SpaceX CRS-16 Landing Failure

Yesterday, 2018-12-05, SpaceX successfully launched a Dragon spacecraft from Cape Canaveral to deliver more than 2500 kg of cargo to the International Space Station (ISS).  The Dragon spacecraft (apart from its disposable “trunk” section) was previously flown on the CRS-10 mission to the ISS in February 2017.  The Falcon 9 booster was new, on its first flight.  Here is a video of the launch, starting at 15 seconds before liftoff through deployment of the Dragon’s solar panels.

The primary mission was delivery of the Dragon to an orbit to rendezvous with the ISS, and was entirely successful.  SpaceX intended to recover the first stage booster for subsequent re-use (it is a “Block 5” model, designed to fly as many as ten times with minimal refurbishment between launches) back at the landing zone at Cape Canaveral.  This involves, after separating the second stage, flipping the first stage around, firing three engines in a boost-back burn to cancel its downrange velocity and direct it back toward the Cape, a three engine re-entry burn to reduce its velocity before it enters the dense atmosphere, and a single engine landing burn to touch down.

Everything went well with the landing through the re-entry burn.  As the first stage encountered the atmosphere, it began to roll out of control around its long axis.  The “grid fins” which extend from the first stage to provide aerodynamic control, were not observed to move as they should to counter the roll moment.  As the roll began to go all Kerbal, the feed from the first stage was cut in the SpaceX launch coverage in the video above.

In the post-launch press conference, Hans Koenigsmann, Vice President of Build and Flight Reliability at SpaceX, showed a video which picks up at the moment the feed was cut and continues through the first stage’s landing off the coast of Cape Canaveral.  He describes how the safety systems deliberately target a water landing and only shift the landing point to the landing pad (or drone ship) once confident everything is working as intended.

Here is a video taken from the shore which shows the final phase of the first stage’s braking and water landing.  Note how the spin was arrested at the last instant before touchdown.

In this video, Everyday Astronaut Tim Dodd explains the first stage recovery sequence and what appears to have gone wrong, based upon tweets from Elon Musk after the landing.

After splashing down, the first stage completed all of its safing procedures, allowing a recovery ship to approach it and tow it back to port.  SpaceX has said it will be inspected and, if judged undamaged by the water landing, may be re-flown on a SpaceX in-house mission (but not for a paying customer).

The most likely cause of the accident is failure of the hydraulic pump that powers the grid fins.  In the present design, there is only one pump, so there is no redundancy.  This may be changed to include a second pump, so a single pump failure can be tolerated.

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Saturday Night Science: Apollo 8 Fifty Years Ago

Apollo 8 EarthriseAs the tumultuous year 1968 drew to a close, NASA faced a serious problem with the Apollo project. The Apollo missions had been carefully planned to test the Saturn V booster rocket and spacecraft (Command/Service Module [CSM] and Lunar Module [LM]) in a series of increasingly ambitious missions, first in low Earth orbit (where an immediate return to Earth was possible in case of problems), then in an elliptical Earth orbit which would exercise the on-board guidance and navigation systems, followed by lunar orbit, and finally proceeding to the first manned lunar landing. The Saturn V had been tested in two unmanned “A” missions: Apollo 4 in November 1967 and Apollo 6 in April 1968. Apollo 5 was a “B” mission, launched on a smaller Saturn 1B booster in January 1968, to test an unmanned early model of the Lunar Module in low Earth orbit, primarily to verify the operation of its engines and separation of the descent and ascent stages. Apollo 7, launched in October 1968 on a Saturn 1B, was the first manned flight of the Command and Service modules and tested them in low Earth orbit for almost 11 days in a “C” mission.

Apollo 8 was planned to be the “D” mission, in which the Saturn V, in its first manned flight, would launch the Command/Service and Lunar modules into low Earth orbit, where the crew, commanded by Gemini veteran James McDivitt, would simulate the maneuvers of a lunar landing mission closer to home. McDivitt’s crew was trained and ready to go in December 1968. Unfortunately, the lunar module wasn’t. The lunar module scheduled for Apollo 8, LM-3, had been delivered to the Kennedy Space Center in June of 1968, but was, to put things mildly, a mess. Testing at the Cape discovered more than a hundred serious defects, and by August it was clear that there was no way LM-3 would be ready for a flight in 1968. In fact, it would probably slip to February or March 1969. This, in turn, would push the planned “E” mission, for which the crew of commander Frank Borman, command module pilot James Lovell, and lunar module pilot William Anders were training, aimed at testing the Command/Service and Lunar modules in an elliptical Earth orbit venturing as far as 7400 km from the planet and originally planned for March 1969, three months later, to June, delaying all subsequent planned missions and placing the goal of landing before the end of 1969 at risk.

But NASA were not just racing the clock—they were also racing the Soviet Union. Unlike Apollo, the Soviet space program was highly secretive and NASA had to go on whatever scraps of information they could glean from Soviet publications, the intelligence community, and independent tracking of Soviet launches and spacecraft in flight. There were, in fact, two Soviet manned lunar programmes running in parallel. The first, internally called the Soyuz 7K-L1 but dubbed “Zond” for public consumption, used a modified version of the Soyuz spacecraft launched on a Proton booster and was intended to carry two cosmonauts on a fly-by mission around the Moon. The craft would fly out to the Moon, use its gravity to swing around the far side, and return to Earth. The Zond lacked the propulsion capability to enter lunar orbit. Still, success would allow the Soviets to claim the milestone of first manned mission to the Moon. In September 1968 Zond 5 successfully followed this mission profile and safely returned a crew cabin containing tortoises, mealworms, flies, and plants to Earth after their loop around the Moon. A U.S. Navy destroyer observed recovery of the re-entry capsule in the Indian Ocean. Clearly, this was preparation for a manned mission which might occur on any lunar launch window.

