Category Archives: Cool Stuff

Phobos in Orbit

Check this out – Hubble captures the Martian moon Phobos in orbit.

Goddard Space Flight Center/NASA/ESAHubble — A football-shaped object just 16.5 miles by 13.5 miles by 11 miles, Phobos is one of the smallest moons in the solar system. It is so tiny that it would fit comfortably inside the Washington, D.C. Beltway.

The little moon completes an orbit in just 7 hours and 39 minutes, which is faster than Mars rotates. Rising in the Martian west, it runs three laps around the Red Planet in the course of one Martian day, which is about 24 hours and 40 minutes. It is the only natural satellite in the solar system that circles its planet in a time shorter than the parent planet’s day.

About two weeks after the Apollo 11 manned lunar landing on July 20, 1969, NASA’s Mariner 7 flew by the Red Planet and took the first crude close-up snapshot of Phobos. On July 20, 1976 NASA’s Viking 1 lander touched down on the Martian surface. A year later, its parent craft, the Viking 1 orbiter, took the first detailed photograph of Phobos, revealing a gaping crater from an impact that nearly shattered the moon.

Phobos was discovered by Asaph Hall on August 17, 1877 at the U.S. Naval Observatory in Washington, D.C., six days after he found the smaller, outer moon, named Deimos. Hall was deliberately searching for Martian moons.

Both moons are named after the sons of Ares, the Greek god of war, who was known as Mars in Roman mythology. Phobos (panic or fear) and Deimos (terror or dread) accompanied their father into battle.

Close-up photos from Mars-orbiting spacecraft reveal that Phobos is apparently being torn apart by the gravitational pull of Mars. The moon is marred by long, shallow grooves that are probably caused by tidal interactions with its parent planet. Phobos draws nearer to Mars by about 6.5 feet every hundred years. Scientists predict that within 30 to 50 million years, it either will crash into the Red Planet or be torn to pieces and scattered as a ring around Mars.

Orbiting 3,700 miles above the Martian surface, Phobos is closer to its parent planet than any other moon in the solar system. Despite its proximity, observers on Mars would see Phobos at just one-third the width of the full moon as seen from Earth. Conversely, someone standing on Phobos would see Mars dominating the horizon, enveloping a quarter of the sky.

From the surface of Mars, Phobos can be seen eclipsing the sun. However, it is so tiny that it doesn’t completely cover our host star. Transits of Phobos across the sun have been photographed by several Mars-faring spacecraft.

The origin of Phobos and Deimos is still being debated. Scientists concluded that the two moons were made of the same material as asteroids. This composition and their irregular shapes led some astrophysicists to theorize that the Martian moons came from the asteroid belt.

However, because of their stable, nearly circular orbits, other scientists doubt that the moons were born as asteroids. Such orbits are rare for captured objects, which tend to move erratically. An atmosphere could have slowed down Phobos and Deimos and settled them into their current orbits, but the Martian atmosphere is too thin to have circularized the orbits. Also, the moons are not as dense as members of the asteroid belt.

Phobos may be a pile of rubble that is held together by a thin crust. It may have formed as dust and rocks encircling Mars were drawn together by gravity. Or, it may have experienced a more violent birth, where a large body smashing into Mars flung pieces skyward, and those pieces were brought together by gravity. Perhaps an existing moon was destroyed, reduced to the rubble that would become Phobos.

Hubble took the images of Phobos orbiting the Red Planet on May 12, 2016, when Mars was 50 million miles from Earth. This was just a few days before the planet passed closer to Earth in its orbit than it had in the past 11 years.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Supersonic Parachute

I am always amazed at parachute tests,.  A capsule (see link below) is speeding along at 12 times the speed of sound and then the parachute is deployed creating incredible stresses on the system, in the end designs it all holds together. For some unknown reason this test got me to wondering how much stretch the attaching parachute cord occurs and what the tensile strength is, for that matter what it is made of.   Oh I’m sure the data is out there, I just need to find it.

About the test:
ESA — This parachute deployed at supersonic velocity from a test capsule hurtling down towards snow-covered northern Sweden from 679 km up, proving a crucial technology for future spacecraft landing systems.

Planetary landers or reentering spacecraft need to lose their speed rapidly to achieve safe landings, which is where parachutes come in. They have played a crucial role in the success of ESA missions such as ESA’s Atmospheric Entry Demonstrator, the Huygens lander on Saturn’s moon Titan and the Intermediate Experimental Vehicle spaceplane.

