CAPE CANAVERAL, Fla. — SpaceX successfully fired up the Falcon 9 rocket booster that will launch the company's next batch of Starlink satellites today (Feb. 14) in a test that sets the stage for a weekend liftoff.

That Falcon 9 rocket is expected to send 60 Starlink internet satellites into space no earlier than Sunday (Feb. 16). Liftoff is set for Sunday at 10:25 a.m. EST (1525 GMT). 

The company originally planned for a launch on Saturday (Feb. 15), but poor weather at the rocket's recovery zone prompted the 24-hour schedule slip. 

The company conducted a so-called static-fire test on Friday (Feb. 14) at 9 a.m. EST (1400 GMT) of a Falcon 9 rocket at Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, the company said on Twitter. The upcoming launch will mark the third Starlink flight this year.

The veteran Falcon 9 rocket rolled out of its hangar on Thursday (Feb. 13) and went vertical on the launch pad in advance of the planned test-firing of its nine first stage engines on Friday morning. 

The two-stage rocket featured in the upcoming launch includes a thrice-flown first-stage booster, having previously lofted two commercial Dragon resupply missions (CRS-17 in May 2019 and CRS-18 that July) as well as a hefty telecommunications satellite in December. 

This marks the fourth time a SpaceX booster will fly four times. 

But before it can launch, SpaceX put the vehicle through a routine launch rehearsal, called a static-fire test. This is a standard part of prelaunch procedures and one of the last major milestones before liftoff. During the test, teams loaded the Falcon's super-chilled propellants — kerosene and liquid oxygen — into the rocket and then briefly ignited the first stage’s nine Merlin 1D engines. 

The engines briefly fired at 12 p.m. EST (1700 GMT), generating more than 1 million pounds of thrust while the booster remained firmly on the ground. 

"Static fire of Falcon 9 complete ahead of launching 60 satellites — due to poor weather in the recovery area tomorrow, now targeting launch on Sunday, February 16 at 10:25 a.m. EST, 15:25 UTC," SpaceX tweeted shortly after the test. 

This test was slightly different from typical hold down tests that SpaceX performs prior to each launch in recent years. 

SpaceX test fired this Falcon 9 with a payload attached. Typically, the company rolls out just the rocket's first stage, fires it up, and rolls it back so they can attach the payload. SpaceX has followed that method since 2016, when a Falcon 9 rocket exploded on the launchpad, destroying its satellite payload, during preparations for a static fire test. 

However, with the Starlink launches, the company has decided to fire up the rockets with the payload sitting on top. This isn't a new practice for this launch, but is something the company is doing with most of its Starlink launches. Since SpaceX owns the payload, it assumes the risk if there were an anomaly. Plus, it cuts down on processing time, allowing the company to test fire one day and launch the next. 

This practice was something SpaceX did in the past, but stopped after the loss of the AMOS 6 satellite in 2016. That explosion was attributed to issues with the composite overwrapped pressure vessels (COPVs) in the rocket's upper stage. The COPVs are responsible for keeping the rocket pressurized during flight as its fuel is depleted

 Since then, the company has redesigned the COPVs and began using them when they started flying the Block 5 version of Falcon 9 in May 2018. In a prelaunch news conference prior to that inaugural launch, SpaceX CEO and founder, Elon Musk, described the COPVs as “the most advanced pressure vessel developed by humanity.”

NASA required SpaceX to fly the newly redesigned pressure vessels at least seven times before the company could begin carrying astronauts to the space station — a task they completed last year. With one successful uncrewed test flight, and a demonstration of the Crew Dragon's launch escape system, the only hurdles SpaceX has left to complete before that coveted crewed mission are a few more parachute tests and paperwork. 

According to SpaceX, the Crew Dragon vehicle has arrived at the launch site. If all goes as planned we could see SpaceX launch people to the International Space Station in the next few months. 

Quelle: SC

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Satellite megaconstellations prompt new warning from astronomy group about impact on science

The more astronomers consider the advent of satellite megaconstellations, the more anxious they get.