(The Soviet manned lunar landing project was actually far behind Apollo, and would not launch its N1 booster on that first, disastrous, test flight until February 1969. But NASA did not know this in 1968.) Every slip in the Apollo program increased the probability of its being scooped so close to the finish line by a successful Zond flyby mission.

These were the circumstances in August 1968 when what amounted to a cabal of senior NASA managers including George Low, Chris Kraft, Bob Gilruth, and later joined by Wernher von Braun and chief astronaut Deke Slayton, began working on an alternative. They plotted in secret, beneath the radar and unbeknownst to NASA administrator Jim Webb and his deputy for manned space flight, George Mueller, who were both out of the country, attending an international conference in Vienna. What they were proposing was breathtaking in its ambition and risk. They envisioned taking Frank Borman’s crew, originally scheduled for Apollo 9, and putting them into an accelerated training program to launch on the Saturn V and Apollo spacecraft currently scheduled for Apollo 8. They would launch without a Lunar Module, and hence be unable to land on the Moon or test that spacecraft. The original idea was to perform a Zond-like flyby, but this was quickly revised to include going into orbit around the Moon, just as a landing mission would do. This would allow retiring the risk of many aspects of the full landing mission much earlier in the program than originally scheduled, and would also allow collection of precision data on the lunar gravitational field and high resolution photography of candidate landing sites to aid in planning subsequent missions. The lunar orbital mission would accomplish all the goals of the originally planned “E” mission and more, allowing that mission to be cancelled and therefore not requiring an additional booster and spacecraft.

But could it be done? There were a multitude of requirements, all daunting. Borman’s crew, training toward a launch in early 1969 on an Earth orbit mission, would have to complete training for the first lunar mission in just sixteen weeks. The Saturn V booster, which suffered multiple near-catastrophic engine failures in its second flight on Apollo 6, would have to be cleared for its first manned flight. Software for the on-board guidance computer and for Mission Control would have to be written, tested, debugged, and certified for a lunar mission many months earlier than previously scheduled. A flight plan for the lunar orbital mission would have to be written from scratch and then tested and trained in simulations with Mission Control and the astronauts in the loop. The decision to fly Borman’s crew instead of McDivitt’s was to avoid wasting the extensive training the latter crew had undergone in LM systems and operations by assigning them to a mission without an LM. McDivitt concurred with this choice: while it might be nice to be among the first humans to see the far side of the Moon with his own eyes, for a test pilot the highest responsibility and honour is to command the first flight of a new vehicle (the LM), and he would rather skip the Moon mission and fly later than lose that opportunity. If the plan were approved, Apollo 8 would become the lunar orbit mission and the Earth orbit test of the LM would be re-designated Apollo 9 and fly whenever the LM was ready.

While a successful lunar orbital mission on Apollo 8 would demonstrate many aspects of a full lunar landing mission, it would also involve formidable risks. The Saturn V, making only its third flight, was coming off a very bad outing in Apollo 6 whose failures might have injured the crew, damaged the spacecraft hardware, and precluded a successful mission to the Moon. While fixes for each of these problems had been implemented, they had never been tested in flight, and there was always the possibility of new problems not previously seen.

The Apollo Command and Service modules, which would take them to the Moon, had not yet flown a manned mission and would not until Apollo 7, scheduled for October 1968. Even if Apollo 7 were a complete success (which was considered a prerequisite for proceeding), Apollo 8 would be only the second manned flight of the Apollo spacecraft, and the crew would have to rely upon the functioning of its power generation, propulsion, and life support systems for a mission lasting six days. Unlike an Earth orbit mission, if something goes wrong en route to or returning from the Moon, you can’t just come home immediately. The Service Propulsion System on the Service Module would have to work perfectly when leaving lunar orbit or the crew would be marooned forever or crash on the Moon. It would only have been tested previously in one manned mission and there was no backup (although the single engine did incorporate substantial redundancy in its design).

The spacecraft guidance, navigation, and control system and its Apollo Guidance Computer hardware and software, upon which the crew would have to rely to navigate to and from the Moon, including the critical engine burns to enter and leave lunar orbit while behind the Moon and out of touch with Mission Control, had never been tested beyond Earth orbit.

The mission would go to the Moon without a Lunar Module. If a problem developed en route to the Moon which disabled the Service Module (as would happen to Apollo 13 in April 1970), there would be no LM to serve as a lifeboat and the crew would be doomed.

When the high-ranking conspirators presented their audacious plan to their bosses, the reaction was immediate. Manned spaceflight chief Mueller immediately said, “Can’t do that! That’s craziness!” His boss, administrator James Webb, said “You try to change the entire direction of the program while I’m out of the country?” Mutiny is a strong word, but this seemed to verge upon it. Still, Webb and Mueller agreed to meet with the lunar cabal in Houston on August 22. After a contentious meeting, Webb agreed to proceed with the plan and to present it to President Johnson, who was almost certain to approve it, having great confidence in Webb’s management of NASA. The mission was on.

It was only then that Borman and his crewmembers Lovell and Anders learned of their reassignment. While Anders was disappointed at the prospect of being the Lunar Module Pilot on a mission with no Lunar Module, the prospect of being on the first flight to the Moon and entrusted with observation and photography of lunar landing sites more than made up for it. They plunged into an accelerated training program to get ready for the mission.