This 1.25-m diameter ‘Supersonic Parachute Experiment Ride on Maxus’, or Supermax, flew piggyback on ESA’s Maxus-9 sounding rocket on 7 April, detaching from the launcher after its solid-propellant motor burnt out.

After reaching its maximum 679 km altitude, the capsule began falling back under the pull of gravity. It fell at 12 times the speed of sound, undergoing intense aerodynamic heating, before air drag decelerated it to Mach 2 at an altitude of 19 km.

At this point the capsule’s parachute was deployed to stabilise it for a soft landing, and allowing its onboard instrumentation and camera footage to be recovered intact.

The experiment was undertaken by UK companies Vorticity Ltd and Fluid Gravity Engineering Ltd under ESA contract.

The data gathered by this test are being added to existing wind tunnel test campaigns of supersonic parachutes to validate newly developed software called the Parachute Engineering Tool (also developed by Vorticity), allowing mission designers to accurately assess the use of parachutes.

BepiColombo Acoustic Test

Very pleased to see a BepiColombo online and at an acoustic test no less. I wondered how they tested for acoustics, was a shake-test enough?  Apparently not.

ESA – The full BepiColombo stack seen in the Large European Acoustic Facility (LEAF) at ESA’s test centre in June 2017. The walls of the chamber are fitted with powerful speakers that reproduce the noise expected during launch.

From bottom to top: the Mercury Transfer Module (sitting on top of a the cone-shaped adapter), the Mercury Planetary Orbiter (with an antenna facing towards the camera), and the sunshield (top), within which sits the Mercury Magnetospheric Orbiter.

The noise of a launch is incredible! The echo is so strong it could knock tiles off a Space Shuttle. The noise is mitigated so some degree with suppression systems, ever wonder what the water is for during launches, it is noise suppression.

Credit: ESA–C. Carreau, CC BY-SA 3.0 IGO


Finally the sounding rocket launched from the Wallops yesterday morning after many-many delays.

If you think I was getting impatient, imaging the undergrads who had experiments onboard. Ha! Well it got off and all is well – good luck you guys and hope you get more data then you can use!

NASA – The mission carried experiments built by undergraduate students from universities and community colleges across the country through the RockOn! and RockSat-C programs.

The experiments, launch on a 36-foot long Terrier-Improved Orion sounding rocket, flew to an altitude of 72 miles and landed, via parachute, in the Atlantic Ocean. The payload has been recovered and the students are expected to receive their experiments this afternoon to begin their data analysis.

RockOn! and RockSat-C are part of Rocket Week at Wallops. Nearly 130 students and instructors participated in the two programs this week conducted in partnership with the Colorado and Virginia Space Grant Consortia.

The June Solstice Is Here!

The June solstice is here occurring at 04:24 UTC / 12:24 EDT.  It is that point were the sun reaches the northern most point directly over the Tropic of Cancer and begins traveling in the other direction.

solstice (n.) Look up solstice at Dictionary.commid-13c., from Old French solstice (13c.), from Latin solstitium “point at which the sun seems to stand still,” especially the summer solstice, from sol “the sun” (from PIE root *sawel- “the sun”) + past participle stem of sistere “stand still, take a stand; to set, place, cause to stand,” from PIE *si-st-, reduplicated form of root *sta- “to stand, make or be firm.” In early use, Englished as sunstead (late Old English sunstede).  – taken from one of my favorite websites Online Etymology Dictionary.

Oh and if you are in the area and can, take in a Stonehenge Tour.  It would be a great day to do it and it is a big event, last year I think about 23,000 people were there.


ESA Contribution to Orion

Wow,  pretty exciting to see all that effort get to this point.  Good Luck!!

ESA – Set to be shipped to the USA around the New Year, ESA’s contribution to NASA’s Orion spacecraft is taking shape at Airbus in Bremen, Germany. This is no test article: the service module pictured here will fly into space by 2020, past the Moon and farther than any other human-rated spacecraft has ever flown before.

The service module will supply electricity, water, oxygen and nitrogen, propulsion and temperature control.

The blue circular frame is the support structure that holds the module as technicians work to get it ready. Yellow ties keep the 11 km of wiring in place as the thousands of components are installed and connected – the ties will be removed before flight. Behind the red support covers are the eight 490 N R-4D-11 thrusters, built by Aerojet.

Technicians are working in three shifts a day to assemble the components that are being shipped from all over Europe to complete this service module in just a few months’ time. In December it will be taken by road to Bremen airport and flown to NASA’s Kennedy Space Center in Florida to meet its crew capsule.

Read more about the Orion mission and Europe’s involvement on the minisite.

Credit: ESA