Tag: spaceflight

Philae’s status on the surface

8:55 am

European engineers have released an overall status update on Philae’s generally good condition after its landing on Comet 67P/C-G.

Later on 12 November, after analysing lander telemetry, the Lander Control Centre (in Cologne) and Philae Science, Operations and Navigation Centre (SONC, Toulouse) reported;There were three touchdowns at 15:34, 17:25 and 17:32 UTC; in other words, the lander bounced. The firing of the harpoons did not occur. The primary battery is working properly. The mass memory is working fine (all data acquired until lander loss of signal at 17:59 UTC were transmitted to the orbiter). Systems on board the lander recorded a rotation of the lander after the first touchdown. This is confirmed by ROMAP instrument data, which recorded a rotation around the Z-axis (vertical).

The lander did receive some power from the solar panels on Wall No. 2 (technical description of the lander’s solar walls here), but it appears that parts of the lander were in shadow during the time that last night’s surface telemetry were being transmitted.

An additional update here.

Philae is between a rock and a hard place. More specifically, it’s on its side, one leg sticking up in the air — and in the shadows of a looming crater wall a few meters away. Solar panels are receiving only about 1.5 hours of light a day, when the goal was for 6 or 7 hours per day to recharge the lander’s batteries. Drilling into the subsurface would have to wait until the very end of Philae’s 60 hours of battery life — for fear that it could upset the lander. Yet mission leaders were largely upbeat about being alive and doing science. Most of the lander’s 10 instruments were taking data, and engineers were exploring options to use the spring of the lander legs or other ground-poking instruments to jostle the lander into a more favorable position.

Even more here, including the first image from the surface.

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Philae might have bounced

4:07 pm

Data from the Philae lander suggests that, when the spacecraft’s harpoons failed to fire, the probe might have bounced and then settled to the surface.

[T]elemetry from the craft suggested it might have drifted off the surface after landing and started to turn. This subsequently came to an end, which the German Space Agency official interpreted as a possible “second landing” on Comet 67P. This “bounce” was always a possibility, but had been made more likely by the failure of the harpoons to deploy, and the failure of a thruster intended to push the robot into the surface.

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A comet picture taken by Philae on the way down

1:06 pm

Comet 67P/C-G as seen by Philae during its descent

I am not sure if the actual landing site is visible in this image. I don’t think so as nothing seems to match what was on the earlier close-up. Moreover, the Rosetta website does not say.

No images on the surface have yet been released. There are also issues that could prevent a full success.

However, while the lander has touched down on the comet using its harpoons, scientists said that it had not yet deployed its anchors which meant that it was not completely attached to the surface. The surface was much softer than they expected, so there were some concerns that it was not securely fixed on the comet – although from a software point of view things seemed to be fine. Engineers will attempt to fire the anchors again soon in order to keep Philae attached to the surface of the comet.

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Philae has landed successfully!

9:14 am

Philae has landed successfully on Comet 67P/C-G.

Philae is on the surface, its harpoons have fired and the landing gear has been moved inside, and Philae is in contact. It’s incredible! Massive smiles on everyone’s faces. The room went mad. Twice — when we first had the hint, and then when Stephan Ulamec and Andrea Accomazzo confirmed it. Unbelievable.

More information and data will be coming in a few hours. Stay tuned.

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Philae is go for separation, despite problem

12:25 am

Engineers have given a go for the separation of the Philae lander from Rosetta, despite the failure of a thruster to operate.

During checks on the lander’s health, it was discovered that the active descent system, which provides a thrust upwards to avoid rebound at the moment of touchdown, cannot be activated.

At touchdown, landing gear will absorb the forces of the landing while ice screws in each of the probe’s feet and a harpoon system will lock Philae to the surface. At the same time, the thruster on top of the lander is supposed to push it down to counteract the impulse of the harpoon imparted in the opposite direction. “The cold gas thruster on top of the lander does not appear to be working so we will have to rely fully on the harpoons at touchdown,”says Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center. “We’ll need some luck not to land on a boulder or a steep slope.”

Update: Separation has occurred and signal reacquired from Philae. We wait for landing.

