December 22, 2015

Last night, Space Exploration Technologies Corporation (commonly called SpaceX) made history when it landed a rocket on Earth. Although landing probes on other bodies or placing people into orbit is usually the goal of space travel, SpaceX’s achievement promises to make spaceflight cheaper and more accessible in the near future.

SpaceX’s Falcon 9 rocket lifts off from Cape Canaveral Air Force Station in Florida on Dec. 21, 2015. The private space exploration company made history after the rocket successfully delivered communications satellites into orbit and then landed back on Earth. Credit: SpaceX

A rocket is a type of engine that pushes itself forward or upward by producing thrust. Unlike a jet engine, which draws in outside air, a rocket engine uses only the substances carried within it. As a result, a rocket can operate in outer space, where there is no air. The word rocket can also mean a vehicle or object driven by a rocket engine.

SpaceX is a private space exploration company founded by South African entrepreneur (business developer) Elon Musk. One of the company’s multistage Falcon 9 rockets lifted off from Cape Canaveral Air Force Station in Florida last night in a successful attempt to deliver communications satellites into orbit. In traditional multistage rockets, discarded stages fall to Earth and burn up in the atmosphere. Last night, however the first stage of SpaceX’s rocket descended back to Earth, slowed by its engines, and landed vertically on a pad using three large retractable legs.

The landing is a major victory for SpaceX, which had made two earlier unsuccessful landing attempts. In June, the company suffered embarrassment when a rocket launched to resupply the International Space Station exploded shortly after takeoff.

The (relatively) gentle landing should allow much of the first stage to be reused in future launches. For now, SpaceX employees are inspecting the rocket and studying how its parts can be safely reused. But as such landing and reuse become more routine, they will allow the cost of spaceflight to plummet. In November, space company Blue Origin, owned by American businessman Jeff Bezos, successfully landed a small rocket after a brief suborbital flight. But SpaceX’s rocket was far larger and part of a more complex orbital flight. Both companies are engineering new ways to make spaceflight cheaper and more reliable.

Additional World Book articles:

• Boeing Company
• Space exploration (2012) – A Back in Time article
  

January 14, 2015

It’s been a week of ups and downs for astronauts and cosmonauts on the International Space Station (ISS). NASA identified signs of a possible ammonia leak in the U.S. module. (Ammonia is used for the heating and cooling systems on the craft.) An alarm was sounded and the crew put on face masks, hurried to the Russian segment of the craft, and closed the hatch behind them. NASA says it may have been a false alarm.  All six astronauts onboard are safe.

On the up side, on January 12, a 2.5-ton (2.25 metric ton) shipment of supplies—including groceries, spare parts, children’s science experiments, and Christmas presents (a little late)—was delivered to the station by a Dragon supply ship, two days after it lifted off.

The International Space Station functions as an observatory, laboratory, and workshop. Astronauts and cosmonauts live and work in cylindrical modules. (NASA)

The space station had been getting low on supplies, as a delivery ship scheduled to arrive in October 2014 exploded during its launch. A Russian Progress ship delivered some supplies to the ISS later in October, but the launch date of the Dragon ship, originally meant for December, had been pushed back three times before its mid-January launch. The Dragon ship is owned by Space X, a space transport company owned by South African entrepreneur Elon Musk.

Other World Book articles and links: 

• International Space Station (NASA site)
• National Aeronautics and Space Administration (NASA)