SpaceX Launches Iridium NEXT-2, Lands Offshore and Pulls Off 'Double-Header' Weekend

The Upgraded Falcon 9 thunders downrange in the first minutes of Sunday afternoon’s flight. Photo Credit: SpaceX/Twitter

With Sunday’s spectacular launch-and-landing of an Upgraded Falcon 9 from Vandenberg Air Force Base, Calif., almost a quarter of all of SpaceX’s missions have flown in 2017 alone. Nine launches in the first six months of the calendar year establishes a new “personal best” for the Hawthorne, Calif.-headquartered organization, which previously achieved eight flights in 2016 and six fully successful missions in 2015 and 2014 apiece. SpaceX has long insisted that it aims to launch its Upgraded Falcon 9s at intervals of around two weeks—a boast which, by and large, it has accomplished in 2017—but this weekend also offered a unique “double-header” for CEO Elon Musk, coming a mere 48 hours after Friday’s successful BulgariaSat-1 launch. It also secured another record for SpaceX, which has now launched three missions in the span of a single calendar month.

“We are once again proud to support another successful launch of Iridium NEXT,” said Air Force Col. Michael S. Hough, who witnessed his first launch since taking over as 30th Space Wing Commander at Vandenberg, earlier this month. “This launch is a perfect demonstration of the high level of teamwork and precision that exists between Team Vandenberg and SpaceX.”

Today’s flight—which left Earth at the start (and end) of an “instantaneous” launch window at 1:25:18 p.m. PDT—represented only the fourth outing by a SpaceX vehicle from Space Launch Complex (SLC)-4E at mountain-ringed Vandenberg on the United States’ west coast. Eight minutes later, its first stage plunged back to Earth and alighted smoothly on the deck of the Autonomous Spaceport Drone Ship (ASDS), nicknamed “Just Read the Instructions”, positioned offshore in the Pacific Ocean. The mission was tasked with delivering a second set of ten Iridium NEXT communications satellites into low-Earth orbit, following on the heels of lofting an inaugural “batch” in January 2017. In doing so, SpaceX would fulfil the second segment of a seven-year-old contract which should see it deliver 75 Iridium NEXT birds into orbit by mid-2018.

When the details for this mammoth contract were agreed between SpaceX and Iridium, back in June 2010, it marked the largest single launch deal ever signed, worth an estimated $492 million. Over the next few months, Iridium NEXT will completely replace an aging network of its first-generation satellites, whose earliest members were launched two decades ago. In June 2010, the second-generation Iridium NEXT system was unveiled, with Thales Alenia Space and its subcontractor Orbital Sciences Corp. (later Orbital ATK) selected to build dozens of operational satellites and on-orbit and ground-based spares.

The second batch of Iridium NEXT satellites are encapsulated within the bulbous payload fairing of the Upgraded Falcon 9. Photo Credit: Iridium

Iridium NEXT is based upon the Extended LifeTime Bus (ELiTeBus)-1000 spacecraft design, previously employed for low-orbiting GlobalStar communications satellites. Weighing around 1,760 pounds (800 kg), they are powered by twin solar arrays and capable of supporting a decade-long lifespan. The solar arrays—spanning 31 feet (9.4 meters) when fully unfurled and capable of generating 2 kilowatts of electricity—would offer a 50-percent uplift over the power-producing potential of the first-generation Iridiums.

SpaceX was originally expected to deliver 70 Iridium NEXT satellites into orbit, spread across seven missions by its Upgraded Falcon 9. The first flight occurred in January and successfully placed ten satellites into low-Earth orbit, with an expectation that the next mission would occur in April, followed by the remainder at roughly two-month intervals. However, on 31 January Iridium announced that it would benefit from a “rideshare” arrangement, flying another five spare satellites on another Upgraded Falcon 9, carrying NASA’s Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission in early 2018. All told, it is expected that SpaceX vehicles will transport no fewer than 75 Iridium NEXT satellites into space. Launch of the second batch was initially targeted for mid-April 2017, but in February a delay of two months was announced.

By the beginning of May, the initial ten satellites completed a rigorous testing and validation process and had been fully integrated into the Iridium on-orbit constellation. “We are deploying the largest satellite constellation and the world and it works,” exulted Bertrand Maureau, executive vice president of telecommunications at Thales Alenia Space. “We met challenges that were unprecedented in the space sector, in terms of end-to-end system performance and production rate.”