NASA approached the mission with its usual “can-do” approach and public confidence, but everybody involved was acutely aware of the risks that were being taken. Susan Borman, Frank’s wife, privately asked Chris Kraft, director of Flight Operations and part of the group who advocated sending Apollo 8 to the Moon, with a reputation as a plain-talking straight shooter, “I really want to know what you think their chances are of coming home.” Kraft responded, “You really mean that, don’t you?” “Yes,” she replied, “and you know I do.” Kraft answered, “Okay. How’s fifty-fifty?” Those within the circle, including the crew, knew what they were biting off.

The launch was scheduled for December 21, 1968. Everybody would be working through Christmas, including the twelve ships and thousands of sailors in the recovery fleet, but lunar launch windows are set by the constraints of celestial mechanics, not human holidays. In November, the Soviets had flown Zond 6, and it had demonstrated the “double dip” re-entry trajectory required for human lunar missions. There were two system failures which killed the animal test subjects on board, but these were covered up and the mission heralded as a great success. From what NASA knew, it was entirely possible the next launch would be with cosmonauts bound for the Moon.

Space launches were exceptional public events in the 1960s, and the first flight of men to the Moon, just about a hundred years after Jules Verne envisioned three men setting out for the Moon from central Florida in a “cylindro-conical projectile” in De la terre à la lune (From the Earth to the Moon), similarly engaging the world, the launch of Apollo 8 attracted around a quarter of a million people to watch the spectacle in person and hundreds of millions watching on television both in North America and around the globe, thanks to the newfangled technology of communication satellites.  Let’s tune in to CBS television and relive this singular event with Walter Cronkite.  (For one of those incomprehensible reasons in the Internet of Trash, this video, for which YouTube will happily generate an embed code, fails to embed in WordPress.  You’ll have to click the link below to view it.)

CBS coverage of the Apollo 8 launch

Now we step inside Mission Control and listen in on the Flight Director’s audio loop during the launch, illustrated with imagery and simulations.

The Saturn V performed almost flawlessly. During the second stage burn mild pogo oscillations began but, rather than progressing to the point where they almost tore the rocket apart as had happened on the previous Saturn V launch, von Braun’s team’s fixes kicked in and seconds later Borman reported, “Pogo’s damping out.” A few minutes later Apollo 8 was in Earth orbit.

Jim Lovell had sixteen days of spaceflight experience across two Gemini missions, one of them Gemini 7 where he endured almost two weeks in orbit with Frank Borman. Bill Anders was a rookie, on his first space flight. Now weightless, all three were experiencing a spacecraft nothing like the cramped Mercury and Gemini capsules which you put on as much as boarded. The Apollo command module had an interior volume of six cubic metres (218 cubic feet, in the quaint way NASA reckons things) which may not seem like much for a crew of three, but in weightlessness, with every bit of space accessible and usable, felt quite roomy. There were five real windows, not the tiny portholes of Gemini, and plenty of space to move from one to another.

With all this roominess and mobility came potential hazards, some verging on slapstick, but, in space, serious nonetheless. NASA safety personnel had required the astronauts to wear life vests over their space suits during the launch just in case the Saturn V malfunctioned and they ended up in the ocean. While moving around the cabin to get to the navigation station after reaching orbit, Lovell, who like the others hadn’t yet removed his life vest, snagged its activation tab on a strut within the cabin and it instantly inflated. Lovell looked ridiculous and the situation comical, but it was no laughing matter. The life vests were inflated with carbon dioxide which, if released in the cabin, would pollute their breathing air and removal would use up part of a CO₂ scrubber cartridge, of which they had a limited supply on board. Lovell finally figured out what to do. After being helped out of the vest, he took it down to the urine dump station in the lower equipment bay and vented it into a reservoir which could be dumped out into space. One problem solved, but in space you never know what the next surprise might be.

The astronauts wouldn’t have much time to admire the Earth through those big windows. Over Australia, just short of three hours after launch, they would re-light the engine on the third stage of the Saturn V for the “trans-lunar injection” (TLI) burn of 318 seconds, which would accelerate the spacecraft to just slightly less than escape velocity, raising its apogee so it would be captured by the Moon’s gravity. After housekeeping (presumably including the rest of the crew taking off those pesky life jackets, since there weren’t any wet oceans where they were going) and reconfiguring the spacecraft and its computer for the maneuver, they got the call from Houston, “You are go for TLI.” They were bound for the Moon.

The third stage, which had failed to re-light on its last outing, worked as advertised this time, with a flawless burn. Its job was done; from here on the astronauts and spacecraft were on their own. The booster had placed them on a free-return trajectory. If they did nothing (apart from minor “trajectory correction maneuvers” easily accomplished by the spacecraft’s thrusters) they would fly out to the Moon, swing around its far side, and use its gravity to slingshot back to the Earth (as Lovell would do two years later when he commanded Apollo 13, although there the crew had to use the engine of the LM to get back onto a free-return trajectory after the accident).

Apollo 8 rapidly climbed out of the Earth’s gravity well, trading speed for altitude, and before long the astronauts beheld a spectacle no human eyes had glimpsed before: an entire hemisphere of Earth at once, floating in the inky black void. On board, there were other concerns: Frank Borman was puking his guts out and having difficulties with the other end of the tubing as well. Borman had logged more than six thousand flight hours in his career as a fighter and test pilot, most of it in high-performance jet aircraft, and fourteen days in space on Gemini 7 without any motion sickness. Many people feel queasy when they experience weightlessness the first time, but this was something entirely different and new in the American space program. And it was very worrisome. The astronauts discussed the problem on private tapes they could downlink to Mission Control without broadcasting to the public, and when NASA got around to playing the tapes, the chief flight surgeon, Dr. Charles Berry, became alarmed.

