Lets say the space shuttle is on one of its routine manuevers (in orbit) and it comes across a foriegn body.
It looks like a satellite but theyre not sure. They also cant figure out what material it is made of. It could be from earth or may have drifted here from some other galaxy. They decide that it does not pose a threat (inactive) and it is relatively small (will fit in the cargo bay).
Could it be retrieved?
My concern would be this, How would they know how much it weighs? What if the foreign material ended up being some incredibly dense material that wheighs too much for the shuttle to bring back.
Can an object such as this be accurately weighed in space? How?
First of all, unless the mystery object is invisible to radar, the shuttle would never get near it. NASA keeps an eye out for anything that might concievably collide with the shuttle, and has the astronauts make course changes to move the shuttle away from satellites or debris in orbit. An unknown object floating in space would be spotted by radar long before it came near the shuttle, and they’d shift the shuttle’s orbit enough to keep them seperated.
Secondly, each shuttle mission is very carefully planned out, both in terms of time to get tasks done and equipment for the mission. Not all the shuttles have robot arms, which would be needed to grab a floating object. The end of the shuttle arm is a special-purpose locking probe designed to latch into recepticles on satellites and space station components, so it can’t be used to grab just any random object. They could grab a piece of random space debris by mounting a work platform to the end of the arm, then have an astronaut in a spacesuit on the work platform grab the object and pull it in, but that requires having a lot of specialized equipment and planning on hand - it’s not something you’d do on the spur of the moment.
Furthermore, the shuttle bay isn’t really set up for storing any random thing that comes along. The interior of the bay is pretty fragile, and the ride back to earth can be rough - anything they’re planning on taking up or down needs to have a custom fixture built to keep it from rattling around inside the bay and breaking anything. Even if the shuttle crew did come across a strange sattalite and decide to take it back down to earth, they wouldn’t be able to, unless it was small enough to bring inside through the airlock and tie down somewhere.
What might be feasable would be for a shuttle crew to see and photograph some strange object in space, and then for a later mission to be sent up solely to retrieve it. Even then, as you’ve noted, they’d have no way of telling the mass of the object before trying to retreive it.
If it’s of significant mass (As I suspect it would have to be, to affect the shuttle’s flight), then they could probably do a simple check with a short engine burn and inertial sensors. They know how much a certain throttle setting should accelerate an unladed shuttle, so they can grab the object and do a short engine burn to find out how much they -did- accelerate by, and compute the change in overall mass from there.
Just my guess. They might even be able to guestimate the approximate mass simply by the work it takes to move it into the shuttle bay.
The orbital period, velocity and path would provide enough information to figure out mass. I’m not at home so actual equations of the top of my head may not be wise.
You can’t tell the mass of an object just by tracking it’s orbit. Just as heavy and light rocks fall at the same rate, heavy and light objects follow the same orbits.
The method of grabbing it and test firing the shuttle’s thrusters would work, so long as you can get a firm grip on the mystery object.
Well, the weight would be zero. But they can calculate the mass per the instructions above. Once you have the mass, you can calculate what the weight would be under the influence of earth’s gravity*.
Suppose an astronaut is doing a space walk and while he is out there he gets into some thick dust flying around in space. Some of the dust collects on the astronaut’s suit and he carries it with him when he re-enters the space shuttle. Then they head off back to earth. What if the dust that had collected on the astronauts space suit were dust particles from a neutron star? From Encarta:
“Calculations predict that a neutron star is perhaps only 10 to 20 km in diameter, yet it retains all of the mass of the star’s core-at least 1.4 times the full mass of the sun. The density of such material could be as high as 1015 grams per cubic centimeter (1,000,000,000,000,000 gm/cc). A teaspoonful of this material would weigh ten billion tons on the surface of the earth.”
If they re-entered earth with the neutron star dust on the space suit, would there be a problem?
Things in space have as much mass as they do on earth. If an astronaut had some ‘neutron star dust’ on his suit (assuming that such a thing was even possible) he would feel its immense weight just trying to move his limbs around.
A more realistic problem which could have occurred is if an astronaut got hydrazine on his suit. Hydrazine is commonly used as fuel for satellites and it is deadly poisonous. Just getting a little on you will kill you. And although it wouldn’t penetrate a space suit there’d be no way of getting it off it. If the astronaut came back inside the shuttle he’d contaminate (and kill) everyone. And he’d probably contaminate himself taking the suit off in the airlock.
So basically, if that ever happened, the astronaut would have to ‘take one for the team’. After Challenger, this was one of the extra risks that NASA decided wasn’t worth taking so the shuttles no longer launch 3rd party satellites for money.
Except that “dust” composed of neutron star particles wouldn’t behave like “dust”. If you ran into a dust sized particle of neutron star matter it wouldn’t collect on your space suit, it would go right through the space suit and the astronaut like a bullet. And there couldn’t be a dust storm of such particles, because their extreme gravitational field would collect all the particles into one body. Instead of a dust storm of small particles you’d have one very massive particle.
Only if the mass of the object is significant compared with the mass of the Earth. An object massing mere billions of tonnes could not be distinguished from an object massing a few grammes by its orbital period, velocity, and path. So long as the object is insufficiently massive for its gravity to affect the orbit of the Earth to a measurable degree, it will as far as can be determined follow the same orbit as any ‘light’ object at its position and velocity.
That is why heavy cannonballs fall at the same speed as light musket balls. [G. Galilei, 1575]
As for ‘dust’ from a neutron star: I think it needs the fantastic compression of a neutron star’s gravity to remain stable. If somehow removed from the neutron star it would explode, degenerate matter into a monatomic vapour of ordinary matter, neutronium into a puff of neutron radiation. An astrophysicist might be able to give a definitive answer.
The particle wouldn’t dissipate away from the neutron star.
A dust particle is 1/1,000,000 of a teaspoon.
The particle would weigh 10,000 tons. It’s unlikely the particle’s velocity would match that of the astronaut. It would either smash him/her at high velocity in some direction, or more likely (as previously stated) go through him/her.
If it did somehow adhere to the suit, as previously stated the astronaut would be too massive to move by his/her own muscular power. At the very least, the shuttle would have to be maneuvered to him/her. But with that much additional mass, landing would probably be impossible. The launch weight of the shuttle is only 2250 tons. They’d have to ditch the suit somehow.
Um, ants, how do you figure? OSHA says it’s a mean carcinogen - but that won’t kill you immediately, if it all. It’s even soluble in water!. The guy goes in airlock, fills it up with air (to keep water from freezing), keeps his suit on, amd washes the hydrazine off. Then he opens airlock to expell contaminated water - problem solved.
Neutron star material is violently unstable - when you remove it from the intense gravitational field it’s in, it instantly explodes back into normal matter.
I recall an incident once when a shuttle’s manuevering fuel tanks leaked a bit when it landed. The astronauts had to stay inside until the fuel vapors dissapated. It wasn’t much of a big deal, IIRC.
