{"id":12635,"date":"2020-02-17T18:16:50","date_gmt":"2020-02-17T10:16:50","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/spacex-delivers-more-starlink-satellites-to-orbit-booster-misses-drone-ship-landing\/"},"modified":"2020-02-17T18:16:50","modified_gmt":"2020-02-17T10:16:50","slug":"spacex-delivers-more-starlink-satellites-to-orbit-booster-misses-drone-ship-landing","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/spacex-delivers-more-starlink-satellites-to-orbit-booster-misses-drone-ship-landing\/","title":{"rendered":"SpaceX delivers more Starlink satellites to orbit, booster misses drone ship landing"},"content":{"rendered":"
\"\"
A Falcon 9 rocket lifted off at 10:05:55 a.m. EST (1505:55 GMT) Monday with 60 more SpaceX Starlink satellites. Credit: SpaceX<\/figcaption><\/figure>\n

Sixty more satellites for SpaceX\u2019s Starlink broadband network launched Monday on a Falcon 9 rocket from Cape Canaveral, bringing the total number of Starlink platforms deployed in orbit since last May to 300.<\/p>\n

More Starlink missions are on tap in the coming months, with the next slated to fly aboard another Falcon 9 launcher as soon as early March.<\/p>\n

Monday\u2019s mission began with a burst of flame from SpaceX\u2019s Falcon 9 booster, followed by the release of hold-down clamps to allow the 1.2-million-pound Falcon 9 to climb into a partly cloudy sky over Cape Canaveral\u2019s Complex 40 launch pad.<\/p>\n

The 229-foot-tall (70-meter) rocket lifted off at 10:05:55 a.m. EST (1505:55 GMT) powered by thrust from nine kerosene-fueled Merlin 1D engines.<\/p>\n

The Falcon 9 quickly cleared lightning towers at pad 40 and steered toward the northeast, sending a window-shaking roar across the Florida spaceport.<\/p>\n

Two-and-a-half minutes into the mission, the Falcon 9\u2019s first stage booster shut down its engines and separated, allowing a single Merlin engine on the launcher\u2019s second stage to fire into orbit.<\/p>\n

Seconds later, the Falcon 9\u2019s payload shroud jettisoned as the rocket soared into space, revealing the launcher\u2019s more than 34,000-pound (15.6-metric ton) payload package, comprised of 60 flat-panel signal relay nodes for SpaceX\u2019s Starlink network.<\/p>\n

While the second stage accelerated into orbit, the first stage of the Falcon 9 descended back through the atmosphere and attempted landing on SpaceX\u2019s football field-sized drone ship \u201cOf Course I Still Love You\u201d holding position nearly 400 miles (630 kilometers) northeast of Cape Canaveral.<\/p>\n

But the rocket missed the drone ship and appeared to make a soft landing in the water nearby, according to streaming video from the offshore vessel. The missed landing marked the first time a first stage booster on a Falcon 9 rocket has missed a landing attempt on a SpaceX drone ship since 2016.<\/p>\n

The rocket used on Monday\u2019s mission was a veteran of three previous launches and landings. It\u2019s not likely to be reused after landing in sea water.<\/p>\n

Two other SpaceX vessels were positioned in the Atlantic Ocean to try to catch the two halves of the Falcon 9\u2019s payload shroud. SpaceX did not announce the results of the fairing recovery attempt, but a company employee said engineers are still experimenting with catching the aerodynamic shroud using fast-moving ships fitted with giant nets. Previous catch attempts have been hit or miss.<\/p>\n

Around the same time as the first stage reached the ocean, a SpaceX launch controller announced that the Falcon 9 upper stage had arrived in orbit and was poised to release the 60 Starlink satellites, the mission\u2019s primary objective.<\/p>\n

After firing thrusters to enter a controlled spin, the upper stage released retention rods holding the Starlink satellites to the rocket. That allowed the spacecraft \u2014 each weighing about a quarter-ton \u2014 to fly away from the Falcon 9 as the vehicles soared over the North Atlantic Ocean.<\/p>\n

One change introduced Monday different from past Starlink missions was the release of the Starlink payloads into an elliptical transfer orbit, instead of a circular orbit.<\/p>\n