As he saw it, there were three possibilities: motion sickness, a virus of some kind, or radiation sickness. On its way to the Moon, Apollo 8 passed directly through the Van Allen radiation belts, spending two hours in this high radiation environment, the first humans to do so. The total radiation dose was estimated as roughly the same as one would receive from a chest X-ray, but the composition of the radiation was different and the exposure was over an extended time, so nobody could be sure it was safe. The fact that Lovell and Anders had experienced no symptoms argued against the radiation explanation. Berry concluded that a virus was the most probable cause and, based upon the mission rules said, “I’m recommending that we consider canceling the mission.” The risk of proceeding with the commander unable to keep food down and possibly carrying a virus which the other astronauts might contract was too great in his opinion. This recommendation was passed up to the crew. Borman, usually calm and collected even by astronaut standards, exclaimed, “What? That is pure, unadulterated horseshit.” The mission would proceed, and within a day his stomach had settled.

This was the first case of space adaptation syndrome to afflict an American astronaut. (Apparently some Soviet cosmonauts had been affected, but this was covered up to preserve their image as invincible exemplars of the New Soviet Man.) It is now known to affect around a third of people experiencing weightlessness in environments large enough to move around, and spontaneously clears up in two to four (miserable) days.

The two most dramatic and critical events in Apollo 8’s voyage would occur on the far side of the Moon, with 3500 km of rock between the spacecraft and the Earth totally cutting off all communications. The crew would be on their own, aided by the computer and guidance system and calculations performed on the Earth and sent up before passing behind the Moon. The first would be lunar orbit insertion (LOI), scheduled for 69 hours and 8 minutes after launch. The big Service Propulsion System (SPS) engine (it was so big—twice as large as required for Apollo missions as flown—because it was designed to be able to launch the entire Apollo spacecraft from the Moon if a “direct ascent” mission mode had been selected) would burn for exactly four minutes and seven seconds to bend the spacecraft’s trajectory around the Moon into a closed orbit around that world.

If the SPS failed to fire for the LOI burn, it would be a huge disappointment but survivable. Apollo 8 would simply continue on its free-return trajectory, swing around the Moon, and fall back to Earth where it would perform a normal re-entry and splashdown. But if the engine fired and cut off too soon, the spacecraft would be placed into an orbit which would not return them to Earth, marooning the crew in space to die when their supplies ran out. If it burned just a little too long, the spacecraft’s trajectory would intersect the surface of the Moon—lithobraking is no way to land on the Moon.

When the SPS engine shut down precisely on time and the computer confirmed the velocity change of the burn and orbital parameters, the three astronauts were elated, but they were the only people in the solar system aware of the success. Apollo 8 was still behind the Moon, cut off from communications. The first clue Mission Control would have of the success or failure of the burn would be when Apollo 8’s telemetry signal was reacquired as it swung around the limb of the Moon. If too early, it meant the burn had failed and the spacecraft was coming back to Earth; that moment passed with no signal. Now tension mounted as the clock ticked off the seconds to the time expected for a successful burn. If that time came and went with no word from Apollo 8, it would be a really bad day. Just on time, the telemetry signal locked up and Jim Lovell reported, “Go ahead, Houston, this is Apollo 8. Burn complete. Our orbit 160.9 by 60.5.” (Lovell was using NASA’s preferred measure of nautical miles; in proper units it was 311 by 112 km. The orbit would subsequently be circularised by another SPS burn to 112.7 by 114.7 km.) The Mission Control room erupted into an un-NASA-like pandemonium of cheering.

Apollo 8 would orbit the Moon ten times, spending twenty hours in a retrograde orbit with an inclination of 12 degrees to the lunar equator, which would allow it to perform high-resolution photography of candidate sites for early landing missions under lighting conditions similar to those expected at the time of landing. In addition, precision tracking of the spacecraft’s trajectory in lunar orbit would allow mapping of the Moon’s gravitational field, including the “mascons” which perturb the orbits of objects in low lunar orbits and would be important for longer duration Apollo orbital missions in the future.

During the mission, the crew were treated to amazing sights and, in particular, the dramatic difference between the near side, with its many flat “seas”, and the rugged highlands of the far side. Coming around the Moon they saw the spectacle of earthrise for the first time and, hastily grabbing a magazine of colour film and setting aside the planned photography schedule, Bill Anders snapped the photo of the Earth rising above the lunar horizon which became one of the most iconic photographs of the twentieth century. Here is a reconstruction of the moment that photo was taken.

On the ninth and next-to-last orbit, the crew conducted a second television transmission which was broadcast worldwide. It was Christmas Eve on much of the Earth, and, coming at the end of the chaotic, turbulent, and often tragic year of 1968, it was a magical event, remembered fondly by almost everybody who witnessed it and felt pride for what the human species had just accomplished.

You have probably heard this broadcast from the Moon, often with the audio overlaid on imagery of the Moon from later missions, with much higher resolution than was actually seen in that broadcast. Here, in three parts, is what people, including this scrivener, actually saw on their televisions that enchanted night. The famous reading from Genesis is in the third part. This description is eerily similar to that in Jules Verne’s 1870 Autour de la lune.

After the end of the broadcast, it was time to prepare for the next and absolutely crucial maneuver, also performed on the far side of the Moon: trans-Earth injection, or TEI. This would boost the spacecraft out of lunar orbit and send it back on a trajectory to Earth. This time the SPS engine had to work, and perfectly. If it failed to fire, the crew would be trapped in orbit around the Moon with no hope of rescue. If it cut off too soon or burned too long, or the spacecraft was pointed in the wrong direction when it fired, Apollo 8 would miss the Earth and orbit forever far from its home planet or come in too steep and burn up when it hit the atmosphere. Once again the tension rose to a high pitch in Mission Control as the clock counted down to the two fateful times: this time they’d hear from the spacecraft earlier if it was on its way home and later or not at all if things had gone tragically awry. Exactly when expected, the telemetry screens came to life and a second later Jim Lovell called, “Houston, Apollo 8. Please be informed there is a Santa Claus.”