As SpaceX’s launch cadence improved during the first few months of 2017, an initial target date of 29 June was announced for the second Iridium NEXT batch. By the third week of May, Iridium CEO Matt Desch revealed that the first pair of satellites for the launch—as well as the first stage of the Upgraded Falcon 9 itself—were en-route to Vandenberg. On the 25th, Mr. Desch noted that the second stage of the rocket had arrived at the West Coast launch site and that four of the Iridium NEXT satellites were deep into processing. At the same time, he revealed that the “instantaneous” launch was being brought forward to 1:25:18 p.m. PDT on 25 June, due to the opening of Western Range availability.

With SpaceX’s launch of the CRS-11 Dragon cargo mission correspondingly moved into the first week of June, and the high-energy BulgariaSat-1 also slated for June, this promised the tantalizing possibility that (for the first time) as many as three Falcons might fly in a single calendar month.

“We’re excited for this next launch,” said Mr. Desch in an Iridium press release. “Satellites have already started to arrive at the launch site and are undergoing pre-launchg preparations, so we’ll be ready to go. An earlier launch date is all the better for our constellation deployment plans.” By 6 June, all ten satellites were on-site at Vandenberg, mated to their specialized dispenser, with fueling about to commence. A week later, fueling was complete and the Iridium batch was encapsulated inside the bulbous payload fairing of the Upgraded Falcon 9. However, following last September’s on-the-pad explosion of Amos-6, customers’ payloads are now installed after the customary Static Fire Test of the nine Merlin 1D+ engines of the first stage.

This firing took place on Tuesday, 20 June, after which the booster was returned to a horizontal configuration and the Iridium NEXT batch was installed. “Static fire a success,” tweeted Mr. Desch. “Weekend VAFB weather looks benign so far as well, so we’re on track for a Sunday launch.” That same day, Iridium Corp. itself tweeted that all ten of its satellites were “locked and loaded” for launch. Late on Saturday, SpaceX released an image of the 230-foot-tall (70-meter) Falcon 9, only hours away from its fourth flight out of Vandenberg Air Force Base. The west coast site was previously used for the launch of Canada’s CASSIOPE science mission in September 2013, followed by NASA’s Jason-3 ocean altimetry spacecraft in January 2016 and most recently the first batch of Iridium NEXT satellites in January 2017.

With Sunday’s successful mission, a total of 20 Iridium NEXT satellites are now in low-Earth orbit. Photo Credit: Iridium/Twitter

Weather conditions at Vandenberg were predicted to be 100-percent favorable, with the 30th Space Wing anticipating the presence of low shallow stratus clouds and fog during the final phase of Sunday’s countdown. “By T-0, the marine layer will have broken out, the stratus will be clearing out and visibility restrictions lifted,” it was noted in an L-2 weather briefing on Friday. “The overall POV [Probability of Violation] will be 0% with no constraints of concern.” This was expected to remain favorable in the event of a 24-hour slip to the backup launch opportunity on Monday.

Due to the requirements of the Iridium NEXT payload, Sunday’s launch window was an “instantaneous” one, timed for 1:25:18 p.m. PDT, with no margin to accommodate last-minute technical issues. Any slip would almost certainly trigger a scrub and a minimum 24-hour recycle of the countdown.

Aiming for the bullseye, the SpaceX team pressed into Sunday with the effort to gets its personal-best-beating ninth Upgraded Falcon 9 of the year off the pad. Fueling of the booster with a highly refined form of rocket-grade kerosene (known as “RP-1”) got underway about one hour before T-0. Shortly thereafter, at 35 minutes before launch, liquid oxygen began flowing into the tanks. Unfortunately, hopes that Vandenberg’s fog would lift proved unfounded and the booster remained virtually shrouded in the gloom.

At 1:15 p.m. PDT, with ten minutes remaining before T-0, the terminal countdown autosequencer was initiated. The nine Merlin 1D+ first-stage engines, arranged in a circle of eight, with a ninth at the centre, were chilled, ahead of ignition, and the Flight Termination System (FTS) was placed onto internal power and armed. In the final minutes, the Upgraded Falcon 9 transitioned to internal power and the Iridium NEXT payload was powered-up, with the vehicle assuming primary command of all critical functions—entering “Startup”—at T-60 seconds. At the same time, the pad deluge system began to flood the SLC-4E surface with water to reduce the reflected energy at liftoff.