SpaceX did not respond to questions from Spaceflight Now on the reason for the change in launch profile, but a host on the company\u2019s webcast Monday said all future Starlink missions will use the new trajectory to inject the satellites into an elliptical orbit after a single upper stage burn.<\/p>\n

\u201cWe are executing a direct inject of the Starlink satellites into an elliptical, or oval-shaped, orbit,\u201d said Jessica Anderson, a manufacturing engineer at SpaceX. \u201cIn prior Starlink missions, we deployed the satellites into a 290-kilometer (180-mile) circular orbit, which required two burns of the Merlin vacuum engine on the second stage.<\/p>\n

\u201cKeep in mind the stack of 60 Starlink satellites combined is one of the heaviest payloads we fly, so putting them directly into this orbit requires more vehicle performance and makes recovery more challenging,\u201d she said. \u201cGoing forward, and starting with today, we will deploy the satellites shortly after the first burn of the second stage, putting the Starlink satellites into an elliptical orbit.<\/p>\n

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A stack of 60 Starlink satellites. Credit: SpaceX<\/figcaption><\/figure>\n

\u201cOnce checkouts are complete, the satellites will then use their on-board ion thrusters to move into their inteded orbits at an operational altitude of 550 kilometers (341 miles).\u201d<\/p>\n

According to preflight predictions, the Starlink craft on Monday were programmed for deployment in an elliptical, or egg-shaped, orbit ranging between 131 miles (212 kilometers) and 239 miles (386 kilometers) in altitude, with an inclination of 53 degrees to the equator.<\/p>\n

As a result of the orbit change, the Falcon 9\u2019s second stage remained in orbit after release the Starlink satellites Monday. It is expected to passively re-enter the atmosphere in the coming months, instead of performing a controlled de-orbit burn, as the stage did after previous Starlink launches.<\/p>\n

Like SpaceX\u2019s previous Starlink launches, the satellites deployed in a tight cluster. SpaceX ground teams will activate krypton ion thrusters and other systems on the satellites to maneuver them into a higher orbit, targeting an altitude of 341 miles for operational service broadcasting signals in Ku-band.<\/p>\n

The first phase of SpaceX\u2019s Starlink program, which aims to beam consumer broadband to customers around the world, will include 1,584 of the flat-panel satellites \u2014 including spares \u2014 in orbit 341 miles above Earth.<\/p>\n

SpaceX has approval from the Federal Communications Commission to operate nearly 12,000 Starlink satellites in Ku-band, Ka-band and V-band frequencies, with groups of spacecraft flying at different altitudes with various orbital tilts, or inclinations.<\/p>\n

Last year, SpaceX signaled to the International Telecommunication Union that it may seek authority to operate up to 30,000 additional broadband satellites in low Earth orbit, potentially bringing the total Starlink fleet to 42,000 platforms.<\/p>\n

But SpaceX says the fleet\u2019s growth will hinge on demand, and the company must launch roughly 20 more missions before completing the first phase of its Starlink network.<\/p>\n

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Artist\u2019s illustration of a Starlink satellite. Credit: SpaceX<\/figcaption><\/figure>\n

SpaceX also needs to test the network and begin selling the Starlink service, and work continues on user terminals to link customers on the ground with the satellite network in space. The company has not announced a price or Internet speeds for its consumer-grade service.<\/p>\n

The rapid-fire deployment of Starlink satellites \u2014 coupled with plans for other large satellite fleets \u2014 has astronomers worried that the proliferation of small spacecraft could impact observations by ground-based telescopes.<\/p>\n

The Starlink satellites are brighter than predicted, sometimes reflecting sunlight and becoming as bright as the most luminous stars in the night sky. But the brightest sightings occur only soon after a launch, when the satellites are flying at lower altitudes and are clumped close together.<\/p>\n

The satellites are harder to spot as they spread out in the weeks after a launch and begin raising their orbits to their 341-mile-high operating altitude. But scientists caution they will pose a threat to high-power telescopes, such as the U.S. government-funded Vera C. Rubin Observatory under construction in Chile.<\/p>\n

The International Astronomical Union \u2014 a global body chartered in 1919 to \u201cpromote and safeguard the science of astronomy\u201d \u2014 said last week that it \u201cconsiders the consequences of satellite constellations worrisome.\u201d<\/p>\n

