Rocket propulsion • Astronomy • Exploration. Curious about the physics that gets us off Earth.
Milky Way galaxy
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26 years ago today a Soyuz lifted off from Baikonur with Bill Shepherd, Yuri Gidzenko and Sergei Krikalev, the first crew to live on the ISS. They docked Nov 2, 2000 and people have been up there every single day since
Image: NASA, Soyuz TM-31 on the pad
The Taurids are active now, the Halloween fireballs. Only about 5 an hour, but they hit slow at 17 miles a second, so big chunks flare bright. Look east after 9pm, before the Moon rises near 11. This is their parent comet Encke and its debris trail
Image: NASA/JPL-Caltech
Artemis III's rocket is taking shape. Crews at Kennedy lowered the 212-foot SLS core stage between its twin solid boosters. This flight stays in Earth orbit so Orion can practice docking with the commercial landers that will later take crews to the Moon
Image: NASA/Sean Cannon
A rocket's loudest enemy at liftoff is its own noise. Engine roar bouncing off the pad can shake the rocket and its cargo hard enough to do damage, so the pad floods itself with water that soaks up the sound. This test at Pad 39B dumped about 450,000 gallons
Image: NASA
41 years ago today Challenger launched STS-61A with eight people, the biggest crew ever sent up on one launch. West Germany paid for the mission and ran its Spacelab D-1 lab from a control room near Munich. It turned out to be Challenger's last successful flight
Image: NASA
Low in the northeast tonight is Algol, the Demon Star in Perseus. Every 2.87 days a dimmer companion slides in front and it fades from magnitude 2.1 to 3.4 for about 10 hours. This is a real infrared movie of the pair from 55 telescope images
Image: Fabien Baron/CHARA CC BY-SA
NASA is taking names for Titan. Sign up by Jan 15 and yours rides a microchip on Dragonfly, a rotorcraft that will fly around Saturn's biggest moon. Launch 2028, arrival 2034. Here part of its mass spectrometer gets a UV check go.nasa.gov/dragonfly-names
Image: NASA/Mike Guinto
Some rocket fuels don't need a spark. Hypergolic propellants, like hydrazine plus nitrogen tetroxide, ignite the instant they touch, so a thruster fires every time. But they're toxic, which is why crews loading Orion's propellant suit up like this
Image: NASA/Frank Michaux
28 years ago today Discovery launched John Glenn back to space at 77, making him the oldest person to fly at the time. It came 36 years after he became the first American to orbit Earth, and part of the mission studied how spaceflight and aging affect the body
Image: NASA
Look northeast tonight, just below the W of Cassiopeia, for a faint fuzzy patch. That's the Double Cluster in Perseus, two star clusters about 7,500 light years away and only around 14 million years old. Binoculars turn it into hundreds of stars
Photo: Taavi Niittee CC0
Rocket engines can't just let fuel drip in. A turbopump, a small turbine spinning a pump, rams it in under huge pressure. This 3D printed one at NASA Marshall hit 36,000 rpm on liquid methane and moved 600 gallons a minute
Image: NASA/MSFC/Emmett Given
17 years ago today NASA launched Ares I-X, a 327 foot test rocket and the first non-shuttle launch from Kennedy's pads since the Saturn days. Its booster was built from parts that flew on 30 shuttle missions, and 700 plus sensors rode along
Image: NASA/Tony Gray, Tom Farrar
Deneb is the bright star high in the northwest tonight, top of the Northern Cross. It's 1,400 to 2,600 light years away and still that bright. Edwin Hubble once guessed it lit up the North America Nebula beside it. A hidden hotter star does
Photo: Giuseppe Donatiello CC0
NASA just locked in UVEX, a telescope that will map the whole sky in ultraviolet. Our air blocks most UV, so it has to fly. It can also swing fast to catch the glow when neutron stars crash together. Launch by Jan 2031, for $590 million
Image: SDL/NASA/JPL-Caltech (concept)
A rocket has no steering wheel. It steers by tilting its engines, called gimbaling. Hydraulic arms swing each nozzle a few degrees so the thrust nudges the tail sideways, like balancing a broom on your palm. These RS-25s will fly Artemis III
Image: NASA/Kim Shiflett
65 years ago today the first Saturn rocket left the pad. SA-1 clustered eight H-1 engines for over 1.3 million pounds of thrust, and only the bottom stage was real. The top was a dummy. It flew a clean 215 mile arc over the Atlantic. Apollo's rockets grew from it
Image: NASA
Look due north tonight for Polaris. It sits about as high as your latitude, around 30 degrees up in Central Texas, and it's only about the 48th brightest star. Hubble showed it's really three stars, one so close it loops around every 30 years.
Image: NASA/ESA/N. Evans/H. Bond
NASA's Swift is done after almost 22 years. Built for a 2 year mission, it caught 2,000+ gamma-ray bursts, swinging around in about a minute to see the afterglow. Drag pulled it down to 171 miles, its last look was Oct 20, and it falls back soon
Image: NASA (2004 launch)
That's Perseverance dangling under a rocket jetpack over Mars, shot from above. About 66 ft up, the descent stage lowered it on 21 ft nylon cords at 1.7 mph. The instant the wheels touched, blades cut the cords and the jetpack flew off to crash far away
Image: NASA/JPL-Caltech
