I Heard It On The X-37

Posted: November 24, 2010 in Uncategorized
Tags: , , , , , , ,

Yes, multiple (well, two) posts in a row on the X-37B, inspired by Stephen Clark writing at Spaceflightnow.com.

The X-37B is an unlovely, reusable, 11,000-pound spaceship with a very modest cargo bay.

It is thought to being readied to de-orbit.  This means the X-37B has probably already accomplished all its on-orbit mission requirements and that staying up any longer would either be ill-advised or would serve little purpose.

Where will the X-37B stop?  Vandenberg is the stated recovery location, a bit of a surprise (to me anyway).  I would have thought Edwards (the backup) would make more sense on this, a first full-flight item that will hit Mach 25 on its way home.  While Vandenberg may get bonus environmental points from Santa Barbara County for being a space recycler, there was no-doubt extra paperwork required to address the potential hearing loss for the whales within the X-37B’s sonic boom footprint.  Come to think of it, it’ll probably scare the Snowy Plovers on the beach as well.

When the X-37B does come in for landing, it will fire its main engine to slow its speed in a maneuver much like the de-orbit burn on the space shuttle. The space plane will plunge into the atmosphere with its nose pitched up, relying on GPS navigation and autopilot computers to guide itself toward the California coast.

The spacecraft’s destruct system will be activated to terminate the flight if it veers off course…(and it) will autonomously line up with the Vandenberg runway and make a steep dive toward the landing site, pulling up in the final moments and touching down at a speed of nearly 300 mph.

Vandenberg has a 15,000-foot-long runway.  That’s a pretty substantial runway for a unit without a flying mission, but of course the runway was built to recover West Coast space shuttles (which never came to be).

The X-37B is unique in that after its 22 April launch it

…entered an orbit more than 250 miles above Earth after launch, but four significant maneuvers have since altered that trajectory, causing observers to lose track of the X-37B for several days at a time.

An engine firing Aug. 9 raised the space plane’s orbit, but three more maneuvers around Oct. 6, Nov. 1 and Nov. 12 reduced the X-37B’s altitude, which is now estimated to be between 174 miles and 182 miles, according to Ted Molczan, a respected and experienced satellite observer in Canada.

Molczan said the inclination of the winged spacecraft’s orbit remains 40 degrees.

In addition to being respected and experienced, Molczan has become one of the go-to guys for the space press.

“At the risk of getting too far ahead of the data, I note that one feature the new orbit would have in common with all of the previous ones, is a ground track that nearly repeats every few days,” Molczan told Spaceflight Now.

Such orbits permit Earth observation satellites to rapidly revisit the same location and collect imagery.

“Ground tracks that nearly repeat every two, three or four days are a common feature of U.S. imaging reconnaissance satellite orbits,” Molczan said.

Well, if the government ever wants the X-37 to deploy an imaging satellite, according to Molczan’s observation, that box can be checked off as being demonstrated.

Where does it all end?  That’s hard to say because the X-37 started life as a NASA project before being transferred to DARPA and now soldiers on as an Air Force program.   Maybe it’s finally found a home.

Oh and the title?  Derived from that little ol’ band from Texas…

  1. Coyote says:

    This capability could help the Russians with their space debris removal program.

  2. Dave says:

    Actually, the spacecraft won’t hit mach 25 on its way home. It’s already at that velocity. It will certainly slow as it de-orbits.

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