The radio waves are measured when the earth is at two points opposite one another in its orbit.

VOA: special.2009.01.20

Military officials immediately offered to use the Jupiter to put a scientific satellite into orbit around the Earth.

VOA: special.2009.06.10

Near the moon, the astronauts fired rockets to slow the spacecraft enough to put it into moon orbit.

VOA: special.2009.07.15

Next year, the Chinese plan to launch a small space laboratory to practice docking of spacecraft in orbit.

VOA: special.2010.04.28

He says there are more than three hundred thousand small objects or pieces of debris in orbit that are larger than one centimeter.

VOA: special.2009.04.01

He would wait in orbit around the moon while Armstrong and Aldrin landed and explored the surface.

VOA: special.2009.07.15

But when the telescope reached orbit, NASA scientists were shocked to discover that the costly mirror of the telescope had not been shaped correctly.

VOA: special.2009.09.30

The timing would put the two spacecraft in the correct orbit to meet in space.

VOA: special.2009.07.01

Once the shuttle is retired this year, the only way for the United States to get astronauts into orbit will be on Russian Soyuz rockets.

VOA: special.2010.04.28

Near the end of his third orbit, Glenn fired other rockets to slow his speed.

VOA: special.2009.06.17

The planet's orbit lies about four billion five hundred million kilometers from the sun.

VOA: special.2011.07.27

And he says five of the planetary candidates are both close to the size of Earth and orbit in the habitable area of their parent stars.

VOA: special.2011.02.09

In nineteen fifty-seven, a Soviet military rocket carried a small satellite into Earth orbit.

VOA: special.2009.06.10

And they placed a small satellite in lunar orbit before they returned to Earth.

VOA: special.2009.07.29