 This is your Space News for April 10th, 2019. My name is Benjamin Higginbotham, and I'll be getting us started today with Space Traffic. On Thursday, April 4th, at 14.45 universal time, a Russian Soyuz rocket lifted off from the Baikonur Cosmodrome in Kazakhstan. Aboard was a Progress cargo freighter bringing food, supplies and fuel up to the International Space Station. Of note, was the extremely fast rendezvous with the Space Station the fastest ever. From launch to docking, it was less than three and a half hours. Then, just a few hours later, another Soyuz launch. This one also happened on April 4th, but at 17.03 universal time, just three hours and 42 minutes after that first launch. This one was run by Ariane Space and launched out of Guyana Space Center in French Guyana. Aboard were four O3B satellites run by SES. These satellites are destined for medium Earth orbit and will build out a constellation for voice and data communications. The O3B stands for Other Three Billion, which refers to the population of the world where broadband internet is not currently available. And finally, a quick update on Israel's bear sheet, Lunar Lander. Launched on February 22, 2019, the Lunar Lander successfully performed a breaking maneuver on April 4th, firing its main engine at 14.18 universal time. It's currently orbiting around the moon. The next big milestone will be Lunar Landing, which is just a day away on April 11th. We're excited to see another vehicle land on the lunar surface. And while we're talking about space traffic, now seems like a good time to mention a new product that Rocket Lab has announced, Photon. On April 8th at the 35th Space Symposium, the all-new Rocket Lab Photon satellite bus was announced. This is basically a platform that can be built upon to get your experiments into orbit, allowing you to focus on the science or tests you may want to perform, instead of needing to deal with spacecraft things like propulsion, station keeping, communications, and all the avionics required to run the satellite itself. Want to put an Earth observation camera up in space? Cool. Call up Rocket Lab, grab a Photon, and drop your camera on. Depending on the complexity of your install, the whole end-to-end process from order to orbit could be as little as four months. The whole platform is based on the Electron Rocket kickstage, which is what's been generally getting the CubeSats riding on Electron into their final destination. By using this existing system, Rocket Lab is building on space-proven technology and allowing others to build satellites on that same proven platform. According to Peter Beck's Twitter account, the Photon can allow for 170 kilograms of mass for your sensor or payload, has one kilowatt of peak power, and one terabyte of data storage. The next question we have on answer is if Rocket Lab will also run the ground stations for your payload communication, or if you need to use something like Amazon's AWS ground station to get Photon's S-band radio signals back to Earth. We should get to see Photon soon. Rocket Lab's targeting Q4 of 2019 for the first demonstration with custom remissions planned for 2020. Now, I'll hand it over to Jared for an update on a spacewalk recently performed on the International Space Station. The second of three long-delayed spacewalks was finally completed last Friday, March 29, 2019, by NASA astronauts Christina Koch and Nick Hake. EVA 53 carried out tasks similar to March 22, EVA 52, swapping out older Nickel-hydrogen batteries for newer lithium-ion batteries. EVA 54 continued battery work, including troubleshooting the recent installations. Nickel-hydrogen batteries are used in space applications thanks to their ability to handle many charge-discharge cycles that they can last long periods in space environments and that they don't accidentally overcharge or reverse current. But Nickel-hydrogen batteries fall victim to battery memory, where a battery can lose its capacity if it's not fully charged and discharged each cycle. Lithium-ion batteries are lighter weight and don't experience battery memory, but they are much more susceptible to overcharging, so management and protection systems are used. The ones on the International Space Station have been certified for 60,000 cycles, roughly 10 years of lifetime. One of these lithium-ion batteries replaces two of the older Nickel-hydrogen batteries on the station. Christina Koch in the Plain White Extravehicular Mobility Unit and Nick Hague in the Red Stripe EMU spent 6 hours 45 minutes working outside of the International Space Station. This was Koch's first spacewalk and Hague's second. Of note, EVA 53 was originally scheduled to be the first all-woman spacewalk with Anne McLean joining Christina Koch, fortuitous scheduling as a result of the cascade of delays from the Soyuz MS-10 abort, but unfortunately several factors, none of the malicious prevented this milestone from occurring. During EVA 52, Anne McLean was