\u201cThey will have a negative impact on the progress of ground-based astronomy, radio, optical and infrared, and will require diverting human and financial resources from basic research to studying and implementing mitigating measures,\u201d the IAU said in a press release.<\/p>\n

\u201cA great deal of attention is also being given to the protection of the uncontaminated view of the night sky from dark places, which should be considered a non-renounceable world human heritage,\u201d the IAU said.<\/p>\n

At the request of the IAU, scientists from the Vera Rubin Observatory, the University of Michigan, the Centro Astron\u00f3mico Hispano-Alem\u00e1n, the European Southern Observatory and the European Space Agency modeled the frequency, location and brightness of satellites in planned \u201cmega-constellations\u201d flying in low Earth orbit.<\/p>\n

The IAU said the results of the simulations are preliminary. Some of the simulations assumed more than 25,000 broadband satellites could be deployed in low Earth orbit, in which case between 1,500 and a few thousand spacecraft could be above the horizon at any given time, depending on the observer\u2019s latitude.<\/p>\n

The \u201cvast majority\u201d of those satellites would not be visible to the naked eye, according to the IAU. The simulations showed that around 250 to 300 of the spacecraft above the horizon at any given time would have an elevation of more than 30 degrees, the region of the sky where astronomers perform most of their observations.<\/p>\n

At astronomical dawn and dusk \u2014 when the sun is 18 degrees below the horizon \u2014 simulations suggest around 1,000 satellites could be illuminated by sunlight and above the horizon. Around 160 of the illuminated spacecraft could be higher than 30 degrees in the sky at one time, and those are the satellites that pose the greatest threat to astronomical research.<\/p>\n

The numbers of illuminated satellites will decrease in the middle of the night, according to the IAU.<\/p>\n

\"\"
This 333-second exposure taken last year by the Dark Energy Camera on the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory shows 19 streaks attributed to Starlink satellites passing through the camera\u2019s field-of-view shortly after their launch Nov. 11 from Cape Canaveral. Credit: NSF\u2019s National Optical-Infrared Astronomy Research Laboratory\/NSF\/AURA\/CTIO\/DELVE<\/figcaption><\/figure>\n

In response to astronomers\u2019 concerns, SpaceX launched one satellite in early January with an experimental darker coating. The long-term effectiveness of the external treatment will not be known until the satellite reaches the Starlink fleet\u2019s operational altitude.<\/p>\n

Gwynne Shotwell, SpaceX\u2019s president and chief operating officer, said in December the company was in dialog with astronomers about the issue.<\/p>\n

\u201cAstronomy is one of a few things that gets little kids excited about space,\u201d Shotwell said. \u201cThere are a lot of adults that get excited, too, who either depend on it for their living or for entertainment. But we want to make sure we do the right thing, to make sure little kids can look through their telescopes. It\u2019d be cool for them to see a Starlink. I think that\u2019s cool. But they should be looking at Saturn and the moon.\u201d<\/p>\n

The other company on the cusp of launching hundreds, and perhaps thousands, of broadband satellites is London-based OneWeb.<\/p>\n

OneWeb has launched 40 satellites to date, with plans to launch roughly 32 to 36 more every month to deploy an initial fleet of nearly 650 spacecraft. But like SpaceX, OneWeb has plans to grow from there.<\/p>\n

The satellites owned by OneWeb are smaller than the Starlink spacecraft, and they orbit higher, allowing the company to provide global coverage with fewer satellites than SpaceX. The higher altitude also means they will be dimmer to ground observers, the company says.<\/p>\n

\u201cWe\u2019re going to do the most we can to mitigate (astronomers\u2019 concerns),\u201d said Adrian Steckel, OneWeb\u2019s CEO. \u201cWe\u2019re not visible to the naked eye. We are visible to telescopes. It\u2019s hard to get around some of those facts.\u201d<\/p>\n

Scientists have also questioned whether constellations of thousands of satellites broadcasting broadband data will interfere with radio astronomy, which uses giant antennas to listen to faint radio signals generated from distant stars and galaxies.<\/p>\n

\u201cWith respect to radio frequency \u2026 we\u2019ll try,\u201d Steckel said earlier this month. \u201cWe\u2019re going to do the most we can. I don\u2019t know if there will be a solution that will make everybody happy. At least we\u2019re in dialog, and we\u2019re trying to get feedback on what can we do.\u201d<\/p>\n

