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OSIRIS-REx on its way back to Earth

OSIRIS-REx today fired its engines and successfully put itself on course for returning its samples from the asteroid Bennu to Earth on September 24, 2023.

The May 10 departure date was precisely timed based on the alignment of Bennu with Earth. The goal of the return maneuver is to get the spacecraft within about 6,000 miles (approximately 10,000 kilometers) of Earth in September 2023. Although OSIRIS-REx still has plenty of fuel remaining, the team is trying to preserve as much as possible for a potential extended mission to another asteroid after returning the sample capsule to Earth. The team will investigate the feasibility of such a mission this summer.

The spacecraft’s course will be determined mainly by the Sun’s gravity, but engineers will need to occasionally make small course adjustments via engine burns.

The science team has already proposed one option, sending the spacecraft on a rendezvous with the potentially dangerous asteroid Apophis shortly after its 2029 close-fly of Earth. It could be that there are other targets as interesting that they need to choose from.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.


  • Jeff Wright

    This may be the most important mission ever-getting a glimpse of this threat. If possible…maybe do a hard burn in passing so as to be able to image as much surface area so as to do a 3D reconstruction-atlas. Too fast to orbit this body-but if it rotates-you might see more sides.

  • As an orbital mechanic, I make a good plumber, but what does it do in the meantime? It’s not as if it will just sit somewhere waiting for a target to appear.

    The goal of the return maneuver is to get the spacecraft within about 6,000 miles of Earth
    Presumably, the sample capsule can then perform whatever maneuver is needed to drop itself into the atmosphere for braking.

    But won’t the spacecraft get a gravity slingshot of some sort that will fling it off into wherever? I can see the goal of making that “wherever” into something useful, but I think the options would be SEVERELY limited.

    I just looked it up: Luna(*) is ~240,000 miles from Earth, so 6,000 miles is very close – significantly under geosync orbit even- that slingshot effect is going to be dramatic.

    (*) I don’t like “the moon” because there are so many moons. Maybe “the Moon” as a compromise?

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