Tag Archives: discoverer 17

[November 16, 1960] Fully Fledged (a November Space Race update)

The bird finally has wings!

By bird, I mean that lawn-dart of a rocket plane, NASA's X-15.  Until yesterday, that sleek black vehicle, designed to probe the edges of space from underneath, had been a work in progress.  The X-15 had already flown 25 times, zooming at faster than Mach 3 and climbing to a height of 40 kilometers.  But its engines, a pair of Reaction Motors XLR11s, were an old set of training wheels: virtually the same rockets that pushed Chuck Yeager's X-1 past the sound barrier in 1947. 

Together, these engines gave the plane a thrust of 32,000 lbf (pounds of force–or the force of Earth's gravity on one pound of matter).  That's nothing to sneeze at, but it was always an interim solution.  Yesterday, veteran test-pilot Scott Crossfield took the X-15 for a spin with the engine it was always meant to have: the Reaction Motors XLR99. 

Unlike the XLR11, the XLR99 can be throttled smoothly from 0-100% (as opposed to the XLR11, which had eight discrete speed settings depending on how many sub-engines were firing).  Moreover, just one XLR99 delivers 57,000 lbf, almost twice as much as two of its predecessors.

Now, Crossfield didn't really test the new engine to its limit, "only" taking the craft to Mach 2.97 and a height of 24 kilometers.  However, the XLR99 is going to make a whole new class of flights possible.  In a couple of years, expect to see the X-15 hitting Mach 6 and reaching the 100,000 kilometer mark. 

Who knows?  Someday, you might take off for orbit from your local airport instead of strapped to the top of a firecracker.

Speaking of which, the first full test of the suborbital Mercury-Redstone (NASA's Mercury one-man space capsule on top of a Redstone booster, the kind at the base of the Juno 1) is set for November 21.  There won't be anyone on board for the mission, but it is the next critical step in the flight-test schedule.

Finally, the Air Force has, at last, come clean regarding its Discoverer capsule-return program.  The newspaper coverage of the latest launch on November 12 and the subsequent recovery of the Discoverer reentry capsule on November 14 was surprisingly detailed.  Discoverer 17 did carry a camera (though, ostensibly, only for testing equipment to be carrried on the next-generation SAMOS satellite).  Moreover, the military even disclosed that they used an upraded Agena second stage on its Thor-Agena boosters.  This means they can lift heavier payloads to higher orbits–great news for the civilian program since NASA will be using Agenas in its upcoming Venus and Mars flights.  This is actually a case of decreased government redundancy since, until the Air Force revealed the Agena, NASA was going to develop its own version, called the Vega.  Now they don't have to.

Discoverer 17 actually did some science this time around, too.  Propitiously timed to launch during a solar flare, the satellite carried a bunch of human tissue samples and a silver bromide emulsion block.  Scientists will study the effects of heightened space radiation on these items, which should provide some useful information to the manned space program.

So smiles all around from all three corners of the American space industry.  1961 is going to be a fun year, methinks.