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Close-up image of Philae’s landing site

9:32 am


Agilkia landing site for Philae

Inset of landing site

In the preparation to Wednesday’s landing of Philae on Comet 67P/C-G, Rosetta’s science team has released a great image of the landing site, shown above. To the right is a higher resolution inset of the site itself, with the smallest object visible about 8.5 feet across.

Looking at this inset, there are some obvious worries that we all should be aware of prior to the landing attempt. Though the Agilkia landing site is generally more smooth than most of the comet’s surface, it still has significant hazards. The lower part is strewn with boulders and rocks, many of which are quite large. Any one of these could do serious harm to Philae should it land on them.

Even more interesting is the upper part of the landing site. Though very smooth, the image suggests to me that this is a very thick pile of softly packed material. Philae might land there and quickly sink below the surface, where its cameras will be able to see nothing.

Nonetheless, the science team has also released this outline of Philae’s science timeline after landing. The lander will also be taking images of both Rosetta and the comet during its descent, so even if the landing is a failure we will still get some worthwhile data.

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Comet Siding Spring’s fly-by of Mars changed the planet’s atmosphere

8:57 am

Data obtained by the various Mars orbiters during the close fly-by of Comet Siding Spring of Mars has revealed that the comet created a new temporary layer in the planet’s atmosphere.

The European Space Agency’s Mars Express spacecraft detected an increase in electrons in Mars’ upper atmosphere, partly ionising it. This was attributed to fine cometary dust penetrating the atmosphere, which led to a meteor storm of thousands of meteors per hour. The increase in electrons led to the creation of a temporary new layer of charged particles in the ionosphere, which runs from an altitude of 120 kilometres to several hundred kilometres above. This is the first time such an event has been seen, even on Earth the extra density of electrons was measured to be five to ten times higher than normal by NASA’s Mars Reconnaissance Orbiter. Another NASA spacecraft, MAVEN, which also observed the new layer in the ionosphere, will monitor for any long-term events as it goes about its regular duties of studying Mars’ atmosphere.

MAVEN’s Imaging Ultraviolet Spectrograph was able to ascertain the species of ions that flooded into the ionosphere from the comet, the first time a comet that has come direct from the distant Oort Cloud has been sampled in this way. It detected the signal of magnesium, iron and sodium ions following the meteor shower, a signal that dominated Mars’ ultraviolet spectrum for hours afterwards, taking two days to dissipate.

The chemistry that MAVEN detected appears superficially somewhat similar to the chemistry that Rosetta is detecting at Comet 67P/C-G, though there are differences.

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China’s struggle to compete with SpaceX

8:41 am

This Aviation Week story provides a detailed update on China’s effort to build a new family of Long March rockets that are less expensive to operate and can effectively compete with SpaceX.

Two main take-aways from the article. First, the first flight of the Long March 7, a direct competitor with the Falcon 9, has been seriously delayed. Originally expected to fly in 2013, that first flight has apparently been pushed back to 2015.

Second, even with extensive cost savings, the Long March 7 will still cost a customer more than a Falcon 9, $70 million vs $61 million.

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Alternative rockets and 2015 launch dates for Cygnus

8:54 am

The heat of competition: Orbital Sciences has pinpointed available launch slots and alternative rockets for getting Cygnus into orbit in 2015.

[Orbital CEO David] Thompson said Wednesday the company has narrowed its options to three launch providers which have openings as early as the second quarter — between April 1 and June 30 — of next year. Two of the launch providers are based in the United States. Orbital could also launch Cygnus missions with a European-based company, Thompson said. The contractors under consideration are presumably United Launch Alliance, SpaceX and Arianespace.

Unlike Virgin Galactic’s claims in my previous post, I find Thompson’s prediction here quite likely. His main problem is not technical but political. He has to convince his competitors to help him, and this story is his first shot across the bow in that negotiation. By making these facts public, Thompson applies pressure on these other companies to agree. And though the request is unstated, he is also enlisting NASA’s aid, since the agency is certain to back him in this negotiation and apply its clout in his favor.

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Virgin Galactic vows to fly again by April

8:34 am

The heat of competition: During a press tour of its Mojave facilities this week Virgin Galactic’s CEO revealed that the company expects to begin flying its replacement to SpaceShipTwo by April.