Now it was just a matter of falling the 375,000 kilometres from the Moon, hitting the precise re-entry corridor in the Earth’s atmosphere, executing the intricate “double dip” re-entry trajectory, and splashing down near the aircraft carrier which would retrieve the Command Module and crew. Earlier unmanned tests gave confidence it would all work, but this was the first time men would be trying it.

There was some unexpected and embarrassing excitement on the way home. Mission Control had called up a new set of co-ordinates for the “barbecue roll” which the spacecraft executed to even out temperature. Lovell was asked to enter “verb 3723, noun 501” into the computer. But, weary and short on sleep, he fat-fingered the commands and entered “verb 37, noun 01”. This told the computer the spacecraft was back on the launch pad, pointing straight up, and it immediately slewed to what it thought was that orientation. Lovell quickly figured out what he’d done, “It was my goof”, but by this time he’d “lost the platform”: the stable reference the guidance system used to determine in which direction the spacecraft was pointing in space. He had to perform a manual alignment, taking sightings on a number of stars, to recover the correct orientation of the stable platform. This was completely unplanned but, as it happens, in doing so Lovell acquired experience that would prove valuable when he had to perform the same operation in much more dire circumstances on Apollo 13 after an explosion disabled the computer and guidance system in the Command Module. Here is the author of the book, Jeffrey Kluger, discussing Jim Lovell’s goof.

The re-entry went completely as planned, flown entirely under computer control, with the spacecraft splashing into the Pacific Ocean just 6 km from the aircraft carrier Yorktown. But because the splashdown occurred before dawn, it was decided to wait until the sky brightened to recover the crew and spacecraft. Forty-three minutes after splashdown, divers from the Yorktown arrived at the scene, and forty-five minutes after that the crew was back on the ship. Apollo 8 was over, a total success. This milestone in the space race had been won definitively by the U.S., and shortly thereafter the Soviets abandoned their Zond circumlunar project, judging it an anticlimax and admission of defeat to fly by the Moon after the Americans had already successfully orbited it.

This is the official NASA contemporary documentary about Apollo 8.

Here is an evening with the Apollo 8 astronauts recorded at the National Air and Space Museum on 2008-11-13 to commemorate the fortieth anniversary of the flight.

This is a reunion of the Apollo 8 astronauts on 2009-04-23.

As of this writing, all of the crew of Apollo 8 are alive, and, in a business where divorce was common, remain married to the women they wed as young military officers.

Kluger, Jeffrey. Apollo 8. New York: Picador, 2017. ISBN 978-1-250-18251-7.


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Seven Minutes of Terror

NASA Mars InSight landingNASA’s Mars InSight lander is now approaching the Red Planet and will attempt to land later today.  Here is a timeline of events during the entry, descent, and landing (EDL) phase if everything goes as planned (adapted from the NASA/JPL “Landing Milestones” page).  All times are in Universal Time (UTC), which you can see in the title bar at the top of the Ratburger page.

  • 19:40 UTC – Separation from the cruise stage that carried the mission to Mars
  • 19:41 UTC – Turn to orient the spacecraft properly for atmospheric entry
  • 19:47 UTC – Atmospheric entry at about 19,800 kilometres per hour, beginning the entry, descent and landing phase
  • 19:49 a.m.UTC – Peak heating of the protective heat shield reaches about 1,500 °C
  • 15 seconds later – Peak deceleration, with the intense heating causing possible temporary dropouts in radio signals
  • 19:51 UTC – Parachute deployment
  • 15 seconds later – Separation from the heat shield
  • 10 seconds later – Deployment of the lander’s three legs
  • 19:52 UTC- Activation of the radar that will sense the distance to the ground
  • 19:53 UTC – First acquisition of the radar signal
  • 20 seconds later – Separation from the back shell and parachute
  • 0.5 second later – The retrorockets, or descent engines, begin firing
  • 2.5 seconds later – Start of the “gravity turn” to get the lander into the proper orientation for landing
  • 22 seconds later – InSight begins slowing to a constant velocity (from 27 km/h to a constant 8 km/h) for its soft landing
  • 19:54 UTC – Expected touchdown on the surface of Mars
  • 20:01 UTC- “Beep” from InSight’s X-band radio directly back to Earth, indicating InSight is alive and functioning on the surface of Mars
  • No earlier than 20:04 UTC, but possibly the next day – First image from InSight on the surface of Mars

Here is a description of the entry, descent, and landing phase.

You can watch live coverage of InSight’s arrival at Mars starting at 18:30 UTC on:

Here is the Landing Day – 1 press briefing.

Two CubeSats called MarCO-A and B are shadowing InSight’s path.  They are the first CubeSats launched on an interplanetary trajectory.  If successful, they will provide a real-time communications link between the lander and Earth.  They are not, however, required for a successful landing.  If they fail, information on the landing may be delayed until it can be relayed by another spacecraft orbiting Mars.  After doing their job, the MarCO CubeSats will fly by Mars and continue to orbit the Sun for billions of years, just like Elon Musk’s roadster.  Here is a video about the MarCO mission.

Here are more details about MarCO.

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Soyuz MS-10 Launch Failure

At 08:40 UTC on 2018-10-11, Soyuz MS-10 launched toward the International Space Station with a crew of two on board: Commander Aleksey Ovchinin of the Russian Space Agency and Flight Engineer Nick Hague of NASA.

