A Rocket You Can Count On

When it comes to dependability, no human-rated rocket will be more critical than the descent engine for the next lunar lander, which will fire to slow the astronauts to a safe and gentle touchdown on the moon. NASA is currently testing various configurations of the descent engine, shown here in a chamber at Pratt & Whitney Rocketdyne’s location in West Palm Beach, Florida. Throttling at various levels between 15 percent and 100 percent of full power, the descent engine will give future astronauts precise control over their landings. As liquid oxygen at -297 degrees F combines with liquid hydrogen at -423 degrees F and combusts, gases containing hot steam are propelled out the nozzle. Because the nozzle is itself supercooled, this steam condenses to form icicles on the rim, right next to 5,000-degree-F exhaust. Video: NASA (1:55)

Latest Videos

Preview thumbnail for video'A spacewalker’s emergency lifejacket
A spacewalker’s emergency lifejacket (2:35)
Preview thumbnail for video'How the Nolinor 737 prevents gravel from crashing its engines
How the Nolinor 737 prevents gravel from crashing its engines (2:49)
Preview thumbnail for video'Was this plane engulfed in St. Elmo’s fire?
Was this plane engulfed in St. Elmo’s fire? (4:01)
Preview thumbnail for video'Yellowstone by air
Yellowstone by air (1:26)
Preview thumbnail for video'What some of the most important Civil Rights sites look like from the air.
What some of the most important Civil Rights sites look like from the air. (3:07)
Preview thumbnail for video'The only live news report from the attack on Pearl Harbor
The only live news report from the attack on Pearl Harbor (2:05)
Preview thumbnail for video'Adapting to the times
Adapting to the times (2:35)
Preview thumbnail for video'Why did this flight crash? Listen to its engine…
Why did this flight crash? Listen to its engine… (4:01)
Preview thumbnail for video'The flying hospital
The flying hospital (3:25)