A few years ago we were all holding our breath during each SpaceX launch, wondering if the company’s innovative Falcon 9 rocket would be able to land itself after sending the second stage into orbit. Now, it’s becoming commonplace. In the last few days, there have been two successful SpaceX launches and landings.
The first of the two launches took place on Friday, and the second was on Sunday. SpaceX didn’t set out to show off by having the two launches so close to each other. The first launch was supposed to take place four days earlier, but a series of delays pushed it much closer to the second launch. The last time two identical US orbital launches took place within two days of each other was 1995, when Lockheed Martin launched a pair of Atlas rockets. Of course, those launches did not also come with landings.
In its Friday launch at Kennedy Space Center, SpaceX hauled a Bulgarian satellite weighing 3,400 kilograms (7,495 pounds) into geostationary orbit. From its location in space, BulgariaSat-1 will be able to provide communication services to most of Europe along with parts of Africa and the Middle East.
This launch used what SpaceX charmingly refers to as a “flight-proven vehicle.” That’s its way of saying the rocket was previously launched and recovered. Because this was a geostationary launch, the rocket needs to reach much higher speeds. SpaceX wasn’t sure it would even be able to recover the rocket, but it was a success nonetheless. It was an impressive display.
Closeup of the titanium grid fins. Not painted, as they glow red hot during a fast reentry. pic.twitter.com/Ltrq1Prg2m
— Elon Musk (@elonmusk) June 25, 2017
The Sunday launch took place at Vandenberg Air Force Base in California. This rocket was carrying 10 smaller Iridium Next satellites, a common cargo for recent SpaceX launches. After sending the satellites off to join the more than 60 iridium satellites already in similar orbits, the first stage core dropped back down and landed safely on SpaceX’s barge in the Pacific Ocean.
CEO Elon Musk noted that this launch was also the first real world test of SpaceX’s new titanium grid fins. These larger, more durable fins are used to guide the rocket in for a landing. They’re machined out of a single piece of titanium, so they should last basically forever without maintenance.
The next SpaceX Falcon 9 goes up on July 3rd from Kennedy Space Center, carrying a communications satellite for Intelsat. Expect another landing after that one. This is the new normal.
source : https://www.extremetech.com/extreme/251628-spacex-nails-two-falcon-9-launches-landings-weekend