wearing a medium-sized hard upper torso and found that the medium fit her better than the planned large hard upper torso she was scheduled to wear during EVA 53. Spacewalks are one of the most dangerous parts of any mission. The threat of being hit by micrometeoroids is greatly increased, and in doing my research for this story, I was surprised to find that the EMUs on the International Space Station have had problems classified as significant during one out of every 10 spacewalks, and these EMUs are leftovers of the shuttle program, with quite a few of them being nearly 40 years old, even though they were originally designed for only 15 years of use. McLean and Hague consulted with mission managers at the Johnson Space Center in Houston, Texas and made the decision to move forward with EVA 53 by replacing McLean with Hague, as these spacewalks to replace the batteries on the station are long overdue, and if not done in a few weeks by mid-April, a series of cargo resupply missions will further delay the replacements. There is an extra medium-sized hard upper torso in storage on the International Space Station, but it would require 12 crew hours to bring it up to spacewalking configuration, which includes tasks such as rewiring the personal life support systems. It's not unusual for physiological changes to an astronaut, such as their height changing or other body dimensions changing, to occur once they get in space, as McLean had been fitted for both medium and large size hard upper torsos during ground tests. Spacewalks also put a tremendous physical demand on the astronauts performing them, requiring physical effort to counteract the pressurization of their suits, even to open and close their fingers. If McLean didn't feel like she'd be comfortable in the large, hard upper torso she was planned to be in, that could have disastrous fatal results. Funding for new spacesuits has been, well, non-existent, and the destruction of two EMUs during the loss of Space Shuttle Columbia in 2003, and one during the launch failure of SpaceX's CRS-7 resupply mission in 2015 hasn't exactly helped. EMUs are roughly $12 million each, not exactly cheap. So whose fault was it? Well, no one's. NASA and McLean made the mutual decision to prioritize safety, which is the right call. That's not to say systemic sexism isn't present in aerospace. It very much was, is, and is something we should talk about openly and often. And maybe this can contribute to a necessary discussion, but in the case of EVA 53, it was a technical error and a desire to stay safe that foiled, but would have been a great moment. On this last week's live show, we've talked about APL's interstellar probe idea, but how long would it take for that probe to reverse the entire Milky Way? To answer that, we need to know how large the Milky Way is, and to help us answer that, we hand it over to Athena. Weight and height are two measurements we use to get a quick snapshot of our health. But how exactly do we do these measurements with something as large as, say, the Milky Way Galaxy? Well, until the day we get our hands on a cosmic-sized scale, we're going to have to rely on things like the effects of dark matter, because 90% of our galaxy is actually made up of dark matter. But we do still have a long way to go before we fully understand how it works. This method gave an estimated mass of somewhere between 500 million to 3 trillion solar masses, but astronomers have just used a new technique to narrow the extremely large range down to 1.5 trillion solar masses, or 5.48 times 10 to the 38 African elephants. Now, instead of using elusive dark matter, astronomers turn their eyes to globular clusters, which are dense spherical globs of stars. Now, there's around 125 to 200 globular clusters orbiting around our galactic center, and their velocities can tell us a lot about the gravitational effects of our galaxy. According to Enwin Evans from the University of Cambridge, the velocities of the globular clusters directly relate to the gravitational pull of the galaxy. So, the faster the cluster, the stronger the gravitational pull, hence the mass of the galaxy. Now, in order to measure this accurately, astronomers must factor in two measurements to obtain the total velocity. The first is radial velocity, which is the speed of the object moving either towards or away from Earth. And the second is the sideways motion, or positional velocity, where the object is moving from side to side. When something is moving through space, it can be tugged on by other gravitational effects causing a jiggle or a wobble, so all of these factors have to be calculated. Now, the cluster's side-to-side wobbles were measured using data from the European Space Agency's GAIA mission and NASA's Hubble Space Telescope. Now, GAIA is a mission that is focused on creating a 3D model of the Milky Way galaxy, and will catalog the positions, distances, and motions of about 1 billion stars in the Milky Way and