Three seconds before launch, the nine Merlin 1D+ engines roared to life, kicking out a combined thrust of 1.5 million pounds (680,000 kg). The vehicle departed SLC-4E precisely on the opening (and closure) of Sunday’s launch window, on the stroke of 1:25 p.m. PDT. Climbing smoothly into the fog, the booster performed with characteristic perfection, passing maximum aerodynamic turbulence (“Max Q”) at 70 seconds. Two-and-a-half minutes into ascent, the first stage was jettisoned, beginning a complex sequence of maneuvers to bring it back through the “sensible” atmosphere to alight on the deck of SpaceX’s West Coast-based drone ship, “Just Read the Instructions”.

The drone ship had been drawn out to sea from Port of Los Angeles by the NRC Quest cargo vessel on Saturday morning, bound for a position about 186 miles (300 km) off the California coastline. Shortly after the separation, the first stage deployed its four hypersonic grid fins, configured in an “X-wing” layout, which for this mission are of a noticeably modified design.

Dual-frame image of the second stage burning to deliver the Iridium NEXT satellites to orbit (at right) and the first stage executing its final descent to land on the drone ship. Photo Credit: SpaceX/Twitter

“Flying with larger & significantly upgraded hypersonic grid fins,” explained SpaceX CEO Elon Musk in a recent tweet. “Single-piece cast & cut titanium. Can take re-entry heat with no shielding.” In a subsequent tweet, Mr. Musk noted that the fins are unpainted, since they would glow red-hot during their hypersonic re-entry. “Trying these things out for the first time today,” added former NASA astronaut Garrett Reisman, who now serves as SpaceX’s head of crew operations.

To accomplish a precise touchdown on the drone ship, the Upgraded Falcon 9’s first stage “flipped” itself, assisted by on-board nitrogen-fed thrusters, and executed Entry and Landing burns to incrementally slow it down, initially to about 560 mph (900 km/h) and finally to a touchdown velocity of 4.5 mph (7.2. km/h). However, conditions were anticipated to be less than optimum, due to weather conditions near the ASDS. “Drone ship repositioned due to extreme weather,” Mr. Musk tweeted, shortly before launch. “Will be tight.” Tightness aside, the first stage headed smoothly back through the “sensible” atmosphere and alighted on the deck at 1:32 p.m., a mere seven minutes and 45 seconds after leaving SLC-4E. “New titanium grid fins worked even better than expected,” tweeted Mr. Musk. “Should be capable of an indefinite number of flights with no service.”

In the meantime, the primary goal of today’s mission continued. Following the departure of the Upgraded Falcon 9’s first stage, the Merlin 1D+ Vacuum engine of the second stage ignited and burned for more than 5.5 minutes, shutting down a little over nine minutes after launch. At this point, the vehicle entered a prolonged period of “coasting”, lasting almost three-quarters of an hour, until the Merlin 1D+ Vacuum was lit a second time to position the Iridium NEXT group of satellites for deployment into an orbit about 390 miles (625 km) above Earth. By this point, the vehicle was moving in excess of 16,700 mph (27,100 km/h).

Fifty-two minutes after leaving Vandenberg, the second stage fell silent for the last time, allowing for the 15-minute deployment process to get underway, with each satellite departing at 100-second intervals. The tenth Iridium departed the second stage approximately 71 minutes after leaving Vandenberg Air Force Base. SpaceX has now successfully transported more than a quarter of its 75-strong Iridium NEXT tally to orbit. Current plans envisage the next load of ten satellites to fly in August and the remainder to follow at approximately two-month intervals thereafter.



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102 comments to SpaceX Launches Iridium NEXT-2, Lands Offshore and Pulls Off ‘Double-Header’ Weekend

  • Ho um, another day, another carnival freak show by the billionaire hobby rocket, covered by the brainless media for the SpaceX fanboys.
    Coming soon, the first launch (kaboom no doubt) of the monstrosity Heavy. [link]


    • Vladislaw

      Ya it is most be a real pain to see an American company bringing launch business back to the United States and launching 11 commercial satellites in one weekend.

    • Richard Malcolm

      Like Paul Spudis, I favor a sustained return to cislunar space, rather than Mars.

      Unlike Paul Spudis, I do not suffer from a terminal case of Musk Derangement Syndrome.

      It boggles the mind that people can still see SpaceX’s successes as a detriment to the long-term exploration and economic development of space.

    • Tracy the Troll

      Regarding Paul Spudis,

      He lives in the Apollo era of NASA budget funding or present day funding of a $500 Billion per year…This guys are always living in the past.