Shortly after the separation of the four first stage boosters, around two minutes into the flight, Russian mission control began to report “failure”.  The animation shown on NASA TV continued to show a nominal mission.  There were several additional reports of failure, including the time.

Shortly thereafter, Ovchinin reported a ballistic re-entry had been selected, and then that they were weightless.  Then, he reported G forces building to 6.5 (consistent with a steep ballistic re-entry), and then declining to something over two [I think 2.5 or 2.7, but I do not have a recording], which would indicate having passed through the peak of re-entry braking.

There have been no reports from the crew since then.  Russian mission control reports that recovery helicopters have been dispatched to the predicted landing zone, and are expected to take around 90 minutes to arrive.  The launch was on a northeast azimuth, so landing would be  expected to be in northern Russia.

After a long delay (presumably because the descent capsule had passed over the horizon from the tracking stations), rescue forces reported that they had contacted the crew by radio.  The crew reported that they had landed and were in good condition.

I will add updates in the comments as events unfold.

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This Week’s Book Review – Blue Collar Space

I write a weekly book review for the Daily News of Galveston County. (It is not the biggest daily newspaper in Texas, but it is the oldest.) My review normally appears Wednesdays. When it appears, I post the review here on the following Sunday.

Book Review

Everyday jobs turn wondrous in ‘Blue Collar Space’

By MARK LARDAS

July 18, 2018

“Blue Collar Space,” by Martin Shoemaker, Old Town Books, 2018, 244 pages, $11.99

What will it be like when humans are living and working in space? Ordinary folk, like those who live down your street?

“Blue Collar Space,” by Martin Shoemaker offers one vision. It is a collection of short science fiction stories set on the moon and Mars, and Jupiter orbit.

The settings are exotic. The jobs are ordinary. EMTs, sanitation workers, teachers, doctors, factory workers and miners feature in these stories. A few stories fall into the category of space adventure. “Not Close Enough” deals with a first manned mission to Mars — sort of a first manned mission to Mars. The explorers from NASA, ESA, Roscosmos, JAXA, and space agencies from India, Australia and China are not allowed closer to Mars’ surface than Martian orbit. There is a sort of spy adventure in the short story “Black Orbit,” with smugglers and secret agents.

Yet most deal with life and work of an everyday sort; dirty jobs in a space setting. A rescue team is sent to assist crash survivors in “Scramble.” A young girl must find help for her injured father — on the surface of the moon — in “Father-Daughter Outing.” The complexities of running a sanitation system on a lunar city gets explored in “The Night We Flushed the Old Town.” A children’s survival class instructor on Mars has to figure out how to fix things when something goes wrong in “Snack Break.” A moon prospector grapples with the discovery that starring in a moon-based kiddie show really is significant in “A Sense of Wonder.”

It is not dull. Shoemaker shows the adventure in doing things that on Earth are ordinary when they must be done in a hostile environment like space. Being on a spaceship, a space station, or surface of the moon and Mars changes things. He writes with a crisp and engaging style that draws readers into the tale. The result is fascinating reading.

“Blue Collar Space” captures what life will really be like when we finally get off Earth and move into space. It will be commonplace, yet at the same time it will be wonder filled.

 Mark Lardas, an engineer, freelance writer, amateur historian, and model-maker, lives in League City. His website is marklardas.com.


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Forty-nine Years Ago Today…

…men from Planet Earth set foot upon another world.

Will you celebrate?

Perhaps, next year, on the 50th anniversary, we should host a global celebration synchronised with the events half a century before.

(I have defined “today” using the conventional date of 1969-07-20 in my local time zone.  The actual landing occurred at 20:18:04 UTC on 1969-07-20 and the first footstep on the Moon was at 02:56:15 UTC on 1969-07-21.)


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TOTD 2018-06-05: First to Fly in Space Twice

Puzzle: Yuri Gagarin was the first person to fly in space.  Who was the first person to fly in space twice?

For the purposes of this puzzle, I adopt the definition of space flight used by the Fédération Aéronautique Interationale (FAI) and NASA: flight above the Kármán line, which is by convention defined as 100 km (330,000 feet or 62 miles) above sea level.  This is the altitude where the Earth’s mean atmosphere becomes sufficiently thin that a winged vehicle would have to be travelling at orbital velocity or greater to develop sufficient lift to support its weight.

Please don’t just type this question into a search engine.  That’s no fun and the odds are many of the results you’ll get will be wrong.

I’ll identify the first correct answer in the comments or, if nobody gets it, post the answer in a spoiler block to-morrow.


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This Week’s Book Review – Ignition!: An Informal History of Liquid Propellants

I write a weekly book review for the Daily News of Galveston County. (It is not the biggest daily newspaper in Texas, but it is the oldest.) My review normally appears Wednesdays. When it appears, I post the review here on the following Sunday.

Seawriter

Book Review

‘Ignition!’ explores the ‘golden age’ of rocketry

By MARK LARDAS

May 22, 2018

Ignition!: An Informal History of Liquid Propellants,” by John D. Clark, Rutgers University Press Classics, 2018, 302 pages, $24.95

Today, rocket science commonly refers to anything dealing with space. Originally, it meant rocket design, especially fuel development.

“Ignition!: An Informal History of Liquid Propellants,” by John D. Clark, harks back to those day. While informal, it is a comprehensive account of rocket fuel development.

In “Ignition!” Clark reveals what went on behind the scenes in the early days of rocketry. He was the perfect man to do so. A pioneer rocket scientist, an active chemist from the early 1930s, between 1949 and 1970 he was one of the leading developers of liquid rocket fuels. A talented writer (publishing science fiction in 1930) he knew all the players, inside and outside the United States.

