of the month Cassini will cross in front of Saturn, pierce the outer rings directly in front of the planet, and begin a 90-minute engine burn high over the bulk of the rings that will bend its path and thread it back through the ring system on Saturn's night side. Years of orbiting and observations will follow.
This particular ring gap is thought to be clear (Pioneer 11 in 1979 and Voyager 2 in 1981 survived the crossing, although Pioneer nearly discovered a new moon the hard way, and Voyager's camera platform chose that moment of high drama to seize up.) To be safe, Cassini will batter its way through the hopefully empty gap with its communications dish pointing troubles way, protecting sensitive instruments, fuel tanks, and the all-important DVD bearing drunken insults to the cosmos.
Rugby-powered Revenge in the House of Pain
36-3!!! victory by the All Blacks over the World Champion English at Carisbrook Stadium, Otago.
Dale Bludge:
More details at haka.co.nz...
And in the cricket, the last Test is in the balance as Chris Cairns, in his last test match, collects 5 scalps to slow England's first innings and give the Black Caps a first innings lead.
Richardson, Fleming and Styris delivered a good first innings for New Zealand, but their second innings has had more patience than runs, thanks in part to some dodgey umpiring. Given the remaining batsmen, and the sad state of New Zealand's bowling attack, it will be up to Cairns to put some runs on the board tomorrow, and then break the English batsmen the day after, if he wants his last Test to be a winning one.
Given the fractured state of the New Zealand team, avoiding a white-wash seemed as unlikely as the sad Detroit Pistons holding the star-powered Los Angles Lakers to under 70 points in a NBA finals game - but patently absurd things do happen in sports. Which is why we watch.
Emma John scratches her head in Wisden/CricInfo.
Dale Bludge:
"After all of the pre-test talk of the powerful English scrum, the All Blacks put a big exclamation mark on their win when they blew the English scrum to pieces in the dying minutes."Sweet.
More details at haka.co.nz...
And in the cricket, the last Test is in the balance as Chris Cairns, in his last test match, collects 5 scalps to slow England's first innings and give the Black Caps a first innings lead.
Given the fractured state of the New Zealand team, avoiding a white-wash seemed as unlikely as the sad Detroit Pistons holding the star-powered Los Angles Lakers to under 70 points in a NBA finals game - but patently absurd things do happen in sports. Which is why we watch.
Emma John scratches her head in Wisden/CricInfo.
Bam! Evidence that Auckland is too big...
The City of Sails is famed for its suburban sprawl - it has expanded to the point where there is now a non-trival chance of being hit by a passing chondrite.
As reported in the Sunday Star*Times:
Somehow the speeding fragment missed Mayor Banks ego.
UPDATE: The Archer's are evidently not geologists:
As reported in the Sunday Star*Times:
"'I was in the kitchen doing breakfast and there was this almighty explosion,' said Brenda Archer. 'It was like a bomb had gone off. I couldn't see anything, there was just dust. I thought something had exploded in the ceiling. Phil saw a stone under the computer and it was hot to touch.'"
Somehow the speeding fragment missed Mayor Banks ego.
UPDATE: The Archer's are evidently not geologists:
"Obviously it's a very rare thing to happen but it's just been a crazy reaction for a piece of rock," said Mr Archer.
Tuesday, June 08, 2004
Opportunity is dying!!!
Maybe.
Mars Exploration Rover-B reached Endurance Crater about a month ago - but has been sluggish since then. Despite more favorable environmental conditions than at the Spirit landing site, a balky heater is chewing up much Opportunity's energy budget. The drain on the batteries is threatening the rover's ability to ward off the effects of the daily 100?C freeze-thaw cycle. The first likely victim - the beamsplitter on the MiniTES spectrometer. There had been ambitious plans to roam Meridiani Planum before committing to a decision regarding Endurance Crater, visiting the pitchains and the heat shield. But there is no power left for such ambitious drives.
Today's press conference apparently brings the news that Opportunity will be going into the crater, to specifically sample the banded material that underlies the sulfate-hematite evaporite "cap" examined at the landing site.
There is a good chance that this is where the mission will end - although there is talk of keeping the rovers alive through to next year. (Funding will be another matter).
Mars Exploration Rover-B reached Endurance Crater about a month ago - but has been sluggish since then. Despite more favorable environmental conditions than at the Spirit landing site, a balky heater is chewing up much Opportunity's energy budget. The drain on the batteries is threatening the rover's ability to ward off the effects of the daily 100?C freeze-thaw cycle. The first likely victim - the beamsplitter on the MiniTES spectrometer. There had been ambitious plans to roam Meridiani Planum before committing to a decision regarding Endurance Crater, visiting the pitchains and the heat shield. But there is no power left for such ambitious drives.
Today's press conference apparently brings the news that Opportunity will be going into the crater, to specifically sample the banded material that underlies the sulfate-hematite evaporite "cap" examined at the landing site.