George Whitesides, the company’s chief executive, said construction of the second spaceship is already 65 per cent complete. Like its doomed predecessor, Enterprise, the new spaceship’s name is a tribute to both Nasa and Star Trek. It will be called SS Voyager, the Sunday Times reports.

Whitesides also said that LauncherOne, designed to put very small payloads into orbit, is 18 months away from its first flight.

I hope this predictions are true, but coming from Virgin Galactic I think I can be forgiven if I am very skeptical. Nonetheless, in referring to the new ship I will make it a policy to call it Voyager from here on out to distinguish it from the first ship.

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Bringing Dream Chaser home

9:47 am

The competition heats up: At an space industry conference this week Sierra Nevada outlined the ability of Dream Chaser to land at almost any airport, including the many financial and safety advantages of that flexibility.

The story notes that because Dream Chaser would not need an unusually long runway, it could land at most airports. Also, because it would have no hazardous materials on board, removing it from the runway after landing would be simple and straightforward. You would simply tow it away. The biggest advantage of this, howevr, is that if the spacecraft was docked at ISS and there was an emergency that required immediate evacuation, bringing Dream Chaser and its passengers home to a runway will be possible any time.

This presentation is part of Sierra Nevada’s sales effort to find new backers for their spacecraft, now that NASA has begged out. I think they make a good sales pitch. I hope someone with money agrees.

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The November 12 timeline of events for Philae’s landing on a comet

10:16 am

ESA has released a detailed timeline of events on November 11-12, when Rosetta’s Philae lander will be released and land on Comet 67P/C-G. They have also released a much more readable summary of the most critical events, describing what will be happening.

For Americans, these events will be occurring from around 3 pm (Eastern) November 11, when the process begins, to 12 pm (Eastern) November 12, when Philae will send back the first signals after landing. Much of the most critical events will take place in the wee hours of the morning.

Meanwhile, one of Rosetta’s instruments has confirmed the presence of water vapor and carbon dioxide in the jets seen near the comet’s narrow neck.

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Orion heat shield redesigned before its launch?

9:59 am

Even before Orion’s first flight next month to test its heat shield, engineers are proposing a major change in the shield’s design and manufacture.

The Orion heat shield’s titanium skeleton and carbon fiber skin was fabricated by Lockheed Martin — the craft’s prime contractor — in Colorado. The skeleton was shipped to Textron Defense Systems in Massachusetts for installation of a fiberglass-phenolic honeycomb structure. More than 330,000 individual cells make up the honeycomb, and Textron technicians — using a special dispensing gun — filled the cells by hand with a material called Avcoat. The Avcoat insulation is supposed to ablate away during the Orion spacecraft’s re-entry, protecting the underlying structure from searing temperatures. The Apollo moon capsule used the same type of manually-applied material for its heat shield, and it worked so well Lockheed Martin and NASA decided to dust off the design.

Engineers scaled up the heat shield for the Orion crew capsule, which is about four feet wider at its base than the Apollo command module. “That’s what worked for Apollo, and that’s what we’ll work with for this mission,” Bray said, referring to the EFT-1 launch in December.

But a review of the heat shield on the Orion spacecraft set for launch Dec. 4 revealed the Avcoat was slightly more uneven than expected, according to Jim Bray, crew module director at Lockheed Martin, Orion’s prime contractor.

It also appears that it is too expensive to build the shield by hand, as it was done during Apollo. Instead, they intend to build future heat shields as single blocks assembled not by hand but by machine.

This is another example of why SLS/Orion is an incredible money black hole. What is the point of next month’s test flight of the heat shield if the shield they are testing is not going to be used on future flights?

Meanwhile, the press (apparently ignorant and uninformed about this subject and brainwashed by a NASA Orion press event) is filled with numerous stories claiming that this test flight is NASA’s first step to getting to Mars. What hogwash.