The IAU said there is still uncertainty in the eventual impacts of huge flocks of satellites on astronomy.<\/p>\n

\u201cAt the moment it is difficult to predict how many of the illuminated satellites will be visible to the naked eye, because of uncertainties in their actual reflectivity,\u201d the IAU said, referencing the unknown outcome of SpaceX\u2019s experiments with darker coatings.<\/p>\n

\"\"
The Vera Rubin Observatory is under construction in Chile. Credit: Vera Rubin Observatory<\/figcaption><\/figure>\n

\u201cThe appearance of the pristine night sky, particularly when observed from dark sites, will nevertheless be altered, because the new satellites could be significantly brighter than existing orbiting man-made objects,\u201d the IAU said. \u201cThe interference with the uncontaminated view of the night sky will be particularly important in the regions of the sky close to the horizon and less evident at high elevation.\u201d<\/p>\n

The IAU said astronomical impacts during the period of time when Starlink satellites are brightest \u2014 soon after a launch \u2014 depend on how long the spacecraft are flying at lower altitudes, and the frequency of launches.<\/p>\n

\u201cApart from their naked-eye visibility, it is estimated that the trails of the constellation satellites will be bright enough to saturate modern detectors on large telescopes,\u201d the IAU concluded. \u201cWide-field scientific astronomical observations will therefore be severely affected. For instance, in the case of modern fast wide-field surveys, like the ones to be carried out by the Rubin Observatory (formerly known as LSST), it is estimated that up to 30 percent of the 30-second images during twilight hours will be affected.\u201d<\/p>\n

Formerly known as the Large Synoptic Survey Telescope, the Vera Rubin Observatory will capture deep, wide-field images of the entire available sky, allowing astronomers to learn more about dark energy and dark matter, and detect potentially hazardous asteroids with orbits near Earth, among other objectives.<\/p>\n

\u201cInstruments with a smaller field of view would be less affected,\u201d the IAU continued. \u201cIn theory, the effects of the new satellites could be mitigated by accurately predicting their orbits and interrupting observations, when necessary, during their passage. Data processing could then be used to further \u2018clean\u2019 the resulting images. However, the large number of trails could create significant and complicated overheads to the scheduling and operation of astronomical observations.\u201d<\/p>\n

The IAU\u2019s statement last week focused on optical astronomy. Astronomers continue studying the possible interference that signals transmitted by broadband satellites in low Earth orbit will have on radio astronomy.<<\/p>\n

The IAU said there are no internationally-agreed rules of guidelines on the brightness of satellites. The group said it will present its findings to the United Nations to bring the attention of world government representatives on the issue.<\/p>\n

\u201cThe IAU stresses that technological progress is only made possible by parallel advances in scientific knowledge,\u201d the group said. \u201cSatellites would neither operate nor properly communicate without essential contributions from astronomy and physics. It is in everybody\u2019s interest to preserve and support the progress of fundamental science such as astronomy, celestial mechanics, orbital dynamics and relativity.\u201d<\/p>\n

SpaceX\u2019s next launch is scheduled for 1:45 a.m. EST (0545 GMT) March 2, again from pad 40 at Cape Canaveral, when a Falcon 9 rocket will loft a Dragon cargo capsule into orbit on a resupply mission to the International Space Station.<\/p>\n

Another Starlink launch on a Falcon 9 rocket is also scheduled as soon as March 4 from nearby pad 39A at the Kennedy Space Center.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

A Falcon 9 rocket lifted off at 10:05:55 a.m. EST (1505:55 GMT) Monday with 60 more SpaceX Starlink satellites. Credit: SpaceX Sixty more satellites for SpaceX\u2019s Starlink broadband network launched Monday on a Falcon 9 rocket from Cape Canaveral, bringing the total number of Starlink platforms deployed in orbit since last May to 300. More […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1661,252,291,1736,479,2329,2330,25],"class_list":["post-12635","post","type-post","status-publish","format-standard","hentry","category-news","tag-astronomy","tag-broadband","tag-commercial-space","tag-complex-40","tag-falcon-9","tag-international-astronomical-union","tag-large-synoptic-survey-telescope","tag-launch"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12635"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=12635"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12635\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=12635"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=12635"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=12635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}