"'If we knew the rover was going to last for a year, we could run around and do other things before we went to the crater,' Squyres said in a telephone interview from the Jet Propulsion Laboratory. 'But that's not the case. Every day there's a falloff in efficiency.'
Opportunity has been scouting the crater for about a month, looking for the best way down and the shortest traverse to the lower layers of rock, but Wallace said the rover's limited electricity has sharply curtailed activity in recent days."
There is a good chance that this is where the mission will end - although there is talk of keeping the rovers alive through to next year. (Funding will be another matter).
Monday, June 07, 2004
A Messy Disintegration
0-2 to England. What a freaking miserable Test series by New Zealand. Although the close first test was a brilliant study in the refined tedium of Test Cricket, with extended innings of unrelentingly stunning boredom by batsmen Mark Richardson, Andy Strauss and the retiring Nassar Hussain, the problem was that the last two names belonged to England.
The second Test was catastropic however. Even though a day was lost to the rain gods, the Poms were able to wrap up the Kiwi's in less than four days. What was worse was the implosion of the New Zealand players themselves. And this after the hype of the first fully fit New Zealand team to tour Britain since the mighty Hadlee bestrode the earth. Secret weapon strike bowler Bond's spine failed to show up at Heathrow; batsmen Papps and McMillian have smashed pinkys; the Venerable Astle is having mysterious bouts of illness and the new big man Oram sides have given out. The captain has groin strain, and now Vettori's leg has apparently fallen off, robbing New Zealand of its only available spin-bowler.
The irony is that New Zealand's traditional human wreck, the old big man Chris Cairns, appears to perfectly fine for his last Test.
The second Test was catastropic however. Even though a day was lost to the rain gods, the Poms were able to wrap up the Kiwi's in less than four days. What was worse was the implosion of the New Zealand players themselves. And this after the hype of the first fully fit New Zealand team to tour Britain since the mighty Hadlee bestrode the earth. Secret weapon strike bowler Bond's spine failed to show up at Heathrow; batsmen Papps and McMillian have smashed pinkys; the Venerable Astle is having mysterious bouts of illness and the new big man Oram sides have given out. The captain has groin strain, and now Vettori's leg has apparently fallen off, robbing New Zealand of its only available spin-bowler.
The irony is that New Zealand's traditional human wreck, the old big man Chris Cairns, appears to perfectly fine for his last Test.
Caesar Rises
The Wall Street Journal discovers a Defence Department memo dating back to March last year, advising Don Rumsfeld how to get away with torture. Among such tasties as advising the Nuremberg defence ("I was only acting on orders!") is this statement:
Discussed at The Intel Dump , Billmon, and and Josh Marshall, who suggests there is a time and a place, but only if Caesar is prepared to burn afterward.
Old special forces type Ken White says his piece here.
"To protect subordinates should they be charged with torture, the memo advised that Mr. Bush issue a 'presidential directive or other writing' that could serve as evidence, since authority to set aside the laws is 'inherent in the president.'"
Discussed at The Intel Dump , Billmon, and and Josh Marshall, who suggests there is a time and a place, but only if Caesar is prepared to burn afterward.
Old special forces type Ken White says his piece here.
Sunday, June 06, 2004
Ronald Reagan 1911-2004
Point. Counterpoint.
And a surprising insightful remark here.
He was literate, self-depreciating and photogenic.
He was an ideologue who loathed ideologues, and an alleged enigma who liked people.
In late 1983 he nearly had the privilege of being the very last President of the United States. He (and everybody else) were lucky bastards.
He played a hawk with little concern for international niceties, whose greatest successes came with diplomacy and treaty-signing. His administration deliberately fueled genocidal blood-baths in central America, southern Africa, central Asia, and the Middle East. And he so hated the genocidal implications of Mutually Assured Destruction, that he tried to stuff the nuclear genie back in its lamp with expensive fantasy-and nearly succeeded. (Or maybe not.)
He also helped detonate the fiscal underpinnings of the United States. He stumbled on AIDS, and demonized welfare.
He traded with terrorists. He apologized for it.
He most likely meant well.
Point. Counterpoint.
And a surprising insightful remark here.
He was literate, self-depreciating and photogenic.
He was an ideologue who loathed ideologues, and an alleged enigma who liked people.
In late 1983 he nearly had the privilege of being the very last President of the United States. He (and everybody else) were lucky bastards.
He played a hawk with little concern for international niceties, whose greatest successes came with diplomacy and treaty-signing. His administration deliberately fueled genocidal blood-baths in central America, southern Africa, central Asia, and the Middle East. And he so hated the genocidal implications of Mutually Assured Destruction, that he tried to stuff the nuclear genie back in its lamp with expensive fantasy-and nearly succeeded. (Or maybe not.)
He also helped detonate the fiscal underpinnings of the United States. He stumbled on AIDS, and demonized welfare.
He traded with terrorists. He apologized for it.
He most likely meant well.