I especially like this quote from the space.com article:

On Dec. 4, NASA officials are expected to launch the Orion spacecraft on its first test flight, putting the capsule through its paces in space before it splashes down in the Pacific Ocean. The goal of the flight is to see how some key Orion systems — like its huge heat shield and parachutes — work before launching humans into deep space sometime in the future. [emphasis mine]

Yet, most of the heat shield test data obtained by this test flight will be worthless and inapplicable to future Orion capsules. In other words, this test flight is, as I said, hogwash, a public relations stunt to sell Orion to Congress and to uneducated reporters. It is also an enormous waste of taxpayer money and the limited resources NASA has.

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Solid rocket motors for American rockets?

9:34 am

The competition heats up: Even as ULA and Blue Origin begin work building an American engine to replace the Russian engines on the Atlas 5 rocket, ATK is offering its solid rocket motors for both Atlas 5 as well as Antares.

The company’s sales pitch is that they can get their product ready faster and cheaper. And since they are merging with Orbital Sciences anyway, I will not be at all surprised if Antares ends up with ATK solid rocket motors for its first stage.

As for Atlas 5, this sales pitch is actually aimed at Congress, which could step in and force ULA to buy ATK motors instead of Blue Origin’s new engine, even if this switch is against the wishes of ULA. As foolish as this might seem, the politics of pork (ATK provides more jobs than Blue Origin) could make it happen.

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A pause in investment commitment to Virgin Galactic

9:19 am

The heat of competition: Virgin Galactic’s Arab investors have decided to hold off further commitment to the project until the investigation of the SpaceShipTwo crash is completed.

The backing of deep-pocketed Aabar Investments, run by the Abu Dhabi government, may be crucial to Virgin Galactic as it struggles to recover from the accident, which killed one test pilot and left another seriously injured. “As an investor, Aabar is concerned of course. It is a challenge – nothing can be decided until investigations are over,” the source said, declining to be named because of the sensitivity of the subject. “For now, it is a wait-and-watch situation.” Asked if Aabar was still committed to Virgin Galactic, the source said only: “There is time to make an assessment of the future strategy.”

This is hardly a surprise. Nor does it guarantee an end to Richard Branson’s company. What it signals is a recognition that Virgin Galactic has had a serious problem and must demonstrate that it can fix that problem before it will regain the trust of its investors.

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Second SpaceShipTwo almost ready for flight

8:32 am

The heat of competition: Virgin Galactic today released hanger photos of the almost finished second SpaceShipTwo.

Even as the investigation into the fatal breakup of Virgin Galactic’s SpaceShipTwo rocket plane continues in Mojave, California, the next SpaceShipTwo is more than halfway complete in a Mojave hangar — and is expected to start going through tests on the ground and in the air next year.

Virgin Galactic’s manufacturing subsidiary, The Spaceship Company, has been working on the plane for two and a half years. It’s variously known as SpaceShipTwo Tail No. 2 or N202VG, and it’s part of Virgin Galactic plan to have a fleet of five SpaceShipTwo rocket planes and two WhiteKnightTwo carrier planes.

This story is a great example of the public relations genius of Richard Branson. Even with the pieces of SpaceShipTwo still being picked up on the ground he finds a way to sell his company positively to the world. They not only intend to continue their effort, they have the ship to prove it!

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Turbopump failure in first stage engine eyed for the Antares launch failure

8:14 am

The investigation into the launch failure of the Antares rocket one week ago is now focusing on the turbopump in one of the rocket’s first stage engines.

“The Investigation Board (AIB) is making good progress in determining the primary cause of last week’s failure. A preliminary review of telemetry and video data has been conducted and substantial debris from the Antares rocket and its Cygnus payload has been collected and examined,” noted Orbital on Wednesday. “While the work of the AIB continues, preliminary evidence and analysis conducted to date points to a probable turbopump-related failure in one of the two Aerojet Rocketdyne AJ26 stage one main engines. As a result, the use of these engines for the Antares vehicle likely will be discontinued.”

It was later noted that the AJ-26 could still be used if they were proven to be completely flight-worthy.

If Orbital Sciences decides to completely cease using the Russian engines, it could mean a very significant delay before they can launch again, maybe several years. If they do that, I expect them to face contract penalties from NASA for the failure to deliver cargo to ISS on a reasonable schedule. It will also mean that their chances of winning a second contract will go down significantly.