    • roflplatypus

      I would like the honor to have replied to Mr. Church in a thread. Isn’t the FH the sort of SHLV you’ve wanted? And don’t forget the ITS can go to the moon too….

      • Richard Malcolm

        Gary does not seem willing to settle for anything less than something on the scale of the SLS Block 2. Launched 8 to 10 times a year, of course.

        It may be unfair to hold him to the fire on ITS until it moves beyond the PowerPoint stage. Falcon Heavy, on the other hand, should be a live reality in 4Q of this year.

        • I think for BLEO missions, it’s instructive to look at payload capabilities of heavy-lift launchers.

          Let’s start with payload. Without a cryo second-stage, what is the FH BLEO payload capability? What is that of the SLS Blk 1 (ICPS), 1A (UPS), and 2?

          Until the FH cryogenic second stage has been completed, its BLEO payload capability ties, or just falls-short of, those of a Delta IV Heavy or Atlas 551, doesn’t it?

          • Chris

            Jim, there is no cryo second stage for FH. There is no need for it. FH without it can hit all necessary mission segments (Commercial, NASA and USAF/NRO) short of H-BLEO. For H-BLEO that will rely on some variation of BFR/BFS. FH is a stop gap until that time. Today F9 block III booster and block IV upper can demonstrate Atlas V 541 throw in expendable mode (INMARSAT-5). FH has the entire commercial/military segment covered.

            • Chris

              I should add by stop gap I mean FH capable of throwing a D2 around the moon with crew but not much more.

              I also should add that first block IV upper already demoed the long duration mission kit after payload sep on NROL-76 and will be demoed again on FH. All EELV missions covered by F9/FH fleet short of vertical integration until that can be done of course.

    • Chris

      Gary, what’s the point of using an alias if it is obviously identifiable as you? Name from SciFi, changed it up from E.E. Smith this time, but none the less the same drivel.

  • Dante80

    Congratulations to SpaceX, Iridium, the Western range and everyone involved for the successful conclusion of another launch campaign.

    Right now there are two ships at sea, one on the Atlantic and one on the Pacific, each carrying a used rocket stage back to land. One of said stages finished its second launch campaign.

    I quite like this timeline.

  • Tracy the Troll

    Maybe now we will see Lockheed Martin get off their AXX and give us the Venture Star that they shelved 25 years ago after taking $1B with absolutely nothing to show for it.

  • Tracy the Troll

    As for Musk…There are a couple of other Industries that could use disruption…Healthcare and Housing.

    • Zippy

      In fairness, he is trying to get housing on Mars…

      • Tracy the Troll

        Musk has backed off of housing on Mars saying he wants to be the train to get there but leave building the actual city to others…No I am thinking more about the economics lesson that is going on by MUSK around the globe in his utilization of in house R&D, design, manufacture with software and robotics. Housing is an easy example of an industry that would be easy to automate with precision software and robotics when you consider the final phase of the Model 3 production plant will be with robots only. Similarly with Healthcare…We are fooling ourselves otherwise.

  • Incidentally, Gary Church has found another website for his rants. For some mysterious reason, Marcia Smith occasionally allows “Bilgamesh” to post on Space Policy Online (dot com). Space Policy is ostensibly a serious website, so I can only assume Marcia Smith is indulging in a sense of humor.

    Enjoy Gary’s posts while you can, before he’s banned for rudeness and vulgarity, as always.

  • …belittled and hounded into silence

    James, I see your posts on this site, The Space Review and others, all the time, how is it you’re “silenced”?

    “Belittled”? yeah sure you bet; dozens of SLS launches a month, giant lunar atomic bomb propelled spaceship factories, no LEO hotels or labs ever, manned comm sats in GEO . . . totally mainstream, constant repetitive replies to yourself, nope nothing to belittle there.

    NewSpace scam has set back exploration at least a decade
    So James, how about some, you know…numbers?
    _How much has NASA spent on seed money and services purchased from “NewSpace”?
    _Given the historical record of NASA budgets for exploration and related activities: how much further along would NASA’s (crewed) exploration be if no funds were ever given to “NewSpace”?
    _Given the lower cost of “NewSpace” services over government supplied services, how much would spending more on government supplied services have not set back exploration?
    _Given the private sector (NewSpace) investment in NASA’s infrastructure upkeep, how would maintaining that infrastructure out of NASA’s facilities budget, have advanced exploration? By how much?

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