Clark shows what made rocket science challenging is not that it is difficult. It is that rocket fuels are very finicky. Do anything wrong and the rocket does not go whoosh. It goes boom.

Clark shows all the ways they go boom. He explains what makes a good rocket fuel, shows readers what works and shows readers what does not work and why. He starts with Tsiolkovsky in the late 1800s, and ending with the Saturn V and the moon missions in the late 1960s.

His focus is on the golden age of rocket fuel development, from 1946 through 1961. Those years saw development of the liquid fuels still used in rockets today, with a lot of dead ends. Clark spends chapters on the dead ends, such as peroxide fuels and monopropellants. Frequently those chapters are books’ most entertaining.

There is chemistry involved, including formidable chemical equations. Readers unfamiliar with chemistry should skip them. They are for the chemistry geeks reading the book. Between the equations are what makes the book entertaining; the technician attacked by bats after a fuel test, the propellant developer who took a year off to develop hula hoops and many similar stories.

“Ignition!,” originally written in 1972, is back in print after a long hiatus. A classic book, it tells a rollicking story of an era when space was the frontier. An informative history, it reads like an adventure story.

Mark Lardas, an engineer, freelance writer, amateur historian, and model-maker, lives in League City. His website is marklardas.com.


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TOTD 2018-03-18: “You Will Not Go to Space Today”

Words by Scott Manley, music and performance by Skye Manley.

You can’t do rocket science (or engineering) without acronyms and jargon, so here’s a list of those used in the video.

There’s one goof: “the day they launched the escape tower” was Mercury-Redstone 1, not Mercury-Atlas 1, which failed for other reasons.


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Falcon Heavy

SpaceX Falcon Heavy

The first launch of SpaceX’s Falcon Heavy is currently scheduled for Tuesday, 2018-02-06, with a two and a half hour launch window which opens at 18:30 UTC and closes at 21:00 UTC (since this is a test flight which need not enter a precise orbit, the launch time is not critical).  If the launch is postponed, the same launch window will be used on successive days, subject to availability of the range.  The Sunday weather forecast predicts 80% probability of favourable conditions for launch during the Tuesday window.

Falcon Heavy consists of three first stage cores derived from the existing Falcon 9 first stage.  The centre core is specially strengthened to accommodate the structural loads of the boosters and heavier payload, and to attach the two side boosters, which are slightly modified Falcon 9 first stages (in fact, the two boosters to be used on this flight have previously flown on SpaceX Falcon 9 missions).  The three cores ignite simultaneously on the launch pad, with a total of 27 Merlin 1D engines, nine on each core, providing liftoff thrust of 22,819 kN (5.13 million pounds of thrust).  This compares to the 34,000 kN thrust of the Saturn V moon rocket, and 30,255 for the Space Shuttle (main engines plus solid rocket boosters).

But what matters isn’t thrust, but rather a launcher’s ability to deliver payload to where the customer wants it.  Here, the Falcon Heavy, if it works, will become the heaviest lift launcher in service.  Here, I’ll compare payload to low Earth orbit (LEO), since that’s the fairest comparison of launchers: regardless of the ultimate destination, any rocket must first achieve orbital velocity.  The Saturn V could put 140 tonnes into LEO, while the Space Shuttle had a maximum payload of 24.4 tonnes (the reusable orbiter itself weighed 78 tonnes, but does not count as payload).  Falcon Heavy can launch 63.8 tonnes to LEO, more than twice the payload of its closest competitor, the Delta IV Heavy (28.79 tonnes).  Russia’s Proton M+ has a payload capacity of 23 tonnes, while the European Ariane 5 can deliver 21 tonnes to LEO.

This test flight will not carry a payload for a customer.  Many things which can only be tested in flight, particularly the structural loads and aerodynamics of the three core first stage at max Q and separation of the two side boosters from the core (which runs at reduced thrust from shortly after liftoff until separation, and then throttles up to full thrust for the remainder of its burn), and customers who require this kind of lift capability aren’t likely to risk their payloads on a first flight.  Instead, Falcon Heavy will be carrying a car.

Falcon Heavy payload

This is Elon Musk’s Tesla Roadster with its Starman test dummy on board, attached to the Falcon Heavy payload adapter.  It will be enclosed in the payload fairing for launch and, if the mission is successful, injected into an orbit around the Sun which will venture as far from the Sun as the orbit of Mars (but will not approach the planet).  The payload serves only as a mass simulator, but has a lot more style than the usual steel or tungsten dummy payload carried on inaugural flights of other launchers.

The three first stage cores are intended to be recovered.  After separating from the centre core, the two side boosters will return to the landing zone at Cape Canaveral for near-simultaneous landings.  The centre core will fly downrange and land on the drone ship in the Atlantic.

The second stage is identical to that of the Falcon 9.  Once the side boosters separate, a Falcon Heavy mission is essentially identical to that of Falcon 9; the white knuckle part will be from liftoff through booster separation.

You can watch a live webcast of the launch attempt on the SpaceX Web site.  Coverage usually starts  around 20 minutes before the scheduled launch time.


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Rocket Lab: Second Privately-Financed Launch Provider Makes Orbit

Earlier today, Rocket Lab successfully launched an Electron rocket into orbit from their launch site on the Mahia Peninsula of the north island of New Zealand.  Here is video of the final countdown and flight.