They need to replace the engine, but they also need to keep launching. The article as well as a company press release today describes how they are exploring other launch vehicles, including the Falcon 9, to launch Cygnus, but I see no reason for them to completely abandon the Russian engines immediately. What they need to do is find what failed, fix it in the remaining engines, and keep flying while they scramble hard to replace the engine entirely.

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A geological score for Curiosity!

10:25 pm

Spectroscopy from Curiosity’s most recent drilling has been found to match and thus confirm the spectroscopy of the same spot taken years ago from orbit.

In observations reported in 2010, before selection of Curiosity’s landing site, a mineral-mapping instrument on NASA’s Mars Reconnaissance Orbiter provided evidence of hematite in the geological unit that includes the Pahrump Hills outcrop. The landing site is inside Gale Crater, an impact basin about 96 miles (154 kilometers) in diameter with the layered Mount Sharp rising about three miles (five kilometers) high in the center.

“We’ve reached the part of the crater where we have the mineralogical information that was important in selection of Gale Crater as the landing site,” said Ralph Milliken of Brown University, Providence, Rhode Island. He is a member of Curiosity’s science team and was lead author of that 2010 report in Geophysical Research Letters identifying minerals based on observations of lower Mount Sharp by the orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). “We’re now on a path where the orbital data can help us predict what minerals we’ll find and make good choices about where to drill. Analyses like these will help us place rover-scale observations into the broader geologic history of Gale that we see from orbital data.”

This is a significant finding. Not only does this data now prove that the orbital data is correct, it demonstrates that scientists can now use that orbital data to direct Curiosity to even more interesting geological surface features. In fact, this ground-based data will help them calibrate all their orbital data more precisely, thus making our geological knowledge of Mars more accurate and reliable.

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Update on SpaceShipTwo investigation

8:20 am

Additional details about the investigation into the crash of SpaceShipTwo have now been released.

The investigators are focusing on the telemetry that the pilots were receiving, as well as the system for activating the ship’s braking feathering system.

As I have noted in the comments, we must try not to speculate on this subject, especially because this issue could do harm to innocent people. For example, some reports have incorrectly attributed the crash to pilot error. To say this now is false. All the investigation has noted is that the co-pilot took the first step to activating the feathering system, as he was supposed to do, though slightly early. The feathering system then deployed on its own, without the second command being given.

We do not yet know the finer details that make his action significant, or not. This is why the investigation is checking into the telemetry the pilots were getting, which might have affected when they did what they did.

We need to wait for more data.

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Some Virgin Galactic customers demand money back

5:22 pm

News reports suggest that — following last week’s SpaceShipTwo crash — more than thirty of the seven hundred people who placed deposits with Virgin Galactic to fly on SpaceshipTwo have pulled out, demanding their money back.

In response to the claim that more than 30 customers are considering their position in the aftermath of the crash, a spokesperson for Virgin Galactic admitted a number of people have asked for their money back. “We can confirm that less than three per cent of people have requested refunds,” the spokesman said.

This is not a surprise, nor should it be. A company can only survive a crisis like this by responding honestly, quickly, and directly. If Virgin Galactic does this, finding the cause of the crash and fixing it, they will likely hold onto most of their customers. If they don’t, those remaining customers will leave. This week’s cancellations are the first immediate response to the crash. The future of the company, however, will be determined by what happens in the next six months.

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SpaceShipTwo’s engine did not cause failure

8:39 am

The investigation into the failure of SpaceShipTwo last week during a powered flight test has determined that the accident was not caused by the spaceship’s engine and that the spaceship’s feathering system for return to Earth began deploying early during powered flight.

The ship’s fuel tanks and its engine were recovered intact, indicating there was no explosion. “They showed no signs of burn-through, no signs of being breached,” Christopher Hart, acting chairman of the National Transportation and Safety Board, told reporters at the Mojave Air and Space Port in Mojave, Calif

Instead, data and video relayed from the ship show its hallmark safety feature — a foldable tail section designed for easy re-entry into the atmosphere from space — was deployed early.

More here. Deployment required two commands, activation and then deployment. Data shows that the co-pilot Michael Alsbury activated the system slightly early. The second command, however, was not given, but the feathering system began to deploy nonetheless, during powered flight when the ship was accelerating upward. That is when the ship broke up.

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