Earth capture orbit?

[HoodedWraith]

I can't for the life of me remember the capture orbit for Earth, if you want to come in between 50 and 55 degrees, or 45 and 50 degrees to keep from bouncing off or burning up, and I figured since I've seen enough real world physics bouncing around here lately, I'd drop it here. It's been too long since I set up a paper trail for a simulated orbital hop.

[loki1950]

It's been too long since I set up a paper trail for a simulated orbital hop.

Same here But IIRC you don't want a steep angle as that is all most guaranteed to punch you into the atmosphere i"ll have a look through my old second edition of "Practical Astronomy with your calculator" and get back.It's usually within hands reach
Edit: had a look through the book no specifics on orbit insertion just lots of general orbit calculations don't even have Holman transfer orbits which the old CRC handbook had cira 1980

Enjoy the Choice

[dividenot]

This particular paragraph was intended for takeoff into orbit. But I suspect entering earth's atmosphere from the outside would involve similar speeds and altitudes. Am I wrong?

"In practical terms, you don't generally want to be less than about 150 kilometers above surface of Earth. At
that altitude, the atmosphere is so thin that it doesn't present much frictional drag to slow you down. You
need your rocket to speed the spacecraft to the neighborhood of 30,000 km/hr (about 19,000 mph). Once
you've done that, your spacecraft will continue falling around Earth. No more propulsion is necessary,
except for occasional minor adjustments. It can remain in orbit for months or years before the presence of
the thin upper atmosphere causes the orbit to degrade. These same mechanical concepts (but different
numbers for altitude and speed) apply whether you're talking about orbiting Earth, Venus, Mars, the Moon,
the sun, or anything."

---JPL's Basics of Space Flight,
---http://www2.jpl.nasa.gov/basics/

[HoodedWraith]

This particular paragraph was intended for takeoff into orbit. But I suspect entering earth's atmosphere from the outside would involve similar speeds and altitudes. Am I wrong?

"In practical terms, you don't generally want to be less than about 150 kilometers above surface of Earth. At
that altitude, the atmosphere is so thin that it doesn't present much frictional drag to slow you down. You
need your rocket to speed the spacecraft to the neighborhood of 30,000 km/hr (about 19,000 mph). Once
you've done that, your spacecraft will continue falling around Earth. No more propulsion is necessary,
except for occasional minor adjustments. It can remain in orbit for months or years before the presence of
the thin upper atmosphere causes the orbit to degrade. These same mechanical concepts (but different
numbers for altitude and speed) apply whether you're talking about orbiting Earth, Venus, Mars, the Moon,
the sun, or anything."

---JPL's Basics of Space Flight,
---http://www2.jpl.nasa.gov/basics/

Well, yes and no. Coming back down from orbit, you have the unfortunate problem of worrying about either burning up or skipping off of the planet's atmosphere. While I could deadstick it for a descent that would let me plop absolutely anywhere (unfortunately that wouldn't give me a location until I touched down ), I wouldn't be able to guide myself down in a somewhat softer landing.

Though that does help quite a bit, thank you. More math for me to file away under my physics notebook.