Apollo 10 LEM in heliocentric orbit?

Don’t ask me why, but I am curious about this.

The Apollo 10 lunar module was supposidly put into a Heliocentric after jettisoning it from the command module. So out of curiosity I was trying to find what its orbit was but I have had no luck. Does anyone know where I can find such info?

Part 2-

If it is still in orbit (as it shoud be, unless some alien took it for a souvenir) would it be possible for the Hubble to see it? Or would it be far to small and far away?

Here are the details of the Apollo 10 LM jettison procedure on May 23, 1969 from the official NASA Apollo 10 Flight Log (this is a .PDF document):

It gives most of the data necessary to calculate the resulting solar orbit. Shouldn’t be too hard, it’s not like it’s rocket science… oh, wait…

There’s not enough information there to calculate an orbit: Notably, nothing is said about the speed of the module after last burn. There’s also the confusing matter that what speeds are given seem to be in lunar or terrestrial coordinates, not solar (those speeds are far too low for solar: The Earth is orbiting the sun at about 30 km/s)

No telescope would be able to resolve the module, but a large amature scope could probably see it as a point source, and any professional scope could definitely see it with a timed exposure.

Just as a minor hijack, by the way, rocket science is probably the simplest application of physics a person could ask for: No friction, isotropic conservative forces, no dependance on material properties. How it ever became the archtypical “difficult task” is beyond me.

What he said. We used to makes jokes all the time in college referring to the simplifications we had to make in class. Like, “Pass me the massless frictionless soda”.

In space, a lot of these simplifications are accurate. Tell me the velocity and mass of a rocket propellant, and the mass of the rocket, and I can tell you how fast the rocket will go. On Earth, I’d have to account for a million things to come up with the answer. And the solution may be so complex that I’ll find it easier to just build a model in a wind-tunnel and test it emperically.

Snoopy (the Apollo 10 lunar module) wasn’t tracked accurately enough for them to know it’s exact speed when it ran out of fuel. Had they been able to exactly determine it’s speed and direction, calculating it’s current location would be simple. Unfortunately, it’s anybody’s guess where it’s at.

It’s still in a solar orbit roughly 1 AU from the sun, as are several of the Apollo third stages. The orbits are quite stable, so they’re expected to remain there for thousands, maybe even millions, of years (although there is always the tiny chance that they’ll pass close enough to hit the earth at some point). At some point they will probably turn up, purely by chance.


I think it’s that “first step” that’s attracted the idiom - once you’re up there, it’s easy - getting there is the problem.

There was in fact something of a flap about a possibly dangerous near-earth asteroid–or perhaps I should say, a possibly dangerous near-earth possible asteroid–that may in fact be an Apollo booster; see Near-Earth Object 2000 SG344 - Is it an asteroid?

So how close does Snoopy get to the Earth?

Rocket Science is not just orbital physics, though. It it Aerospace Engineering, the science of converting millions of joules of chemical energy stored in volatile, cryogenic, materials into a stable, controlled plasma jet that can reliably launch a machine from STP to vacuum and from sealevel to orbit while not breaking a sensitive and expensive payload (human or otherwise), and possibly return the payload to the surface of the planet without turning it to a crisp. It took the finest minds of the times decades to get it right, and we can’t do it reliably yet.

So don’t diss the Rocket Scientists. Brain surgery, on the other hand … :wink:



Its not writing a stable operating system.

Nope, just doesnt have the same ring to it.

So …

What was the “massless, frictionless soda?” Coke Zero?

<Golf clap>

Consider a Spherical Cow

If I’m reading the flight log transcript correctly, they jettisoned the LM Ascent Stage and then had it fire it’s engines? I’m surprised it had enough residual fuel to break lunar orbit. Was the Ascent Stage designed with a significant fuel margin?

Nah, si_blakely, that’s rocket engineering. The science is easy; it’s just putting the science into practice that’s difficult.

Ah, this would be the result of difficulties with rocket science then?

Obligatory xkcd comic.

After seeing what Snoopy did to The Red Baron, I’m getting worried…

The physics is easy, the engineering can be a witch. I’m a EE, so lets look at space electronics requirements:

-Must be very reliable, most likely triple redundant. There well may be congressional hearings if it fails.
-Must be as light and low power as possible…then lighter and less power.
-Must not require air for cooling, insulation, or arc control.
-Must survive and function at high vacuum. Must not outgas and impact other systems.
-Must survive and or function with outrageous vibration at launch.
-Must survive and or function considering Van Allen belts x-rays, etc.
-Must survive and/or function at lower than arctic and greater than Saharan temperatures, possibly with frequent cycling between these.
-Must have all costs amortized over qty= maybe 1-5.
-May not be possible to test much of the above prior to launch, so analysis will have to be done instead.

Consumer widgets are way easy by comparison…mostly just make it cheap.

I think his nitpickery is in the literal meaning of ‘rocket’ ‘science’–which is pretty simple–when in common parlance the phrase is really an idiomatic substitute for ‘aerospace engineering.’

I believe it’s because Apollo 10 never landed on the moon. So the ascent stage never had to launch from the surface. The closest it came to the surface was about 8 miles meaning that, when they did fire it’s engines, it was already in orbit as opposed to on the surface. Since it was a dry-run for Apollo 11, I’m sure it was fully fueled. I’m guessing they had it fire it’s engines as another test to make sure everything worked well.