Now, the International Astronomical Union (IAU), a premier group of astronomers, has spoken out again, voicing scientists' concerns about how the satellites that make up OneWeb and SpaceX's Starlink will interfere with observations of the night sky. The statement accompanies the publication of a new page designed for the public about satellite constellations and optical astronomy.

"The IAU considers the consequences of satellite constellations worrisome," the organization said in the new statement. "They 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."

SpaceX's Starlink constellation has inspired particular consternation; at each launch of 60 satellites, astronomers have rediscovered how severely Starlink interferes with optical observations. The satellites naturally reflect a lot of light, resulting in bright lines running across the images produced by observatories. The outcry was particularly strong after the first Starlink launch, and the IAU released an initial statement about satellite constellations soon after, in June 2019.

In the new statement, the organization highlighted the urgency these concerns have gathered over the past year. "The IAU notes that currently there are no internationally agreed rules or guidelines on the brightness of orbiting manmade objects," the statement read. "While until now this was not considered a priority topic, it is now becoming increasingly relevant."

The IAU also asked two subgroups to evaluate the ways this sort of massive network of satellites could affect astronomers and to reach out to the companies launching such satellites. The new statement focuses on the first of those tasks, and the results offer a more detailed look at what astronomers can expect from these megaconstellations. The astronomers found that many of the satellites would pass low over the horizon, and those passing higher overhead would likely be too faint to observe by eye.

The findings also note that because the satellites are most obtrusive right after they launch, the impact on astronomy will depend based on how frequently new satellites are launched: The same number of satellites grouped into fewer launches will interfere less with astronomers' observations.

The IAU statement also highlighted particular concerns that the constellations would interfere with observing programs that watch large swaths of the sky at a time. That's because the satellites could easily overexcite the detectors on the large telescopes that conduct this sort of observing. Certain telescopes could lose up to 30% of their twilight observations, the IAU found.

And the organization isn't going to let the night skies brighten without a fight. The new statement ended with a condemnation of interfering with astronomical observations: "The IAU stresses that technological progress is only made possible by parallel advances in scientific knowledge. Satellites would neither operate nor properly communicate without essential contributions from astronomy and physics. It is in everybody’s interest to preserve and support the progress of fundamental science such as astronomy, celestial mechanics, orbital dynamics and relativity."

Quelle: SC

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Update: 15.00 MEZ

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SpaceX delays next Starlink launch from Cape Canaveral due to hardware issue

SpaceX has delayed the launch of its next Starlink mission from Cape Canaveral due to hardware issues, the launch provider confirmed Saturday evening.

"Standing down from (Sunday's) Starlink launch," SpaceX said via Twitter. "Team is taking a closer look at a second-stage valve component."

The Falcon 9 rocket is now scheduled to lift off from Launch Complex 40 about 10:04 a.m. Monday. The Air Force's 45th Weather Squadron is expecting 80% "go" conditions for the attempt.

After liftoff, the rocket's first stage will return for a computer-controlled landing on the drone ship named Of Course I Still Love You in the Atlantic Ocean. It will be its 50th landing to date. 

Squeezed into Falcon 9's payload fairing are 60 flat-packed Starlink satellites, which are designed to beam internet access to the ground. Monday's flight will mark the fifth mission for Starlink, which will boast 300 spacecraft in low-Earth orbit after the satellites separate from the upper stage about an hour after liftoff.

Launch Monday

• Rocket: SpaceX Falcon 9
• Mission: 60 Starlink satellites
• Launch time: About 10:04 a.m.
• Location: 40 at Cape Canaveral Air Force Station
• Landing: Drone ship named Of Course I Still Love You 
• Weather: 80% "go"

Join floridatoday.com/space at 8:30 a.m. Monday for countdown chat and updates including streaming of SpaceX's launch webcast.

Quelle: Florida Today

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Update: 17.02.2020 / 9.00 MEZ

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Quelle: AS

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Erfolgreicher Start von SpaceX Falcon-9 mit 60 Starlink-Satelliten

Quelle: SpaceX