The Electron is a “smallsat” launcher with a maximum payload capacity of 225 kg to low Earth orbit, with the ability to place 150 kg in a 500 km Sun-synchronous orbit.  The launcher uses Rocket Lab’s Rutherford engines: nine in the first stage and one with a vacuum nozzle extension in the second stage.  The engines are largely produced by additive manufacturing (“3D printing”) and are designed for high volume and low cost production.  Uniquely among current rocket engines, fuel is pumped into the combustion chamber by an electric pump powered by a lithium polymer battery.  This increases the efficiency of the engine from the 50% typical of gas generator cycle engines to around 95% without the plumber’s nightmare complexity and propensity to explode of staged combustion designs.

On this flight, the Electron carried three small satellites for two customers.  Previously, most small satellites were launched as piggyback or ride-sharing payloads on launches of other satellites, which constrained the small satellite operators to use the same orbits and operate on the schedule of the primary payload.  Rocket Lab hopes to provide responsive launch to whatever orbit the customer requires.  Launch costs are quoted as less than US$ 6 million for a dedicated launch, lower than any other current launch provider.  The initial goal is to support up to fifty launches per year, with the ability to grow to one hundred if demand emerges.  This isn’t quite a rocket a day, but it’s a step in that direction.


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The Zuma Mystery

Zuma (spacecraft) mission patchEarly Monday, January 8th, at 01:00 UTC (20:00 EST on January 7th at the launch site in Florida), SpaceX launched a spacecraft identified only as “Zuma”.  This mission has been a mystery since word of it first became public, and the mystery appears to have just deepened even more.

In October 2017, SpaceX filed paperwork with the Federal Communications Commission requesting permission for a “Mission 1390”.  This was unusual, as no mission for the range of dates requested appeared on the SpaceX mission manifest statement.  A few days later, several sources reported that the flight would launch a payload built by Northrop Grumman for the U.S. government.  A Northrop Grumman spokesman confirmed this, but said nothing further about the payload or its government customer.  This is already unusual: classified payloads launched by the Air Force or the National Reconnaissance Office are usually identified by at least the name of the contracting agency.  All that is known about this payload is that the customer is an unnamed part of the U.S. government.

Further, the intended orbit, which was not disclosed but which can be inferred from the launch site and azimuth which were disclosed as part of the range’s announcement of the exclusion area for ships and aircraft, was odd.  Most spy satellites launch into polar orbit from California, or to geostationary orbit from Florida.  But this satellite was headed to low Earth orbit inclined around 51 degrees to the equator—curious.

The flight was scheduled for November, 2017, and after several delays, on November 17th it was announced the flight was postponed while data on a fairing (the nose cone which encapsulates the payload during ascent through the Earth’s atmosphere) test performed for another customer were reviewed.  Then it was announced that the launch attempt would stand down indefinitely, with no reason given.  Launches for other customers, some of which used a payload fairing, continued nonetheless.

The mission was then announced to be launched in early January from the newly-refurbished Launch Complex 40.  After additional postponements, the mission was launched on the night of January 7/8, 2018.  As is usual for launches of secret payloads, the SpaceX launch webcast ceased coverage of the mission after separation of the second stage, and showed only the landing of the first stage.  Here is the complete webcast; the launch occurs at the 13 minute mark.

Everything appeared to go normally, including a successful landing of the first stage.

Then, yesterday, several sources reported that the mission had failed, some saying that the spacecraft had failed to separate from the second stage, and/or the combined second stage and spacecraft had fallen to Earth (presumably to burn up in the atmosphere).  Well, these things happen.  But then a SpaceX spokesperson said, “We do not comment on missions of this nature; but as of right now reviews of the data indicate Falcon 9 performed nominally.”  If the rocket performed nominally (as planned), then the second stage and satellite would be in orbit, whether they separated or not.

Yet another unusual aspect of this mission is that unlike most SpaceX missions, where SpaceX provides the interface between the satellite and the launcher and is responsible for separation of the satellite when it reaches the intended orbit, in this case it had been disclosed that the payload adapter had been developed and provided by Northrop Grumman.  This raises the possibility that it is the adapter which failed, which would be consistent with the SpaceX statement that the Falcon 9 performed successfully, since if the satellite failed to separate, that would be Northrop Grumman’s responsibility, not theirs.  SpaceX has not announced postponement of other Falcon 9 missions on its manifest, as would be expected after a mission failure due to their hardware.

But again, failure of the satellite to separate would still leave it in orbit.  Did it actually go into orbit, and if so, what happened subsequently?  More enigmas…the National Space Science Data Center (NSSDC), a part of NASA, assigned the satellite the COSPAR designation 2018-001A, but released no orbital elements, which is routine for classified missions.  But NSSDC does not assign designations to objects which failed to achieve orbit.  Does this mean it did make orbit?  Hard to tell: the object is now missing from the NSSDC catalogue.  The US Strategic Command, which operates the Space Surveillance Network, added the object to its catalogue as USA 280, using the numeric designation customary for secret satellites.  That usually means the object completed at least one orbit.  But Strategic Command now says there is “nothing to add to the satellite catalog at this time”.  What does that mean?  Was USA 280 added by error, or is there nothing to add to its entry?  They aren’t saying.

It may be conceivable that, if the satellite failed to separate from the second stage, it used its on-board propulsion to de-orbit the combined satellite and stage.  That would be consistent with the SpaceX statement, the entry into the orbital catalogues, and the report that the object fell to Earth.  Since nothing is known about the satellite and its capabilities, this is pure speculation.

In cases such as these, amateur sky watchers often provide clues as to what is going on, but an object in the expected orbit is presently positioned poorly with respect to the Sun for optical observation.

In summary: a secret satellite from an undisclosed government agency, launched after numerous delays into an unusual orbit, which may or may not have failed, and may or may not be in two separate catalogues of objects in orbit.  Which the launch contractor says their rocket performed nominally and the satellite contractor isn’t talking.

Let the speculation begin!


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