surrounding areas. It actually took a total of 34 globular clusters from GAIA and 12 even more distant clusters from Hubble in order to get the accuracy of these measurements. Now, something else that's cool is this research also determined the length of the Milky Way, which came to 260,000 light years from end to end. That means if you're moving at the speed of light, it's going to take you 260,000 years to go from one end of the Milky Way to the other. Good luck, future interstellar voyagers! Since we are unable to view the Milky Way from the outside looking in, missions like GAIA and Hubble are so extremely important to understanding more about our home galaxy and, of course, our place in the universe. And finally, this week, I'll hand it over to Dr. Tamatha Scove for our Space Weather Report. Space weather this week continues to be a bit unsettled. As we switch to our front-side sun, you can see a coronal hole that rotated through the Earth's strike zone. It had bumped us up to active conditions a few times this week and even brought us some aurora at high latitudes. But that's not the big story. The big story is the bright region, 2738, that is rotating into Earth view. This is a returning sunspot and it is massive. As we switch to our stereo view, which is looking at the sun pretty much from the side, you can see that huge sunspot there. It's the only thing that draws your eye and, believe it or not, it is still firing low-sea-class flares and a few solar storms. It even fired one near Mars the other day. So this region is still a very active region and we are watching it as it continues to boost the solar flux up for emergency responders. We're back into marginal radio propagation on Earth's day side and it looks like these conditions are going to continue easily over the next week. Switching to our moon, this week we are passing through the first quarter phase and by the 13th the moon will be a little bit over half illuminated. So unite sky watchers. If you want to search for dim objects, you're going to need to check your moon rise and set times. And now for your Leo, miogeo orbit outlook. Even though we haven't had any intense solar storming over the past week, we've managed to bump up to active conditions several times over a longer duration and this has a tendency to really wreak havoc with our near Earth's space environment. As we switch to our low energy particles, these are the ones that cause surface charging on the outside of spacecraft, including the solar arrays that then can cause electrical discharges and short circuits. You can see that flux ring begin to build up around the seventh and the eighth and it begins to get really thick and very intense around geo and mio orbits. So you satellite operators are guarantee you've been probably fighting some issues here over the past few days. Luckily we'd get all of this flux dumped right around midday on the eighth and that is giving us a little bit of a reprieve until things begin to build back up again. And did you happen to capture the strange lights in the sky back on the fifth when there was some aurora? Well don't worry, it's not aliens. These lights are part of a NASA rocket mission called Azure in which scientists are studying the neutral and charged atmosphere by throwing out dust clouds that kind of act like fireworks and light up the sky a little bit. They want to be able to see how the winds move during aurora and it gave us such an amazing show and I want to thank Miguel Larson, Colby Lemon and Jim Hecht among others for giving us such an incredibly dazzling display and I hope the results that you guys get are worth every moment. For more details on this week's space weather conditions including when and where you can see aurora, how GPS reception will fare and what radio propagation looks like, come check out my channel or see me on spaceweatherwoman.com. That's our new show this week but the fun continues live this Saturday at 1800 universal time. This week we welcome on Brittany Zimmerman who will be talking about life support and environmental control systems in space. Going to need a bit of that if we want to send humans to Mars and beyond. Make sure to check it out and the easiest way to remember is to subscribe to our YouTube channel and hit that little bell icon so you always know when we're live and have new content up. And a special thank you to all of the citizens of tomorrow. The names you see going by on the screen right now are people who contribute week after week to bring these great shows to everyone. We are almost completely crowd funded which means a lot to us. If you'd like to get your name on the screen and help fund all of the shows of tomorrow head on over to patreon.com slash tmro for per episode support or subscribe star.com slash tmro for monthly contributions. That's our show this week. Thank you so much for watching and I look forward to talking to you tomorrow. This is your space news for April 20th, 20th.