In Today’s Deep Space Extra… Mississippi rocket engine tests prepare NASA’s Space Launch System exploration rocket for future flight tests.

Human Deep Space Exploration

NASA moves ahead on Space Launch System tests
Mississippi Public Broadcasting (3/22): NASA is test firing the RS-25 engine at the Stennis Space Center in Mississippi in preparation for future flight tests of the Space Launch System exploration rocket. One recent ground test firing spanned 500 seconds, long enough for the SLS to journey from the launch pad to orbit with astronauts seated aboard the Orion spacecraft.

So you say there’s a chance?: Yuri’s Night offers patch for astronaut applicants
Collectspace.com (3/22): More than 18,000 Americans submitted applications for an opening in NASA’s astronaut corps earlier this year. On Tuesday, Yuri’s Night began marketing a “Be An Astronaut patch” to pay tribute to the remarkable interest in space exploration. Yuri’s Night celebrates the launching of the first human space traveler, Russian Yuri Gagarin, on April 12, 1961.

Space Science

Biggest ever space telescope steps closer to lift-off
The Engineer (3/22): A pair of key instruments for the James Webb Space Telescope are undergoing tests prior to their installation on the joint NASA, Canadian Space Agency and European Space Agency observatory. The James Webb, the designated successor to the Hubble Space Telescope, is slated for a late 2018 liftoff to study the formation of the earliest star systems and to check the atmospheres of alien planets for signs of biomarkers.

Dwarf planet Ceres’ mystery bright spots get their close-up from Dawn probe
Geek Wire (3/22): Bright spots on the surface of the dwarf planet Ceres, a resident of the main asteroid belt, were among the surface features scientists discussed Tuesday at the 47th annual Lunar and Planetary Science Conference. The bright spots and flow features suggest Ceres has an icy subsurface, and perhaps an ocean in the distant past.

Did the new Russia-Europe Mars mission narrowly escape a launch disaster?
Popular Mechanics (3/22): The joint European/Russian ExoMars mission team celebrated last week as their spacecraft began its journey to the red planet with an orbiter and lander. The Proton launch vehicle’s Breeze M upper stage, apparently, did not separate cleanly from its payload during the Mar. 14 boost. The mission’s Trace Gas Orbiter and Schiaparelli lander will seek evidence of biological activity on Mars.

Did Mars’ methane come from comets?
Discovery.com (3/22): Comets could be the puzzling source of methane on Mars. NASA researcher Marc Fries presented the concept to fellow planetary scientists at the Lunar and Planetary Science Conference this week. One source of methane is biological activity.

Commercial to Low Earth Orbit

Second Cygnus ship in three months rockets to orbit aboard Atlas 5
Spaceflightnow.com (3/23): An Orbital ATK Cygnus spacecraft filled with 7,500 pounds of supplies lifted off atop an Atlas V rocket for the six man International Space Station late Tuesday. The departure from Cape Canaveral Air Force Station, Fla., placed the crew supplies, research equipment and other gear on a course to rendezvous with the orbiting science lab early Saturday. Astronaut Tim Kopra will be positioned at the internal controls of the station’s robot arm to grapple the capsule which will remain berthed for about two months.

Cargo, cargo everywhere — Cygnus launch first of three in next two weeks
Spacepolicyonline.com (3/22): Orbital ATK’s successful launch to the International Space Station late Tuesday is to be followed by a Russian Progress cargo mission launch next week. A SpaceX Dragon cargo delivery is planned the week after that as well.

NASA shows off access arm, “last place on earth” for astronauts on Space Coast
Orlando Sentinel (3/22): Early this week, representatives of NASA, United Launch Alliance and Boeing gathered in Oak Hill to preview the access arm and  “White Room” that future International Space Station astronauts will use to board Boeing’s CST-100 Starliner for commercial transportation to the orbiting science lab. Launches are to begin by the end of 2017.